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1.
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
2.
Robert J. Harrison John G. Howieson Ron J. Yates Bradley J. Nutt 《Grass and Forage Science》2021,76(1):72-81
Knowledge of the hard seed content of annual legumes, and its pattern of breakdown, is critical to the understanding of their ecology and management within farming and natural ecosystems. For logistical reasons, seed that has been stored for varying lengths of time is often used for pasture establishment and agronomy experiments. However, the implications of storage on hard seed physiology are unknown. The aim of this study was to explore the impact of seed storage on its subsequent pattern of hard seed breakdown when exposed to field conditions. Experiments examined seed from six different annual legume cultivars that had been either produced the prior year or stored under ambient conditions for 11–22 years. Comparisons were then made between the two seed sources on hard seed breakdown patterns in situ. Although initial hard seed levels were mostly unaffected by storage (seed of five cultivars remained over 93% hard after more than 11 years of storage), the patterns of release from dormancy during exposure to hard seed breakdown conditions of stored seed differed greatly (p < .05) from freshly produced seed. Hard seed in the stored seed of most cultivars was reduced from >90% to <10% within 68 days over autumn, with shallow burial, whereas fresh seed remained >90% hard during the same period. Given this large and consistent impact, it is recommended that studies of the patterns of hard seed breakdown in legumes compare seed stored under consistent and well‐defined conditions. 相似文献
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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
4.
Stephen Morse 《Journal of Crop Improvement》2018,32(4):511-531
White yam (Dioscorea rotundata Poir.) is an important tuber crop grown throughout West Africa, the Caribbean, and Latin America. Propagation of the crop is primarily vegetative, through the use of small whole tubers (seed yams) and cut pieces of tuber (setts) planted to produce the larger tubers (ware yams) that households consume and sell. The Yam Minisett Technique (YMT) was introduced in Nigeria in the late 1970s as a means of increasing the production of seed yams. The YMT is different from many other agricultural technologies in that it requires farmers to do something – cut their tubers into small pieces – which they feel based on experience is potentially damaging as it causes rot. Indeed, the existing literature suggests that adoption of the YMT tends to be low and variable. However, to date there has been no systematic analysis of the existing literature on YMT adoption designed to explore which factors are reported to be the most important and why. Hence, the objective of this paper is to analyze the YMT adoption studies published to date to explore which factors are particularly important, and how this may help guide future research in YMT adoption. The results suggest that uncertainty – risk and ambiguity aversion – as perceived by farmers is a key consideration in YMT adoption and needs to be considered in future work. 相似文献
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To test the effects of the growth regulator trinexapac-ethyl (Moddus 250 EC) in the main seed crop of grasses in the Netherlands, 10 field trials were conducted in perennial ryegrass (Lolium perenne L.). These field trials were carried out in first and second seed harvest crops during 1999–2002. Four rates of Moddus (untreated, 0.4, 0.8 and 1.6 L product ha−1) were applied at the start of stem elongation (DC 30–31, zero to one node) during the first two years. In addition, the effect of timing of the application of 0.8 L Moddus ha−1 was studied (untreated, DC30–31, DC31–33, DC33–37). In most trials, in addition to the normal amount, 45 kg N ha−1 extra spring nitrogen was applied. The work reported is valuable, and has relevance to all areas of the globe where this perennial ryegrass is grown for seed, e.g., northern Europe, the US (particularly, Oregon), New Zealand, Australia, Chile and Argentina. 相似文献
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Predicting anthesis date of perennial ryegrass (Lolium perenne L.) with growing degree‐days at heading 
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下载免费PDF全文 The agronomic significance of heading date in crop species is well documented; however, the date of anthesis is often less emphasized even though it has important applications for seed quality and yield. Moreover, the relationship between heading and anthesis is not well defined. We propose that growing degree‐days to heading can be used as a good predictor of anthesis date. Using a broad range of 520 diploid perennial ryegrass accessions, anthesis was found to be highly correlated with growing degree‐days to heading, and growing degree‐days to heading could be used to predict anthesis date in historical data sets collected over many years. The ability to adequately predict anthesis will allow seed‐producing farmers to improve seed quality by identifying times when high disease pressure will coincide with anthesis, thus allowing control measures to be applied. 相似文献
7.
