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C. N. Ngugi, P. M. Wachira, J. N. Mbaka, S. Okoth, S. Haukeland, E. G. Thuranira
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p107

Abstract:
Globally, vegetable production including tomato is constrained by pests and diseases. The tomato leafminer, Tuta absoluta (Meyrick.), is a major pest of tomato, mainly managed using chemical pesticides. There is a need for integrated pest management (IPM), approaches that are human and environmentally friendly. The study aimed at molecular identification and virulence evaluation of four entomopathogenic nematodes (EPNs) against T. absoluta larvae. The DNA was extracted, sequenced, and phylogeny analyzed. The EPNs virulence was evaluated using the insect baiting technique at different nematode concentrations (0-Control, 100, 150, 200, and 250 infective juveniles/ml of distilled water). Larval mortality data were collected for five days. Molecular identification resulted in nucleotide sequence lengths of 877-895 base pairs (bp). All the isolates were found to be Steinernema species of EPNs. The % similarity of the isolates and their close relatives ranged between 82-100%. The isolates closely matched Steinernema spp. AY230184 (Sri Lanka); AY230186 (Kenya), JN651414 (Ethiopia), and MW151701 (Kenya). The sequences were deposited to Genbank as Steinernema sp. Isolate Kalro 75 (MW150871), Steinernema sp. Isolate Kalro S86 (MW150872), Steinernema sp. isolate Kalro97 (MW150873) and Steinernema sp. Isolate KalroR52 (MW150874). All the EPN isolates were virulent against T. absoluta. Isolate Kalro R52 and Kalro S86 recorded the highest mortality of 76±7.5%; 72±15.0% respectively in the 48 h. There was a significant difference (P < 0.001), between all the isolates and the Control. The four EPNs were virulent and have bio-control potential against, T. absoluta. Research on their virulence against T. absoluta in the field is recommended.
Patrícia Conceição Medeiros, Yule Roberta Ferreira Nunes, Juliana Pimenta Cruz, Dayse Marcielle de Souza, Marly Antonielle Ávila, Franciellen Morais-Costa, Sônia Ribeiro Arrudas, Viviane De Oliveira Vasconcelos, Thallyta Maria Vieira, Ana Paula Venuto Moura
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p142

Abstract:
Variations in the concentrations of plant secondary metabolites can occur due to the phenological stages of the plants, combined with environmental variations. Plants rich in tannins are used in folk medicine for different purposes. Xylopia emarginata Mart. (Anonaceae)-“Pindaíba” has been used to treat skin edema, bronchitis and malaria. We evaluated variations in condensed tannin (CTs) contents in relation to phenological variables in leaves of Xylopia emarginata during one year. The study took place in a Vereda in northern Minas Gerais State, Brazil. Monthly phenological observations as well as quantifications of the contents of condensed leaf tannins in ethanol and aqueous extracts were performed. The production of X. emarginata leaves occurred throughout the study, with greater budding and leaf fall in the dry season. Phenological observations were correlated with CT levels and climatic data of precipitation and temperature. There was a significant correlation (p < 0.05) between fruiting and CT levels in the extracts, which were higher during the dry season, 13.2% in the ethanol extract and 7.8% in the aqueous extract.
Anne Brown
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p175

Abstract:
Reviewer acknowledgements for Journal of Agricultural Science, Vol. 13, No. 10, 2021.
Allen Oppong, Abu M. Dadzie, Beatrice Ifie, Maxwell D. Asante, Ruth N. A. Prempeh, Linda A. Abrokwah, Zipporah Appiah Kubi, Esther A. Marfo, Esther A. Ananng, Marilyn L. Warburton
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p15

Abstract:
Maize (Zea mays L.) is the most important cereal crop in sub-Saharan Africa providing food for many of its inhabitants. However, production is hampered by low yields and aflatoxin contamination, among others. The toxin contaminates maize before harvest and during storage. Ghana lacks regulatory infrastructure for monitoring and detecting aflatoxin in grains prior to market, and most of the local maize varieties have been found to be susceptible to aflatoxin accumulation. Host resistance is envisaged as a key approach in addressing the aflatoxin menace. Thus, this study was conducted to identify new hybrids that combine high yield with resistance to aflatoxin accumulation as well as study the mode of gene controlling tolerance to aflatoxin accumulation. Sixteen aflatoxin resistant inbreds from exotic sources were crossed as males to 10 local germplasm in a North Carolina II design to generate 160 new hybrids. These were planted together with 9 checks using a 13 × 13 alpha lattice with three replications. The new hybrids were evaluated across six environments in two seasons. Five plants each per hybrid were inoculated with a local strain of Aspergillus flavus at a concentration of 9 × 107conidia/ml. Ninety-six out of the 169 crosses were analyzed statistically. Significant effect of environment and genotypes for all traits especially, for aflatoxin accumulation resistance and yield were observed. The general combining ability effect of males for all traits were found significant (P < 0.05) whereas that of the females were not significant for all traits. Inbreds with consistent significant negative GCA effect for aflatoxin reduction were identified (MP715, TZI8, MP719). Furthermore, the underlying genetic control for the aflatoxin accumulation resistance trait was found to be via both GCA and SCA effects. Heritability estimates were moderate, suggesting permissible transfer of traits during selection to create high yielding aflatoxin resistant hybrids for consumers.
Eduardo Carvalho Faca, Fabrício Fagundes Pereira, Winnie Cezario Fernandes, Ivana Fernandes da Silva, Valmir Antônio Costa, Ana Paula Gonçalves Da Silva Wengrat
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p96

Abstract:
The study of the interaction between parasitoid and host, especially the age of these organisms, is an important step towards the implementation of biological control programs. Therefore, we investigated the performance of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) and Trissolcus sp. aff. urichi (Hymenoptera: Scelionidae) parasitizing eggs of Nezara viridula (Hemiptera: Pentatomidae), considering different ages of the parasitoids and the host. We performed four laboratory bioassays: two using females of O. submetallicus and Trissolcus sp. aff. urichi at 24, 48, 72, 96, 120, or 144 hours of age exposed to parasitism in N. viridula eggs (24 h) and two trials with N. viridula eggs at 24, 48, 72, 96, 120, or 144 hours exposed to the parasitism of O. submetallicus and Trissolcus sp. aff. urichi (24 h). We evaluated the percentage of parasitism and emergence, life cycle length, progeny, sex ratio, and the longevity of the parasitoids. The parasitism of O. submetallicus in N. viridula eggs was influenced by the age of the parasitoid, 120 hours being the minimum to obtain better parasitism. From this age on, there is interference in the longevity of the progeny. Trisolcus sp. aff. urichi, at all ages, parasitized N. viridula eggs relatively well, but with almost no emergence of the parasitized eggs. Females of O. submetallicus parasitized and developed in eggs of N. viridula of all ages. Females of Trissolcus sp. aff. urichi parasitized their host, but there was barely any emergence. These pieces of information regarding the breeding methodology contribute to the implementation of new protocols for the multiplication of these parasitoids in the laboratory, and later, their release in the field.
Victor Gustavo Soares Ribeiro, Carlos Henrique Eiterer de Souza, Murilo Mendes Machado, Lara Lúcia Gonçalves, Miguel Martins Neto, Edilson Souza Santos, Henrique Teixeira Santos
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p61

Abstract:
For commercial soybean production, the presence of phosphorus in the soil is essential, not only to increase productivity but also because it affects basic functions in plant metabolism. Phosphate fertilizers have low efficiency in Cerrado soils. For this reason, the use of technologies associated with phosphate fertilizers is important to increase their efficiency in the soil. The experiment was conducted at Fazenda Rio Brilhante in Coromandel, MG. The experiment was laid out in a randomized block design in a 4 × 4 + 1 factorial arrangement. Treatments consisted of four phosphate fertilizer sources (MAPCONVENCIONAL, MAPpol 1, MAPpol 2, and FOM), four P2O5 doses (40, 80, 120, and 160 kg ha-1), and the control treatment (no phosphorus application). The soybean cultivar RK8115 IPRO with a plant population of 340 thousand plants per hectare was used. The experimental plots consisted of five planting lines with a spacing of 0.5 meters and a length of 7 meters. In the experiment, phosphorus leaf, morphological evaluation of plant height, stem diameter, number of stems, and pods were measured. For plant biomass, the dry matter of leaves, stems, and pods were determined. For yield evaluation, the calculation of productivity and RAE was compared with MAPCONVENCIONAL. For sources, data were subjected to analysis of variance, and means were separated by Tukey’s rate test (p < 0.05). For P2O5 doses, regression model fitting was performed using the ExpDes.pt package of R Studio software. Morphological assessments responded linearly to P doses, except for DPM. Leaves and pods P content and yield were affected by P dosage and P sources, with a quadratic response to P dosage. Maximum yield efficiency was achieved at P2O5 doses of 122.73; 145.07; 112.03; and 94.71 kg ha-1, with yields of 3818.30; 4064.67; 4089.03; and 3952.63 kg ha-1 for MAPCONVENCIONAL, MAPpol 2, MAPpol 1, and FOM, respectively. However, MAPpol 1 and FOM provided a dose reduction of 26 and 15 compared to the maximum yield of MAPCONVENCIONAL, respectively.
Nader Soltani, Christy Shropshire, Peter H. Sikkema
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p1

