Efeito do stress hídrico no crescimento de três variedades de feijão nhemba - Vigna unguiculata (L.) Walp

Abstract

The present study examined the phenological and physiological responses of three varieties of cowpea (IT82E-18, Tete2 and Timbawene) when subjected to water stress. The experiment used 108 seeds, 36 per variety, which were subjected to two treatments: control, where the pots were watered every other day (80% of field capacity) and water stress (20% of field capacity) when the volumetric water content reached 5%. The three varieties of cowpea started showing signs of the effects of water stress from the seventh week and were represented by long roots, small, curled leaves and fewer in number compared to the control. By the tenth week, there was leaf necrosis and death of plants of Tete2 and Timbawene varieties in the water stress treatment. The growth parameters linked to water stress in IT82E-18, Tete2 and Timbawene varieties were: increased root length, root dry weight ratio, root dry weight to aboveground ratio and total water content in the plant. The highest water stress tolerance index and water content in the plant was found in variety IT82E-18 throughout the experiment and this variety showed higher RCT and AAR values compared to Tete2 and Timbawene varieties. IT82E-18 was more tolerant to the effect of water stress than Tete2 and Timbawene varieties.(TRADUÇAO NOSSA)