对红小豆、大豆以及菜豆3种豆类品种的种子形态特性进行了调查。3种豆类品种种子的粒重和粒长、粒宽以及粒厚之间有很高的正相关关系。把各种豆类的粒长、粒宽以及粒厚之间的关系用直线回归系数来表示,并使粒形的形态特征数值化。另外,大豆和菜豆种子的粒重和种子所占子叶比率之间成正相关关系,种子的粒重和种子所占胚芽比率之间成负相关关系,但红小豆没有相关关系。通过两年试验,从播种到出苗日数,3种豆类中红小豆最晚（15～20d）。在降雨量多的年份红小豆的出苗日数和种子的大小没有相关性,但是大豆和菜豆的粒重和出苗日数之间成负相关关系。播种时期土壤水分充足时,大豆和菜豆粒重轻的种子比粒重重的种子先出苗,但是红小豆没有看到这种关系。这可能与种子的吸水速度有关。 相似文献
8.
Edward C. Lulai 《American Journal of Potato Research》2000,77(5):303-310
The wound response within damaged potato tubers (Solanum tuberosum L.) must be a coordination of suberization with other resistance responses if infection is to be avoided. Previously, we showed that wound healing was affected by wound severity and consequently the type of tissue damaged within the tuber. Using arachidonic acid-induced accumulation of rishitin as a model for phytoalexin accumulation, we now demonstrate that this tuber resistance response is also influenced by wound severity and the type of tissue exposed to the elicitor. Kennebec and Reddale tubers that were superficially wounded by removing a thin tissue slice (0.75 mm thick) from the surface and then treated with the elicitor arachidonic acid produced significantly less rishitin than more severely wounded tubers (e.g., tubers cut in half) and excised tuber tissue disks (17 mm × 4 mm). Excised, elicitortreated tuber tissues accumulated significantly more rishitin in cortical cells than in perimedullary and pith cells. Rishitin accumulation was routinely measured 96 h after wounding and was found to be declining by 144 h regardless of wound severity. Induction of rishitin accumulation was very localized with more than 80 % of the rishitin found within 0.75 mm of the treated wound. These results indicate that excised tuber tissue disks, often used as models in wound research, are not fully representative of intact tubers. Perhaps more important, the results show that superficial wounds of intact tubers, i.e., similar to shallow nick and abrasion type wounds typically incurred during harvest, accumulate very little rishitin. However, rishitin accumulation in the tuber disk model system is much greater than that found in superficially wounded tubers, but is similar to the accumulation that could be elicited in cut (seed) tubers. The complications contributed by these wound-related and tissue-specific interactions must be factored into the model system(s) used in describing the role(s) of phytoalexins in the broad framework of disease resistance for stored potatoes and cut seed. 相似文献
9.
Farmers in Africa have limited resources to invest in Striga control practices and longer term, low-input approaches are needed. Long-term Striga control approaches focus on controlling the production of new Striga seeds and on reducing the number of seeds in the soil. Several seasons of hand weeding are required before the beneficial effect on the cereal crop can be observed. Rotations with trap crops can reduce Striga seed banks but selection of a rotation crop should be based on socio-economic factors such as market value in addition to whether or not it can stimulate Striga seeds to germinate. Striga seed banks can be readily reduced in suppressive soils. Organic matter and fertilizer additions may help induce suppressiveness. Extension of long-term Striga control approaches requires intensive interaction with farmers. 相似文献
10.
Mark E. Ukhun Grace M. Uwatse 《Plant foods for human nutrition (Dordrecht, Netherlands)》1988,38(4):309-318
Four Nigerian rubber seed products (whole and shelled rubber seed flours and oils) were subjected to various chemical analyses to provide a basis for their nutritional evaluation. The shelled rubber seed oil was stored for 4 weeks under different temperatures, light and dark conditions and at water activities of 0.33 and 0.95, to assess changes in some of its indices of nutritional quality. From the results of these studies, it would appear that the rubber seed product can meet, to varying degrees, the recommended daily requirements for various nutrients such as protein, fat and mineral elements. The shelled rubber seed oil also promises to be a valuable edible oil with a very low saturated/unsaturated fatty acid ratio and which is rich in the essential fatty acid, linoleic acid. Generally, dark storage, non-extreme temperature, and a water activity of 0.33 proved to be relatively effective in maintaining the nutritive aspects of the shelled rubber seed oil. 相似文献
11.
