World Vegetable Center Research Articles

Urban effects on the adoption of soil conservation practices in urban and peri‑urban vegetable production of Yaoundé, Cameroon

Rapid urbanisation has put farming systems under stress. Yet, conservation agriculture promotes environmentally friendly and productive agriculture. This paper therefore aims at estimating the effects of urbanisation on the adoption of soil conservation practices (SCPs) in urban and peri‑urban vegetable production in Yaoundé, Cameroon. Data from a survey conducted by the World Vegetable Center among 185 vegetable producers and Google Maps were analysed using a Multivariate Probit model with robust standard errors to investigate the adoption of four interdependent SCPs. Descriptive results showed that the most SCP adopted was organic manure (85 %), the least adopted was mulching (61 %), and that the adoption intensity was relatively high as the mean number of SCPs adopted was 2.87 out of 4. In addition, the regression results showed that urbanisation reduces the adoption of SCPs; in particular, proximity to city centre reduces the adoption of crop rotation, organic manure, mulching, and fallow, while population density decreases the practice of fallow. Henceforth, to ease the perverse effects of urbanisation on the adoption of SCPs, decision-makers and local authorities should ensure the preservation of productive agricultural zones by elaborating urban master and zoning plans that take into account agricultural purposes, and by formalising property rights on agricultural lands in urbanising areas.

Guidance on farmer participation in the design, testing and scaling of agricultural innovations

CONTEXTDespite accelerated developments in agricultural innovations, there has been a limited progress in their adoption by smallholder farmers, especially in the Global South. Innovations are not adequately reaching farmers, and new technologies are often unsuitable for farmers, or the overall innovation landscape is discouraging the deployment of innovations at scale. The methodological approaches to designing, testing and scaling of innovations play an important role. Involving farmers in the innovation process from the start increases the likelihood of them being more relevant and having a higher chance of adoption. Whereas there is much literature on participatory approaches, there is a limited guidance on choosing an appropriate level of farmer participation across the innovation process. OBJECTIVEThis study aims to develop practical guidance for researchers, development agents and project managers on how to choose an appropriate methodological approach with a suitable level of farmer participation for designing, testing and scaling of agricultural innovations, according to levels of innovation readiness and innovation use. METHODSRelevant scientific literature on participatory design, research and scaling of agricultural innovations was reviewed, followed by compiling lessons learned from selected vegetable innovation projects implemented by the World Vegetable Center (WorldVeg) in Asia and Africa. A list of methodological approaches for participatory design, testing and scaling of innovations was generated, with various levels of farmer participation. A simple guiding framework was then developed for choosing an appropriate approach with a suitable level of farmer participation, according to the readiness and use of the innovations. Examples of selected approaches and application of the proposed guidance are given in project case studies. RESULTS AND CONCLUSIONSBased on the literature review and experience at WorldVeg, we believe it is critical to choose the right level of participation based on how ready are the innovations for application in the local setting. This dimension of how ready the innovations are has been largely overlooked in earlier frameworks on farmer participation. The developed guidance generally recommends increasing participation with higher levels of technology readiness and use. In addition, farmer consultation in early research design should also be strengthened, to co-design locally relevant innovations. The overall innovation systems' landscape must be considered when researching and scaling new innovations. SIGNIFICANCEThe guidance, experiences and lessons provided in this paper will be useful to various scholars, researchers, development agents, funders and project managers who aim to design, test and scale agricultural innovations in a more inclusive and responsible way.

Evaluation of Hot Pepper (Capsicum annuum L.) Genotypes for Yield and Quality in Mid-hills of Bagmati Province, Nepal

