Farmer participatory variety selection conducted in high- and low-toposequence multi-location trials for improving rainfed lowland rice in Lao PDR

2014 ◽  
Vol 65 (7) ◽  
pp. 655 ◽  
Author(s):  
J. H. Mitchell ◽  
Sipaseuth ◽  
S. Fukai

Lowland rice in Lao PDR is predominantly grown under drought-prone, rainfed conditions in the wet season. We utilised a farmer participatory variety selection (PVS) approach in combination with multi-location yield trials (MLTs) conducted in high- and low-toposequence positions to test advanced breeding lines with the aim of improving the efficiency of the rice-breeding program and encouraging rapid adoption of improved lines. Upper position fields were utilised to screen for traits for unfavourable environments, including drought resistance, while lower fields were used to target yield potential. Yield was, on average, 13% lower in upper than lower (2.85 t/ha) field positions, and varieties adapted to high-toposequence position were identified. Farmer preference was not associated well with grain yield performance, with a significant positive relationship (r = 0.34*, n = 23) identified only in the Vientiane (VTN) low-toposequence trial; rather, the famers tended to choose lines they believed were best adapted to their own farm. Although a significant relationship existed for both farmer preference (r = 0.42*, n = 23) and grain yield (r = 0.50*, n = 23) in high and low toposequences across all provinces in 2010, this relationship was not significant in VTN, where the high position was low-yielding (1.2 t/ha). By utilising farmer preference information in combination with traditional MLT data, only lines agronomically acceptable to farmers were progressed into a seed-multiplication system for country-wide, farmer yield testing. Thus, the PVS-MLT approach has provided efficient delivery of highly acceptable lines to farmers, which directly contributes to improved efficiency of the rice-breeding program.

2021 ◽  
Vol 01 (01) ◽  
pp. 001-006
Author(s):  
Deressa Tesfaye

Field pea is one of the grain food legumes contributing an enormous amount of protein to the human diet in Arsi zone. It is a long time ago that fi eld pea crop improvement started in which more than 16 new varieties released those are selected primarily for yield potential, but there is a trait left considered as a very import by majority of farmers. The current study intended to identify traits that farmers consider most important when deciding which varieties to grow. The study was conducted at south eastern Arsi of Ethiopia, representing fi ve major fi eld pea producing location, in one growing season, using a participatory variety selection approach. A total of nine improved and one local check fi eld pea varieties are used. Majority of farmers’ were found around fourteen traits that can infl uence the selected varieties across all locations. There are also some traits those are more sensitive to gender diff erence. Among fourteen traits, nine were considered particularly important in one or all the location in a growing season. Unfortunately, there are preferred traits that are not given high priority by the current fi eld pea breeding program in Ethiopian. This study indicated that there is no fi eld pea variety possesses all desirable characteristics that meet the diverse farmers’ selection criteria that adapted to varied location and a growing season. It is better if farmers’ preference traits would be considered in breeding program for a country Ethiopia where the crop is consumed as a stable food.


2020 ◽  
Vol 21 (20) ◽  
pp. 7593
Author(s):  
Fabrice Ntakirutimana ◽  
Wengang Xie

Awns, which are either bristles or hair-like outgrowths of lemmas in the florets, are one of the typical morphological characteristics of grass species. These stiff structures contribute to grain dispersal and burial and fend off animal predators. However, their phenotypic and genetic associations with traits deciding potential yield and quality are not fully understood. Awns appear to improve photosynthesis, provide assimilates for grain filling, thus contributing to the final grain yield, especially under temperature- and water-stress conditions. Long awns, however, represent a competing sink with developing kernels for photosynthates, which can reduce grain yield under favorable conditions. In addition, long awns can hamper postharvest handling, storage, and processing activities. Overall, little is known about the elusive role of awns, thus, this review summarizes what is known about the effect of awns on grain yield and biomass yield, grain nutritional value, and forage-quality attributes. The influence of awns on the agronomic performance of grasses seems to be associated with environmental and genetic factors and varies in different stages of plant development. The contribution of awns to yield traits and quality features previously documented in major cereal crops, such as rice, barley, and wheat, emphasizes that awns can be targeted for yield and quality improvement and may advance research aimed at identifying the phenotypic effects of morphological traits in grasses.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 591 ◽  
Author(s):  
Liu ◽  
Zhan ◽  
Hussain ◽  
Nie

