6,026 research outputs found
Determinants for Use of Certified Maize Seed and the Relative Importance of Transaction Costs
No full textThe rising world prices for major tradable staples such as maize have been a concern for sub- Saharan countries such as Kenya which are maize deficit countries. Maize is a major staple food for over 80 percent of Kenya’s population. Kenya relies on maize for up to 40 percent of its dietary energy supply and is accordingly searching for ways to increase maize productivity. Maize productivity has been rising in the last decade manly as a result of the use of improved germplasm and fertilizer. However, the proportion of farmers using these technologies is low and the aggregate productivity in maize is low compared to other countries and its potential. Previous studies on input adoption have often assumed the existence of perfect supply and product markets, tending to ignore the important but significant role played by institutions as well as the role of transaction costs associated with market exchange. This study makes use of qualitative information from institutions and actors in seed input value chains as well as quantitative information collected from a sample of 150 farmers, in the Moist Transitional Maize Zones of Kenya. A two stage regression model was applied to analyze determinants of adoption and factors affecting degree of adoption of certified improved maize seed. The results show that as farmers adopt certified seeds, they incur higher transaction costs than non adopters, rural infrastructure, social capital such as membership in groups and trust play an important role in the decision of whether or not to use certified seed.Crop Production/Industries,
Inscription By Author of Like a Mustard Seed: The Slavia Settlement
No full textAn inscription from author, Paul Wehr, to Judy and Walter Duda, to celebrate the completion of his work on Like a Mustard Seed: the Slavia Settlement. c.https://stars.library.ucf.edu/cfm-images/1410/thumbnail.jp
Planting a Seed of Respect
No full textKostanecki, Adam. (2017). Planting a Seed of Respect. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/189071
Developments in Marine Energy, Mutriku Wave Energy Plant
No full textSeed Matthew, Young Adam. Developments in Marine Energy, Mutriku Wave Energy Plant. In: 33èmes Journées de l’Hydraulique Grands Aménagements Hydrauliques Enjeux Sociétaux, Bénéfices Economiques et Innovations Techniques 14 - 16 novembre 2012. 2012
Heteromorphism in seeds of Leptocereus scopulophilus (Cactaceae) from Pan de Matanzas, Cuba
No full textSeed heteromorphism is the formation of different seed morphs from the same individual. Two seed morphs have been preliminarily observed in Leptocereus scopulophilus. One morph shows an apparent natural scarification of its coat. Herein we describe the seeds, taking into account shape, coat integrity, surface, dimensions, mass and the position of germination cracks. We defined two seed morphs using the integrity of the spermoderma: fragmented seed coats (FSC) and complete seed coats (CSC). We also evaluated minimum germination time, germination rate and germinability. The seed morphs did not differ significantly in traits; however, regular striations along the cuticle of the periclinal walls were more visible in the FSC compared with the CSC. Both seed morphs displayed anticlinal cell boundaries in the border region that are channelled and straight in the dorsal-ventral region but difficult to define in the lateral region. We found four morphological variations in different positions where the radicle or cotyledons emerge and variations in cuticle thickness in different regions of the seed that could determine the formation of cracks during germination. All germination variants occurred in both seed morphs, albeit in different proportions. Germination was higher and faster for the FSC compared with the CSC. These germination differences could be related to a thinner cuticle in the FSC and the punctual release of its spermoderma, which facilitates a quick imbibition of the embryo and the breaking of the seed coat. Our results indicate that differences in germination parameters between the two seed morphs relate to differences in the percentage of dormant seeds, which favour the temporal expansion of germination and reduce competition between siblings. To propagate the species for conservation purposes, we recommend using FSC, while CSC may be used to establish a seed collection ex situ.Peer reviewedFinal article publishedwall sculpturecell boundariesgermination variantsseed coatseed morpholog
Author, Dr. Paul Wehr. c. 1980
No full textDr. Paul Wehr, as he appeared c. 1980. Dr. Wehr was a professor of history at UCF and the author of Like a Mustard Seed: the Slavia Settlement (1982 - Mickler Publishing House), a history of the early years of Slavia and St. Luke\u27s history.https://stars.library.ucf.edu/cfm-images/1413/thumbnail.jp
Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.)
