Showing papers in "Journal of Crop Improvement in 2017"
TL;DR: The present review deals in detail with various aspects of CRISPR/Cas systems but briefly with other genome-editing tools.
Abstract: Genome editing refers to a process by which a specific chromosomal sequence is changed. The edited chromosomal sequence may comprise an insertion of at least one nucleotide, a deletion of at least one nucleotide, and/or a substitution of at least one nucleotide. Genome editing is a relatively new technology that is gaining importance as a tool for crop improvement because of its advantages over routinely used methods of genetic engineering. Genome-editing technology is precise and efficient. Genome editing is now considered a safe technique because no foreign sequences are left behind in the final genome-edited organism (GEO). Genome editing involves the induction of double-stranded breaks (DSBs) at specific sites of DNA, which turns on endogenous repair mechanisms—homology-dependent repair (HDR)—when homologous sequences are present, and nonhomologous end-joining (NHEJ) in the absence of homologous sequences. During repair, site-specific mutations are produced. A range of molecular tools for indu...
55 citations
TL;DR: The role of seed producer cooperatives (SPCs) in the Ethiopian seed sector and their contribution to seed supply improvement have received attention from researchers, policymakers, and development experts as discussed by the authors,.
Abstract: The role of seed producer cooperatives (SPCs) in the Ethiopian seed sector and their contribution to seed supply improvement have received attention from researchers, policymakers, and development ...
38 citations
TL;DR: In this paper, a study was carried out to better understand non-adoption of improved varieties of potato (Solanum tuberosum) and associated technologies by smallholder farmers in Chencha, Ethiopia.
Abstract: This study was carried out to better understand non-adoption of improved varieties of potato (Solanum tuberosum) and associated technologies by smallholder farmers in Chencha, Ethiopia. Data were collected through a survey (n = 47) and in-depth interviews (n = 20). It shows how wealth status was a factor of major importance. Most wealthy and some medium-wealthy farmers adopted improved potato varieties and many of the improved production practices; they had access to seed, associated knowledge and support, and sufficient resources that were necessary to apply the improved practices. Non-adoption was common among many medium-wealthy and most poor farmers: they lacked—next to access to the technologies and knowledge—cash, land, and labor. Results indicated the need to rethink research and intervention efforts. Next to paying attention to differences in the access to technology and the related knowledge, there is a need to consider the variation in technology needs, supporting microcredit services, a...
26 citations
TL;DR: Three inbred lines emerged as potentially useful sources of resistance to AER and a flatoxin accumulation as they showed low levels of aflatoxin contamination in both localities in Kenya and in South Africa.
Abstract: Aflatoxin, a carcinogenic toxin, is produced mainly by Aspergillus flavus and Aspergillus parasiticus. Contamination of maize (Zea mays L.) grain by these fungi occurs before harvest, and the easie...
24 citations
TL;DR: This review highlights the available genetic resources, the major wheat genebanks and databases, as well as the breeding methodologies for drought tolerance in wheat, including prebreeding, conventional breeding, hybrid breeding, and genomics-assisted breeding.
Abstract: Yield gains from rain-fed wheat (Triticum aestivum L.) production, particularly in areas experiencing intermittent and terminal dry spells, can be realized through integrated breeding with promising genetic and genomic resources using appropriate methodologies. This enables targeted recombination of novel genes for drought tolerance and selection of desirable genotypes. Continuous exploration of new sources of genetic variation and introgression of suitable genes into elite drought-susceptible genotypes, including via transgenic approaches, and the use of genome editing could offer exciting future prospects in acquiring drought-tolerant wheat genotypes. This review highlights the available genetic resources, the major wheat genebanks and databases, as well as the breeding methodologies for drought tolerance in wheat, including prebreeding, conventional breeding, hybrid breeding, and genomics-assisted breeding. The potential of genetic modification through the transgenic and genome-editing approach...
