Growth aspects and production of cotton under salt stress as a function of organic fertilizer

The cotton plant is a species cultivated in many parts of the world, with enormous economic importance. The objective of this study was to evaluate the effect of salinity levels in earthworm humus quantities function on the growth and production of cotton. The experiment was conducted in a greenhouse at the Campus IV in the State University of Paraiba, municipality of Catolé do Rocha-PB, Brazil.  A completely randomized design with four replications, in a factorial 4 x 4 was used. The first factor consisted of salinity levels in irrigation water (0.8, 3, 4.5 and 6 dS m-1) and the second factor of earthworm humus amounted to: 0, 1, 2 and 3 kg/plant. At the end of the experiment, the growth characteristics: plant height, stem diameter, leaf number, unit leaf area and leaf area of the plant were evaluated. The production: number of flower buds, number of bolls per plant, seed weight per boll, number of seeds per boll, 100 seed weight, total production, fiber production and seed production were also estimated. The interaction between salinity levels and quantities of earthworm humus did not affect the growth and production of cotton. The increase in salinity levels adversely affected the cotton crop. Largest earthworm humus quantities gave an increase in cotton production.   Key words: Gossipium hirsutum r. latifolium H., Electrical conductivity of water, humus earthworm.