Estudo de parâmetros morfo-fisiológicos na cultura do algodoeiro herbáceo (Gossypium hirsutum L.) em condições diferenciadas de irrigação no vale do Assu-RN.

Abstract

The main objective of the present work was to analyze some morphophysiological parameters of herbaceous cotton (Gossyplum hirsutum r. latifolium Hutch cultivar NCPA 6H) in an experiment conducted in the municipality of Ipanguassu-RN from August to December 1992. Two experimental plots were used. measuring 40m x 30m, in each of which a treatment of irrigation. In the non-stressed treatment the culture did not suffer water restrictions during its whole cycle, whereas in the Stressed treatment The culture underwent stress from the thirtieth day after germination. The non-stressed portion received a total blade of 671.7mm and the portion considered as stressed received a 437.1mm blade. The results showed that the cultivar CNPA 6H, cultivated under non-stressed regime, presented a tendency of superiority in plant height, green and dry epigea phytomassas, and leaf area, in relation to the treatment that underwent stress. The absolute growth and net assimilation rates of the non-stressed treatment were higher than the stressed treatment, while the relative growth rate had a slightly higher tendency than that of stressed treatment. The stomatal conductance, transpiration and temperature of the leaves presented virtually different patterns between treatments. CNPA 6H cultivar in the treatment not stressed showed a yield of 3,960 kg / ha and 2,690 Kg / ha in stressed treatment. Laboratory tests of fiber showed very little difference between the variables studied, by treatment. In general, most morphophysiological parameters analyzed in the non-stressed treatment presented a tendency of superiority to those of stressed treatment.