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1.
Despite efforts made by the Ethiopian research and extension system during the past 40 years to disseminate improved maize (Zea mays L.) variety seeds for increased crop production, the diffusion and use remained low, particularly in moisture-stressed areas. The topic of smallholder farmers’ access to quality seed is an ongoing issue in Ethiopia. The purpose of this paper is to identify and explain maize seed sources for smallholder farmers and assess the seed quality status in the drought-prone Central Rift Valley (CRV) of Ethiopia. Data for this study were obtained from farm households and other stakeholders survey in 2011 from East Shewa Zone, Oromia Regional National State. The survey results indicated that informal seed sources contributed 84% of annually planted maize seed. Sixty percent of maize growers obtained improved seed through farmer-to-farmer seed exchange and the informal seed market (ISM). Regarding the socioeconomic characteristics and maize seed acquisition behavior of the farm-household heads, a higher proportion of female-headed households and resource-poor farm households depended on other farmers and ISM than male-headed farm households. A quarter of the better-off maize-grower households also used ISM. Formal seed sources were found to be key in new variety introduction. The quality of the seeds obtained from informal sources was found to be acceptable relative to purity and germination. The effectiveness of the seed-supply system tended to rely on the complementary integration of formal and informal seed systems, as both systems had their own peculiarities in serving the farm community to enhance food security. 相似文献
2.
In this study, 151 households were randomly drawn from three randomly selected Kebele in probability proportional to size method. The demographic and socio-economic factors that determine the participation in improved varieties were household labor availability, education level of the household head, land holdings, distance to the nearest village market, proximity to the main market, and distance to access agricultural extension and access to the source of rice seeds. However, determinants of choice decision varied from cultivar to cultivar. The evidence of the study from the interdependence among the decision of adoption of improved rice varieties suggested that technology adoption will be accelerated by launching a progressively developing package and scheme of rice technology generation, and points to the importance of mobilising additional resources to augment households’ efforts at popularization and promotion of improved rice cultivars. The findings from Linearized Almost Ideal Demand Systems (LA/AIDS) model showed that compelling evidence for small proportion changes in own prices and cross price of improved rice varieties led to greater than unitary proportionate changes in their purchases. The results generally showed that farmers were very sensitive to changes in improved rice seed prices and incomes. The major implication of the findings was that any intervention to improve farmers’ seed purchases should take into account efforts to increase farmers’ purchasing power of agricultural inputs like improved seeds and fertilizers. 相似文献
3.
农户选择玉米新品种行为及影响因素分析 总被引：2，自引：0，他引：2
自2000年《中华人民共和国种子法》正式颁布后,农户可更加自主的选择新品种。吉林省作为我国著名商品粮生产大省,在全国粮食主产省份中占重要位置,其农户对新品种的选择行为具有典型性和代表性。基于吉林省粮食主产区129个农户的调查数据,运用Logistic模型对吉林省农户选择玉米新品种行为及影响因素进行实证分析。研究结果表明,吉林省农户选择玉米新品种行为受多种因素的影响,玉米种植规模、受教育年限、增产效果、对种子熟悉程度、新品种宣传推广力度、农户种植经验、农户风险偏好对农户选择玉米新品种行为有正向影响,玉米种植收入占总收入比重、种子价格对农户选择玉米新品种行为有负向影响。在此基础上,从资金投入、价格、品种、新品种宣传推广力度4个方面提出调动吉林省农户选择玉米新品种积极性的相应对策。 相似文献
4.
It is shown for the first time how participatory variety demonstration (PVD) trials can establish modern varieties in informal seed systems in a developing country by targeting nodal multipliers occupying hub locations. A series of relatively few, small (each 36 m2) PVD trials was conducted over a period of 3 years in sweetpotato multipliers’ fields at three locations in Uganda; multipliers and farmers were encouraged to visit during crop growth and on field days; yields at final harvest and other traits considered important to multipliers and farmers were recorded. In the following dry season, the areas of the introduced varieties established in the lowland crops used by multipliers to conserve planting material were recorded. The two most popular varieties had a recorded area of about 1 ha each and were calculated to have increased sixfold annually from the trials; the next two occupied 0.5 ha each, confirming that the method is effective, cheap, and efficient. 相似文献
5.
