Made available in DSpace on 2014-06-11T19:30:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-17Bitstream added on 2014-06-13T20:40:16Z : No. of bitstreams: 1 ribeiro_rn_me_botfca.pdf: 314680 bytes, checksum: 0739977bf488f39e0145d473cbeaf72f (MD5) / O presente estudo teve por objetivo comparar os sistema hidropônico e o de fertirrigação no desenvolvimento de mudas da espécie florestal nativa jequitibábranco (Cariniana estrellensis). O experimento foi conduzido no Viveiro da Fazenda Experimental Cantareira, pertencente à Faculdade Integral Cantareira (FIC), no município de Mairiporã – SP - setor de Pesquisa Florestal. Foi estudado o desenvolvimento da Cariniana estrellensis sob dois sistemas de produção: fertirrigação e hidropônico. Os sistemas tiveram quatro parcelas com 25 plantas cada, totalizando 100 plantas por sistema. Para avaliação morfológica não destrutiva realizada a cada 14 dias, considerou-se a altura da planta e o diâmetro do colo das 100 plantas de cada sistema, totalizando 200 plantas e, ao término do experimento, para avaliação morfológica destrutiva, foram consideradas como plantas úteis as 9 centrais, totalizando 36 plantas úteis de cada sistema. A qualidade das mudas produzidas no sistema hidropônico foi superior àquelas do sistema de fertirrigação para os seguintes parâmetros e relações: diâmetro do coleto (D), altura da parte aérea (H), massa seca da parte aérea (MSPA), massa seca total (MST), área foliar (AF), relação altura e diâmetro (H/D), altura e massa seca da parte aérea (H/MSPA), massa seca da parte aérea e do sistema radicular (MSPA/MSR), e o Índice de Qualidade Dickman (IQD). Em função dos resultados obtidos, pode-se inferir que para Cariniana estrellensis o sistema hidropônico proporcionou melhor desenvolvimento, reduzindo o período de produção das mudas / This study aimed to compare hydroponics and fertigation systems on seedlings production of native species (jequitibá-branco, Cariniana estrellensis). The experiment was conducted at Cantareira Experimental Farm Nursery, owned by Integral Cantareira College (FIC) at the Forestry Research Sector of Mairiporã, SP. We studied the development of jequitibá branco under two production systems: drip irrigation and hydroponics. The systems presented four plots with 25 plants each, totaling 100 plants per system. It was considered for the non-destructive morphological evaluation the plant height and stem diameter of 100 plants per system, totaling 200 plants. This procedure was conducted every 14 days. At the end of the experiment, the morphological destructive assessment was performed on the central 9 plants, with a total of 36 useful plants per system. The quality of seedlings produced in the hydroponic system was superior to the fertigation system for the following parameters and relations: the collar diameter (D), shoot height (H), shoot dry mass (MSPA), total dry mass (MST), leaf area (LA), height and diameter ratio (H/D), dry mass of shoot and root system (MSPA/MSR), and Dickman Quality Index (IQD). Based on the results, we can infer that the hydroponic system enhanced Cariniana estrellensis, growth reducing the period of seedlings production

Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2017 / Refer to document / National Research Foundation of South Africa, and Agricultural Research Council-Universities Collaboration Centreꞌ for scholarship and research

Call number: LD2668 .T4 1984 E45 / Master of Science

Call number: LD2668 .T4 1986 A42 / Master of Science

Germination of seeds of desert annual plants is reduced where there are high densities of annual seedlings. This is interpreted as a response by seeds to avoid a severe biotic environment in which growth rate and fecundity are likely to be reduced by larger established competitors. This density-dependent germination response is due primarily to reduced germination of small-seeded annuals where densities of large-seeded annuals are high. Because of this germination response, and because of competition at the plant stage, large-seeded annuals could, in the absence of significant levels of predation by seed-eating rodents, dominate the annual plant community to a much greater extent than is commonly observed. By reducing densities of large-seeded annuals, rodents allow densities of small-seeded annuals to increase and thus exert a positive indirect effect on granivorous ants. Seed-eating rodents and a parasitic fungus both prey on Erodium cicutarium, a dominant annual plant. These two unrelated predators significantly influence each other's densities by their use of a common prey species. Dispersal of desert annual seeds that successfully germinate is apparently not as widespread as is suggested by observations that some desert annual seeds are redistributed throughout the year by wind and water. Removal of plants during seed set significantly reduced densities of seedlings on sample plots the next year.