22 citations
TL;DR: In this paper, the authors compared yield, yield components of cauliflower (Brassica oleracea var. botrytis) and tomato (Solanum lycopersicum L.), and income of smallholder vegetable farmers within different innovative technology practices (with plastic mulch and indigenous microorganism (IMO) vs.
Abstract: Production gaps exist in vegetable crops at the farm level in inland and coastal regions of Bangladesh and these gaps could be minimized using different innovative/new agricultural technologies and improved crop management practices. The present study was conducted to compare yield, yield components of cauliflower (Brassica oleracea var. botrytis) and tomato (Solanum lycopersicum L.), and income of smallholder vegetable farmers within different innovative technology practices (with plastic mulch and indigenous microorganism (IMO) vs. without plastic mulch and IMO) at Baliakandi, Rajbari (inland region); and Dashmina, Patuakhali; and Charfession, Bhola (coastal region) in Bangladesh. Yield and gross margins of cauliflower and tomato with plastic mulch and IMO were higher compared with no plastic mulch and no IMO, regardless of location. At Baliakandi, Rajbari, cauliflower yield with plastic mulch was 42.5 t ha–1, which was a 24.3% improvement over cauliflower yield obtained without plastic mulch (3...
21 citations
TL;DR: A sesame history in theUSA is provided, a description of the botanical characteristics of the crop that make it suitable for mechanized production in the USA, and an overview of the principal sesame production methods of interest for the southeastern USA are provided.
Abstract: Sesame is a new crop for the southeastern USA, most recently being considered for this region because of frequent drought events in the historical farming area of the crop, that is, Texas and Oklahoma, and for overall expansion of its domestic production. Although sesame was introduced in the USA in the 19th century, its commercial cultivation was not possible before the 1990s with the release of non-dehiscent cultivars. The southeastern USA has been considered promising because of its greater annual precipitation as compared with the southwestern USA. In addition, sesame has some highly valuable agronomic characteristics that could make the crop a beneficial addition to crop rotations in the southeast. These crop characteristics include the following: nematode resistance potential, drought tolerance, nitrogen recovery ability, rotational suitability with the predominant agronomic crops in the region, and capacity to attract a wide variety of pollinators. Since very little United States-based lite...
19 citations
TL;DR: Inbred lines with desirable GCA effects for GY and other agronomic traits and hybrids with good performance under both optimal and drought stress conditions are potential parents for development of various types of high-yielding, stress-tolerant, and early-maturing hybrids.
Abstract: Early-maturing maize (Zea Mays L) germplasm developed from diverse sources has the potential for use in developing maize hybrids suitable for increasing maize production in the dry ecologies of eastern Africa A diallel study was conducted to estimate general combining ability (GCA) of 12 early-maturing maize inbred lines, identify potential single-cross hybrids for use as parents, assess genetic diversity among the inbred lines, and relate genetic distance to specific combining ability (SCA) and hybrid performance Sixty-six F1 diallel hybrids were evaluated under optimal and drought stress conditions at four locations in Kenya and Uganda The parental inbred lines were genotyped using 94 single nucleotide polymorphism (SNP) markers Additive gene action was more important than nonadditive gene action for inheritance of grain yield (GY) under optimal conditions However, nonadditive gene effects were more important in the inheritance of GY under drought and across all environments Inbred lines
18 citations
TL;DR: The PVS research showed the possibility of ensuring food security of smallholder farmers as new high-yielding varieties gave an additional 0.3 –0.5 tons of grain per ha, sufficient to feed two to three persons per year.
Abstract: We conducted this research because earlier research revealed that Pakistani farmers were growing 8–10-year-old wheat (Triticum aestivum L.) varieties and hence not benefitting from the recent advances in wheat breeding. Participatory varietal selection (PVS) trials were conducted to have farmers validate and include newly released wheat varieties into seed-production stream to speed up replacement of old and obsolete wheat varieties by farmer-preferred new high-yielding varieties. Fourteen new varieties recommended for irrigated and eight for rainfed environments were evaluated in this research involving smallholder farmers in food-deficit districts of Pakistan. Collaborating farmers preferred 10 varieties from the PVS trials, eight of which were germplasm from the International Maize and Wheat Improvement Center (CIMMYT) that yielded on average 5–17% more grain than local checks. Local checks used in the PVS trials in Sindh and Khyber Pakhtunkhwa were old improved varieties. Greater yield advanta...