The study was carried out to evaluate and select high yielding, insect pest and disease resistant hot pepper genotypes with preferred characters at open field conditions for central mid-hills of Nepal in 2018 and 2019. Seedlings of six hot pepper genotypes AVPP9905, AVPP9813, AVPP0506, Suryamukhi, Pusa Jwala and Kantipure were transplanted on April first week at Khumaltar, Lalitpur. Crop geometry was maintained with the 60 x 60 cm in randomized complete block design with three replications and fertilized with 150:120:100 NPK kg + 20 ton FYM per hectare. Observations were recorded on vegetative growth, insect pest and disease, yield attributing parameter and response of consumers and farmers. Among the tested genotypes, AVPP9905 showed superior performance that was vigoros, earliest days to flowering (41) and fruit set (47 days), least insect damage (2.0), least disease; alternaria leaf spot (1.8 ), higher number of fruits per node (1.25), superior yield (26.19 t/ha) and 960 g per plant. Consumers and farmers preference were 4.4 and 4.5.and the maximum fruit size was 18.7 g. The second superior cultivar was AVPP0506 which showed vigor (4.0), medium days to flowering (44.3) and fruit set (49 days), less insect damage (2.2), less disease; alternaria leaf spot (2.1), higher number of fruits per node (1.3), superior yield (14.28 t/ha) and 548 g per plant, consumers (3.8) and farmers preferred (4.8). Hence it could be generalized that introduced genotypes from the world Vegetable Centre, Taiwan were more promising than local check cultivars (Pusa Jwala and Kantipure) in terms of growth, fruit yield and insect pest and disease resistance, and farmers and consumers preference. These two genotypes are recommended for cultivation in central mid-hills of Bagmati Province in open field conditions.

Genetic analysis of yield and yield component traits in exotic soybean germplasm (Glycine max (L.) Merrill) for vegetable type under Indian Conditions

The present investigation was carried out at ICAR-Indian Institute of Soybean Research, Indore during kharif, 2019 to evaluate 105 soybean germplasm accessions received from World Vegetable center (AVRDC), Taiwan for vegetable type under Indian Conditions. Genetic parameters such as genetic variability, heritability and genetic advance were estimated for 11 quantitative characters. High estimates of PCV and GCV were recorded for row yield, grain yield per plant, number of primary branches per plant, 100 seed weight, number of pods per plant, number of pod clusters per plant and plant height. This indicates considerable variability and provide scope for genetic improvement through selection. High heritability coupled with high genetic advance as percent of mean was found for row yield, grain yield per plant, 100 seed weight, and number of pods per plant, plant height and days to 50 per cent flowering. This designates careful selection leads to improvement of traits and provides better opportunitiesfor selecting plant material for these traits in soybean breeding program for vegetable type.

Leveraging genomics and phenomics to accelerate improvement in mungbean: A case study in how to go from GWAS to selection

AbstractGrown on 7 million ha, mungbean is a warm‐season grain legume with regional importance in parts of Asia and Africa. Under forecasted climate change, due to its tolerance to drought and heat, the short crop duration, and its nutritional properties, mungbean could serve to fill an important need for human diets. However, selection of accessions becomes difficult where plant and consumer market variation is large. We performed selection on genebank accessions, specifically the mini‐core collection at the World Vegetable Center, for yield and yield component traits. Our selection index uses refined accuracy by leveraging genomics, phenomics, and genotype‐by‐environment interactions. Best linear unbiased prediction (BLUP) is used to predict the genotypic effects of the 292 mini‐core accessions toward seed yield based on genomic relationships formed from ∼200,000 SNPs. We expanded BLUP analysis to predict phenotypic effects based on the phenomic relationships formed from ∼75,000 measurements from three‐dimensional multispectral data. While this method is restricted to a single environment, our multi‐environment trials across eight countries and 4 years serve to quantify the genotype‐by‐environment effect. K‐fold cross‐validation finds predictive ability to vary by methods but to be related to the narrow‐sense heritability of the yield component trait. Our weighted rank sum index (WRSI) linearly combines yield component traits to proxy yield within our single environment phenomics trial by first ranking genomic and/or phenomic BLUPs, then weighting by predictive accuracy from the cross‐validated model, and then summing the component weighted ranks for each accession. Selections were made from the predicted random effects in each location, identifying three accessions overlapping across both methodologies: PI 369787 (VI001339A‐G) and EG‐MD‐6D (VI000380A‐G) from the Philippines, and PI 363534 (VI003220A‐G) from India.