Aerobic rice has the potential to replace transplanted flooded rice, as rice cultivation is seriously threatened by environmental and social factors. Although the recently released upland rice cultivars have higher drought tolerance, low yield potential of these cultivars makes them less feasible for high-yielding rice planting regions under aerobic cultivation. In this study, typical lowland rice cultivars (Huanghuazhan and Yangliangyou6) were evaluated for grain yield and resource use efficiencies under aerobic cultivation as compared with upland rice cultivars (Lvhan1 and Hanyou3). Averaged across different years, lowland rice cultivars recorded 26.9%, 14.6%, and 26.6% higher grain yield, water productivity, and nitrogen use efficiency for grain production (NUEg), respectively, as compared with upland cultivars. The higher grain yield of lowland rice cultivars under aerobic cultivation was mainly attributed to the higher aboveground biomass and the spikelet number per panicle, along with a higher harvest index and panicle number per unit area with respect to upland rice cultivars. During the entire growing season in aerobic cultivation, rainfall accounted for 60% to 85% of the total water use, which indicates that lowland rice cultivars could make better use of the rainfall because of a longer growth duration and a higher growth potential. In summary, this study suggests that with appropriate irrigation, lowland rice cultivars could grow well and furnish higher yield than the current upland rice cultivars under aerobic cultivation.


1994 ◽  
Vol 34 (7) ◽  
pp. 897 ◽  
Author(s):  
KS McKenzie ◽  
CW Johnson ◽  
ST Tseng ◽  
JJ Oster ◽  
DM Brandon

An accelerated rice-breeding program was initiated in 1969 at the California Rice Experiment Station. The program is broad in scope, developing cultivars in all US market classes (long, medium, and short grains) and special purpose types (waxy and aromatics). This grower-funded rice-breeding program has released 27 new cultivars as well as improved germplasm lines. Statewide paddy rice yields have risen from 6.2 to 9.3 t/ha since 1978. The incorporation of semi-dwarfing genes, earlier maturity, and increased yield potential have contributed significantly to increases in grain yield. High experimental yields (>I1 t/ha) are routine and achieving increased increments of yield will become more difficult. After the initial shift to semi-dwarf cultivars, increasing efforts were directed toward improving adaptation to environmental stresses and grain quality. Screening and selection for cold tolerance in the form of seedling vigour for water seeding and resistance to cool temperature induced sterility at the reproductive stage are integral parts of the rice-breeding program. Progress is being made on incorporation into California rice cultivars of resistance to stem rot (Sclerotiurn oryzae Cattaneo) and aggregate sheath spot [Rhizoctonia oryzae-sativae (Swada) Mordue] from wild species and tolerance to rice water weevil (Lissorhoptus oryzophilus Kuschel). New restrictions and regulations of agronomic management practices may negatively impact rice production, creating problems in stand establishment, soil fertility, and weed, disease, and insect control. Breeding efforts to help minimise the adverse effect of these restrictions on yield and quality will increase in the future. Increased emphasis is being placed on improving milling yield and cooking and processing characteristics, and new laboratory methods are being explored to aid in evaluation and selection for grain quality.


2011 ◽  
Vol 43 (1) ◽  
pp. 131-142 ◽  
Author(s):  
L. Lanier Nalley ◽  
Karen A. Moldenhauer ◽  
Nate Lyman

This study estimates the proportion of rice yield increase in University of Arkansas Division of Agriculture's (UofA) released rice cultivars that are attributable to genetic improvements through the University's breeding program. Test plot data from eight UofA experiment stations were used to quantify the yield increases and potential yield growth decreases over time. In addition to quantifying the yield and yield variance evolution at the UofA, this study also calculates the economic benefits of the UofA rice breeding program. Results indicated that by releasing modern rice cultivars, the UofA rice breeding program increased average producer yield by 0.68 bu/ac annually. During the last decade, 1997-2007, the average annual economic benefits were 34.3 million (2007) dollars. When accounting for the spillover of UofA rice varieties to neighboring states the average annual economic benefit of the breeding program increases to 46.7 million (2007) dollars.


Agromet ◽  
2009 ◽  
Vol 23 (2) ◽  
pp. 123
Author(s):  
Didiek Setiobudi ◽  
Hasil Sembiring