17 citations
TL;DR: In this paper, the authors proposed a new method that requires relatively low skill levels from enumerators and respondents, engages farmers without the need for extrinsic incentives, and gives statistically robust results.
Abstract: Participatory methods to characterize farmers’ needs and preferences play an important role in plant breeding to ensure that new varieties fulfill the needs and expectations of end users. Different farmer-participatory methods for priority setting exist, each one responding differently to trade-offs between various requirements, such as replicability, simplicity, or granularity of the results. All available methods, however, require training, academic skill, and staff time of specially qualified professionals. Breeding and variety replacement may be accelerated by empowering non-academic organizations, such as NGOs and farmer organizations, to carry out farmer-participatory priority setting. But for this use context, currently no suitable method is available. A new method is needed that demands relatively low skill levels from enumerators and respondents, engages farmers without the need for extrinsic incentives, and gives statistically robust results. To achieve these objectives, we followed prin...
17 citations
TL;DR: In this article, an irradiated wheat (Triticum aestivum L.) M5 population was generated in the background of spring wheat cv. Almaken to broaden genetic variation.
Abstract: To broaden genetic variation, an irradiated wheat (Triticum aestivum L.) M5 population was generated in the background of spring wheat cv. Almaken. This resource was used to measure components of p...
TL;DR: Extracts of pawpaw, neem and red acalypha reduced disease incidence and severity of common bacterial blight disease and increased yield of cowpea, suggesting these plant extracts could serve as viable alternative to synthetic chemicals to control Xanthomonas-caused diseases incowpea.
Abstract: Common bacterial blight disease of cowpea, caused by Xanthomonas axonopodis pv phaseoli, has been identified as the most important biotic constraint to cowpea production worldwide. Continuous and indiscriminate application of chemical pesticides has necessitated the search for an environment friendly method of control. Azadirachta indica (neem), Acalypha wilkisiana (red acalypha) and Carica papaya (pawpaw) extracts were field-tested against common bacterial blight disease. The experiment was laid out as a randomized complete-block design (RCBD) with three replicates. Cold extracts of 6.67% concentration of the plant leaves were sprayed on cowpea (variety ‘Ife brown’) foliage. Streptomycin sulfate of 0.2% concentration was applied as a positive control and sterile distilled water as a negative control. Incidence of common bacterial blight ranged from 20.00 to 43.74% and severity from 1.02 to 2.00 on a 1–6 scale, where 1 = no symptoms of common bacterial blight and 6 = necrotic lesions on more than ...
TL;DR: Overall, normal irrigation, combined with humic acid application and mycorrhizal inoculation, partially improved the quality indices of roselle.
Abstract: Crop management is an important factor affecting the quality of medicinal plants. Therefore, objectives of our investigation on roselle (Hibiscus sabdariffa L.) were: 1) To identify an appropriate ...
TL;DR: A Liberty® leaf-painting method is applied to screen transgenic maize plants and validated the results through PCR and quantitative real-time PCR (qRT-PCR), which shows good correlation with gene expression in planta.
Abstract: Screening of gene manipulation events (transgenic, mutation/genome editing, etc.) is a cost/labor-intensive and time-consuming process in plant science research. While polymerase chain reaction (PCR) is the most commonly used method for screening, the process still requires efficient DNA extraction and subsequent confirmation. However, PCR cannot predict gene expression. To screen a larger number of transgenic plants, it would be ideal to develop a quick and reliable screening procedure. We have applied a Liberty® leaf-painting method (against bar gene under 4x35S promoter) to screen transgenic maize (Zea mays L.) plants and validated the results through PCR and quantitative real-time PCR (qRT-PCR). Liberty leaf painting at 500 mg L−1a.i. was > 95% accurate in identifying transgenic events that agreed with the PCR results. Further investigation of bar gene expression in sensitive lines that were PCR positive shows very low expression of the bar gene. We have provided a simple, and rapid assay to d...