Increasing lettuce productivity through Starter Solution Technology (SST)

Starter Solution Technology (SST), which is a highly concentrated liquid fertilizer, has been researched by AVRDC the World Vegetable Center. SST is a technological innovation to reduce fertilizer input while also increasing the efficiency of fertilizer use and crop productivity. The purpose of this research is to apply starter solution technology which is an efficient way of using fertilizer in order to increase lettuce production. The research was conducted in Tawangargo Village, Karangploso District, Malang Regency from July to September 2022. There were 10 treatments, including P1 = NPK 3 gr/plant, T2 = NPK 2 gr/plant, P3 = 1.5 g/plant, P4 = 1 g /plant, P5 = 0.5 g/plant, P6 = NPK 3 g/plant + SST, P2 = NPK 2 gr/plant + SST, P3 = 1.5 g/plant + SST, P4 = 1 g/plant + SST, P5 = 0.5 g/plant + SST. The results showed that the use of SST technology was able to produce better growth and yield and was able to reduce the use of inorganic fertilizers by more than 60% from the current level of fertilizer use without significant reduction in yield. Adding fertilizer to the starter treatment reduced lettuce production.

GENETICS OF CERCOSPORA LEAF SPOT RESISTANCE IN MUNG BEAN

Pulses are notably good nutritive complements of carbohydrate-rich staple diets, such as, wheat, maize, and rice. Mung bean is an essential pulse crop with different proteins and antioxidants proven beneficial for health. The yield of mung bean in Pakistan is comparable to the world average, but overall production is low because of several biotic and abiotic factors. Cercospora leaf spot (CLS) is one of mung bean’s most damaging diseases, limiting its productivity, causing significant losses in yield and an overall gap in production. The presented investigation progressed to comprehending the genetics of resistance to CLS in mung bean. A minicore set of 293 mung bean genotypes developed and maintained by the World Vegetable Center, Taiwan, served as samples in the study. Observed CLS attacks occur during flowering and reduce the yield by decreasing the number of pods per plant. The genetics to resistance against CLS has a single recessive gene controlling it; hence, homozygous recessive plants will be CLS-resistant. Therefore, single gene transfer methods, such as, backcross breeding, are recommendable for incorporating CLS resistance in high-yielding mung bean genotypes.

Adoption and impact of improved amaranth cultivars in Tanzania using DNA fingerprinting

Traditional vegetables are very important for food and nutrition security in sub-Saharan Africa but have not received much attention in crop improvement research. One exception is amaranth (Amaranthus spp.) for which international breeding research began at the World Vegetable Center in Tanzania in 2004. This study is the first impact evaluation of this research program. It uses a representative sample of 1,355 amaranth-producing households from five agroecological zones of Tanzania to collect questionnaire-based data and plant material. The genetic identity of the amaranth cultivars used by the farmers was identified using DNA fingerprinting, while the impact on crop yield, production cost and sales was quantified using propensity score matching. The analysis shows that 66% of Tanzania’s cultivated area under amaranth uses cultivars derived from the amaranth breeding program. These cultivars had a mean vegetable yield that was 6.1 ton/ha higher (+ 48%; p = 0.002) than that of other cultivars, while there was no significant impact on the cost of production or quantity sold. This suggests tremendous impact of genetic improvement research in traditional vegetables.

Agrophysiological Performance of Mungbean Accessions (Vigna radiata (L.) R. Wilczek) and Nitrogen Balance under Mungbean in Burkina Faso

Mungbean (Vigna radiata (L.) Wilczek) is a seed legume that is not well known in the cropping systems and dietary habits of Burkina Faso. The objective of this study was to evaluate the physiological and agronomic performance of fifteen mungbean accessions from a collection of the World Vegetable Center in Mali under rainfed conditions in Burkina Faso. The experimental design was a Fischer block with three replications, and the measurements focused not only on the growth, development cycle, and yield parameters of the plants but also on the total nitrogen balance in the soil at harvest. The results show that growth parameters such as the plant height at the beginning of flowering (HP), stem neck diameter (SCD), and number of branches per plant (NBrP) significantly discriminate between dealerships. The same was true for all the developmental parameters. The tallest plants with a higher crown diameter and number of branches were those of accession A3. The early flowering cycle varied from very early (29 days) to medium (41 days), with an average of about 34 days. On the other hand, the cycle at harvest varied from 82 days to 93 days depending on the accessions, with an average of about 88 days. The best performances in terms of yield were expressed by the accessions A3, A2, and A12 with 850.50 kg·ha−1, 625.2 kg·ha−1, and 544.8 kg·ha−1, respectively. At harvest, the soil nitrogen balance was generally positive with an increase of 0.326 g·N·kg−1 of soil, which represents a nitrogen input from the mungbean contributing to the improvement of the soil nitrogen status. As nitrogen is an essential nutrient that is often lacking, limiting plant growth, farmers are obliged to supply this nutrient in the form of fertiliser; with mungbean’s ability to supply nitrogen to the soil, it could therefore be used in crop rotations as a solution to make up for the lack of nitrogen.

