OLIVEIRA, Francisco Assis de.
Résumé:
Using a randomized block experimental design with six treatments and four replicates, the effect of different irrigation levels on the phenology and productivity of herbaceous cotton (Gossypium hirsutum, L.), cultivar "IAC131" was studied. The treatments consisted of irrigating the crop when the soil lost 30%, 45%, 60% and 90% of the available moisture and irrigating due to wilting symptoms presented by the plants from 9 to 10 am, respectively, T1, T2, T3, T4, T5 and T6. The different soil moisture levels did not influence the crop cycle. The numbers of irrigations required by the crop were 22, 15, 11, 9, ° and c. The applied net water depths were 615, 617, 605, 598, 659 and 591 mm, the final plant heights were 81, 79, 79, 60, 65 and 60 cm and the productivities were 2,564, 2,824, 2,716, 2,821, 2,234 and 2,706 kg/ha, respectively, for the treatments T^, T^ T^, T^, T^ and T^. The Production results did not show significant difference by the F test at the 5% probability level, between the treatments.