TL;DR: In this article, the authors investigated three primary hypotheses for trait expression that could explain slow-wilting trait in soybeans: low osmotic potential in the leaves allowing greater water retention, high elastic modulus of leaves resulting in delayed development of wilting, and high hydraulic conductance allowing rapid water redistribution in the plants.
Abstract: Soybean [Glycine max (L.) Merr.] genotype PI 471938 expresses a slow-wilting phenotype in the field, and the progeny of this genotype have shown to have high yield under water deficit conditions. However, the physiological basis for the slow-wilting trait in PI 471938 remains unclear, and failure to understand the causal mechanism may limit future breeding efforts. This study investigated three primary hypotheses for trait expression that could explain slow-wilting trait in PI 471938: (1) a low osmotic potential in the leaves allowing greater water retention, (2) high elastic modulus of leaves resulting in delayed development of wilting, and (3) high hydraulic conductance allowing rapid water redistribution in the plants. Experiments included three other soybean genotypes as references for the results obtained with PI 471938. Surprisingly, the results for PI 471938 did not prove to be unique as compared to the other three tested genotypes for any of the three hypotheses. These negative results ind...
TL;DR: In this paper, the authors investigated the comparative effect of two growing environments (open field vs. polyhouse), three planting dates (15 October, 30 October, and 15 November), and four mulch treatments (black polythene, clear polythenea, paddy straw, and no-mulch) on growth and yield of bell pepper.
Abstract: Bell pepper (Capsicum annuum L. var. grossum Sendt.) production is often constrained by prevailing sub-optimal temperature conditions. The treatments that enhance earliness and extend availability period may substantially increase value of the crop. This two-year study (2010–11 and 2011–12) was conducted to investigate the comparative effect of two growing environments (open field vs. polyhouse), three planting dates (15 October, 30 October, and 15 November), and four mulch treatments (black polythene, clear polythene, paddy straw, and no-mulch) on growth and yield of bell pepper. The highest fruit number, fruit weight, early yield, marketable yield, and total yield were obtained when the crop was planted in the polyhouse on 30 October under black polythene mulch. Thus, the use of polyhouse and black plastic mulch, when combined with appropriate planting date, improves early and total yields of bell pepper in areas where the production is constrained by sub-optimal temperature conditions.
TL;DR: Recurrent parent (RP) grafted onto IL and donor (D) rootstocks, and self-grafted IL and RP were examined at different combinations of optimal and suboptimal temperatures to improve tolerance of the scion to drought and low RZT.
Abstract: Grafting tomato (Solanum lycopersicum L.) onto introgression lines (ILs) derived from S. habrochaites with introgression of a quantitative trait locus (QTL), stm9, for shoot turgor maintainer located on chromosome 9 has been suggested for improving yield under abiotic stresses. However, the physiological and agronomic responses of grafts with IL rootstocks to low root-zone temperature (RZT) and drought stresses are not yet clearly understood. Therefore, recurrent parent (RP) grafted onto IL and donor (D) rootstocks, and self-grafted IL and RP were examined at different combinations of optimal (20°–26°C RZT and well-watered) and suboptimal (10°C RZT and well-watered, and 20°–26°C RZT and cyclic drought) temperatures. Graft combinations were compared with self-grafted controls for dry weights, stomatal conductance (gs), leaf parameters, osmotic adjustment, and stress tolerance index. The RP grafted onto IL rootstocks regulated gs efficiently, retained the green trait, and produced higher biomass tha...