Regional adaptability evaluation of pepper and tomato accessions from the World Vegetable Center

Regional adaptability evaluation of pepper and tomato accessions from the World Vegetable Center

Novel sources of resistance to fusarium wilt in Luffa species.

Fusarium wilt is a serious disease of cucurbit crops including cultivated Luffa species (Luffa aegyptiaca, Luffa acutangula) causing considerable amount of reduction in yield and quality. Luffa is starting to be used as rootstocks for major commercial cucurbit crops, but little is known of its resistance against soilborne diseases. Here, 63 Luffa accessions from the World Vegetable Center genebank were evaluated for resistance to an aggressive isolate of Fusarium oxysporum f. FoCu-1 (Fsp-66). According to visual screening based on disease severity rating, 14 accessions exhibited a high level of resistance against Fsp-66. These accessions were further evaluated for resistance against Fsp-66 and two more isolates FoCu-1 (isolated from infected cucumber plants) and FoM-6 (isolated from infected bitter gourd plants). Of the 14 accessions, 11 were confirmed resistant against isolate Fsp-66. In addition, 13 accessions showed high resistance against isolates FoCu-1 and FoM-6. This is the first report of Fusarium wilt resistance in Luffa and these sources will be valuable for the development of Luffa rootstocks/cultivars resistant to soil-borne pathogen to manage this serious disease.

Effects of urbanisation on urban residents’ perception of vegetable production in Yaoundé, Cameroon

In the context of rapid and unplanned urbanisation in many Sub-Saharan African cities, the social and political context of urban and peri-urban vegetable production is becoming unfriendly despite its multifunctionality in achieving human development. This paper aims at measuring the effects of urbanisation on urban residents’ perception of vegetable production in urban and peri-urban areas of Yaoundé, Cameroon. Data from a survey conducted by the World Vegetable Centre among urban residents living within and around vegetable production areas was employed for the study. The results show that urban residents agree with vegetable production in their vicinity, but depending on the extent of urbanisation, the magnitude of their positive perception varies significantly from one production area to another. More specifically, while proximity to the city centre increases the likelihood of urban residents’ ability to agree with local vegetable production, the density of the population decreases this positive perception instead.

Evaluation of Germplasm for Breeding High-temperature Tolerant Paprika

Other SectionsAbstractPaprika (Capsicum annuum) cannot grow or set fruit in temperatures that are higher than the optimal level. This study assesses the characteristics of 52 paprika accessions introduced from the agrobiodiversity center and the world vegetable center during a high temperature period in order to develop heat tolerant lines. As a result of controlling the temperature in two greenhouses by side ventilation and fogging system, the average daily temperature of the high temperature regime was 34.3℃, which was 2.4℃ higher than that of the normal temperature regime. Plant height, stem diameter, fruit set, fruit weight, fruit shape, pericarp thickness, soluble sugar content, yield, and marketable fruit development rate were all investigated as vegetative and reproductive growth-related parameters. Plant height, fruit weight, pericarp thickness, and yield were all reduced during high temperature treatment. Six germplasm lines (T12, T15, T26, T29, T32, and T36) were selected as high-temperature tolerant lines based on these parameters. The selected lines will be used to breed heat-tolerant cultivars as well as crossbreeding for genetic analysis.Keywords : evaluation, germplasm, heat tolerance, high-temperature, paprika

Performance of Wild Tomato Accessions and Elucidation of Resistance against Invasive Pest Phthorimaea absoluta Damage under Tropical Conditions