No description available.

Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018. / This study evaluated the effects of 5 different soaking treatments in conjunction with 5 varying irrigation intervals on the germination, growth and nutritional values of seed of Hordeum vulgare Sv13. The 5 different soaking times consisted of 1, 3, 8, 16 and 24 hours. The barley seed was first cleaned and then placed in a vessel containing 500 ml of distilled water with a 20 % solution of sodium hypochlorite (bleach) at room temperature. Thereafter the pre-soaked seeds were transferred to a perforated container, containing no medium and placed into a growing chamber equipped with drip irrigation. The seed was then irrigated with 1245 ml of water at 5 different intervals namely every 2, 4, 8 10 and 12 hours. The temperature of the hydroponic growing room was kept at a constant 23 °C using a hotoperiod of 16-hour day/ 8-hour darkness. The seed was allowed to germinate and grow for a period of 8 days before being harvested. The objectives of this study were to determine the most beneficial combination of soaking treatment in conjunction with the most beneficial irrigation interval on the germination rate of the seed allowing for radicle emergence and coleoptile production. It was also used to determine which combination of treatments was most beneficial to the growth and nutritional values of the seed post-harvest. Another objective was to ascertain the shortest soaking time for application in a small-scale, hydroponic growing unit as well as the frequency of irrigation required to grow seedlings, thereby determining the amount of water required to produce a seedling mat for a small-scale, subsistence farmer, with the emphasis being on water reduction. Each treatment was replicated 10 times and consisted of 500 grams of seed, which when placed into its container measured 2 centimetres in depth, totalling 25 treatments in all. Germination was measured by observing radicle emergence in the first 2 days of the growing period first after a 24-hour cycle and again after 48 hours. The numbers of leaves present at harvest after an 8-day growing period were also counted to determine germination rate of the seeds. Growth was determined by average leaf height as well as the tallest leaf on day 8 of the growing cycle. Root mat expansion was also measured, post-harvest, which was compared to the initial 2 cm planting depth of seed. Wet and dry weights of the plant material were measured post-harvest. Samples of the harvested material were also sent for nitrogen and protein analysis. It was discovered that most of the results favoured a shorter soaking time and an increase in irrigation frequency, bar a few exceptions. Most favoured a pre-soaking time of only 1 hour together with an irrigation frequency of between 2 and 4 hours. This shows that small-scale farmers would be able to reduce the time spent on soaking of their seed. Although the frequency of the irrigation interval remained high further testing would be required to determine if the amount of water applied at each irrigation interval could be reduced and still produce favourable results. It would also remain to be seen if no irrigation during the 8-hour dark photoperiod would have any negative impact on germination, growth and nutritional values of the seedlings.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Morpho logical, anatomical, and histochemical effects of S-ethyl dipropylthiocarbamate (EPTC) on Avena sativa var . overland were studied after treatment of seeds at various EPTC concentrations. The oat seed germination percentage was not affected by EPTC treatment. EPTC delayed initial root and coleoptile development at all concentrations used . Two or three days after treatment, however, the roots of seedlings treated with EPTC concentrations lower than 3 ppm grew at the same rate as the untreated seedlings and showed no abnormalities. Primary and adventitious root growth of seedlings treated with 3 ppm and higher was inhibited. Most of the adventitious roots remained in the radicle stage and failed to elongate. Bases of the roots became necrotic and were quite brittle . Formative effects were greater in the shoot than in the root. As result of treatment, coleoptiles became chlorotic, thickened, and were hard and brittle . The first true leaf of treated seedlings tended to adhere to the coleoptile and was broken as the coleoptile elongated . The complete shoot meristem of 12 ppm EPTC treated seedlings broke at the base . Young leaves formed within coleoptiles of treated seedlings oftain failed to emerge. His tochemica l studies s howed more carbohydrates in the coleoptiles of the EPTC treated oat seedlings than in those of the untreated seedlings . The lip1d-containing materials in the coleoptiles of the germinating oat seedlings disappeared from the coleoptiles of fully grm;n untreated oat seedlings , while they still persisted in the coleoptiles of 5-day-old EPTC treated oat seedlings. This suggests that EPTC might inhibit the breakdown and utili zation of stored foods .

Includes bibliographical references