Abstract:
Five field experiments were conducted in Ontario Canada during 2018-2020 to determine the level of crop injury, weed control and white bean yield with up to four-way mixtures of herbicides applied preplant incorporated (PPI). The trials were arranged in a factorial design: Factor 1 was “Grass herbicide” including no grass herbicide, trifluralin, S-metolachlor and trifluralin + S-metolachlor and Factor 2 was “Broadleaf herbicide” including no broadleaf herbicide, halosulfuron, imazethapyr and halosulfuron + imazethapyr. At 2 and 4 weeks after emergence (WAE), there was minimal (≤ 4%) white bean injury. At 8 weeks after herbicide application (WAA), trifluralin, S-metolachlor or trifluralin + S-metolachlor averaged across Factor 2 controlled velvetleaf 69, 71 and 62%, respectively; halosulfuron, imazethapyr and halosulfuron + imazethapyr averaged across Factor 1 controlled velvetleaf 75, 95 and 97%, respectively. At 8 WAA, trifluralin, S-metolachlor and trifluralin + S-metolachlor controlled pigweed 93, 90 and 97%, respectively, and halosulfuron, imazethapyr and halosulfuron + imazethapyr controlled pigweed 97, 79 and 98%, respectively. At 8 WAA, trifluralin, S-metolachlor and trifluralin + S-metolachlor provided poor (≤ 32%) control of common ragweed while halosulfuron, imazethapyr and halosulfuron + imazethapyr controlled common ragweed 86, 53 and 87%, respectively. The 4-way tankmix of trifluralin, S-metolachlor, halosulfuron + imazethapyr controlled common ragweed 95%. At 8 WAA, trifluralin, S-metolachlor and trifluralin + S-metolachlor controlled common lambsquarters 81, 38 and 91%, respectively, and halosulfuron, imazethapyr and halosulfuron + imazethapyr controlled common lambsquarters 94, 97 and 99%, respectively. At 8 WAA, trifluralin, S-metolachlor and trifluralin + S-metolachlor provided poor (≤ 46%) control of wild mustard while halosulfuron, imazethapyr and halosulfuron + imazethapyr provided excellent (≥ 97%) wild mustard control. At 8 WAA, trifluralin, S-metolachlor and trifluralin + S-metolachlor controlled barnyardgrass 70, 85 and 94%, respectively, and halosulfuron, imazethapyr and halosulfuron + imazethapyr controlled barnyardgrass 9, 50 and 59%, respectively. At 8 WAA, trifluralin, S-metolachlor and trifluralin + S-metolachlor controlled green foxtail 89 to 98% and halosulfuron, imazethapyr and halosulfuron + imazethapyr controlled green foxtail 19, 69 and 67%, respectively. Weed interference reduced white bean yield 76%. Generally, white bean yield reflected the level of weed control. Based on these results, the 2- and 3-way tankmixes of herbicides evaluated generally provide similar weed control as the 4-way tankmixes.
Pietro E. Vicari, Esther S. Chang, André L. P. Perondini, Denise Selivon
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p70

Abstract:
In genera Anastrepha, Bactrocera and Ceratitis of the tephritid fruit flies the auto-regulatory function of gene transformer is assumed to be activated by maternal derived mRNA or the proteins of the gene transformer (tra-2 mat) and transformer-2 (tra-2mat). However, this maternal effect was not yet been demonstrated. The objective of the present study was to test the effect of absence of tra-2mat in the eggs on the sex determination of A. sp.1 affinis fraterculus. This was achieved by silencing gene tra-2 in the parental females via the pRNA interference. The data showed that tra-2 was transiently silenced in the female for three weeks period. The progenies sex ratio produced by these females during the silencing of tra-2 depart from 1:1 in favor of males. The excess of males was due to the transformation of a fraction of genotypical female XX embryos into XX males, the so-called pseudomales, Individual F1 males from the offspring of treated females crossed to females from the stock, revealed that majority of them showed regular mating behavior and were fertile. However, no offspring was produced in the crosses by a fraction of males that have produced sperms, showed regular mating behavior but did not transfer sperms to the females. The data allow the conclusion that the absence of tra-2mat in the eggs had impaired the self-regulation of the embryonic gene tra resulting in the transformation of XX embryos into pseudomales and also that these pseudomales are sterile. This effect may be useful improve more sustainable technologies for fruit fly control such as SIT.
Walquíria F. Teixeira, Evandro B. Fagan, Antônio P. M. Machado, Daniel Fortune, Fernando R. Moreira
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p31

Abstract:
Soybean is one of the world’s most economically important crops and several factors can affect the productivity of this culture. Among these factors is the supply of needed nitrogen, especially in the reproductive stage, as it acts in photosynthetic activity and in grain filling. In view of this, the objective of our work was to evaluate the effect of foliar application of nitrogen in different reproductive stages in soybean culture. Two sources of nitrogen were used: conventional urea and urea-formaldehyde/triazone, both applied in reproductive stages R2, R3, R4, or R5, as well as a control treatment without foliar application of nitrogen. Plants submitted to foliar application of urea-formaldehyde/triazone showed an increase in nitrogen metabolism (percentage of nitrogen derived from the atmosphere [Ndfa] and nitrate reductase activity [NR]), an increase in peroxidase (POD), and the consequent reduction in hydrogen peroxide (H2O2) in all stages of application of this treatment. When urea-formaldehyde/triazone was applied in R4, it resulted in a 7% increase in yield. The application of conventional urea in reproductive stages R4 and R5 increased nitrogen metabolism and resulted in an increase in yield by 4%. However, conventional urea reduced yield when applied in stages R2 and R3. The use of low doses of foliar nitrogen in stages R4 and R5, increased nitrogen metabolism in soybean plants. The timing of the application has a direct impact on the results with the slow-release nitrogen (urea formaldehyde /triazone) showing better results when applied in stage R4 and better results for conventional urea in R5.
Naheif E. Mohamed, Ismail M. Bedawy, Yasser A. M. Hefny
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p45

Abstract:
To study genetic analysis of some physiological traits of drought stress in wheat using diallel techniques, an experiment was performed on ten bread wheat genotypes as parents and their 45 F1 hybrids in a randomized complete block design with three replicates under well-watered and drought stress conditions at the Research Farm of Faculty of Agriculture, Sohag University, Egypt during season of 2018/19. The results showed significant differences between the genotypes (G), Parents (P), F1 crosses, P vs. F1, GCA and SCA under well-watered and drought stress in the flag leaf area (FLA), flag leaf chlorophyll content (FLCC) and flag leaf temperature (FLT), except FLCC for F1 crosses exhibited insignificant differences. The significant differences were found in the interaction of SCA × Env., in all studied traits and GCA × Env., for FLT., indicating the involvement of both additive and dominance gene action in their inheritance. The most desirable heterotic effects were considered as the largest positive heterosis estimates for FLA and FLCC, and the lowest negative for FLT. The parent numbers P9, P8 and P3 were the best general combiner for FLA under normal irrigation and drought stress. While the parents P2, P7 and P9 were the best general combiner for FLCC, under normal irrigation and (P1, P2 and P3) under drought stress. Therefor the parents P1, P4 and P5 were the best general combiner for FLT under normal irrigation, also the P3, P4 and P5 were the best general combiner for FLT under drought stress conditions. Under normal irrigation and drought stress conditions as well as the combined data, the additive genetic components of variation (VA) in F1 ’s was much greater than dominance component (VD), as expressed by the (VA/VD) ratio which was more than unity for the FLA, and FLT under normal irrigation and their combined. This indicates that the additive gene effects in F1 crosses are more important than dominance and plays the major role in the inheritance of these studied traits.
Pierre Fils Rodrigue Magwell, Emile Minyaka, Oscar Wamba Fotsop, Marlyse Solange Leng, Léopold Gustave Lehman
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p115

