International Crops Research Institute for the Semi-Arid Tropics
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Identification and Functional Characterization of Two Major Loci Associated with Resistance against Brown Planthoppers (Nilaparvata lugens (Stål)) Derived from Oryza nivara
Get PDFThe brown planthopper (BPH) is a highly destructive pest of rice, causing significant economic losses in various regions of South and Southeast Asia. Researchers have made promising strides in developing resistance against BPH in rice. Introgression line RPBio4918-230S, derived from Oryza nivara, has shown consistent resistance to BPH at both the seedling and adult stages of rice plants. Segregation analysis has revealed that this resistance is governed by two recessive loci, known as bph39(t) and bph40(t), contributing to 21% and 22% of the phenotypic variance, respectively. We later mapped the genes using a backcross population derived from a cross between Swarna and RPBio4918-230S. We identified specific marker loci, namely RM8213, RM5953, and R4M17, on chromosome 4, flanking the bph39(t) and bph40(t) loci. Furthermore, quantitative expression analysis of candidate genes situated between the RM8213 and R4M17 markers was conducted. It was observed that eight genes exhibited up-regulation in RPBio4918-230S and down-regulation in Swarna after BPH infestation. One gene of particular interest, a serine/threonine-protein kinase receptor (STPKR), showed significant up-regulation in RPBio4918-230S. In-depth sequencing of the susceptible and resistant alleles of STPKR from Swarna and RPBio4918-230S, respectively, revealed numerous single nucleotide polymorphisms (SNPs) and insertion–deletion (InDel) mutations, both in the coding and regulatory regions of the gene. Notably, six of these mutations resulted in amino acid substitutions in the coding region of STPKR (R5K, I38L, S120N, T319A, T320S, and F348S) when compared to Swarna and the reference sequence of Nipponbare. Further validation of these mutations in a set of highly resistant and susceptible backcross inbred lines confirmed the candidacy of the STPKR gene with respect to BPH resistance controlled by bph39(t) and bph40(t). Functional markers specific for STPKR have been developed and validated and can be used for accelerated transfer of the resistant locus to elite rice cultivars
First Report of Phakopsora euvitis Causing Leaf Rust Disease on Grapevine (Vitis labrusca) in India
Get PDFGrapevine (Vitis labrusca L.), a member of the family Vitaceae and native of North America, is grown as a table grape. During the survey for grapevine diseases in May 2022, we noticed numerous yellow pustules of rust on the lower side of leaves of “Bangalore Blue” in Nandi Village (13°22′59.7″N, 77°42′33.4″E), Chikkaballapur District, Karnataka, India. The crop was at the maturity stage, and the rust disease severity was determined using the scale developed by Angelotti et al. (2008), which was up to 10%. The disease symptoms were numerous small, raised yellow pustules on the abaxial surface corresponding to adaxial surface chlorotic spots. In severe conditions, spots cover the entire leaf, and defoliation occurs. Similar disease symptoms were reported by Ono (2000), Primiano et al. (2017), and Weinert et al. (2003)
Mapping Shrimp Pond Dynamics: A Spatiotemporal Study Using Remote Sensing Data and Machine Learning
Get PDFShrimp farming and exporting is the main income source for the southern coastal districts of the Mekong Delta. Monitoring these shrimp ponds is helpful in identifying losses incurred due to natural calamities like floods, sources of water pollution by chemicals used in shrimp farming, and changes in the area of cultivation with an increase in demand for shrimp production. Satellite imagery,
which is consistent with good spatial resolution and helpful in providing frequent information with temporal imagery, is a better solution for monitoring these shrimp ponds remotely for a larger spatial extent. The shrimp ponds of Cai Doi Vam township, Ca Mau Province, Viet Nam, were mapped using DMC-3 (TripleSat) and Jilin-1 high-resolution satellite imagery for the years 2019 and 2022. The 3 m spatial resolution shrimp pond extent product showed an overall accuracy of 87.5%, with a producer’s accuracy of 90.91% (errors of omission = 11.09%) and a user’s accuracy of 90.91% (errors
of commission = 11.09%) for the shrimp pond class. It was noted that 66 ha of shrimp ponds in 2019 were observed to be dry in 2022, and 39 ha of other ponds had been converted into shrimp ponds in 2022. The continuous monitoring of shrimp ponds helps achieve sustainable aquaculture and acts as crucial input for the decision makers for any interventions