The water saving technology for lowland rice cultivation was very crucial because of in the future irrigation water become scarce and competed with other sectors. The lowering of the availability of irrigation water had the impact for sustainability of rice production. The review of the paper described the pattern of basic water requirement, yield responses of several lowland rice varieties to moisture stress, days interval irrigation and the alternatives of water saving techniques for improving yield and water productivity. The pattern of the actual water requirement (ET+P&S) showed the maximum value of 8.8 mm/day (1.02 lt/sec/ha) for high yielding varieties (HYV) that occurred from heading to 50% flowering. Under limited water supply, irrigation water should be applied that period to prevent yield loss. Soil moisture stress at moderate level (- 0.5 bar) from heading to full flowering was significantly decreased yield about 30% when compared with the yield of continuously flooded 3 cm depth. This period was a critical period of HYV to soil moisture stress. For rotational irrigation purposes, information of the optimum days interval irrigation was important. It was found that 3 days irrigation interval was a critical limit for HYV to achieve higher yield. The SRI model of rice cultivation had the lowest rice yield in the lowland soil, poor drainage, clay soil texture and low permeability. The modified irrigation of the SRI plus fertilizer N based on LCC readings gave a greater yield as well as water productivity. The hybrid and NPT line rice varieties had higher yield components and grain yield than Ciherang variety. Ciherang variety was not favor to grown for the wet season, it was more productive when grown in dry season even with AWD irrigation model. The plant spacing of 25 cm x 25 cm gave higher number of panicle/hill and number of spikelet/panicle under both AWD and continuously flooded 3 cm depth for dry and wet season consistently. The fertilizer N management based on SSNM with low and high rates for the early vegetative stage were not significantly affected all yield components and grain yield. The AWD irrigation could save irrigation water about 18% when compared to the continuously flooded conditions.The grain yield of the hybrid, inbred and NPT line rice varieties was higher for the dry season than wet season under both AWD irrigation and continuous flooding consistently.


2015 ◽  
Vol 60 (4) ◽  
pp. 395-406
Author(s):  
El Hassan ◽  
Yasir Gamar ◽  
Ibrahim Elzein ◽  
Asma Ali ◽  
Tareg Ahmed

Sorghum (Sorghum bicolor (L) Moench) is the most widely produced and consumed cereal crop in Sudan. However, productivity is low since the crop is produced in favorable and unfavorable environments where the crop suffers from drought stresses at different growth stages. In the present study, six sorghum inbred lines developed by local breeding program and two commercial checks were evaluated for grain yield potential, yield stability, some important agronomic characters and grain quality properties. Series variety trials were conducted at Elobeid and Suki, Damazin areas of Sudan, during three consecutive rainy seasons. The selected locations represent low, medium and high rainfall areas of Sudan. The trial was laid out in a randomized complete block design. The results revealed that mean squares of genotypes, seasons, locations, location x season, location x genotypes, season x genotypes and season x location x genotype interactions were highly significant (P=0.01) for grain yield. The sorghum genotypes Edo 34-23-4, Edo 26-18 and Edo 16-dwarf produced substantially higher grain yields than commercial checks and the trial mean. Their percentage yield increase ranged from 5% to 75% over commercial checks. The stability analysis revealed that the above mentioned Edo-genotypes had high yield potentials and were stable across a wide range of agricultural conditions. Moreover, the same Edo-lines showed early maturing compared to selected commercial checks and also the Edo-lines possessed good food grains and were market preferred and acceptable for making quality kisra (fermented sorghum pancake-like flatbread). The Edo developed lines also possess the acceptable grain quality in addition to moderate physical grain characteristics such as protein content, fat acidity and moisture content.


2016 ◽  
Vol 35 (2) ◽  
pp. 89
Author(s):  
Trias Sitaresmi ◽  
Cucu Gunarsih ◽  
Nafisah Nafisah ◽  
Yudhistira Nugraha ◽  
Buang Abdullah ◽  
...  

Grain yield of rice is determined by genotype (G), environment (E), and interaction between genotype x environment (G x E). Variety can achieve its maximum yield potential if it is grown in suitable environments. This study was aimed to determine the adaptability and the yield stability of rice genotypes grown in different environments. Sixteen rice genotypes were tested using RBD in 16 sites during the wet season of 2010/2011, and dry season of 2011. The tested rice lines were developed for resistance to pest and diseases. The experiment unit was 4 m x 5 m of plot, plants were fertilized with urea, SP36, and KCl at rates of 250 kg/ha, 100 kg/ha, and 100 kg/ha, respectively. Variable observed was grain yield per plot. Combined analyses of variance showed that there was no lines yielded higher than did check variety Conde. The AMMI analysis showed that the largest variation was contributed by the environment factors (76.49%), genotype x environment interactions (17.55%), and the smallest was contributed by the genotypes (5.97%). Data exploration using boxplot method indicated that the low contribution of the genotype x environment interaction variance in this study was due to the high degree of similarity of yield potentials among the genotypes, and due to high similarity of environmental conditions of the sites.Based on the analysis of AMMI 2, lines B12743 - MR-18-2-3-8, IPB107-F-82-2-1, and Conde was each classified as widely adapted genotypes, while G8, IPB107-F-27-6-1, and BIO111-2-BC-PIR-3714, each was considered as genotype having a specific adaptation.


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