Variations in agronomic and grain quality traits of rice grown under irrigated lowland conditions in West Africa

Rice breeding in West Africa has been largely skewed toward yield enhancement and stress tolerance. This has led to the variable grain quality of locally produced rice in the region. This study sought to assess variations in the agronomic and grain quality traits of some rice varieties grown in this region, with a view to identifying sources of high grain yield and quality that could serve as potential donors in their breeding programs. Forty‐five varieties were grown under irrigated conditions in Benin and Senegal with two trials in each country. There were wide variations in agronomic and grain quality traits among the varieties across the trials. Cluster analysis using paddy yield, head rice yield, and chalkiness revealed that 68% of the total variation could be explained by five varietal groupings. One group comprising seven varieties (Afrihikari, BG90‐2, IR64, Sahel 108, WAT311‐WAS‐B‐B‐23‐7‐1, WAT339‐TGR‐5‐2, and WITA 10) had high head rice yield and low chalkiness. Of the varieties in this group, Sahel 108 had the highest paddy yield in three of the four trials. IR64 and Afrihikari had intermediate and low amylose content, respectively, with the rest being high‐amylose varieties. Another group of varieties consisting of B6144F‐MR‐6‐0‐0, C74, IR31851‐96‐2‐3‐2‐1, ITA222, Jaya, Sahel 305, WITA 1, and WITA 2 had high paddy yield but poor head rice yield and chalkiness. The use of materials from these two groups of varieties could accelerate breeding for high yielding rice varieties with better grain quality for local production in West Africa

Climate Change Impact on Rice Yield and Production Risk

The relationship among rice yield and weather variables in Korea is explored using a stochastic production function. The results reveal that average rice yield is positively related to temperature and negatively associated with precipitation. Both temperature and precipitation, which are risk-increasing inputs, are positively related to rice yield variability. The widened yield variability can be transferred to the fluctuation of rice production and rice price instability. Larger market risk is expected in the future since both temperature and precipitation are anticipated to increase. An evaluation of climate change impact on rice yield variability reveals that it may increase by up to 10%~20%. Reducing yield variability and managing market risk would be the primary goals of the government's farm policy and research.climate change, production risk, stochastic production function, Agribusiness, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Production Economics,

Farmers\u27 Perception on the Performance of Different Rice Varieties in Kapilvastu District, Nepal

Rice is the major staple food crop in Nepal. To date, several rice varieties have been developed and released in Nepal. However, rice production is far below in comparison with its production potential. A household survey was conducted in Bangaganga municipality of Kapilvastu district in 2018 to assess farmers\u27 perception on performance of four different rice varieties (Radha-4, Ramdhan, Gorakhnath, and Sawa). The data were collected from a total of 120 rice farmers (randomly selected) using the interview schedule and analyzed using descriptive statistics, Likert scale, and indexing technique. Statistical analysis showed that the Ramdhan variety had the highest yield (4.95 t/ha), whereas Radha-4 had the lowest yield (3.15 t/ha). The most disease and drought-tolerant variety, as perceived by the farmers, was Radha-4. Smut and Khaira were perceived as the primary diseases whereas Brown planthopper and Rice Gundhi bug were the most important insects of all studied rice varieties. The study recommended that the plant breeders should focus on developing site-specific rice varieties to meet the multiple concerns of the farmers, such as higher yield and stress-tolerant. The farmers should be made aware of varietal selection and crop pest management techniques via training programs, which further helps to reduce the yield gap between farmers\u27 field and research field

Linking climate change, rice yield, and migration: the Philippine experience

This study tests the hypothesis that climate change, through its rice productivity impacts, induces out-migration in the Philippines. Results show that climate change effects such as increasing night time temperature and extreme rainfall pattern, by way of reduction in rice yield and farm revenues, significantly increases the number of Overseas Filipino Workers. Findings also show that overseas migration of female workers is more sensitive to climate and rice productivity changes compared to male overseas migration. However, unlike overseas migration, the reduction in yield and farm revenues act as a constraint to domestic migration

Milling Characteristics of High and Low Quality Rice

Harvest moisture contents (HMCs) have been proven to play a role in rice quality, especially affecting head rice yield (HRY) due to fissuring or immature kernels. Differences in milling characteristics between samples having high and low level milling quality were studied in this experiment. Two hybrid, long-grain cultivars (CL XL729 and CL XL745) and two pureline, long-grain cultivars (CL 181 and Wells) were harvested at near optimal and low HMCs, representing high and low milling quality, respectively. Lots were dried to approximately 12.5 ± 0.5% and milled in triplicate for durations of 10, 20, 30, and 40 s. Results showed that low quality rice achieved a greater degree of milling (DOM) than high quality rice when milled for the same duration. Low quality rice also reached a given surface lipid content (SLC) at a faster rate as supported by greater SLC reduction rates. As DOM increased, milled rice yield (MRY) of low quality rice decreased at a statistically greater rate than that of high quality rice. The rate at which HRY decreased, however, was not greatly impacted by milling quality as a function of HMC