Abstract:
The growth of Spirulina platensis is dependent on culture conditions. This study has established adequate conditions for the quality and quantity production of S. platensis. The effect of sulphate salts nutrition on growth performance and biochemical status of S. platensis was assessed in vitro. Prior to culture, the Paracas strain of S. platensis from SAGRIC pond was analysed in different magnesium sulphate (MgSO4; 0.08, 0.16, 0.32, 0.64 and 1.28 g/L), potassium sulphate (K2SO4; 0.08, 0.16, 0.32, 0.64 and 1.28 g/L) and MgSO4/K2SO4 (0.16/0.00, 0.08/0.08, 0.04/0.12, 0.02/0.14 and 0.01/0.15 g/L) concentrations. Culture media pH, total dissolved solids (TDS) and conductivity rate were monitored. Microscopic analysis revealed sulphate salt concentrations influenced the number of whorls and filaments of S. platensis. K2SO4 (1.28 g/L) produced the highest number of whorls and filaments. Moreover, pH level fluctuated by sulphate treatments. K2SO4 (1.28 g/L) had a pH level of 8.77±0.01 (day 5 of culture incubation). TDS and conductivity rate, protein and cysteine contents increased with culture age and K2SO4 concentration in a culture medium. Conversely, negative correlations between protein and cysteine contents were observed, and sugar content decreased. Sulphate salt type and concentrations affected polyphenol oxidase (PPO) and peroxidase (POD) activities. MgSO4/K2SO4 (0.02/0.14 g/L) displayed the best PPO and POD activities. Both enzymes appeared to be negatively correlated to the decreasing sugar content. These results indicate growth performances and biochemical status of S. platensis are significantly improved with the adequate supplementation of sulphate salts (MgSO4 and K2SO4) in culture media.
Mohammed Rasheed Igbal
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p162

Abstract:
Mastitis is a devastating disease condition in the dairy industry throughout the world and is caused due to the inflammation of the mammary gland. The etiological agents causing mastitis varies from one place to another depending on the animal breed, climate, and husbandry practices. However, the etiological agents causing mastitis include an extensive variety of gram-negative and gram-positive bacteria and fungi. Furthermore, the most common bacterial species responsible for causing mastitis include Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus (Strep.) agalactiae, Strep. Uberis and various Gram-negative bacteria. This review highlights the type of bacteriological etiology causing intramammary infection (IMI) is an essential part of effective mastitis control, prevention, and treatment. It also discusses the diagnostic tests used to test for mastitis in Fiji include Somatic cell count, California Mastitis Test (CMT), and bacteriological culturing. The development of Polymerase Chain Reaction (PCR) technology along with the version of real-time and multiplex PCR has improved the sensitivity and rapidity of mastitis diagnosis. The subclinical and clinical forms of mastitis can be treated with early detection of the signs of mastitis infection. Moreover, it is also essential to create awareness to the farmers about the cost, knowledge about mastitis and the loss it can cause.
Bruno Castro Kuinchtner, Fernando Luiz Ferreira de Quadros, Fernanda Maurer Taschetto, Gabriela Machado Dutra, Liane Seibert, Fernando Ongaratto, Pedro Trindade Casanova
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p85

Abstract:
Grasslands develop a multifunctional role to humanity, with unique fauna and flora, besides being the primary feed source for herbivores. However, grasslands are usually considered a low-efficiency production system, often converted into other land uses such as crops and forestation (e.g., south Brazil). This study aimed to evaluate the effect of two rest intervals between grazing occupations in rotational grazing on the grazing behavior and feed intake of beef heifers. Two grazing intervals, 375 and 750 DD (degree-days) were used; based on the cumulative thermal sum necessary for the leaf expansion of native grasses of two functional groups. The experiment was conducted as a completely randomized block design, with two treatments, three replications, and repeated measures over time. The grazing behavior was evaluated continuously for 18 hours (7 a.m. to 11h59 p.m.). Herbage intake was estimated using an external marker (Cr2O3) in four periods (one for each season). The green leaf mass was similar between treatments, with a mean of 40% of the pregrazing mass (kg DM ha-1). On average grazing, time was 50% of the period, and the bite rate was 38.7 bites min-1. The number of daily meals was 6.5, with an average of 84 minutes for each meal. The number of feeding times (feeding stations by minute) visited was 6.4. On average, there was a 2.23% difference in dry matter intake (% BW) among seasons. Neither ingestive behavior or forage consumption of heifers was affected by the treatments, both maintain similar chemical composition on natural grassland.
Eza Soumaley Sylvie, N’Goran Koffi Celestin
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n10p152

Abstract:
Many studies have shown that rising prices are not transmitted in the same way as falling prices and vice versa. There is an asymmetry in price transmission between agricultural commodity markets that is an important issue in household food security. The main objective of this study is to examine the nature of price transmission in yam markets in Côte d’Ivoire. To do so, two regression models were used, namely the Ordinary Least Squares (OLS) method and Vector autoregressive (VAR) model. The results revealed that a variation in prices on Abengourou and Korhogo markets affects the price on the Abidjan market even though trade between these markets is not direct. Similarly, the price one month later on Abidjan market is affected by its past price and that of Korhogo market one month earlier. As recommendation, the study suggests that the government should strengthen and improve road infrastructure as well as communication networks to enhance trade between markets.
Anne Brown
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p230

Abstract:
Reviewer acknowledgements for Journal of Agricultural Science, Vol. 13, No. 9, 2021.
Thomas Thomidis, Ioanna Prodromou, Argyrios Farmakis
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p93

Abstract:
Plant parasitic nematodes are a global threat to tomato production due to severe damages they cause to roots. The main aim of this study was to investigate the effect of rhamnolipids to control the nematode Meloidogyne incognitain tomato plants. It was applied as soil drench in soil naturally infested with the nematodes. The results showed that the number of small size galls was statistically less in the plants treated with fluopyram than untreated control or rhamnolipids. Plants treated with rhamnolipids had significantly less number of small size galls than untreated control. The number of medium size galls was significant less in plants treated with fluopyram than untreated control. Plants treated with rhamnolipids did not show any difference in the number of medium size galls than untreated control or fluopyram. No significant difference was found among all treatments in the number of big size galls although the plants treated with rhamnolipids or fluopyram had the tendency to show less number. Generally, this study demonstrated the potential of rhamnolipids (biological) to control M. incognita in tomato cultivars.
M. G. Kaiira, G. N. Chemining’Wa, F. Ayuke, Y. Baguma, E. Atwijukire
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p202

Abstract:
Allelochemicals regulate the productivity of crop ecosystems. A screen house experiment was conducted (2016) at the National Crops Resources Research Institute, Namulonge, Uganda to determine the effects of NERICA 1 rice (an interspecific hybrid between Oryza sativa and O. glaberrima species), Cymbopogon nardus (C), Desmodium uncinatum (D), Mucuna pruriens (Mc) and LONGE 6H, Zea mays (Mz) on crop relative growth rates (RGR), nitrogen (N), phosphorus (P) and potassium (K) nutrient levels. One field study was conducted on a farm (2017) to establish the allelopathic interactive effects of RCDMcMz on Striga hermonthica (a parasitic weed), crop competition and productivity. Data was collected on striga, RMz growth, nutrient levels and yield. Potted rice reduced (30%-47%) in root length but Mz leaf length increased (31% & 15%) with Mc & D. RMc reduced (73%) striga and increased rice RGR (14-42 days). RD similarly reduced (67%) striga. RC increased (96%, 44% & 73%) rice NPK uptake, RGR (14-42 days), reduced (57%) striga and increased (1.56) the combined land equivalent ratio (CLER) and rice grain yields. RMz reduced (16%, 38% & 38%) rice NPK reserves, RGR (14-42 days), CLER (1.0), grain yields and increased (36%) striga. RD recorded higher CLER (1.56). MzMc reduced (15% & 27%) maize P uptake and NP uptake increased (42% & 9.3%) under MzC & MzD (73% & 29%). RMc increased rice RGR (14-42 days). Maize RGR (14-28 days) increased under MzD, MzMc & MzC and reduced (28-42 days) under MzD, RC & MzMc.. The ecosystems’ productivity was attributed to allelopathy.
Hira Mannan, Qurban Ali Nahiyoon, Jilian Li
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p148