Yield and Mineral Composition among Mungbean [Vigna radiata (L.) R. Wilczek] Genotypes Grown in Different Agroecologies in East Africa
Get PDFMungbean [Vigna radiata (L.) R. Wilczek var. radiata] also referred to as green gram is a key crop especially in the marginal areas of East Africa. It is rich in micronutrients and protein and thus can help ameliorate malnutrition if incorporated into diets. 'is study was conducted to evaluate the performance of 26 fixed elite mungbean breeding genotypes for yield and micronutrient composition across di6erent locations in East Africa (Uganda, Kenya, and Tanzania). 'e genotypes displayed significant variability for nutritional, phenology, and yield-related traits across test environments. Significant genotype e6ects were observed
for most of the traits except for average yield per plant and dry matter content (P < 0.05). Random effect of environment was significant for all traits, and significant GXE was observed for all traits except for dry matter and iron content (P < 0.05). Moderate to high broad-sense heritability (H2) was found among traits except for dry matter content which was low (H2 =10.4%). 'ere was
a signi4cant and positive correlation between Fe and Zn (r =0.58), and Fe and Ca (r=0.46), indicating the potential to enhance these traits simultaneously through breeding and/or selection. However, the correlation between yield and nutrients (iron, zinc, and calcium) was negative. Environments KAT_SR_2019, KYM_LR_2020, and KYM_LR_2020 were found to be discriminating (informative) and representative of grain yield, calcium, and zinc content, respectively. Genotypes AVMU 1679, AVMU 1685, and AVMU 1686 combined both stability and high micronutrient content, while the high yielding and stable genotypes were AVMU 1689, AVMU 1681, and AVMU 16102. The identified genotypes need to be assessed for farmer preference in on-farm trials before they can be recommended for release as new varieties. Additionally, these genotypes will be useful in future breeding efforts as
donors aimed at developing nutrient-dense and high yielding mungbean varieties
Diseases of Chickpea
Get PDFChickpeas are one of the most economically important legumes and a rich source of carbohydrates, proteins, vitamins, minerals, and fiber. Chickpea is grown mainly in the tropics, in arid and semiarid countries in Asia and Africa, but it is also present in Europe, Oceania, North America, and Latin America. The varieties available for cultivation vary in productivity according to edaphoclimatic conditions
and the incidence of diseases. The incidence and severity of diseases in chickpeas vary in relation to the planting time, cultivated variety, and the causal agent. Among the main diseases with major economic importance causing losses
in productivity are those caused by soil-borne fungal and nematode pathogens, and diseases of the aerial plant portion caused by viruses and fungi. Integrated management and preventive measures such as pathogen identification, field
selection, seed quality, use of fungicides, and crop rotation are effective practices for managing chickpea diseases. This chapter will address the main characteristics
of the economically important diseases affecting chickpeas in several prominent and expanding production countries
Grain legumes and dryland cereals contribute to carbon sequestration in the drylands of Africa and South Asia
Get PDFGrain legumes and drylands cereals including chickpea (Cicer arietinum), common bean (Phaseolus vulgaris),
cowpea (Vigna unguiculata), groundnut (Arachis hypogaea), lentil (Lens culinaris), pigeon pea (Cajanus cajan),
soybean (Glycine max), finger millet (Eleusine coracana), pearl millet (Pennisetum glaucum) and sorghum (Sorghum
bicolor) are the leading sources of food grain in drylands of Africa and South Asia. These crops can help
smallholder agriculture to become more resilient, productive, and profitable, but their quantitative impact on
carbon sequestration is unknown. The aim of this review study was to quantify their contribution to carbon
sequestration across the drylands of Africa and South Asia based on 437 publications with 1319 observations in
studies conducted across 32 countries. Cropping systems with grain legumes showed the greatest increase in soil
organic carbon (SOC) concentrations, while cereals (and pigeon pea) gave the largest amount of aboveground
carbon stock (>2 Mg C ha-1). Estimated carbon stock in post-harvest residues of these crops was 1.51 ± 0.05 Mg
C ha-1 in Africa and 2.29 ± 0.10 Mg C ha-1 in South Asia. These crops produced more aboveground carbon, and
significantly increased SOC, when grown as intercrops. Soils with low initial SOC (<1%) and high clay content
(>32%) showed the greatest potential for carbon sequestration when cropped with grain legumes and dryland
