{"title":"Inheritance of resistance to three endemic viral diseases of cowpea in Nigeria","authors":"K. E. Ogunsola, C. Fatokun, O. Boukar, P. Kumar","doi":"10.1080/15427528.2022.2090476","DOIUrl":"https://doi.org/10.1080/15427528.2022.2090476","url":null,"abstract":"ABSTRACT Mosaic diseases, caused by bean common mosaic virus-blackeye cowpea mosaic strain (BCMV-BlCM), southern bean mosaic virus (SBMV), and cucumber mosaic virus (CMV), hamper the productivity of cowpea (Vigna unguiculata (L.) Walp.). Under single or mixed infections, these endemic viruses significantly reduce cowpea yield in sub-Saharan Africa. Planting resistant varieties is the most effective control method. Knowledge of the mode of inheritance of viral resistance is crucial in developing resistant varieties. Inheritance of resistance to BCMV-BlCM, SBMV, and CMV was investigated in two improved cowpea breeding lines. For BCMV-BICM, crosses were made between resistant IT97K-1042-3 (female) and susceptible IT99K-1060 (male); for SBMV, between resistant IT98K-1092-1 (male) and susceptible IT99K-1060 (female); and for CMV, between tolerant IT98K-1092-1 (female) and susceptible IT99K-573-1-1 (male). The F1 progenies were advanced to F2, and some F1 plants were backcrossed to the two parental lines. Reciprocal crosses were made and the 7-day-old seedlings of P1, P2, F1, F2, BCP1, and BCP2 were phenotyped by mechanical inoculation with BCMV-BlCM, SBMV, and CMV under screenhouse conditions. Data on disease incidence and severity were taken at weekly intervals for 5-week post-inoculation. Virus infections were confirmed via antigen-coated plate enzyme-linked immunosorbent assay or reverse transcription-polymerase chain reaction. Chi-square analysis of the genetic segregation indicated that a recessive gene pair in IT97K-1042-3 controlled the inheritance of resistance to BCMV-BlCM. Duplicate dominant genes conditioned the resistance to SBMV and tolerance to CMV in IT98K-1092-1. The backcrosses confirmed the monogenic and digenic inheritance patterns, whereas reciprocal crosses indicated absence of cytoplasmic effects.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"291 - 308"},"PeriodicalIF":1.3,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46905918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Ravelombola, A. Acuña, L. Florez‐Palacios, C. Wu, D. Harrison, M. de Oliveira, J. Winter, M. D. da Silva, L. Mozzoni
{"title":"Spatial models for seed yield, wilting, and maturity in furrow-irrigated soybean plots","authors":"F. Ravelombola, A. Acuña, L. Florez‐Palacios, C. Wu, D. Harrison, M. de Oliveira, J. Winter, M. D. da Silva, L. Mozzoni","doi":"10.1080/15427528.2022.2074933","DOIUrl":"https://doi.org/10.1080/15427528.2022.2074933","url":null,"abstract":"ABSTRACT Field experiments are subjected to spatial variability due to factors such as soil moisture, fertility, pH, and structure, as well as the pressure of diseases and pests. Soybean yields are highly variable across fields. Controlling spatial variability could decrease the risk of erroneous inferences in breeding trials. This study aims at evaluating the spatial variability of furrow-irrigated soybean for seed yield, wilting, and maturity under four different irrigation levels. The field experiment was conducted in four environmzents (location-year combination). A total of 165 soybean lines of similar relative maturity (maturity group 5) along with commercial checks were planted in an augmented strip plot design. Irrigation treatment decisions were triggered using an atmometer based on a threshold at a designated growth stage. Data were analyzed via Analysis of Variance as a linear mixed model using a blocking structure (block model) and spatial covariances using range and column. Two different spatial models were used: exponential and Gaussian. Results showed that the spatial models displayed better data fitting (lower AIC and/or BIC) than the block model in each different irrigation level across different environments and traits. Indeed, genotype ranking for seed yield was different between the block model and the best spatial model, suggesting that spatial adjustment may be necessary for soybean breeding operations under furrow irrigation. Further validation in a breeding yield trial demonstrated similar results of the effectiveness in terms of AIC and/or BIC of the spatial model compared to the block model for soybean seed yield.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"209 - 228"},"PeriodicalIF":1.3,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42171665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Long Le Hoang Nguyen, Alrence S. Halibas, Trung Quang Nguyen