TL;DR: Gene pyramiding (assembling multiple desirable genes into a single genotype) via conventional methods to combat Asian rust resistance in soybean varieties with durable resistance to this disease continues to be a challenge.
Abstract: Gene pyramiding (assembling multiple desirable genes into a single genotype) via conventional methods to combat Asian rust resistance in soybean (Glycine max (L.) Merrill) and developing soybean varieties with durable resistance to this disease continues to be a challenge. Therefore, our objectives were to pyramid four Asian rust (caused by Phakopsora pachyrhizi) resistance (Rpp) genes, viz., Rpp1, Rpp2, Rpp3, and Rpp4 from their respective donors, PI200492 (Komata), PI230971, PI462312 (Ankur), and PI459025 (Bing Nan). Two single crosses (PI200492 × PI230971; PI462312 × PI459025) and a double-cross [(PI200492 × PI230971) × (PI462312 × PI459025)] were made for present study. The scoring of parents and crosses was done according to a 0–9 grading scale, where 0 = 0% disease intensity (absolutely resistant), 1 = 1% disease intensity (highly resistant), 3 = 1.1–10% disease intensity (moderately resistant), 5 = 10.1–25% disease intensity (moderately susceptible), 7 = 25.1–50% disease intensity (suscepti...
TL;DR: It is indicated that resistant segregants possessed two genes, one contributed by PBW 621 or HD 2967 (depending on the cross) and the other, unexpectedly but obviously, came from the most susceptible cultivar, PBW 343.
Abstract: With continuous outbreaks of stripe rust (Puccinia striiformis f. sp. tritici) epidemics and rapid breakdown of deployed resistance in bread wheat (Triticum aestivum L.) cultivars in North West Plains Zone (NWPZ) in India warrant knowledge and deployment of new and durable sources of resistance to stripe rust. Bread wheat cultivar PBW 343, until recently the most widely cultivated wheat variety in India, is now highly susceptible to stripe rust (score 9 on a 1–9 scale), whereas PBW 621 (score 5.05–5.65) and HD 2967 (score 5.40–6.20) show low levels of resistance. We conducted an experiment, spanning three crop seasons (2013–2014 to 2015–2016), in which parental lines, F1 and F2 populations, F3 and F4 families from two bread wheat crosses, PBW 621/PBW 343 and HD 2967/PBW 343 were generated and evaluated for stripe rust resistance against a virulent pathotype. While the F1 revealed partial dominance, the segregation pattern for stripe rust resistance in F2 and F3 showed transgressive segregation for...
TL;DR: This study considers many previous protocols and optimized these methods to devise a general method for extraction of DNA from the seeds of diverse plant genera and uses the new SGS buffer to extract intact DNA from seeds with yield and quality better than in the previous protocols.
Abstract: High-quality DNA is a prerequisite for a range of molecular biology experiments and thus DNA extraction is one of the most important steps for several downstream experiments. DNA isolation directly from seeds could save time and effort, particularly for large-scale experiments where growing and maintaining multitude of genotypes in parallel is cumbersome. However, seeds often contain polysaccharides, polyphenols, mucilage, oils, etc., which cause DNA extraction from seeds difficult and sometimes a research limiting step. In the present study, we have considered many previous protocols and optimized these methods to devise a general method for extraction of DNA from the seeds of diverse plant genera. The new SGS buffer (sucrose, glycerol and sodium dodecyl sulphate) was used to extract intact DNA from seeds with yield and quality better than in the previous protocols. Moreover, the proposed protocol is devoid of hazardous and expensive reagents and can be scaled up.
TL;DR: In this paper, the root architecture in two genotypes of sorghum (Sorghum bicolor (L.) Moench) differing in root angles and to assess the influence of different deficit irrigation regimes on root architecture was evaluated.