Abstract:
Okra (Abelmoschus esculentus L.) is an essential vegetable crop with good nutritional significance. Insect pests are the major threat for poor production of the okra crop. Thrips of vegetable crops are known to be serious pests on a wide range of fruit, vegetable, flower, and agronomic crops. The present field study was carried out to know the efficacy of different insecticides (acetamiprid 19% weightable water (ww), lambda 25% ww, colarphipare 32% ww, lambda 2.5% ww and abamectin 1.3% ww) against Thrips, Thrips tabaci (Lindeman) on okra crop during the year 2019, and observations against T. tabaci (Lindeman) were recorded after 24 hrs, 48 hrs, 72 hrs and 07 days of each spray in all the treatments. The pre-treatment count of thrips on okra was non-significant (P > 0.05); while the evaluated efficacy of different insecticides against thrips was significant (P < 0.01). It was noted that all the insecticides showed their highest efficacy after 7 days of spray and acetamiprid 19% weightable water (ww) was more efficient to combat the T. tabaci as compared to other pesticides that produced field efficacy of 73.92 and 74.91% against thrips after 7 days of 1st and 2nd spray respectively. Abamectin, 1.3% ww, was reasonably successful, yielding 53.81 and 56.66% field efficacy against T. tabaci (Lindeman) after 7 days of first and second spray. Also, moderately effective was colarphipare 32% ww, which developed field effectiveness of 56.41 and 61.49% against T. tabaci (Lindeman) after 7 days of first and second spray, respectively.
S. Tsvuura, M. Mudhara, M. Chimonyo
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p73

Abstract:
Small-scale goat farming can significantly contribute to livelihoods, particularly in semi-arid areas where rainfall is erratic and crop farming is too risky. The study investigated the gendered-differentiated contribution of goat farming to household food income and food security in the semi-arid area of Msinga in South Africa using focus group discussions, key informant interviews and a questionnaire survey of 241 households. Using the Household Food Insecurity and Access Scale to measure the household food security of goat farming households, descriptive statistics and the Chi-square statistics, results showed a significant relationship between food security and the household socio-economic parameters such as the education level of the household head (p < 0.05), the gender of the household head (p < 0.05) and the total household income (p < 0.01). The Tobit regression model showed that the main factors determining food security at the household level were education levels, gender and the total household income. Female-headed households were less food secure than male-headed households because they did not have reliable employment to provide adequate and nutritious food for their households. Therefore, empowering women is crucial to ensuring food security because unstable employment opportunities lead to households’ failure to cope with food insecurity adequately. Goat farming did not contribute to household food security because it generated little income as goat sales were generally low, with a mean of 2.1 for male headed-households and 1.0 for female headed-households in 12 months (p < 0.05). Farmers obtained little income from goat farming because goat flock sizes for most households did not increase due to poor nutrition, diseases, predation, and theft. With the household food basket cost reported to be ZAR3 400/US$188, a household would need to sell up to four goats each month to survive solely on goat farming. However, where goat flock size was small, households limited goat sales to maintain the potential to increase their flock size. Empowering women by promoting rural education may increase their chances of being exposed to better management options, acquiring a better understanding of goat management practices, and making informed decisions, thereby contributing to the improvement of food security. Enhancing goat production is essential to increase flock sizes, as this enables farmers to make more sales, thereby improving food security. Therefore, extension workers need to help farmers better manage and utilize goat farming to their full potential. Finally, rural households need to reduce their autonomy and dependency on supermarket goods and become more agri-oriented.
Rose Luiza Moraes Tavares, Cleire Luciano de Oliveira, Renato Lara de Assis, Silvio Vasconcelos De Paiva Filho, Camila Dos Santos Ferreira, Paulo Fernandes Boldrin
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p104

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This study aimed to evaluate the alternative use of humic substances (humic and fulvic acid) combined or not with mineral fertilization containing Nitrogen (N), Phosphorus (P) and Potassium (K) in the process of nutrient retention in the soil. For this, an experiment was conducted in a greenhouse with PVC columns of 40 cm high and 5 cm in diameter, where they were filled with Oxisol sample, being half of the treatments fertilized with NPK and half without at. Humic substances were added at doses equivalent to 0, 60, 120 and, 240 L ha-1. After this, 10 irrigations were made with 32 mm rain simulation. After 30 days, soil samples were collected in the upper (0-20 cm) and lower (20-40 cm) layers of the columns. Soil samples were evaluated for P, K, Ca, Mg content, pH, and soil conductivity. The experiment was in a completely randomized design, with a factorial statistical scheme of 2 × 2 × 4 with three replicates. The results showed that mineral fertilization complemented with the use of humic acid promoted a higher residual effect of Ca and K in the soil after 30 days. The fulvic acid, when used in a complementary way to mineral fertilization, promoted a higher amount of P in the soil. In the absence of mineral fertilization, the effect of humic substance use is low on the availability of nutrients in the soil.
N’Goran Koffi Celestin
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p213

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In Côte d’Ivoire, women occupy an important place in the agricultural sector, which is the basis of the country’s economy. There is unanimous agreement on the essential role that these women must play through their empowerment for the country’s development. Therefore, we must find appropriate solutions to the problem of women’s empowerment in order to enable them to participate vigorously in the country’s development. This study aims to address the problems of women’s empowerment in agriculture by highlighting the potential opportunity that the practice of market gardening represents for women’s empowerment. Based on a qualitative approach using ENV (2019) data, the Women’s Empowerment in Agriculture Index (WEAI) shows that women producer of market garden produce are as self-reliant as their counterparts in other agricultural sub-sectors. In the same logic, the WEAI shows us that the practice of this crop has a positive effect on women’s empowerment. By using these four (4) methods of effect determination, namely the Nearest Neighbour Method, Radius Method, Stratification Method and Kernel Method, the following values were obtained: 0.007; 0.039; 0.017; 0.027, which are all positive. The objective of the study is to determine the impact of market gardening on the empowerment of the women who practice it.
T. T. Liu, J. R. Shao, L. Shen, X. Y. Wang, Tayier Tuerti, L. H. Li, W. Zhang
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p17

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In Xinjiang Uygur Autonomous Region of China, we conducted an experimental study to evaluate the root morphology and crop yield for the intercropping of maize and cotton. Due to the shading effect of maize and the reduced root surface area of cotton root system, intercropped cotton yield was smaller (14.7%) than monoculture cotton yield. By contrast, intercropped maize with cotton yield was higher than monoculture maize yield. Compared with typical production of each crop separately, intercropping of maize and cotton showed several benefits: increased the land utilization rate, with a land equivalent ratio (LER) greater than 1; and increased the root length, root surface area, and light interception in maize, which contributed to an increase in maize yield.
W. L. Zhang, J. R. Shao, L. Shen, T. T. Liu, Tayir Tohti, L. H. Li
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p48

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In the semi-arid areas of Xinjiang in China, the agricultural community is facing long-term challenges in improving crop productivity and economic profits. A potential way to improve crop productivity is by intercropping food crops with cash crops. In this two-year field experimental study, we analyzed the advantages of the cumin/maize intercropping system as compared to cultivating them separately from three perspectives: crop growth, interspecific interactions, and water use efficiency. At the experimental site, each cropping systems (i.e., the cumin/maize intercropping system, monocropping cumin system, and monocropping maize system) had three replicates. In the experimental of 2019 and 2020, the three cropping systems showed significant differences in plant height, stem diameter, and leaf area index (LAI). The yields of the cumin/maize intercropping system were both lower than monocropping maize and cumin. However, the cumin/maize intercropping system had a higher land equivalent ratio (LER) than either of the monocropping systems, with a two-year average value of 1.65. Intercropped cumin was less dominant; as shown by aggressivity (Acm; averaging—0.22) and relative crowding coefficient (Rcm; averaging—3.15). In addition, the cumin/maize intercropping system significantly improved the Water equivalent ratio (WER) as compared to the monocropping systems, with a two-year average value of 1.67. Therefore, the cumin/maize intercropping system is a promising agricultural strategy to improve the utilization rate of agricultural resources and economic benefits in Xinjiang.
Giovani Mansani de Araujo Avila, Gislaine Gabardo, Henrique Luis da Silva, Djalma Cesar Clock
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p97

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Buckwheat (Fagopyrum esculentum Moench) is a prominent crop in today’s agriculture. However, information about its behavior at different doses of NPK fertilization is scarce. The aim of this work was to determine the ideal fertilizer dose for the buckwheat cultivar IPR 91 Baili by establishing the dose-response curve. Two experiments were carried out (greenhouse and in the field). The treatments consisted of different doses of NPK (0, 100, 200, 300, 400 and 500 kg ha-1). After the crop cycle, productivity was obtained. There was a statistical difference between the treatments and the control, in both experiments. The lowest yields were obtained in the controls, 2,301.156 and 2,262.500 kg ha-1, and the highest 4,052.023 and 4,027.778 kg ha-1 at the dose of 500 kg ha-1, in the greenhouse and in the field, respectively. There was no statistical difference between the NPK doses for the yield obtained. The rural producer must use the lowest dose (100 kg ha-1). Future experiments are needed to evaluate the culture response to doses below 100 kg ha-1.
Sandro C. L. Montalvão, Marcelo T. de Castro, Luiz E. B. Blum, Rose Gomes Monnerat
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p1