{"title":"Determinants of precision agriculture technology adoption in developing countries: a review","authors":"Long Le Hoang Nguyen, Alrence S. Halibas, Trung Quang Nguyen","doi":"10.1080/15427528.2022.2080784","DOIUrl":"https://doi.org/10.1080/15427528.2022.2080784","url":null,"abstract":"ABSTRACT Precision agriculture (PA) technology has proven effective in optimizing yield with minimum inputs and in reducing environmental pollution. In this paper, we aim to investigate factors influencing PA adoption in developing countries at both the farmer (individual) and farm (organizational) levels. Findings from 59 high-ranking journal articles were reviewed to determine factors that facilitate or hinder PA adoption: 63% of studies reported factors at the farm level and 37% at the individual level. At the individual level, factors promoting PA adoption included the technology’s relative advantages, observability, trialability, farmer experience in using technology, innovativeness, risk tolerance, education, and knowledge, whereas farmer age and technology complexity hindered PA adoption. Factors promoting PA adoption at the farm level included farm size, resource availability, perceived need for technology characteristics, technology compatibility, social influence, competitive pressure, and government support. PA adoption should, thus, include both levels; hence, a multi-level set of adoption determinants is presented in this study. The findings not only broaden the research agenda for future PA adoption studies that address gaps in the existing literature but also provide a holistic way for entrepreneurial technology developers and policymakers to understand factors that affect PA adoption. The study, thus, paves the way for further investigations to address the causes of slow progress in adoption of innovative technologies, such as PA, especially in developing countries.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"1 - 24"},"PeriodicalIF":1.3,"publicationDate":"2022-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47785717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Philip Miriti, Mekdim Dereje Regassa, Chris O. Ojiewo, M. Melesse
{"title":"Farmers’ preferences and willingness to pay for traits of sorghum varieties: Informing product development and breeding programs in Tanzania","authors":"Philip Miriti, Mekdim Dereje Regassa, Chris O. Ojiewo, M. Melesse","doi":"10.1080/15427528.2022.2079038","DOIUrl":"https://doi.org/10.1080/15427528.2022.2079038","url":null,"abstract":"ABSTRACT Smallholder farmers’ decisions to adopt improved varieties are expected to be critically governed by their preferences and willingness to pay for different traits of these varieties. This study examined farmers’ preferences for sorghum (Sorghum bicolor (L.) Moench) variety attributes and estimated their willingness to pay (WTP) for these attributes using choice experiment data from >1,300 sorghum farmers in Tanzania. Empirical findings showed that farmers had strong preferences for sorghum varieties that were tolerant to environmental stresses, high yielding, early maturing, fetching higher grain prices, and white in color. Significant heterogeneity was observed in farmers’ preferences across various traits. The WTP estimates revealed that farmers were willing to pay the highest premium for tolerance to environmental stresses, amounting, on average, to three times higher than the WTP for other traits. Our results have important implications for demand-driven variety development that could contribute to improving crop productivity and household welfare.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"253 - 272"},"PeriodicalIF":1.3,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45379576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Genetic diversity of Ethiopian potato (Plectranthus edulis (Vatke) Agnew) genotypes using simple sequence repeat markers","authors":"Meseret Fanta, F. Mekbib, A. Wakjira, Z. Tadele","doi":"10.1080/15427528.2022.2074932","DOIUrl":"https://doi.org/10.1080/15427528.2022.2074932","url":null,"abstract":"ABSTRACT Plectranthus edulis is among the most ancient and native tuber crops in Ethiopia, which is mainly cultivated by smallholder farmers. Being an orphan crop, it has not received due research attention. To tackle major crop-production constraints through breeding, knowledge of its genetic diversity is a prerequisite. Thus, the current study was carried out to assess the nature and extent of genetic diversity in 130 genotypes using 20 cross-transferable expressed sequence tag-simple sequence repeat (EST-SSR) markers developed from a related species, Plectranthus barbatus. Among the 20 SSR markers, 15 were transferable to Plectranthus edulis, from which 14 polymorphic markers were used for diversity analysis. A total of 101 alleles were detected, with a mean of 7.2 alleles per locus. Allele frequency ranged from 0.23 to 0.54, with mean value of 0.40. Polymorphic information content (PIC) ranged from 0.54 to 0.84, with a mean of 0.70, indicating a high level of informativeness. The Nei’s genetic distance ranged from 0.026 to 0.247, with the highest similarity being between Wolaita and Gamo Gofa populations. About 97% of the genetic variation was attributable to differences within populations; only 3% was attributable to variation among populations. The Neighbor-Joining cluster analysis grouped the 130 genotypes into three clusters. In general, the EST-SSR markers were effective in identifying genetic diversity in Ethiopian potato. This information can help to identify parental lines for crossing and exploiting the existing variability through selection.