Abstract: Plant root architecture offers the potential for increasing soil water accessibility, particularly under water-limited conditions. The objectives of this study were to evaluate the root architecture in two genotypes of sorghum (Sorghum bicolor (L.) Moench) differing in root angles and to assess the influence of different deficit irrigation regimes on root architecture. The response of two sorghum genotypes, ‘Early Hegari-Sart’ (EH; steep root angle) and ‘Bk7’ (shallow root angle) to four irrigation treatments was investigated in two replicated outdoor studies using large pots. The results indicated that EH possessed steeper brace and crown root angles, fewer brace roots, greater root biomass, and root length density than Bk7 at deeper soil depths (i.e., 15–30 and 30–45 cm) compared with a shallower depth (i.e., 0–15 cm). Across the soil profile, EH had greater root length density and length of roots of small diameter (<1 mm) than Bk7. Accordingly, EH showed more rapid soil-water capture than Bk7. ...
TL;DR: Across the whole plant, numbers of primary and secondary grains increased at the higher nitrogen application, but weight per primary grain and kernel contents were unaffected, thus improving uniformity of grain size which is of value to millers.
Abstract: The relationship between panicle structure and oat grain quality characteristics was examined in a winter oat (Avena sativa) experiment, cv. Gerald, fertilized with 80 and 200 kg/ha N. Spikelets on...
TL;DR: In this paper, the authors estimate farmers' demand for rice variety attributes and identify the factors that influence their decision regarding varietal choice, such as cooking and eating quality, drought tolerance, and maturity period.
Abstract: Despite the release of many modern varieties of rice (Oryza sativa), farmers in Nepal have been cultivating relatively few rice varieties. The objective of this study is to estimate farmers’ demand for rice variety attributes and to identify the factors that influence their decision regarding varietal choice. Yield increase is considered jointly with other attributes, such as cooking and eating quality, drought tolerance, and maturity period. Choice experiments were conducted and results showed that there was significant demand from farming households for yield increase, improvement in cooking and eating quality, tolerant to drought, and short maturing varieties. The choice data were analyzed using a multinomial and random parameter logit model. From a policy perspective, results showed that for broader adoption of crop varieties, variety development programs should give priority to aforementioned attributes rather than solely on increased crop productivity.
TL;DR: In this article, weather uncertainty and soil spatial variability impact nitrogen cycling and corn (Zea mays L) growth, making accurate N predictions a challenge, and field studies were conducted in Lansing, Michi...
Abstract: Weather uncertainty and soil spatial variability impact nitrogen (N) cycling and corn (Zea mays L.) growth, making accurate N predictions a challenge. Field studies were conducted in Lansing, Michi...
TL;DR: In this article, participatory variety demonstration (PVD) trials are used to establish modern varieties in informal seed systems in a developing country by targeting nodal multipliers occupying hub locations.
Abstract: It is shown for the first time how participatory variety demonstration (PVD) trials can establish modern varieties in informal seed systems in a developing country by targeting nodal multipliers occupying hub locations. A series of relatively few, small (each 36 m2) PVD trials was conducted over a period of 3 years in sweetpotato multipliers’ fields at three locations in Uganda; multipliers and farmers were encouraged to visit during crop growth and on field days; yields at final harvest and other traits considered important to multipliers and farmers were recorded. In the following dry season, the areas of the introduced varieties established in the lowland crops used by multipliers to conserve planting material were recorded. The two most popular varieties had a recorded area of about 1 ha each and were calculated to have increased sixfold annually from the trials; the next two occupied 0.5 ha each, confirming that the method is effective, cheap, and efficient.
TL;DR: Increasing the genetic base of current parental cacao varieties grown in West Africa with clones that are able to perform well under marginal conditions could improve cacao production.
Abstract: Increasing the genetic base of current parental cacao varieties grown in West Africa with clones that are able to perform well under marginal conditions could improve cacao production. Survival and...
TL;DR: In this paper, a study aimed at analyzing soybean (Glycine max [L] Merr] seed systems in Benin is presented, with the aim of improving farmers access to quality seed.
Abstract: Facilitating farmers’ access to quality seed requires proper understanding of the functioning of seed systems. This study aimed at analyzing soybean (Glycine max [L.] Merr.) seed systems in Benin t...