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The wilt caused by Fusarium oxysporum f.sp. vasinfectum in cotton is one of the main diseases of this crop. The pathogen is difficult to control because it produces chlamydospores, which allows it to survive in the soil for long periods without the presence of its main host. The control of this disease is based on varieties with some resistance, certified seeds, and fungicides used to treat seeds. Thus, the development of control alternatives is needed to increase the number of resources to manage this disease in the field. Bacillus are bioregulators and antagonists of several important phytopathogens. Therefore, the objective of this work was to select strains of Bacillus (Paenibacillus alvei, Bacillus thuringiensis, B. megaterium, and B. lentus), whose metabolites are toxic to F. oxysporum in laboratory and greenhouse conditions, in addition to adjusting in vitro methodologies to perform and evaluate selection tests. This work determined the best culture medium for the direct confrontation assays, proposed a grading scale to facilitate decisions about selection with the dual tests, identified among the strains selected in the confrontation assays those that produce volatile and non-volatile metabolites toxic to F. oxysporum, and tested these selected strains for disease control during seed germination in greenhouse trials. In last test, some strains of Bacillus had a potential protective effect during the germination of cotton seeds.
Samuel Kouadio Oi Kouadio, Mohamed Doumbouya, Oumar Silué, N’Guessan Kan Pulcherie Kouakou, Tanoh Hilaire Kouakou
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p135

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The heavy use of pesticides in banana cultivation is associated to environmental and human health degradation. Environmentally friendly alternatives for sustainable agriculture are needed to mitigate the negative impacts of chemicals. This study aims to evaluate the efficiency of biocontrols in the synthesis of bioactive secondary metabolites, mainly polyphenols. Thus, three biocontrols (Vacciplant®, Callel®, and Calliete®) were applied on three cultivars of banana (Orishele, Corne, and French) for 24 h, 48 h, and 72 h and the polyphenol contents were measured. Results showed that the polyphenol contents varied in function of the incubation time and the variety of banana. The highest polyphenol contents were 170.8 and 169.47 µg/g FM and were obtained with Corne-Calliete (Co-Ca) and Corne-Vacciplant (Co-V) respectively. Biocontrols Vacciplant® and Calliette® showed had the best action in stimulating polyphenol production in the three cultivars of banana.
Paulo Fernandes Boldrin, Ana Carollina Pereira dos Reis, Vinícius De Mello Benites, Rose Luiza Moraes Tavares, June Faria Scherrer Menezes, Veridiana Cardozo Gonçalves Cantão
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p61

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Knowledge of the solubility of phosphate fertilizers is fundamental for phosphorus (P) recommendation management and for choosing the laboratory evaluation method of nutrient availability in the soil according to the history of fertilization. The aim was to evaluate the initial development of corn plants as a function of the application of triple superphosphate (TSP) and natural phosphate of Arraias (NPA) with and without liming and incubation time, as well as to evaluate the available P in the soil with the use the extractors Mehlich-1 and Mehlich-3. An experiment was installed in an 8 × 3 × 2 factorial scheme, being 8 fertilizer incubation times (180, 140, 100, 80, 60, 40, 20, 0 day(s) before planting), 3 P sources (control—without P, TSP and NPA) and 2 refers to the application of limestone (with and without limestone). Were evaluated the shoot and root dry matter, analysis of P, Ca, Mg, and Zn in shoot and P in roots. In the soil, P levels were determined by Mehlich-1 and Mehlich-3 extractors. There was a greater accumulation of P with the application of TSP with limestone in all incubation times. The application of the NPA allowed a greater accumulation of P in the plants without the application of lime. The previous incubation of the NPA did not favor the efficiency of this source, neither in the soil with corrected acidity nor in the soil with its original acidity. Mehlich-3 proved to be adequate to determine the phosphorus content in soil fertilized by NPA.
Isadora Nogueira, Anne Pinheiro Costa, José Ricardo Peixoto, Michelle Souza Vilela
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p112

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Passion fruit is infected by many plant pathogens, including Xanthomonas axonopodis pv. passiflorae, causing bacterial spot disease. This disease has been impaired orchards all over Brazil, resulting in low yield and production. In addition, it results in premature death of plants in the field. This study aimed to analyze the reaction of sour passion fruit genotypes to bacterial spot in leaves under protected cultivation (Experiment 1) and the bacterial spot severity in fruits under field conditions (Experiment 2). Experiment 1 was carried out as a randomized block design (RBD) with subdivided plots, composed of 24 treatments (genotypes), three replications, five plants per plot, and five evaluation dates. Bacterial spot incidence and severity were evaluated using a 0 to 5 grading scale. Evaluations were carried out at a 7-day interval after disease symptoms first appeared. Genotypes differed for mean disease severity and incidence. The bacterial spot disease evaluations showed that genotypes MAR20#46 P3 R4 X Rosa Claro R4 and MD 16 P3 X MAR20#39 P1 R4 presented the lowest scores for the disease incidence in the leaves. S2L AP R1, MAR20#19 ROXO R4 X ECRAM P3 R3, and MD 16 P3 X MAR20#39 P1 R4 were the genotypes with the lowest disease severity scores. Experiment 2 consisted of a RBD with 24 treatments, three replications, and seven plants per plot. Severity assessments were monthly performed on five fruits per plot, totaling three evaluation dates. In this experiment, the percentage of total fruit area with necrotic lesions was measured using a 1 to 4 grading scale. Bacterial spot severity assessments in fruits identified interactions between genotypes and evaluation dates (p ≤ 0.05). The lineages S2L MAR 20#15 R4 and S2L MAR20#19 R2 showed the lowest mean severity scores of bacterial spot in fruit. The genotypes with the lowest mean scores were selected to continue the breeding program.
Antonida V. Kalistratova, Мaxim S. Oshchepkov, Maria S. Ivanova, Leonid V. Kovalenko, Marina A. Tsvetikova, Nataliya A. Bystrova, Konstantin A. Kochetkov
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p36

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Extreme environmental conditions increase the risk of abiotic stresses in plants, which reduce productivity of land. The investigation and developmentof synthetic approach to new antistress compounds, increasing the resistance of plants to negative factors, are relevant to the present. The objective of this study was to synthesize and to test the effect of a series of new carbamate and oxamate plant growth regulators on early vegetation processes of wheat (Triticum aestivum L.). Three independent series of experiments were conducted using lipophilic compounds N-(2,4-Dimethylphenyl)-N’-i-propoxycarbonylaminoethylurea (1) and O-Isopropyl-N-[2-(4-methylphenylaminocarbonyloxy)etyl]oxamate (2) and water-soluble compounds O-i-Propyl-N-(2-hydroxyethylamino)carbamate (3) and O-i-Propyl-N-(2-hydroxyethyl)oxamate (4). Strong stimulating effect on shoots and roots growth in the wheat was found for all studied compounds in all experiments. The highest germination rate (89.6-96.3%) was registered for compound 4. The use of the studied substances 1, 3 and 4 in all cases leads to significant increase in the Seedling Vigor Index (SVI). The high energy index of compounds 3 and 4 can lead to increased photosynthesis and, as a result, to an increase in crop yield. Based on the data obtained on the values of relative water content (RWC) indicators and their components, it can be assumed that all plants after treatment with substances 1-4 are able to tolerate unfavorable weather phenomena. Experimental results show that the percentage of plant recovery after resuming watering was 84-100%. Thus, the data obtained indicate that the synthesized compounds exhibit antistress and growth regulatory activity.
M. G. Kaiira, G. N. Chemining’Wa, F. Ayuke, Y. Baguma
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p183

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Crop residues and mulches release phytotoxic substances into the soil that affect plant growth. An experiment was conducted at the Uganda National Crop Resources Research Institute, Namulonge during 2016, to identify compounds in the stover of potted Cymbopogon nardus, Desmodium uncinatum, Oryza sativa, (NERICA 1), Mucuna pruriens and Zea mays (LONGE 6H) at fourty five days after germination. This marked near the average stationary phase for test crops’ growth when secondary metabolites are maximum. Organic compounds in the stover were extracted using solid phase micro-extraction. Samples were subjected to analysis using a 7890A Gas Chromatography system. Data files were transferred into a distinct folder and data was uploaded onto XCMS online platform for pair wise comparison and other related statistical analysis in the National institute of Science and Technology library. Ten terpenoids and one ester were identified in cymbopogon stover. Desmodium stover released six terpenoids and three phenols. Rice stover produced six terpenoids, three phenolic compounds and one ester. Mucuna stover released two terpenoids and four phenols. The maize stover produced five terpenoids and four phenolic compounds. Profiled compounds from cymbopogon, desmodium, rice, mucuna and maize could be responsible for the reported negative allelopathic effects such as auto-toxicity and suppression of companion crops expressed in agricultural ecosystems. Allelopathic activity of the profiled compounds should be confirmed through bioassays extracts and residues studies. The development and incorporation of the profiled metabolites into agricultural management system may lead to the production of bio-herbicides that reduce environmental degradation and increase crop productivity.
M. G. Kaiira, G. N. Chemining’Wa, F. Ayuke, Y. Baguma, E. Atwijukire
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p192