Mathieu Anatole Tele Ayenan Patrice Lagnon Sèwadé Sègbégnon Martin Agboton 《Journal of Crop Improvement》2017,31(3):379-399
Facilitating farmers’ access to quality seed requires proper understanding of the functioning of seed systems. This study aimed at analyzing soybean (Glycine max [L.] Merr.) seed systems in Benin to pave the way for strengthening this sector. The research approach consisted of desk research, focus group discussions, individual interviews and validation workshop with stakeholders involved in soybean seed systems. Our findings revealed that despite the existence of an institutional and organizational framework, the formal soybean seed system is not at all functioning. Farmers mainly relied on informal seed system through self-saved seed and seed purchase in the markets. There is an emerging soybean seed system led by NGOs and farmers’ organizations. Current soybean seed systems are ineffective in timely supplying desired soybean varieties to farmers. Creation of enabling environment to attract private investment and develop local seed businesses is proposed along with new organizational arrangements among stakeholders. Farmers’ training in seed production, processing and managerial skills, as strategy to improve informal seed system, are proposed to strengthen local seed business. Farmers’ organizations have a critical role to play, as they serve as intermediary between their members and seed producers. Information and Communication Technology (ICT) could be exploited not only to promote improved seeds but also to ensure traceability in the system. Quality Declared Seed could be the most adapted quality insurance scheme in remote areas. The proposed arrangements among stakeholders in the seed systems in this study could be applied to legume crops other than soybean. 相似文献
6.
The use of improved high yielding crop varieties is an important avenue for reducing hunger and food insecurity in developing countries. Using cross-sectional data obtained from a survey conducted during 2013 crop season, we performed a probit model(plot-level analysis) to determine the probability of adopting new improved rice varieties(NIRVs) by smallholder farmers particularly from two main agro-ecological regions(hills and tropical plain terai regions) of Central Nepal. The results revealed that education, extension services and seed access play significant roles in adoption decisions.Additionally, farm and field characteristic variables such as farm size, endowment of favorable land type(e.g. lowlands), and animal power(e.g. oxen) are the key factors influencing the probability of adopting NIRVs. The results showed that technology specific variables(e.g. yield potential and acceptability) are significant for explaining adoption behavior, implying that it is important to take farmers' preferences to varietal characteristics into consideration in the design of a research and development program. Given the significant role played by extension and access related variables, increased emphasis on information dissemination, field demonstration, and farmers' participatory research and training programs to popularize new rice varieties and enhance their adoption rate are required. This also suggests that policy intervention should be made on improving the educational status of farming households, and developing programs on varietal package of rice seed which offer farmers a variety of choices among the appropriate pools of germplasm. Such programs ultimately help farmers develop more profit-oriented behavior which are necessary to enhance adoption rate, production and food security in the long run. 相似文献
7.
To study the impacts of nanometer pottery trays(NPTs) on different rice varieties, three rice varieties, Zhongzheyou 1, Jinzao 47 and Xiushui 09, were treated with four NPTs(NPT-A, NPT-B, NPT-C and NPT-D) with different energies, respectively. The results showed that when the same rice variety was treated with different NPTs or different rice varieties were treated with the same NPT, the impacts on seed germination rate, seedling growth, plant height, panicle length and weight, the number of filled grains, seed-setting rate and 1000-grain weight varied between different rice variety-NPT interaction groups. In general, high energy NPT-C and NPT-D treatments obviously enhanced the functions of most examined rice characters. For example, NPT-C and NPT-D treatments improved the germination rate of all the three rice varieties, and promoted the root growth of seedlings, and increased seedling fresh weight, single panicle weight, filled grain number per panicle, seed-setting rate and 1000-grain weight. On the contrary, low energy NPT-A treatment restrained the seed germination rate in Jinzao 47 and Zhongzheyou 1, and decreased the seedling fresh weight in Zhongzheyou 1. NPT-B treatment restrained the seedling growth in Jinzao 47 but increased the panicle length of Zhongzheyou 1. NPT-A and NPT-C treatments obviously decreased the 1000-grain weight in Xiushui 09. Therefore, when treating crop seeds or plants using nanomaterials or nanotechnologies, different types of crops/varieties should select the nanomaterials or nanotechnologies with suitable energies to reduce the negative effects. 相似文献
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9.
Kazuki Saito Hidetoshi Asai Dule Zhao Alice G. Laborte Cécile Grenier 《Plant Production Science》2018,21(3):145-158
Enhancing rice yield in upland rice systems through genetic improvement remains a major challenge in the tropics. This review aims to provide the trends on upland rice cultivation over the last 30 years and recent distribution of upland rice in the tropics, and to report progress in studies on genetic improvement for enhancing productivity in Africa, Asia, and Latin America. While upland rice cultivation area has reduced in Asia and Latin America over the last 30 years, the area in Africa has increased. The current share of upland rice area in total rice area is related to rainfall and gross national income per capita, especially in Africa, and higher share is associated with lower rice self-sufficiency at national level. Breeding programs in Asia and Latin America have developed high-yielding varieties using indica materials as parents. In Africa, New Rice for Africa (NERICA) varieties were developed from crosses between improved tropical japonica and Oryza glaberrima. However, recent studies report that there is scope for improving existing NERICA using upland indica materials from Asia. In highlands of Africa, there are ongoing breeding programs using japonica varieties, such as the Nepalese Chhomrong Dhan. Key important plant traits used in the breeding programs are not largely different across regions, especially intermediate plant height and tillering capacity (which may be related to weed-suppressive ability), and high harvest index. In conclusion, we propose an international network for breeding upland rice with accelerating seed exchange across regions that could enhance upland rice productivity through genetic improvement. 相似文献
10.
