130 resultados para Water Availability


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Physiological responses like the thermal requirements for germination may be influenced during seed formation by environmental conditions such as water availability and temperature. Here we analyzed germination of embryos of Ingavera subsp. affinis from different sources in response to various temperature regimes, including calculation of degree days and accumulated rainfall during development and maturation. Embryos were taken from ripe fruits collected on trees located in São Paulo and Minas Gerais, and were analyzed as to germination, water content and dry matter content. The results showed that the origin of the embryos was related to variation in response under sub-optimal temperatures. Depending on the origin, I.vera subsp. affinis embryos were able to germinate even at low temperatures (10 to 15 ºC), with better performance attained from 20 to 25 ºC. This variation may be associated, among other factors, to environmental conditions during maturation and to the maturation stage at seed dispersal.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Physiological potential characterization of seed lots is usually performed by germination and vigor tests; however, the choice of a single test does not reflect such potential, once each test assesses seeds of differentiated mode. Multivariate techniques allow understanding structural dependence contained in each variable, as well as characterize groups of seed lots according to specific standards. The study aimed at evaluating variability among soybean seed lots and discriminate these lots by multivariate exploratory techniques as function of seed vigor. Experiment was performed with 20 soybean seed lots (10 lots cv. BRS Valiosa RR and 10 lots cv. M-SOY 7908 RR). Seed physiological potential was assessed by testing for: germination (standard, and under different water availability); vigor (accelerated aging and electrical conductivity); and field seedling emergence. Cluster analysis of seed lots, as well as Principal Component Analysis was performed using data obtained on all tests. Multivariate techniques allowed stratifying seed lots into two distinct groups. Principal Component Analysis showed that values obtained for variables: field seedling emergence, accelerated aging, and germination under different water availability were linked to BRS Valiosa RR; while to variables germination and electrical conductivity, were linked to M-SOY 7908 RR.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Conduziu-se este trabalho, com o objetivo de estudar as respostas fisiológicas de cinco genótipos de eucalipto à disponibilidade hídrica e adubação potássica. As mudas foram plantadas em vasos preenchidos com sete litros de um Neossolo Quartzarênico, com baixo teor natural de potássio (0,2 mmol c.dm-3 K), e submetidas a dois regimes de irrigação (RI1 - diário e RI2 - irrigação suspensa até o aparecimento de sintomas iniciais de murcha), sem (K0) e com suprimento de potássio (K1 - 200 mg.dm-3 K2O), em casa de vegetação. Avaliou-se a taxa fotossintética (A), condutância estomática (gs), transpiração (E), índice de conteúdo de clorofila (ICC), conteúdo relativo de água (CRA), eficiência fotoquímica (Fv/Fm), eficiência intrínseca (EUAintr) e instantânea no uso da água (EUAinst) e potencial hídrico foliar (Ψf). O experimento foi estabelecido no delineamento de blocos ao acaso, em esquema fatorial 5 x 2 x 2 (5 genótipos, 2 regimes de irrigação e 2 níveis de adubação potássica), com cinco repetições. À exceção da eficiência fotoquímica, as demais características apresentaram alterações significativas no regime RI2, com redução nos valores de A, gs e E e aumento em ICC e EUAinst. O suprimento de potássio nas plantas do RI2 proporcionou maiores valores de A, gs, E e CRA. Dos genótipos avaliados, o G1 é o mais resistente e o G2 o mais sensível à deficiência hídrica. Conclui-se que a adubação potássica pode amenizar os efeitos negativos da deficiência hídrica nos estádios iniciais de crescimento de eucalipto.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Ciências Biológicas (Botânica) - IBB

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Agricultura) - FCA

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia - FEIS

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

When handling soil conservation practices isn’t applied correctly, they cause problems at the level of structure, cohesion and fertility in soils and lack of water availability. In the case of this monograph, conducted in a rural property located at Álvares Machado City, identified that most areas are intended for use activities of beef cattle and dairy and subsistence agriculture, which historically addition to withdraw native flora, resulting in problems such as compaction and increase soil exposure to climatic agents, generating a serious frame of erosion problems. In the case of water from rainfall, the soil exposed, causes the “splash” effect and therefore when it becomes runoff carries the spalled particles mainly for low land areas. Without the vegetation, especially trees or shrubs species, the velocity of runoff increases, initiating the appearance of furrows, which consequently may become a kind of ravine erosion and gully, which makes invalid any area in your surroundings... (Complete abstract click electronic access below)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Biociências - FCLAS

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Ciência do Solo) - FCAV