Dependence of Cotton Productivity from Agrometeorological Factors

A. STOILOVA and G. NIKOLOV
Cotton and Durum Wheat Research Institute, BG-6200 Chirpan, Bulgaria

Abstract

STOILOVA, A. and G. NIKOLOV, 2002. Dependence of cotton productivity from agrometeorological factors. Bulg. J. Agric. Sci., 8: 387–391

Using the results from the variety trials carried out under non-irrigated conditions, there was found correlation dependence of yield from the agrometeorological factors: rainfall, temperature sum in the July-August period; deficits of air humidity and relative air humidity in the May-August period; hydrotermical coefficient of Selyaninov in the July-August period. Eleven cultivars and candidate-cultivars were included in the 1989–1995 period, and 7 cultivars – in the 1996–1999 period. The methods of correlation and regression analyses were applied. The positive correlation was found: of the fibre lint percentage from the temperature sum during the first ten days of August, and of the setting height of first simpodia from the temperature sum in June. The found regression equation on the basis of studied meteorological factors allow the possibility to forecast significantly the quantity of cotton yield, fibre lint percentage and setting height of first simpodia.

Key words: cotton, meteorological factors, productivity, correlations, regressions