Comportamiento de dos genotipos de algodón (Gossypium hirsutum L.) ante el déficit hídrico durante la fase de floración

Abstract

Cotton (Gossypium hirsutum L.) is the most important non-food agricultural crop in the world, being the main natural fiber planted. However, both the development and the productivity of this crop are severely affected by the restriction in the water supply. The objective of this study was to evaluate the behavior of two cotton genotypes (Cocker 310 and DP Alcala 90) in the face of water deficit during the flowering phase. This research was carried out in a shade house, where the two genotypes grew with an irrigation sheet of 16 L/m2 per day, until 30 days after sowing; from that moment part of the plants of each genotype were subjected to water deficit by suspending irrigation during the entire flowering phase, leaving in parallel a control treatment that continued to be irrigated with the already indicated sheet. Thirty days after the start of the water deficit period, the following variables were determined: stem diameter, plant height, number of leaves, number of flower buds, number of flowers, root depth, root volume, dry weight of root, stem, leaves and flowers, root/shoot ratio, leaf area, chlorophyll index and relative water content. The results obtained showed that all the variables determined were reduced under the condition of water deficit, in relation to the control treatment, this behavior being more accentuated in the Cocker 310 variety, except for the root depth, the root/shoot ratio and the relative content of chlorophyll in the leaf, since the value of these three variables increased with water stress in both genotypes. The results obtained suggest that the flowering phase is quite sensitive to water deficit, with the DP Alcala 90 variety being the one that was less affected by the water deficit condition.