Abstract:
Allelochemicals cause yield differences under various ecosystems worldwide. Studies were conducted at the National Crops Resources Research Institute, Namulonge, Uganda during 2016 to investigate allelopathic properties of bioactive compounds in upland rice (NERICA 1), Desmodium uncinatum, Zea mays (LONGE 6H) and Mucuna pruriens root leachates. Studies involved pot screening, equal compartment agar experiments, germination tests and growth of potted plants. Results under the pot study indicated that maize, rice and mucuna leachates significantly (P ≤ 0.05), reduced root lengths (49%-63%), plant heights (48%-66%) and biomass (63%-75%) for Ageratum conyzoides, Bidens pilosa and Gallinsoga. parviflora weeds. G. parviflora root growth was reduced (20%-41%) and stem growth declined (19%-42%) when maize, rice and mucuna leachates were applied in the equal compartment agar study. Increased leachate concentrations (25%-75%) significantly (P ≤ 0.05), increased the mean germination time (0.4-2.8 days) for mucuna, desmodium, rice and maize as seed germination indices (SGI) were reduced (1.3%-49%). Potted mucuna, maize and desmodium reduced (1.3%-49%) rice root length. Potting mucuna with maize reduced (32%) mucuna leaf width while desmodium growth parameters were reduced (49%-64%) when potted with maize and mucuna. Potting maize with mucuna or desmodium increased the maize leaf length (18%) and SGI (25). Application of higher (25%-75%) rice/maize leachate concentrations similarly increased the maize leaf length (31%) and SGI (119). Allelopathic properties affect seed germination, crop growth and development, and characterise ecosystems age structures. Strategic management of crops under allelopathic ecosystems is critical.
Kai Li, Liuhao Wang, Zhengyi Zhang, Yulong Guo, Jun Guo, Yanping Chen, DaoHua Zhuang, Jilian Li
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p163

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The gut microbiota plays a key role in the development and health of bumble bees. Male bees are important for the reproductive activity of a colony, yet there are few studies on their gut microbiota. By using qPCR, we found that significant changes in total bacteria and six important bacteria genera from different developmental age points in males. And we compare the gut bacteria of male bees with workers. The results indicate that Gilliamella, Snodgrassella, and Lactobacillus are the dominant gut bacteria in male bees, which is consistent with the previous studies in worker bees, however, there are more total bacteria in male bees. Another gut bacteria genus, Bacillus may be a probiotic bacteria for reproduction in male bees, although the possible function of these bacteria require further study. This research can provide insight into the relationship between the bacterial community and the physiological health and reproductive capacity of male bumble bees.
Radi A. Tarawneh
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p171

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Since early 2020, an outbreak of the coronavirus disease 2019 (COVID-19) has started to spread in Jordan challenging the sustainability of Jordan’s economic sectors and the agricultural sector. A study was conducted in Jordan to evaluate the role of Jordanian Agricultural Policies to mitigate the effects of COVID-19 on the agricultural sector while its full impact on the Jordanian agricultural sector is not yet evident. A scientific questionnaire was distributed to 100 samples of Jordanians who had direct contact with the effect of agricultural policies and they can touch the effect of Coronavirus and Agricultural Policies on the agricultural sector, data selected from farmers, farm labour, fruits and vegetable traders and merchants, and Jordanian citizens were selected randomly from different areas in Jordan. The study summarizes target group opinion and some evidence on the different COVID-19 impacts on the Jordanian agricultural sector. The virus limits the free flow of labour, the agricultural labour force had a slightly decreased in 2020 compared with the year 2019 to about 7%, the country lockdown led to damage of crops due to lack of harvest and/or crop accumulation, as a result, the Jordan Agricultural Contribution to GDP growth rate at current prices was decreased 1.4%, and the growth rate at constant prices was also decreased 1.6%, the exported agricultural commodities value were not affected by COVID-19 pandemic but the imported of Agricultural commodities value was increased. Jordanian government try to facilitate the process of agricultural production and the provision of food during the Corona pandemic through issue agricultural policies and measures to alleviate the effects of the Corona pandemic on the agricultural sector.
Janaina F. Matsumoto, Paulo S. G. Cremonez, Samuel Roggia, Angela M. F. Falleiros, Sheila M. Levy, Pedro M. O. J. Neves, Daniela O. Pinheiro
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p27

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The aim of this study was to determine the effect of the insecticide pyriproxyfen (Tiger™ 100 CE), juvenile hormone analogue, when applied in a sublethal LC30 concentration (0.668 mL a. i. L-1), on the morphological and morphometric parameters of external and internal connective tissue (CT) of the Neotropical-brown stink bug Euschistus heros testicles. The insecticide was applied on nymphs from the 4th instar using a Potter tower with a working pressure of 82.73 kPa (12 lb pol-²) and 1 mL of the emulsion per replicate. A completely randomized experimental design was used, consisting of two treatments (control and pyriproxyfen-treated), five repetitions, and 10 adults of E. heros per experimental unit. The insects were maintained under controlled conditions until the emergence of adults. After 48 h of emergence of adults, the testicles were collected, fixed, and processed for morphological and morphometric analyses. A change was observed in the collagen fibers of the CT of treated insects when compared with those of controls. It was also observed that both types of CT (dense irregular and loose) over the internal tunic of the treated insect were thinner than those in control insects. The analysis showed that pyriproxyfen significantly reduced the external and internal CT width and the conformation of its fibers in all the observed regions when compared with the controls; this may affect the production of the three different types of sperm present in this species.
Bo Peng, Jia-Qi Liang, Ran Zhang, Xia-Yu Tian, Chao Dong, Cuifeng Tang, Xin-Xiang A, Fang Yang, Yan-Ming Zhang, Ya-Qin Huang, et al.
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p122

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Black rice has very superior medicinal value. Since ancient times, it has been used as a nourishing and health-care rice for medicine and food. It has powerful functions such as disease prevention, regulation of circadian rhythm, and promotion of physical recovery. It is suitable for long-term consumption. In this paper, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS) were used successively to visualize and quantitatively analyze the element distribution in the chalky and non-chalky areas of two indica rice varieties in Southern Henan. The results showed that black rice has rich C and O content, followed by N, P, S content, Mg, K, Ca, Mn, Zn content is less. The content of the O element in the chalky area is higher than that of the non-chalky area, while many elements such as C, N, P, S are significantly higher in the non-chalk areas than in the chalk areas; especially the N and S elements are the best indicators of protein, the content in chalkiness area was lower than that in non-chalky area. It can be inferred that the protein content in non-chalky part was higher than that in chalky part, that is, chalkiness character of black rice would affect the nutritional quality of rice. Therefore, our results showed the distribution of elements and protein in black rice, which is helpful for the cultivation of new high-quality black rice varieties in the future.
Kai Li, Liuhao Wang, Zhengyi Zhang, Yulong Guo, Jun Guo, Nasar Amjad, Hira Mannan Shaikh, Jie Wu, Jilian Li
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n9p155

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The gut of bumblebees harbors bacteria that play a crucial role in physiology, nutrition, and health. The mating rate is important for the reproductive activity of a colony; however, few studies have investigated the relationship between mating and gut bacteria. In this study, bacterial functions were identified in the intestinal tract of bumblebees, and biochemical identification and screening were performed using genetic detection technology. By isolating and identifying bacteria, we obtained a single strain and fed it to queens. The results indicated that Bacillus cereus and Bacillus pumilus are present in the gut. The queen mating rates were 48.89% at the period of 4 days and higher than 28.89% mating rates of the control group (P < 0.05), and the latency time were 16.90 min (from entering the mating cage to mating success) and decreased than control (P < 0.05) which was 28.20 min. This finding confirmed that Bacillus was important in Bombus terrestris mating.
Roderick Bastian, Supeno Surija, Michelle Faustine
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p89