cereals. This study is the first of its kind to provide evidence that grain legumes and drylands cereals improve
carbon sequestration across Africa and South Asia
Climate change and cropping pattern in Keonjhar District of Odisha, India
No full textClimate change is one of the most pressing challenges facing humanity and the natural environment in the 21st century. The agriculture sector is particularly vulnerable to climate change, as it depends on the availability and quality of natural resources, such as land, water, and soil. Climate change can affect the cropping pattern in various ways, such as altering the length and timing of the growing season, changing the water availability and quality, increasing the frequency and intensity of pests and diseases, and creating new opportunities and challenges for crop diversification. The agriculture sector in the Keonjhar district of India has been experiencing changes in its cropping pattern. This study investigates the key drivers for changing cropping patterns in the district. Secondary data was collected from 2011 to 2019 on the areas under crops and production of agricultural and horticultural crops grown in Keonjhar. For primary data, the interview method has been adopted with a sample of 327 marginal and small farmers from two villages in the district. The study revealed positive changes in the area allocated for paddy and mango, but negative changes in the area allocated for maize, mung (Yellow Lentil), biri (White Lentil). Climate change, market status, land ownership, education, the decline in yield, and the production of crops were the main drivers of the changes in crop patterns during the past few decades. This research proposes agricultural intensification and policy direction to promote the cultivation of paddy, maize, and mango trees to sustain livelihoods in the Keonjhar district
Groundnut Value Chain Innovations to Enhance Farmer Profitability and Promote Oil, Food and Confectionery Industries in Telangana, Mapping Groundnut Technologies in Telangana (Baseline survey) Report, Research Bulletin No. 29
Get PDFGroundnut is a major oilseed crop grown in Telangana state, India, mainly during the post-rainy season (rabi) and to a limited extent during the rainy season (kharif). The state’s high quality and aflatoxin-free groundnut produce in the post-rainy season provides a unique opportunity to expand the groundnut value chain in the country. This study on “Mapping of groundnut technologies in Telangana” was carried out to achieve the outputs under Objective 1 of the four-year project on “Groundnut value chain innovations to enhance farmer profitability and promote oil, food and confectionery industries in Telangana”. The project is supported by the Government of Telangana (2022-2025) and is being implemented jointly by Professor Jayashankar Telangana State Agricultural University (PJTSAU) and International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).
This study aims to document existing practices in groundnut cultivation through a representative primary survey in the state and to identify key constraints and potential opportunities to expand the crop area. A state-level representative baseline survey was undertaken covering about 994 groundnut growers drawn from three major districts of Telangana state (Nagarkurnool, Wanaparthy and Mahabubnagar), 14 mandals, and 56 villages. The household data were complemented by Focus Group Discussions (FGDs) in the study villages. Tablet-assisted CS-Pro programming formats and highly trained field investigators were used to collect the data. Primary data was validated and analyzed to derive meaningful conclusions.
The study found that small and medium groundnut farmers comprised nearly 2/3rd of the total sample. The average age of the sample households was 45 years. More than half of the total sample had no formal education. Nearly 98% of the total sample was highly dependent on agriculture and allied activities for their livelihoods. The mean operational landholding of the baseline sample stood at 2.84 ha, of which 0.40 ha were dryland and 2.44 ha accounted for irrigated land. In the study areas, groundnut cultivation was highly preferred during the post-rainy season on red chalka/sandy soils, while the preferences were for paddy, maize and cotton in the rainy season under irrigation and for cotton in the drylands. Fallow followed by groundnut or maize-groundnut were the preferred cropping system choices practiced in the study districts. This pattern of cultivation was quite similar in all the sample villages. The mean groundnut area allocated for the entire sample was around 1.98 ha per household, a significant figure that reflects the importance farmers give to groundnut in the study region.
