Crescimento vegetativo e reprodutivo do algodoeiro sob anoxia temporária.

Abstract

ABSTRACT: Herbaceous cotton (Gossypium hirsutum L. r. latifolium Hutch) it is very sensitive the temporary lack of oxygen in the soil, presenting modifications in your physiology when cultivated under soil anoxia. Cotton crop suffer intense modifications in your metabolism, happening reduction of production, depending on the phonological stage, duration of the stress, soil and cultivate characteristics. It is a sensitive plant to deficiency of oxygen in the soil, happening several alterations in the metabolism that affect the growth and development. The purpose of this work was to evaluate the phytomass production of annual cotton, genotype BRS Rubi, grown under protected ambient conditions and exposed to periodic flooding stress of the soil, in three phenological stages. The experiment was carried out in randomized complete blocks with five flooding levels (0 = control or not flooded, 2, 4, 6 and 8 days of waterlogging), three phonological stages (vegetative, flower-bud and flowering) with four replications. Studied variables, after harvest, bolls phytomass and shoot phytomass, as well as, root/shoot relationship did not suffer significant effect under periodic anoxia, however root phytomass decreased significantly with increment of waterlogging. There was not significant difference among the averages of the phenological phases, as well as, was not verified significant interaction among waterlogging and stages.