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Basal stem rot caused by Ganoderma boninense causes fall and death of oil palm crops, and will drastically reduce plantation productivity by up to 50% and become one of the most serious problems in oil palm cultivation. This study aims to determine the effectiveness of the Colonized System of Ganoderma Vaccine (CHIPS®), as a biocontrol agent against the suppression of Ganoderma disease that infects oil palm trees in-field conditions. This research was conducted from early 2016 to the end of 2020 in a plantation located in Langkat area, North Sumatra by using 216 trees on 1 block as a sample experiment. Plants that infected with Ganoderma is treated with T1 treatment (MOAF™ & CHIPS®) shows the value of Disease Severity Index (DSI) decreasing to 37.50%, compare to T2 treatment (NPK Granular Fertilizer 13-6-27 & Trichoderma bio fungicides) which has DSI value of 100% in week 232 (in 2020) and C1 treatment (control) with the highest DSI value of 100% in week 212 (in 2020). The conclusions of this study shows that the treatment of T1 (MOAF™ & CHIPS®) is more successful in eradicating Ganoderma and have the highest profit ratio than any other treatments. The results of this study are useful as references for in-field inspection and large-scale production.
Okongo Caroline, Ouma Evans, Gudu Samuel
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p63

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Sorghum is an important food security crop for arid and semi-arid tropics but its production is hampered by many biotic and abiotic factors including covered kernel smut disease (CKSD) caused by fungus Sporosorium sorghi in the Ustilaginaceae family. The disease attacks susceptible sorghum genotypes causing yield losses estimated at 43% in Western Kenya. This study determined the response of selected sorghum genotypes to CKSD under field and greenhouse conditions. A total of 15 elite sorghum genotypes were screened under field conditions in Migori and Homa Bay sites and under greenhouse at the University of Eldoret. Data on disease incidence and severity were collected per genotype and analyzed using R-Studio software and means were separated at 1% using Tukey’s test. Results showed significant differences among genotypes for disease incidence and severity under fields and greenhouse conditions. Disease incidence varied significantly (p < 0.001) among the genotypes ranging from zero (for T53, T30, IS3092, N4 and N68) to 64% (for Nyadundo2) under field conditions but ranged from 0-69% under greenhouse conditions. Similarly, severity followed the same trend with C26 having the worst attack with a score of 5 while T53 recorded the least (score of 1). This study has identified potential sources of resistance for covered kernel smut disease that can be utilized to manage the disease and significantly improve sorghum yields in the target regions.
Cristiane G. L. Ruiz, Marilza S. Costa, Santino Seabra Jr, Mônica J. B. Pereira
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p47

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Collard greens are commonly grown in family farming systems; however, damage caused by the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) reduces yields, leading to successive applications of insecticides and consequently, environmental and toxicological problems. Therefore, it is essential to search for alternatives that reduce the use of pesticides and are economically viable and accessible to small farmers. This study was aimed at evaluating the insecticidal activity of aqueous extracts of neem and tobacco on P. xylostella. First instar caterpillars were offered collard leaf discs treated with different concentrations (30 caterpillars per treatment) and after the third day, mortality was evaluated. To evaluate ovicidal properties, collard leaves with 30 eggs were immersed in extracts and after 48 h, viability was measured. Oviposition deterrent activity was assessed with 23 couples of P. xylostella released in cages (repetitions) containing treated collard plants and after 48 h, the number of eggs per plant was recorded. Neem and tobacco extracts exhibited larvicidal, ovicidal, and oviposition deterrent properties against P. xylostella, indicating that the use of these extracts may be promising alternatives in family farming systems.
Christian Willemse, Nader Soltani, Lauren Benoit, Amit J. Jhala, David C. Hooker, Darren E. Robinson, Peter H. Sikkema
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p21

Abstract:
The evolution of multiple-herbicide-resistant (MHR) waterhemp (resistant to Groups 2, 5, 9, and 14) in Ontario, Canada is challenging for growers. The complementary activity of the co-application of hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides with atrazine has been well documented. The objective of this research was to determine if the addition of atrazine to 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides applied postemergence improves their consistency of MHR waterhemp (including Group 5 resistance) in corn. Five field trials were conducted over a two-year period (2018, 2019) in Ontario, Canada. Five HPPD-inhibiting herbicides [isoxaflutole (105 g ha-1), mesotrione (100 g ha-1), topramezone (12.5 g ha-1), tembotrione (90 g ha-1), and tolpyralate (30 g ha-1)] were applied postemergence with and without atrazine to 10-cm-tall waterhemp. Corn injury (≤ 10%) was observed at specific sites where the application of tembotrione, isoxaflutole and isoxaflutole + atrazine resulted in characteristic white bleaching of corn foliage; however, yield was not affected. Averaged across field sites, the addition of atrazine to isoxaflutole, mesotrione, topramezone, or tembotrione improved MHR waterhemp control 15%, 11%, 7%, and 7%, respectively at 4 weeks after application (WAA). Averaged across herbicide treatments and sites, the addition of atrazine reduced the standard error of MHR waterhemp control by 13% to 100%. This study concludes that the co-application of atrazine with HPPD-inhibitors applied postemergence reduced the risk of herbicide failure and resulted in greater and more consistent control of MHR waterhemp.
Anne Brown
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p113

Abstract:
Reviewer acknowledgements for Journal of Agricultural Science, Vol. 13, No. 7, 2021.
Liaqat Ali Khan, Zoia Arshad Awan, Asad Ullah Imran, Muhammad Saleem, Fawad Sufyan, Muhammad Azmat
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p74

Abstract:
Better management practices (BMPs) as a sustainable approach made it attractive for growers to control the provision of pollutants from agricultural activities as well as enhance the financial return. The experiments of cotton production were conducted in four different regions of Punjab in cotton-growing years 2017-2019. The objective of the study was to evaluate the potential impact of BMPs among cotton farmers by rationalizing the use of input resources (viz., seed, fertilizers, pesticides and water). The data were collected from randomly selected adopters of BMPs (n = 400) and non-adopters of BMPs (n = 100) through a well-structured pretested questionnaire using a multistage sampling procedure from four different regions of Punjab province. Descriptive analysis was employing an independent two-sample t-test to evaluate the significant effect of BMPs on the utilization of input resources and profitability of cotton production between adopters and non-adopters of BMPs. The results indicated that adopters of BMPs were efficiently used input resources (at p ≤ 0.001 & p ≤ 0.01) and significantly enhanced the average cotton yield (855.09 kg acre-1) in Punjab, while non-adopters of BMPs had a significantly high cost of production by 11% (35,655 PKR acre-1) and output was lower by 15% (751.70 kg acre-1) under conventional farming for cotton cultivation. The economic analysis revealed that the average gross income gained by adopters of BMPs was significantly high by 11% (72,648 PKR acre-1 at p ≤ 0.001) with the maximum net return of 36% (40,785 PKR acre-1 at p ≤ 0.001) as well as a good B:C (1.28) as compared to non-adopters of BMPs. This study provides useful information about the potential impact of BMPs among cotton farmers even without the extra use of inputs. It is concluded that precision in inputs and management practices with lower input costs can significantly improve cotton productivity leading to uplift the farmers’ profit.
Thiago C. V. Stacciarini, Aurélio R. Neto, José M. Alves, Marina G. Marques
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p1

Abstract:
In Brazil, sugarcane (Saccharum spp.) is considered one of the most economically important crops. Nitrogen (N) is one of the most required elements in sugarcane cultivation. Nevertheless, the information about the soil and foliar applications of this nutrient in crops are discrepant. Therefore, the importance of this study is evident. Given the above, this study aimed to evaluate the soil-applied and foliar N fertilization of sugarcane. The experiment was conducted at the Araporã Bioenergia S.A. power plant, located at Fazenda Santa Rita, in the municipality of Itumbiara-GO. The 5 × 5 factorial design was adopted, with four repetitions, including five doses of soil-applied ammonium nitrate and five doses of foliar Amidic N polymer. The nutrient extraction, the experiment’s initial and final total chlorophyll content, the biometric indexes and the industrial quality indexes were analyzed for sugarcane. The ammonium nitrate doses caused differences in fiber, sacarose content, total recoverable sugar, sugar cane Brix, magnesium, and zinc, which was statistically different for the foliar polymer doses. There was no increment of the production variables with the increase of the nitrogen supply in the soil. On the other hand, the levels of zinc and magnesium in the leaves increased 12% and 27%, respectively, reflecting the importance of this fertilization in sugarcane cultivation.
Bosco Chemayek, Arthur Wasukira, Robert Gidoi, Stephen Wobibi, Doreen Nampamya, Park Teason, Lawrence Owere
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p37