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"183 - 208"},"PeriodicalIF":1.3,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46866514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Missing the bigger picture? Integrating supply chains, consumers and agro-processors into crop improvement strategies in sub-Saharan Africa","authors":"Lisa F. Clark, J. Hobbs","doi":"10.1080/15427528.2022.2075513","DOIUrl":"https://doi.org/10.1080/15427528.2022.2075513","url":null,"abstract":"ABSTRACT Determining how crop improvements like biofortification are integrated into agri-food supply chains across sub-Saharan Africa (SSA) is a growing focus in food security frameworks. Nevertheless, improved crop traits meant to address food insecurity are often developed well before practical concerns of adoption are considered. Improved crop varieties such as orange-fleshed sweet potato (Ipomoea batatas) and vitamin A cassava (Manihot esculenta) have gained wider acceptance among producers, but other factors along the supply chain inhibit rates of diffusion and adoption. This article reviews how socioeconomic and logistical factors interact at multiple stages of crop improvement strategies. We examine the challenges associated with “top-down,” siloed models of food security frameworks, and then discuss how information flows among stakeholders significantly influence adoption decisions. We conclude by examining how market structures and institutions act as gatekeepers to the successful diffusion of improved crops across SSA.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"229 - 252"},"PeriodicalIF":1.3,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44862745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sustainable intensification under resource constraints: Estimating the heterogeneous effects of hybrid maize adoption in Nepal","authors":"G. Paudel, V. Krishna, D. Rahut, A. J. Mcdonald","doi":"10.1080/15427528.2022.2066041","DOIUrl":"https://doi.org/10.1080/15427528.2022.2066041","url":null,"abstract":"ABSTRACT Managerial practices for farming-system intensification have received increased focus in research-and-development (R&D) initiatives. These technologies are proven to close the yield gaps in researcher-managed field trials and are recommended for farmer’s adoption. However, not all farmers have the technical, financial, and social capital to adopt and benefit from these recommended technologies. Is the current level of productivity enhancement achieved by smallholder system intensification sufficient to sustain rural livelihoods? To this end, the study assessed the impacts of hybrid maize (Zea mays L.) adoption on productivity and livelihoods in the mid-hill region of Nepal. Smallholders in the study region face severe shortages of labor, improved cultivars, and inorganic fertilizers, resulting in very low yields and profitability. We find that maize hybrid adoption increased crop productivity by 109%, making the crop profitable for smallholders and enhancing the per capita food expenditure by 20%. Nevertheless, these benefits were unevenly distributed: relatively small farms (≤0.3 ha) achieved greater gains in productivity and livelihood per land unit from hybrid maize adoption, but only larger farms (>0.3 ha) enjoyed the aggregate livelihood benefits of the technology. System intensification gains economic relevance because of the severe scarcity of resources, whereas the resource scarcity itself determines the economic relevance of system intensification, presenting a paradox. Increasing market access to material inputs did not significantly alter the observed patterns. More studies are required on the relationship between farm size and the livelihood impacts of sustainable intensification to facilitate R&D targeting and ensure inclusive development.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"157 - 182"},"PeriodicalIF":1.3,"publicationDate":"2022-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43346528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Mahrokh, Hadi Hassanzadeh Moghadam, H. Najafinezhad, A. Shirkhani, B. Ahmadi, F. Azizi, F. Golzardi
{"title":"Bouquet ears in maize inbred lines as affected by agronomic factors","authors":"A. Mahrokh, Hadi Hassanzadeh Moghadam, H. Najafinezhad, A. Shirkhani, B. Ahmadi, F. Azizi, F. Golzardi","doi":"10.1080/15427528.2022.2063776","DOIUrl":"https://doi.org/10.1080/15427528.2022.2063776","url":null,"abstract":"ABSTRACT “Bouquet ears” is known to reduce grain yield in maize (Zea mays L.). The impact of agronomic factors on the bouquet occurrence rate (BOR) needs to be investigated. Two separate trials were conducted to assess the effects of nitrogen fertilizer, planting density, herbicide application, and planting date on the BOR in maize inbred lines (Mo17, K615/1, and KE72012/12) across two locations and 2 years (2018 and 2019). In Trial 1, the effects of nitrogen rate (200, 450, and 700 kg ha−1) and planting density (55,000, 70,000, and 85,000 