Drought sress and the distribution of vegetative and reproductive traits of a bean cultivar

Abstract

Soil water deficits may affect the location and pattern of flower and pod production on different stem axes of a bean plant. The objective of this study was to understand the effect of drought stress on the distribution of flowers and pods on the main stem and on branches of bean plants. The experiment was conducted in a shelter field facility. Water stress was imposed from the end of the vegetative stage to physiological maturity and soil water was measured with a neutron probe every two weeks. Formation of flowers at each node of the main stem was monitored at 44 days after planting (DAP) and formation of pods at 55DAP and 65 DAP. Dry weight of stems and leaves as well leaf area were measured during the middle of the pod filling stage (55DAP). The total number of flowers reached maxima of 32 and 44 flowers per plant for the drought and irrigated treatments, respectively. Number of flowers on branches decreased 50% in the stress treatment when compared to the control. Pod setting was also reduced on the branches of the lower nodes of the main stems. Under drought, the leaf area diminished by 60.1% and 10.4% on branches and main stem, respectively. The field drought conditions of this experiment had a greater effect on the vegetative and reproductive growth of branches as compared to the main stem affecting the final yield. Key words: dry beans, soil water, flowers, pod setting, branches STRESS HÍDRICO E A DISTRIBUIÇÃO DE CARACTERÍSTICAS VEGETATIVAS E REPRODUTIVAS DE UM CULTIVAR DE FEIJÃORESUMO: Défices de água no solo podem afetar a localização e o padrão de produção de flores e vagens em diferentes ramos de uma planta de feijão. O objetivo deste trabalho foi o de compreender o efeito do stress hídrico na distribuição de flores e de vagens no tronco principal e nos ramos de plantas de feijão. O experimento foi conduzido em ambiente controlado. O Stress hídrico foi imposto a partir do fim do estágio vegetativo até a maturidade fisiológica e a umidade do solo foi medida por meio de sondas de nêutrons à cada duas semanas. A formação de flores em cada nó do ramo principal foi monitorada aos 44 dias após semeadura (DAP), na formação de vagens aos 55 DAP e a 65 DAP. Mediu-se o peso seco de ramos e folhas, bem como área foliar, no estádio de enchimento de grãos (55 DAP). O número total de flores alcançou os máximos de 32 e 44 flores por planta para os tratamentos com stress e irrigado, respectivamente. O número de flores em ramos decresceu de 50% no tratamento de stress, em relação ao controle. O pegamento de vagens foi também reduzido nos ramos dos nós mais baixos do tronco central. Sob falta d'água a área foliar diminuiu de 60.1% a 10.4% em ramos e tronco principal, respectivamente. As condições de stress hídrico neste experimento tiveram um efeito maior nos crescimento vegetativo e reprodutivo dos ramos, em comparação com o tronco principal, afetando a produção final. Palavras-chave: feijão, água no solo, flores, pegamento de vagens, ramos

Differential Effects of Post-Flowering Drought Stress on Growth and Yield of the Basic Generations of Two Common Bean (<i>Phaseolus Vulgaris L</i>.) Populations

“…The most adverse effect of the stress among the yield components was on the number of pods per plant. This is in agreement with the findings of Nunez- Barrios et al, (2005) that a yield reduction due to drought stress by about 60% in dry bean was attributed to losses of 63.3% in pods per plant, 28.9% in seeds per pod, and 22.3% in seed weight. The highest geometric mean for seed yield was recorded for F1 (3721.8) and P2 (4077.1) in Roba-1 X SER-16 and Melka-Dima X SAB-623, respectively.…”

“…In dry bean, excessive abortion of flowers, young pods, and seeds occurs because of drought stress 12 days before an thesis) and reproductive periods. Moderate to severe drought stress reduced biomass and seed yield (from 20 to 90%), harvest index, number of pods and seeds, seed weight, and days to maturity (Nunez-Barrios et al, 2005). Whether yield under stress is compatible or not with maximum yield potential is an open question for different crops (Blum, 2005).…”

Morphological Changes and Antioxidant Activity of &lt;i&gt;Stevia rebaudiana&lt;/i&gt; under Water Stress

“…Severe stressed plants had minimum leaf area and the control plants had maximum leaf area. Our result is similar to the findings of Barrios et al [16] and Ghanbari et al [17].…”

Análise da capacidade combinatória em feijoeiro comum submetido ao déficit hídrico

“…These combinations are promising as to drought tolerance, since positive effects for NPP, in dry conditions, tend to minimize the reduction in GY. The NPP is a production component severely affected by drought (Nuñes Barrios et al, 2005;Sousa & Lima, 2010).…”