Abstract:
Field pea is a key source of household income, food and nutrition in Uganda mainly produced in the high land areas of country including south western and Mt. Elgon. The crop fetches a high stable price across markets compared to other grain pulses and yet it has remained outside the mainstream of the research process. The status of this commodity is largely unknown yet such information would support its research agenda to improve productivity and marketing. A study was conducted in the Mt. Elgon sub-zone to determine the status of field pea production, understand its constraints and map out its production cycle. This was done through a survey covering 5 districts namely; Bulambuli, Kapchorwa, Kween, Namisindwa and Mbale. In each district two major field pea growing sub counties were purposively selected, in each sub-county 25 respondents were randomly sampled from a list of field pea producers. A structured questionnaire was then administered; data collated, and analyzed using descriptive statistics and chi-square test. The results revealed that the crop is grown by all gender categories with 60% grown for home consumption and 40% for income. In the districts of Kween and Mbale it is mostly grown for income since the Kween farmers have relatively larger pieces of land whereas Mbale being a commercial hub of the region there is relatively higher price throughout the year which attracts farmers to sell. Field pea is grown alongside other crops which varied by district but was largely grown as sole crop, along boundaries and intercrops depending on availability of land. It is also important to note that it forms a very important part of the rotation system because it plays a significant role in soil fertility restoration as well as serving as a break crop suitable for rotation to minimize the negative impact of cereal based mono-cropping.
Daniel Debona, Angela Pivotto, Alexsandro J. Tetzlaff, Darlan F. Sartori, Luiz A. Borelli, Murilo S. de Oliveira, Lilian Y. Yamamoto, Jociani Ascari
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p10

Abstract:
Alternaria rot, caused by Alternaria alternata, is one of the most destructive diseases of pitahaya (Hylocereus spp.). We investigated the effect of the essential oil of Baccharis dracunculifolia (Asteraceae) (EOB) in the control of A. alternata. Two studies were performed in Petri dishes containing potato dextrose agar medium amended with concentrations of the EOB ranging from 5 to 1,000 µg mL-1 (first study) and from 30 to 2,000 µg mL-1. The diameter of the fungal colony was recorded daily. These data were used to calculate the the area under the mycelial growth progress curve (AUMGPC) and mycelial growth index (MGI). In the third study, the control of Alternaria rot in pitahaya fruits by EOB was investigated by adding the EOB into an edible coat based on cassava starch and sorbitol which was prepared in Tween 20. Three treatments, containing EOB at 500, 1,000 or 2,000 µg mL-1, were assessed. Two additional treatments, one containing water and another containing only the edible coating served as controls. Pitahaya fruits were immersed in those solutions for 10 min, allowed to dry and inoculated with A. alternata 48 h later. The EOB was found to inhibit the mycelial growth and a negative and quadratic model best described the relationship of the EOB concentrations with MGI and AUMGPC. Results from the experiment performed with pitahaya fruits showed that Alternaria rot was decreased with increasing EOB concentrations. Therefore, EOB is a promising and ecofriendly method that may be included in the management of Alternaria rot in pitahya.
Thunwa Wiyabot, Piyalap Manakit
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p101

Abstract:
The objective of this study was to investigate the feasibility and reasonable production costs for small cattle farmers in Nakhon Sawan Province of Thailand. Small-scale beef cattle are naturally reared by farmers without planning. Studying the primary data of beef cattle farming models and comparing the economic return costs of each form of beef cattle farming among smallholder farmers in Nakhon Sawan Province of Thailand shows that the yields are not worthwhile. By applying the specific method to 25% of the area of all farms in Nakhon Sawan Province and comparing the descriptive statistical yields, the results showed that two types of cattle with 4 characteristics predominate. The first is rearing pregnant mother cows for sale and buying mother cows. The second category is feeder cattle, release cattle and fattening cattle. A study of the costs and economic compensation of suitable small-scale beef cattle farmers in Nakhon Sawan Province of Thailand found that cattle farms should raise cattle because the yield from farming is valued and because of the economic returns and the time spent. The payback for this form is faster than other forms of investment.
Patricia Aparecida de Carvalho, Maria Juliana A. de Oliveira, Rafaela Aparecida A. de Almeida, Silvério De Paiva Freitas, Geraldo De Amaral Gravina
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p55

Abstract:
The species Ocimum gratissimum L. is widely utilized in food, cosmetics, and folk medicine, and is also an important source of essential oils. Understanding its behavior in response to environmental conditions is of paramount importance to improving crop management methods. In this context, the following study aimed to evaluate the effects of shade, and of competition with weeds (Cyperus rotundus L.), on the growth of Ocimum gratissimum L. The experimental design adopted was randomized blocks, in a 5 × 5 factorial scheme, with 5 levels of shading (48%, 75%, 77%, 83% and 90%) and 5 densities of Cyperus rotundus L. (0, 5, 10, 15 and 20 per pot), with 4 repetitions. The variables analyzed were main stem height (MSH), diameter of stem base (DSB), number of leaves on the principal branch (NL), number of ramifications (NR), chlorophyll index of leaves (CIL), foliar area (FA), dry mass of the aerial part of the medicinal species (DMAPm), dry mass of the aerial part of the weed species (DMAPw) and essential oil content (EOC). The results demonstrate that the Ocimum gratissimum L. plants presented compatible tolerance responses to up to 70% shading, and that competition with Cyperus rotundus L. was detrimental in a density above 13 plants per pot in interaction with shading. The highest dry mass production and, consequently, the highest oil yield, were obtained from the 48% shading treatment.
Harbans L. Bhardwaj
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n7p32

Abstract:
With a view towards expanding the menu of available summer forages, a study was conducted to characterize forage traits of Chia (Salvia hispanica L.). When grown in Virginia (mid-Atlantic region of the United States) during 2019 and 2020, 60-day old whole vegetative plants of both black-seeded and white-seeded Chia contained approximately 21 percent protein, 1.5 percent potassium, 2.06 percent calcium, 2.4 percent crude fat, 21.2 percent ADF, and 29.4 percent NDF. The fresh and dry biomass yields were 8310 and 814 kg ha-1, respectively. Based on forage quality values of Chia produced in other countries and other forages, it was concluded that Chia is a potential forage crop.
Janilson Pinheiro de Assis, Roberto Pequeno de Sousa, Isaac Reinaldo Pinheiro de Lima, Paulo César Ferreira Linhares, Walter Rodrigues Martins, Eudes De Almeida Cardoso, Joaquim Odilon Pereira, Robson Pequeno de Sousa, Aline Carla de Medeiros, Lauvia Moesia Morais Cunha, et al.
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n6p70

Abstract:
This paper aims to estimate, using the Penman-Monteith method, the probabilities of reference evapotranspiration (ET0) in millimeters, as well as their accumulated values for ten days (decendial), in Mossoró, northeast Brazil. The Meteorological Station of the Federal Rural University of Semi-Arid (UFERSA) provided the daily records of evapotranspiration. The construction of tables based on the approximation of the variable to the Gamma distribution allows the use of data without transformations. The probabilities were estimated with the Gamma distribution at confidence levels of 1% to 95% over the 1970-2007 data period. The results of the chi-square and Kolmogorov-Smirnov tests at 10% probability (p ≥ 0.10) demonstrated the adequacy of the table construction process, providing essential support in the planning of agricultural activities in the region to obtain the maximum benefit from evapotranspiration data. The Gamma probability distribution best described the ET0 for scaling irrigation systems in the county. The maximum daily ET0 for irrigation projects in the Mossoró region is 10 mm, and the cumulative 10-day ET0 averages 80 mm.
Vinícius Almeida Oliveira, Eliana Paula Fernandes Brasil, Welldy Gonçalves Teixeira, Felipe Corrêa Veloso dos Santos, Atila Reis da Silva
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n6p31

Abstract:
While over-use of N fertilizers can suppress microbial biomass, application of urease inhibitors is known to be a potential way to rebuilt microbial diversity and improve soil functions. However, the hypothesis of this study is that the application of N fertilizers regardless of the source would increase soil microbial biomass and reduce soil respiration. A two-year field experiment was conducted to assess the effects of enhanced-efficiency N sources on soil microbial biomass, and soil respiration. The experiment was set up in a randomized block design in a 3 × 4 + 1 factorial scheme, with four replicates. Treatments comprised three sources (conventional uncoated urea, NBPT (N-(n-butyl) thiophosphoric triamide)-treated urea, and polymer-coated urea) and four rates (30, 60, 90 and 120 kg ha-1) of N, in addition to a control treatment (no fertilizer application). Microbial biomass C (MBC) and microbial biomass N (MBN), and soil respiration (C-CO2 and qCO2) were determined in upland rice rhizosphere in each crop season. Responses of soil microbial properties to N fertilization were dependent on the N rates, but no significant effect of the N sources was observed. All measured parameters, except MBC in the first season and C-CO2 in the second season, were increased with increasing N rates. However, the application of N higher than 60 kg ha-1 suppressed soil microbial biomass, as well as soil respiration.  Therefore, the lack of response by added urease inhibitors to the N sources indicate that optimizing N rates for upland rice production is a far more effective option for improving soil microbial community than using enhanced-efficiency N sources.
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