Efeito do encharcamento do solo no crescimento, desenvolvimento e produção do algodoeiro herbáceo.

Abstract

The objective of the work was t o study the effects of the soil waterlogging on the g owth, development and yields upland cotton (Gossypium hirsutum L.r. letifolium Hutch . ). For this , an experiment was conducted from 04.02 to 08.13.87 i n a greenhouse located at the CNPA/EMBRAPA,in Campina Grande-PB. The cotton was planted on a sandysoil - manure mixture (10 : 1) placedin steel boxes 50 X 50 X 25 cm, two plants for box were grown. The experiment was a 2 x 4 factorial on a randonized block statistical desing with two verieties (CNPA-3Hand CNPA-Precoce1), four leveis of the soil moisture factor and 4 replicates. The four leve is were: EQ, the plants were maintained during the whole growing period with a soil water contentat field capacity; E1, the plants were waterlogged during the square formation for a period of five days; E 2, the plants were waterlogged during the flowering beginning for a period of five days; E 3, the plants were waterlogged five days during the square and 5 days during the flowering. It was observed that the plants submitted to the E1 treatments produced a leaf area and a aereal bio-mass 30 and 36%, respectively less than the check plants ; the seed cotton and lint production were reduced i n 38 and 4 1 %, respectively less than the check. The precocity of the CNPA-3H also was reduced (38%) when compareci with the check. The plants submitted to the E 2 treatment produced plant heights, aereal bio-mass, root bio-mass and total bio-mass 22, 28, 74 and 38%, respectively, higher than the check. The plants submitted to the E 3 treatment produced seedcotton and lint yields , 29 and 34% respectively, less than the checks, and 8% longer Eiber compriment and the precocity for the CNPA - Precoce 1 was reduced in a 23%. It was concluded that the studied cultivars were sen sitive to the conditions to which the cotton was expessed, mainly to waterlogging during the square period.