Dawit Tsegaye Sisay Frans J. H. M. Verhees Hans C. M. van Trijp 《Journal of Crop Improvement》2017,31(3):323-355
The role of seed producer cooperatives (SPCs) in the Ethiopian seed sector and their contribution to seed supply improvement have received attention from researchers, policymakers, and development partners. However, limited work has been done in reviewing and documenting their involvement in the seed sector development. In this paper, we review and discuss the SPCs in the Ethiopian seed sector. Specifically, we reflect on the contribution of SPCs to improving seed availability and access in the country. The current liberal market system of Ethiopia creates new opportunities for growth as successful enterprises, but also brings new challenges, such as more intense competition for smallholder producers. The government policy encourages SPCs to engage in seed business. We draw on scientific literature, reports, white papers, project documents, and websites. The review reveals that the seed sector in Ethiopia consists of three seed systems: formal, informal, and intermediary seed systems. Each seed system has a specific contribution to the delivery of seed to farmers, but they vary in their approach and respective strategies. The SPCs are categorized in the intermediary seed system because they have features of both formal and informal seed systems. They play a key role in meeting seed demand and contribute greatly to seed supply improvement through high-volume production of seed, crop, and variety diversification, and seed delivery to farmers. They produce and market the seed through various market channels, including direct sales to farmers, sales through contractual agreement, and sales directly to institutional buyers. Their contribution to improving the seed supply and seed security has received considerable recognition by policymakers and development practitioners. Therefore, government and development partners should support and strengthen SPCs to maximize their success in the seed business and their contribution to improving the seed supply in Ethiopia. 相似文献
12.
石榴籽粒硬度特征及其相关生理指标研究 总被引：1，自引：0，他引：1
籽粒硬度是石榴果实品质的重要指标之一,探究石榴籽粒硬度特征及其相关生理指标,旨在为进一步的籽粒硬度形成与调控研究奠定基础。本研究建立了一套用TA.AX质构仪测定石榴籽粒硬度的体系,并对不同品种果实内不同着生部位籽粒的硬度进行了测定,发现果实内籽粒硬度普遍存在着异质性。通过籽粒硬度与木质素、纤维素含量的相关性研究,发现籽粒硬度与其木质素、纤维素含量显著相关,因此认为籽粒木质素、纤维素含量可作为评价石榴籽粒硬度的生理指标。尽管木质素含量可反映石榴籽粒硬度,但不同硬度籽粒的木质素染色后肉眼无法分辨,因此木质素染色法尚不能作为判断石榴籽粒硬度的直观方法。研究结果中籽粒硬度的异质性及籽粒硬度与木质素、纤维素间的相关性结果为后期籽粒硬度相关研究中的取样及代谢机制研究奠定了良好的基础。 相似文献
13.