TL;DR: Experimental results revealed that heterosis could be exploited for developing antioxidant-rich hybrid cabbage because of outbreeding depression, and implied that for these traits, nonadditive gene effects were more important than additive effects.
Abstract: The paucity of research on development of antioxidant-rich hybrids in cabbage by utilizing combining ability estimates, gene action, and heterosis motivated us to undertake this study. We made 60 crosses between 5 cytoplasmic male-sterile lines and 12 male-fertile testers during the summer of 2015, as per the line × tester design. The seedlings of all the parents and 60 F1 crosses, along with three checks, were transplanted during the Rabi (winter) season of 2015–2016 and evaluated using a randomized complete-block design. Combining ability, gene action, and heterosis were determined for different antioxidant compounds. Experimental results revealed that the range of cupric ion reducing antioxidant capacity (CUPRAC) [parents = 1.26–7.33 and hybrids = 0.04–6.54 μmol trolox/g], ferric reducing ability of plasma (FRAP) [parents = 1.65–4.76 and hybrids = 0.16–4.67 μmol trolox/g], β-carotene (parents = 0.44–2.29 and hybrids = 0.04–1.89 μg/100 g), and chlorophyll-a (parents = 0.71–4.08 and hybrids = 0.1...
TL;DR: Fungal growth, as quantified by the GFP expression in the fungus, was highly correlated with toxin production and the nature of relationship between lipids and the ability of the fungus to infect and produce aflatoxins in mature cottonseed, a protein-rich animal feed, has been addressed previously.
Abstract: Aspergillus flavus infects several food and feed crops, such as corn (Zea mays L.), cotton (Gossypium hirsutum L.), peanuts (Arachis hypogaea L.), and tree nut crops and contaminates the seed with carcinogenic aflatoxins. These susceptible crops contain rich reserves of lipids and fatty acids. The nature of relationship between lipids and the ability of the fungus to infect and produce aflatoxins in mature cottonseed, a protein-rich animal feed, has been addressed previously. In this study, we tracked lipid accumulation in developing cottonseed (15–35 days post-anthesis [DPA]) and also the ability of an aflatoxigenic strain and an isogenic non-aflatoxigenic strain to grow and produce aflatoxins in planta. The aflatoxigenic strain Af-70 green fluorescent protein (GFP) and the isogenic, non-aflatoxigenic strain SRRC 1500 (fungal collections maintained at the Southern Regional Research Center) did not differ much in infection and colonization of cottonseed. The non-aflatoxigenic strain did not produc...
TL;DR: In this paper, the authors evaluated the relationship among a suite of near-surface soil properties and soybean yield across average-and high-yield areas using state yield-contest sites.
Abstract: State yield contests offer a unique opportunity to examine the high end of crop productivity. Yield-contest-entered and average-yielding areas on the same or a similar soil can provide large yield and soil property variations to better examine the relationships among various near-surface soil properties and soybean (Glycine max L. [Merr.]) yield. The objective of this study was to evaluate the relationships among a suite of near-surface soil properties and soybean yield across average- and high-yield areas using state yield-contest sites. Multiple regression analyses were conducted to evaluate best-fit relationships among various soil physical, chemical, and biological properties and yield separately for average- and high-yielding areas and for data combined across yield areas. Soybean yield variation was most explained for the high-yield-area dataset (R² = 73%) and less explained for the average-yield-area (R² = 51%) and the combined (R² = 50%) datasets. Extractable soil Ca and S explained the largest proportion of yield variation (37% and 31% of total sum of squares) in the high-yield setting and both were inversely related to yield. A better understanding of the soil environment may be a key component of more frequent attainment of the 6270 kg ha⁻¹ (100 bu acre⁻¹) soybean yield mark. Additional soil properties, beyond those evaluated in this study, may need to be included for a more complete understanding of the soil environment that is associated with high-yield soybean production.