Invasive tomato leaf miner, Phthorimaea absoluta causes serious damage and yield loss in tomato production in open-field and protected cultivation. Use of chemical pesticides is uneconomical and adversely affects humans and the environment. Host-plant resistance is an effective, economical and eco-friendly alternative to chemical pesticides. In this study, four wild tomato accessions from the World Vegetable Center along with one susceptible check were evaluated for their antixenosis and antibiosis effects on P. absoluta. The accessions VI037241 (Solanum galapagense) and VI037240 (S. cheesmaniae) were highly resistant, leading to 85% larval mortality under no-choice conditions. Choice assay also showed less oviposition preference and reduced pupal weight. Both VI037241 and VI037240 showed the highest resistance under field conditions. The accessions of S. habrochaites (LA1777) and S. habrochaites var. glabratum (VI030462) demonstrated moderate resistance against P. absoluta. Wild accessions recorded significantly less eggs and leaf damage in field trials compared to the susceptible genotype, S. lycopersicum (CL5915). Trichome density, type and higher production of acylsugar contributed to the insect resistance. Acylsugar production in wild accessions was less during the rainy season but significantly higher than in susceptible genotype. These findings can be useful to develop P. absoluta-resistant tomato varieties in tropics.

Genetic diversity analysis and core collection construction for Amaranthus tricolor germplasm based on genome-wide single-nucleotide polymorphisms

• Genetic diversity among Amaranthus tricolor accessions was evaluated using genome-wide SNPs. • A set of 5638 SNPs without missing data in accessions was identified. • The population structure was analyzed among accessions. • A core collection of 105 accessions was created. The genus Amaranthus includes 60 to 70 species, some used as grain or leafy vegetable crops, others as ornamental crops. A. tricolor is used as a traditional leafy vegetable in Asia. It has a remarkably valuable nutrient composition and a high tolerance to environmental stresses but has been neglected in modern breeding. Detecting DNA polymorphisms among accessions helps in understanding the genetic diversity and population structure of germplasm collections. The genetic diversity and population structure were analysed among 465 A. tricolor accessions held by the World Vegetable Center genebank with genome-wide single-nucleotide polymorphisms (SNPs) developed by the double-digest restriction-site-associated DNA sequencing method. We found a total of 10 509 SNPs among the accessions and identified a set of 5638 SNPs without missing data in 440 accessions. This marker set was used to verify the species attribution of the germplasm, to analyse genetic diversity and population structure of the collection, and to create a core collection of 105 accessions representing the genetic diversity of 377 source accessions. This core collection is available for research and breeding (World Vegetable Center: info@worldveg.org). The SNP data generated here will contribute to exploring genetic loci related to economically and agronomically important traits in this species.

Variation of Seed Traits and Initial Quality among Selected Cowpea, Mungbean, and Soybean Accessions

Seed traits are essential quantitative variables to assess seed quality and are also indicators of crop success. The World Vegetable Center Genebank in Arusha, Tanzania, has an important legume collection; however, there is limited information on seed traits per genotype, i.e., 1000-seed weight, the number of seeds per gram, germination percentage (GP), and mean germination time (MGT). In this study, 8 cowpea, 54 mungbean, and 15 soybean accessions were evaluated for the abovementioned parameters. A significant difference was observed among the genotypes of the selected legumes with respect to all the measured parameters. An intraspecific variation was also observed for the measured seed traits. The 1000-seed weight decreased with an increase in the number of seeds per gram. Unlike cowpea, the GP of mungbean and soybean accessions was significantly and negatively influenced by the number of seeds per 1 g. Hence, the smaller-sized seeds (with many seeds in 1 g) exhibited lower GP. It is concluded that the seed traits and initial quality among the selected legumes are strongly influenced by their genetic makeup. These results are useful to inform seed management, exchange, utilization, and have a high potential in breeding programs, and require further research attention.