Kadiri 6 (K 6) is the single dominant cultivar (>90%) in the three targeted districts, followed by K 1812 or TAG 24, based on farmers’ choices. Wide variations were observed in groundnut productivity levels under different climatic conditions (bad, good and best). Mean groundnut productivity stood at 1754 kgs/ha during the 2021-22 rabi season, remarkably lower than a good year’s productivity level and much closer to that in a bad year. Mean haulm productivity too is low at 618 kgs/ha. These figures clearly reveal that the groundnut farmers are not happy with current productivity levels and are experiencing significant income losses in its cultivation, underlining the need to enhance mean productivity levels.
A majority of the farmers in the survey felt access to improved seed is their biggest challenge. Informal seed systems play a pivotal role in the state. Traders/dealers/millers play a crucial role in seed supply and distribution. The timely provision of quality seed in sufficient quantities is the entry point that the project should focus on for sustaining the groundnut area in the study districts. Promoting low-cost on-farm seed storage technologies such as Purdue Improved Crop Storage (PICS) bags is critical for improving seed access. Biotic stress (such as pod borer and late leaf spot) plays a major role in limiting productivity. The crop never gets exposed to moisture stress conditions; hence abiotic stress has a limited role in crop genetic improvement. Aflatoxin contamination is very limited in the study area and farmers have a reasonably good knowledge about it.
More than 90% of the groundnut produced goes to the market as kernel. There is no practice of preserving seed for the next season. Hence there is huge scope for promoting such interventions to reduce costs as well as introducing quality seed in the sample villages. The introduction of effective crop management strategies can reduce the high seed rate (90 kg kernel/acre) and excessive irrigation during the first 30 days of the crop. Immense scope also exists for promoting mechanization in different operations which will ultimately reduce the cost of cultivation and enhance profitability
Farmers’ heterogeneous preferences for traits of improved varieties: Informing demand-oriented crop breeding in Tanzania
Get PDFUnderstanding farmers’ preferences and willingness to pay for different traits is critical for demand-driven varietal development and designing targeted strategies that stimulate adoption of varieties by farmers. This study uses choice experiment data from a random sample of 1299 Tanzanian farmers to analyze their preferences for traits of groundnut varieties, investigate trade-offs involved in valuation of attributes, and explore heterogeneity in preferences. Results reveal that farmers have strong preferences for groundnut varieties that are high yielding, tolerant to environmental stresses, early-maturing, red-colored, and
fetching high sale prices in grain markets. Farmers are willing to pay the highest premium for high-yielding
attributes, closely followed by the tolerance trait. Further, a latent class analysis identifies four distinct
classes of farmers, confirming considerable heterogeneity in farmers’ preferences for various groundnut traits. A specific distinction is notable between preferences of consumption-oriented and market-oriented farmer classes. Our results have important implications for demand-driven variety development and targeted dissemination of improved varieties
Indigenous Peoples’ Psychological Wellbeing Amid Transitions in Shifting Cultivation Landscape: Evidence from the Indian Himalayas
Get PDFRecent changes in the shifting cultivation landscape (SCL) of the Indian Himalayan region—a global biodiversity hotspot—is of great concern due to their implication to conservation and economic development of the region and their impact on ecosystem services as well as the wellbeing of the region’s inhabitants. The present study investigated the changes in land use in the SCL and their impact on the psychological wellbeing of the indigenous people of the region. Longitudinal data for over 15 years on land-use patterns and cross-sectional data from 481 respondents across 52 villages representing six states in India’s North East that are part of the Indian Himalayas were utilized for the study. To analyze subjective wellbeing, Cantril’s self-anchoring scale was used, followed by focused group discussions to triangulate the self-reported responses. Results reveal that the respondents were aware of the effects of landscape changes on their psychological wellbeing. These changes mostly represented a decline in shifting cultivation (SC), land ownership, food systems, social cohesion, cultural fulfillment, the diversity of cultivated native plants, and the availability of wild edible plants. Although the decline in SCL led to a gain in the area under green cover, it led to a marked decline in the diversity of cultivated and wild edible plants. This, the respondents perceived as adversely impacting their wellbeing. Empirical analysis established positive effect of SC on the psychological wellbeing of the respondents. However, a decline in SC seemed to have had an adverse impact on the perception of their wellbeing and thus increasing the migration. Therefore, optimized and ecosystem-based approaches and frameworks of socio-ecological systems are essential to harmonize the ecosystem services with wellbeing of the people