Edward G. Hagop Suhaila A. Younis Hisham A. Shahatha 《Plant foods for human nutrition (Dordrecht, Netherlands)》1990,40(4):309-315
Proteins and amino acids in four local rice (Oryza Sativa L.) varieties were identified. Albumin and globulin were extracted from rice seeds, and the major promoters of these proteins were investigated by polyacrylamide gel electrophoresis to show their patterns.Amino acid composition of the rice seed were determined quantitatively and qualitatively, and classified according to their acidic, basic and uncharged polar groups.Essential amino acids for each variety were determined, and the hydrophobicity index value of Amber 33 was (0.6078), Mishkhab 1 (0.63372), Hybrid 2 (0.6523) and Hwazawi (0.7411). 相似文献
11.
“十二五”以来,我国水稻审定品种数量快速增加,结构类型逐步优化;杂交稻制种面积波动明显,制种结构不断优化;种子市场价格稳步上涨,市场规模不断扩大;大面积推广品种数量和面积双减,品种优质率明显提升;水稻种子出口贸易量窄幅波动,贸易金额稳步增长。但同时,我国水稻种业发展也面临育种创新能力有待增强、企业竞争力有待提升、种子生产水平有待提高、杂交稻种子出口有待扩大等问题与挑战。从未来发展看,生物育种等新技术将加速发展,突破性新品种将加快推广应用,种子市场集中度将持续提升,杂交稻国际战略将从产品输出向技术输出转变。 相似文献
12.
镉胁迫对不同水稻品种种子萌发特性的影响 总被引：8，自引：0，他引：8
【目的】为了研究不同水稻品种的镉胁迫抗性差异,为早期预测镉污染,选育镉低积累水稻提供参考。【方法】采用50个不同遗传背景的水稻品种(系)种子,研究了0(蒸馏水,对照)、0.5、1.0、2.0 mmol/L等4种不同镉浓度胁迫对不同水稻品种种子发芽率、发芽指数、活力指数、胚芽长、胚根长、胚芽鲜质量与胚芽干质量等性状的影响。【结果】镉胁迫对水稻种子的萌发及幼苗生长具有抑制作用,且随着镉胁迫浓度的增高,抑制作用逐渐加强。0.5 mmol/L Cd~(2+)胁迫浓度对各水稻品种种子的发芽率和发芽指数影响不显著,而对其种子活力指数、胚根与胚芽生长则具有显著的抑制作用;不同镉胁迫浓度对水稻种子胚根的抑制作用明显大于胚芽;1.0mmol/L和2.0 mmol/L Cd~(2+)两种胁迫浓度处理下,不同水稻品种种子萌发期的各性状指标间差异达极显著水平,且达到极显著正相关。不同水稻品种对不同镉胁迫浓度的耐性存在明显差异。【结论】根据不同水稻品种萌发期不同镉胁迫浓度处理的各性状指标与对照的相对值进行聚类分析,可将50个供试水稻品种(系)分为镉胁迫敏感型、中间型和耐受型等3种类型。 相似文献
13.
对2001-2018年通过河南省审定的水稻品种基本情况及其产量、米质等性状进行了介绍分析。结果表明,2001-2018年河南省通过审定品种132个,其中籼型水稻77个、占比58.33%,粳型水稻54个、占比40.91%,籼粳杂交稻1个、占比0.76%;育种单位涉及科研、教学及推广单位、种业企业等,种业企业选育或参与选育的品种比例正逐渐增加;审定品种年度间产量总体呈上升趋势,并以粳型杂交稻和籼型两系杂交稻产量最高;46.21%的水稻品种达到国标优质稻谷等级,粳型水稻优质达标率高于籼型水稻,垩白粒率和垩白度是限制河南稻米品质等级的主要因素,有待进一步提高。 相似文献
14.
Summary Toasted polished rice with less than 1% moisture content was used as desiccant for potato seed stored in closed jars. To reduce
the moisture content of about 20 g of true potato seed from 11.5% to 4–5%, 30 to 40 g of toasted rice is needed depending
on how fast drying is desired. For most crops, 5% seed moisture content is considered by the International Board for Plant
Genetic Resources as a safe level for storage. Toasted rice was also used with small lots of tomato, pepper, lettuce, turnip
and soya bean seeds to dry them to a safe level for storage. Toasted grains of wheat, maize and soya bean were also used successfully
as desiccants, but proved to have less drying capacity than rice. 相似文献
15.