Low-input and organic farming systems have notable differences in nitrogen (N) sources, cycling and management strategies compared to conventional systems with high inputs of synthetic N fertilizer. In low-input and organic systems, there is greater reliance on complex rotations including annual and perennial crops, organic N sources, and internal N cycling that more closely mimic natural systems. These differences in farming system practices fundamentally affect N availability and N use efficiency (NUE) and could impact crop traits and breeding strategies required to optimize NUE. We assess genetic and environmental factors that could assist breeders in improving crop performance in low-input and organic farming systems by examining NUE in natural and agricultural ecosystems. Crop plants have often been bred for high N productivity, while plants adapted to low N ecosystems often have lower productivity and higher levels of internal N conservation. Breeders can potentially combine N productivity and N conservation through the use of elite and wild germplasm. Beneficial genetic traits include the ability to maintain photosynthesis and N uptake under N stress and the ability to extract soil N at low concentrations, perhaps through beneficial associations with soil microorganisms. In addition, breeding for specific adaptation to climactic and management practices so that crop uptake patterns match N availability patterns, while minimizing pathways of N loss, will be critical to improving NUE. 相似文献
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X. Q. He Y. R. Wang X. W. Hu C. C. Baskin J. M. Baskin Y. Y. Lv 《Grass and Forage Science》2016,71(4):641-648
Leymus chinensis (Trin.) Tzvel. is a perennial grass with high productivity and forage value; however, poor stand establishment, often due to seed dormancy, limits its widespread use for forage production. To investigate the mechanism of seed dormancy and to develop effective methods of improving germination, the contribution of each part of the caryopsis to dormancy was investigated, and a number of single or combined dormancy‐breaking pre‐treatments were conducted using three seed lots. The palea, lemma, pericarp/testa, and endosperm all contributed to seed dormancy. The contribution of each part to dormancy was 23·4%, lemma; 6·2%, palea; 28·4%, pericarp/testa; and 42·0%, endosperm. Hull (palea and lemma) removal, pericarp/testa piercing, and soaking in distilled water or 30% sodium hydroxide (NaOH) significantly decreased the percentage of dormant seeds (i.e. increased germination). Treating hull‐removed and pericarp/testa‐pierced seeds with gibberellic acid (GA3) also significantly decreased the percentage of dormant seeds. Compared with each of the single pre‐treatments, the combined pre‐treatment of pre‐soaking in water for 1 d, then 30% NaOH for 60 min and treating with 300 μm GA3 resulted in the highest germination (89%); and seed viability was 91%. 相似文献
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四川省马铃薯种薯体系现状、问题和对策 总被引：2，自引：1，他引：1
受立体气候条件影响,四川省不同地区一年四季均有马铃薯种植和收获。自2006年来全省马铃薯年种植面积已达到60万hm2以上,2009年达到了73.3万hm2。全省需要种薯量达到了近150万t,其中来自农民自留种的比例约为70%,外购种薯约占30%。虽然各级部门正想方设法改进种薯体系,但存在着优质种薯供应量不足、三代种薯体系尚未建立、质量控制体系尚未健全和种薯质量较差等问题,造成全省马铃薯产量长期徘徊在每公顷16.5~17.9 t之间。通过建立省级基础脱毒种苗供应中心、建立三代种薯体系、增加各级种薯生产能力、改进种薯贮藏条件、提高自留种薯质量和规范种薯繁供体系,将迅速提高全省种薯质量,促进马铃薯产业健康发展。 相似文献
19.
Establishment of seedlings of Bromus inermis , a native grass species of China, into a degraded steppe grassland was studied in an experiment with a factorial combination of different soil disturbance (control and harrowing), cutting post-sowing (control and cutting), nitrogen (N) fertilizer application (0 and 100 kg KNO3 hm−2 ) and seed rate (400, 800 and 1200 seeds m−2 ) treatments. Seedling emergence and survival rates, and plant performance, were followed over 2 years. Seedling emergence was increased by soil disturbance (harrowing). Cutting post-sowing and N fertilizer application did not increase seedling emergence. Seedling survival rates at the end of first growing season were strongly influenced by harrowing and the use of higher seed rates. Seedling height was higher in the harrowing and the N fertilizer application treatments and at the higher seed rates. Seedling survival rates in the second growing season were low but much higher with harrowing than the other treatments. Soil disturbance by harrowing may have increased contact between seed and soil, and reduced competition from established plants. It is concluded that, for the restoration of degraded semi-arid grassland in China by re-seeding, soil surface disturbance is necessary for successful seedling establishment, and modest seeding rates should be used to control costs. 相似文献
20.
大豆种子泥膜蔓生性和种皮色的遗传及其与蛋白质含量的关系 总被引：2，自引：1，他引：1
本文应用6个种间杂交组合研究了种子泥膜、种皮色和蔓生性的遗传以及它们各自与籽粒蛋白质含量的相关。结果表明:种子泥膜的遗传存在基因互补作用,蔓生性是数量性状;种皮色遗传较复杂。种子泥膜和种皮色基本上与籽粒蛋白质含量无关;蔓生性与蛋白质含量有一定相关。 相似文献