Status of amaranth improvement at the world vegetable center in sub-Saharan Africa

Status of amaranth improvement at the world vegetable center in sub-Saharan Africa

Development of core collections in soybean on the basis of seed size

AbstractCore collections display a large fraction of the diversity contained in large collections in smaller germplasm panels. We used historical data (1973–2015) collected at the World Vegetable Center, Taiwan, for developing soybean (Glycine max L. Merr.) core collections representing the diversity of the whole collection of 7853 accessions held by the Center. The collection was split into two groups on the basis of the 100 seed weight: large seeded (>25 g or equal to 25 g) and small seeded (<25 g). The large‐seeded group (vegetable soybean/edamame) comprised 456 accessions, while the small‐seeded group contained 7397 accessions. Within these two groups, we developed core collections based on seven quantitative and 14 qualitative traits collected during the autumn season, resulting in a core collection of 112 large‐seeded vegetable soybean accessions and 1480 accessions for the small‐seeded types.

Increasing the yield of melon in a greenhouse at vegetative grafting on vegetable marrow rootstocks

In Uzbekistan, there is a demand of the population for fresh melon fruits during the off-season. In the Research Institute of Vegetable, Melon Crops and Potato for the first time studies were carried out, when grown in a greenhouse, on the vegetative grafting of melon’s Zarkhal variety on the vegetable marrow varieties used as rootstocks. The aim of the research was to study the effect of vegetable marrow rootstocks on the variability of economically valuable traits of the Zarkhal melon variety and to identify promising combinations of vegetable marrow rootstocks that increase the yield and quality of melon fruits.Methods. The studies were carried out in accordance with the guidelines of the World Vegetable Center. As a control, ungrafted plants of the Zarkhal melon variety were used. For comparison with the control, plants of this variety were grafted onto their own plants. Also, plants of the melon variety Zarkhal (scion) were grafted in combinations on 10 varieties of vegetable marrow, which served as rootstocks. Vegetative grafting of melon on vegetable marrow rootstocks was carried out “in a split” in the phase of the first true leaf when the stem diameter reached 4.1–4.3 mm and plant height 4.4–5.9 cm.Results. In comparison with the control, in combinations of grafting the Zarkhal melon variety onto the Grecheskiye 110, Unumdor, Delicates and Skvorushka varieties of vegetable marrow, the flowering of paternal and female flowers, the onset of fruit formation was observed 2 days earlier. In the same combinations, fruit ripening was observed on 81-82 days, which is 4-5 days earlier than the control (86 days). They also had the tallest plants (203-205 cm), the plants formed 2-4 leaves more than the others. Marketable yields between combinations ranged from 7.89 to 9.75 kg/m2 . The melon variety Zarkhal, grafted onto its own plants, lagged behind the control in all phases of development and yield. The early yield in combinations was from 3.95 to 5.75 kg/m2 and amounted to 53-59% of the yield. The average fruit weight varied from 785 to 810 g.

De novo SNP calling reveals the genetic differentiation and morphological divergence in genus Amaranthus

Amaranth species (Amaranthus spp.) serve as pseudo cereals and also as traditional leafy vegetables worldwide. In addition to high vigor and richness in nutrients, drought and salinity tolerance makes amaranth a promising vegetable to acclimatize to the effects of global climate change. The World Vegetable Center gene bank conserves ∼1,000 amaranth accessions, and various agronomic properties of these accessions were recorded during seed regeneration over decades. In this study, we verified the taxonomic annotation of the germplasm based on a 15K single-nucleotide polymorphism (SNP) set. Given that the yield components of grain amaranth are different from those of leaf amaranth, we observed that grain amaranth species presented larger inflorescences and earlier flowering than leaf amaranth species. Dual-purpose amaranth showed larger leaves than leaf amaranth and later flowering than grain amaranth, which seemed reasonable because farmers can harvest more leaves during the prolonged vegetable stage, which also provides recovery time to enrich grain production. Considering frequent interspecific hybridization among species of the grain amaranth complex, we performed an interspecific genome-wide association study (GWAS) for days to flowering, identifying a AGL20/SOC1 homolog. Another GWAS using only A. tricolor L. accessions revealed six candidate genes homologous to lba1, bri1, sgs1, and fca. These homologous genes were involved in the regulation of flowering time in Arabidopsis thaliana (L.) Heynh. This study revealed the usefulness of genotypic data for species demarcation in the genus Amaranthus and the potential of interspecific GWAS to detect quantitative trait loci (QTL) across different species, opening up the possibility of targeted introduction of specific genetic variants into different Amaranthus species.