plants ha−1) and in Trial 2, the effects of herbicide application (no-2,4-D application and 2,4-D at V5 and V7 stages) and planting date (May 25, June 4, and June 14) were evaluated. Planting density had no significant impact on the BOR in the inbred lines Mo17 and KE72012/12. In the inbred line K615/1, the BOR was inversely affected by planting density; BOR was 14% at 55,000 plants ha−1, 10% at 70,000 plants ha−1, and 8% at 85,000 plants ha−1. Delaying the planting date (PD) from May 25 till June 4 did not affect BOR; however, delaying PD to June 14 drastically increased BOR; KE72012/12 showed 3.56% BOR for June 14 PD, which was 215% higher than that for June 4 PD. Overall, the BOR could be significantly decreased in maize, provided proper genotypes are planted at suitable times (May 25 to June 4) at densities higher than 55,000 plants ha−1.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"140 - 156"},"PeriodicalIF":1.3,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42411835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Floral volatiles may influence honey bee visitations in oilseed Brassica species","authors":"Sanju Sharma, Sarwan Kumar, G. Kaur, S. Banga","doi":"10.1080/15427528.2022.2059604","DOIUrl":"https://doi.org/10.1080/15427528.2022.2059604","url":null,"abstract":"ABSTRACT Understanding foraging preferences of honey bees (Apis mellifera L.) is essential to maneuver pollinator movement to enhance outcrossing and hence the crop yields. In this communication, we report the role of floral volatile organic compounds (VOCs) in structuring foraging decisions of honey bees. Supercritical fluid extraction of VOCs, coupled with gas chromatography-mass spectrometry, revealed 75 VOCs. Of these, 19 were strong attractants and 8 were strong repellants. Moreover, we detected significant, but variable, species- or genome-level differences in floral scents. Honey bees avoided Brassica juncea cv. PBR357 (0.81 bee visits/sq m/min) and B. carinata cv. PC5 (0.77 bee visits/sq m/min), which possessed peak concentrations of antifeedants or repellents (dibutyl phthalate and 9-octadecenoic acid) in their floral volatiles. B. napus cvs. GSC6 and GSC7 attracted the highest number of bee visitations (1.07 and 0.99 bee visits/sq m/min, respectively), as these possessed VOCs with honey-fruity odor in high amounts and negligible levels of antifeedants. Our results highlight that variability in floral reward chemistry should be considered when breeding crops that are frequently visited upon by bee pollinators to support bee pollinators, in general, and honey industry, in particular.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"119 - 139"},"PeriodicalIF":1.3,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49152241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Srisawad, S. Sraphet, Nawarat Suksee, Rungravee Boontung, Duncan R. Smith, K. Triwitayakorn
{"title":"Use of Diversity Arrays Technology (DArT) for detection of QTL underlying plant architecture and yield-related traits in cassava","authors":"N. Srisawad, S. Sraphet, Nawarat Suksee, Rungravee Boontung, Duncan R. Smith, K. Triwitayakorn","doi":"10.1080/15427528.2022.2058668","DOIUrl":"https://doi.org/10.1080/15427528.2022.2058668","url":null,"abstract":"ABSTRACT Cassava (Manihot esculenta Crantz) is an important starchy root crop representing food security for more than one billion people in the world. Plant architecture (PA) is a key factor underlying yield, and understanding the physiological basis of PA may lead to improved yield plants. In this study, we identified genomic regions controlling several traits associated with plant architecture and productivity in Thai cassava cultivars. The analysis was conducted in an F1 population derived from a cross between “Huay Bong 60” (female parent) and “Hanatee” (male parent). A genetic linkage analysis was undertaken with 167 conventional DArT markers using JoinMap 3.0 software. Plant architecture and productivity were evaluated over four years at the Rayong Field Crops Research Center, Thailand. DArT markers associated with five traits of plant architecture (number of mainstems per plant (NMain), number of apices per plant (NAp), plant height (PH), first branching height (BH), branching level (BL)) as well as two productivity measurements harvest index (HI) and fresh root yield (FRY) were identified by simple interval mapping (SIM) using MapQTL 4.0. Small effects of 22 plant architecture quantitative trait loci (QTL) were detected, with phenotypic contributions varying from 5.1 to 10.9%. Small effects of four QTL of FRY and five QTL of HI were also detected. Additionally, PH showed a significant correlation with FRY. However, this study has limitations from the low density of the markers, therefore additional markers would be necessary for an efficient genetic linkage map and QTL detection.","PeriodicalId":15468,"journal":{"name":"Journal of Crop Improvement","volume":"37 1","pages":"99 - 118"},"PeriodicalIF":1.3,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42873436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}