No full textA series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits inmaize (Zeamays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method
Parasitoid wasps indirectly suppress seed production by stimulating consumption rates of their seed-feeding hosts
No full text1. In parasitoid-herbivore-plant food chains, parasitoids may be simultaneously linked with both herbivore hosts and plants, as occurs when herbivores attacked by parasitoids continue to consume plants although they are destined to die. This peculiar property may cause parasitoids to confer a differential trophic cascading effect on plants than that known for typical predators. 2. We hypothesized that larval koinobiont parasitoids would confer an immediate negative effect on plant seed production by stimulating consumption of their seed-predator hosts. We tested this hypothesis in an alpine parasitic food chain of plant seeds, pre-dispersal seed predators (tephritid fly larvae) and koinobiont parasitoids using field observations, a field experiment and a microcosm study. 3. We first compared observed seed production in (i) non-infected capitula, (ii) capitula infected only by seed predators (tephritid flies) and (iii) capitula infected by both seed predators and their parasitoids in five Asteraceae species. Consistent with our hypothesis, seed loss in the capitula with both seed predators and parasitoids was significantly greater than in the capitula infested only by seed predators. 4. This effect was replicated in a controlled field experiment focusing on the most common parasitoid-seed predator-plant interaction chain in our system, in which confounding factors (e. g. density and phenology) were excluded. Here, we show that parasitoids indirectly decreased plant seed production by changing the behaviour of seed predators. 5. In a microcosm study, we show that larval parasitoids significantly extended the growth period and increased the terminal size of their host tephritid maggots. Thus, parasitoids suppressed plant seed production by stimulating the growth and consumption of the fly maggots. 6. In contrast to the typical predator-induced trophic cascade, we highlight the significance of parasitoids indirectly decreasing plant fitness by stimulating consumption by seed predators. Future studies on trophic interactions should consider the net effect of both increased consumption by seed predators and their death after development of parasitoids
Paper (essay) on seed
No full textBased on detailed studies of the past of the agrarian thought of the world (evolution of agro-innovation), and within it, the relationship of man and seed, the author has selected key data for Table 1. In addition, more or less known folk sayings, proverbs, curses and allegories in which the seed is the key word have been collected. Then, religious books, folk art and literature works (sayings) of prominent individuals and experts and observations of the author himself have been studied. According to the collected opus, it can be concluded that the vast importance of seed meaningfully entwined into all spheres of folk life and cultural heritage. Seed is directly tied to the following eight key (r)evolutionary milestones in the food and economic life of mankind: 1. the first and for the longest time, the seed used to be the main food of the people and the first food reserve; 2. Neolithic Revolution was simply caused by the sowing of seeds; 3. for the sake of sowing man began to develop more complex processing techniques; 4. everywhere and forever, especially since the late 15th century, the seed has been a carrier of (rescuing) plants between Europe and the New World, that is, between continents; 5. seed was the first product that has been chemically treated since the mid-18th century; 6. standard operation procedures and quality are promoted on seed by which it became the first product to have prescribed (compulsory) methods, but it also became a good whose quality has to be tested before sale; 7. hybrid seed is a 'perpetrator' of the green revolution in the mid-20th century and at last there is disputable seed of genetically modified organisms that are spreading with certain reactions. The author proposes that the United Nations Standard International Trade Classification includes a special section (division) which would classify the seed for sowing, while beyond this Classification terms such as seed, plant seed should be replaced with non-seed expressions such as grain, kernel
Seed production of cucumber and its specifications
No full textSeed production of cucumber differs from mercantile production and has a number of specific characteristics. The conditions of successful production are the selection of plots, the proper selection of pre-crop and adequate and timely irrigation. When fertilizing, there have to be taken into account the feeding of nutrients, the state of fertility of the soil and the planned yield of the fruit (although only seed is extracted). The factors of key importance include: sow density, cropping, hoeing between rows of crops, the protection of crop from weeds, causes of diseases and pests and the moment of harvesting the fruit. Other important factors are the determination of ripening, the duration of fermentation, washing and drying of seed. As with any seed production, there are to be observed legal regulations regarding spatial isolation, varietal purity and adult-ration with other plant species and weeds. Only the production and trade of seed of cucumber varieties included in the list of agricultural and forestry varieties is permitted. The minimum seed quality prescribed by the law: the minimum purity of 98%, the minimum germination of 80%, no presence of weeds and other plant species, while the maximum moisture in the seed is 14%
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