Multi-site monitoring of heat stresses and micrometeorological conditions in the rice plants communities under various climates. The micrometeorological measurements system for a common measure of the paddy environments

Rice yield can be reduced substantially when the crop is exposed to excessive hest, which will likely occur more frequently under future climates, but the magnitudes of yield losses under open-field conditions are still difficult to predict, despite many efforts being conducted to detennine temperature response in the closed environments. To better understand the occurrence of heat stress under field conditions. we need thermal conditions of rice canopy under heat conditions, which can be very much different depending on other environmental factors, but taking correct measurements of canopy micrometeorology needs careful considerations. In this study, we will distribute a simple but well-designed system for measuring thermal environments of the canopy to different rice growing regions covering continental and coastal climates in low and mid latitude regions. With them, we attempt to establish a monitoring network of canopy thermal environments in the paddy fields that will help to bridge gaps between chamber and open-field and to better assess potential impacts of climate change on rice production. Keyword.: Canopy heat budget, Climate change, Micrometeorology, Multi-lateral research network, Rice. (Résumé d'auteur

On-farm trials with rice fish cultivation in the west Kano rice irrigation scheme, Kenya

The viability of integrating rice farming with fish culture was studied in ten (10) rice plots. The on-farm research was done during one rice-growing season starting May 2003. The rice variety used was IR 2793-80-1 while the fish species was the Nile tilapia, Oreochromis niloticus. The fish culture period lasted 77 days. An average fish production of 132.4 kg/ha was obtained. The mean recovery rate of tilapia was 43 per cent. Total rice yield from the fields stocked with fish was lower than from unstocked fields. The net returns were not significantly different

Genetic Diversity of Selected Upland Rice Genotypes (Oryza sativa L.) for Grain Yield and Related Traits

Seventy-seven upland rice genotypes including popular cultivars in Nigeria and introduced varieties selected from across rice-growing regions of the world were evaluated under optimal upland ecology. These genotypes were characterised for 10 traits and the quantitative data subjected to Pearson correlation matrix, Principal Component Analysis and cluster analysis to determine the level of diversity and degree of association existing between grain yield and its related component traits. Yield and most related component traits exhibited higher PCV compared to growth parameters. Yield had the highest PCV (41.72%) while all other parameters had low to moderate GCV. Genetic Advance (GA) ranged from 9.88% for plant height at maturity to 41.08% for yield. High heritability estimates were recorded for 1000 grain weight (88.71%), days to 50% flowering (86.67%) and days to 85% maturity (71.98%). Furthermore, grain yield showed significant positive correlation with days to 50% flowering and number of panicles m-2. Three cluster groups were obtained based on the UPGMA and the first three principal components explained about 64.55% of the total variation among the 10 characters. The PCA results suggests that characters such as grain yield, days to flowering, leaf area and plant height at maturity were the principal discriminatory traits for this rice germplasm indicating that selection in favour of these traits might be effective in this population and environment

Effect of Different Dates of Dry Seeding and Staggered Nursery Sowing on Growth and Yield of Kharif Rice

A field experiment was conducted to study the effect of different dates of dry seeding and staggered nursery sowing on growth and yield of Kharif rice. The experiment was based on the difficulties faced by the farmers in the coastal areas of Andhra Pradesh and those who depend on canal irrigation and are located at the tail end areas. The experimental results have showed no difference among the methods of stand establishment in terms of yield. However, among the dates of sowing the delay in sowing beyond 30th July significantly reduced the grain yield and returns per rupee invested. It has been concluded that the rice crop may be established either by direct seeding or by transplanting nurseries but the sowing of the respective cultures should be done by the end of July for obtaining maximum yield and profits

EFFICIENCY OF WIND INDEXED TYPHOON INSURANCE FOR RICE

Index-based weather insurances are innovative tools for mitigating weather risks in agriculture. Several donor agencies and development organisations are investing substantially to propagate these programmes in developing countries. However, often due to high basis risks, these products mitigate risk only through diversification effect, thereby defeating the intended purpose. Besides, they send confusing messages to the farmers regarding the very concept of insurance. Therefore, this paper investigates the efficiency of two such index-based weather insurances in Philippines, designed to mitigate rice yield loss caused by strong typhoon winds. The insurance products are designed assuming negative linear correlation between wind speed and rice yield. To verify, we used satellite data and GIS tools to tabulate typhoon wind speeds, concurrent crop stage and the subsequent rice yield in five provinces which have both the programmes. Regression analyses and Ramsey RESET tests confirm that rice yield loss is not a function of incident typhoon wind speed, irrespective of the crop stage. Basis risk estimations, based on minimum variance hedging ratio for a risk averse expected utility maximising consumer show that the products entail basis risks of the order of 99%. Typhoons damage all crops, but wind indexed insurance is inadequate when the insured crop has low head weight and is agile like rice, since wind onslaughts do not determine the degree of yield loss. Notably, a thorough burn analysis for basis risk is a necessity before investing time and money implementing index-based weather insurance schemes as a tool for poverty alleviation.Basis risk, Typhoon, Index-based Insurance, Crop Production/Industries, Risk and Uncertainty,