Seed yield is of crucial importance for the marketing of lucerne varieties. Statistical records for farmers’ production of certified seed suggested a slightly higher seed‐yielding ability of Italian landraces over improved varieties (proportionately 0·052). The aims were to: (i) assess the variation among landraces, and compare the germplasm of landrace and improved varieties, for seed‐yielding ability; and (ii) investigate the relationships between seed yield, environment of origin and forage yield of the landraces. Thirteen farm landraces belonging to the seven commercial ecotypes of northern Italy and four improved varieties were evaluated for seed yield in the third cropping year and for herbage yield over twelve harvests. Landraces differed in seed yield and herbage yield (P < 0·05). Landrace material, compared with variety germplasm, showed a non‐significant trend towards higher seed yield (proportionately 0·047) and had similar herbage yield and plant density at the onset of the third cropping year. Seed yield of landraces was unrelated to forage yield and was associated with frequent mowing and earlier year of seed production on its farm of origin. 相似文献
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Unmanned
aerial vehicle (UAV) has offered a promising platform for rice direct seeding
that can substantially reduce labor input in the crop establishment process.
However, the insufficient payload capacity of UAV-based seeders is currently
limiting its intensive and large-scale use for rice direct seeding. This study
indicated a large variation in seed weight across varieties, ranging from 15.0
to 36.5 mg and 14.0 to 31.3 mg for inbred and hybrid varieties, respectively, with
average seed weights of 25.3 mg for inbred and 24.7 mg for hybrid varieties.
Seed weights of 160 out of 4 106 inbred varieties and 17 out of 311 hybrid
varieties ranged from 15.0 to 20.0 mg. Reducing seed weight from 25.0 to 15.0
mg increased the seeding area per UAV flight by 67% regardless of inbred and
hybrid varieties, although the absolute increase in seeding area for hybrid
variety was greater than that for inbred variety because of the difference in
seeding rate. The grain yield of inbred varieties was reduced when the seed
weight was less than 24 mg. Moreover, 87% of inbred varieties with a seed
weight ≤ 20 mg were distributed in South China where rice consumers prefer
small rice grains. Therefore, the use of low-seed-weight inbred varieties for
improving UAV seeding efficiency might be considered in South China. Unlike
inbred rice, 64% of hybrid varieties had higher grain weights compared with
their seed weights, and reducing seed weights did not necessarily cause yield
loss. Therefore, the small-seed-and-large-grain strategy in hybrid rice could
be used for improving UAV seeding efficiency without yield loss. This strategy
can be considered for improving UAV seeding efficiency in rice production regions
other than South China. 相似文献
19.
以2个早籼稻品种的超干种子、干种子、鲜种子、湿种子、露白种子为材料,研究了高温处理对不同状态水稻种子发芽率的影响。结果表明,水稻不同种子状态耐受高温能力存在极显著差异,从强到弱依次为超干种子干种子鲜种子湿种子露白种子;水温对种子发芽率的影响比气温更显著;处理温度超过一定范围,发芽率随着温度升高和时间延长极显著下降;不同品种高温处理后的种子发芽率表现相同规律趋势,但也存在极显著个体差异;种子水分制约种子耐受高温能力,种子水分含量越高,耐受高温能力越弱。 相似文献
20.
In seed priming, seeds are soaked in a solution of low water potential and dried back to their original weight. This study was conducted to evaluate the comparative performance of different seed priming treatments and to investigate whether re-drying is essential or not? Seeds of fine grain aromatic rice (Oryza sativa L.) cultivar Super-Basmati were subjected to hardening, osmohardening with CaCl2 and KCl (ψ s ?1.25 MPa) each for 24 h (one cycle), and hydropriming and ascorbate priming (10 mg L?1) for 48 h. Seeds were primed in two sets. In one set after each treatment, seeds were given three surface washings with distilled water and dried back near to original moisture contents with forced air. In the other case, after surface washings with distilled water, seeds were surface dried using blotting paper and sown immediately. All the priming treatments improved the emergence, seedling growth and reserve metabolism. Use of surface drying was more effective for rice seed invigoration, as evident from earlier and synchronized seedling emergence. Moreover, shoot and root length, seedling dry weight, root score, α-amylase activity, soluble sugars and dehydrogenase activity were also improved, although germination percentage and leaf score were similar from both strategies. Results suggested that surface drying, rather than re-drying close to original weight, was more effective, while among the treatments, osmohardening with CaCl2 was the most effective. Increasing rice production with judicious use of water is need of the day, and aerobic rice cultivation is an attractive alternative for this purpose. However, poor and erratic stand establishment is one of the major hindrances in its wide scale adoption. In this regard, seed priming techniques are pragmatic approaches to achieve proper stand establishment in the new rice culture. They help in improving seedling density per unit area under optimal and adverse soil conditions and may be opted to improve the performance of aerobic rice. 相似文献