Effect of Extended Irrigation Intervals at Different Growth Stages on Growth and Yield of Cotton in the Sudan Gezira

Abstract

A field experiment was conducted for two consecutive seasons
(1998/1999 and 1999/2000) at the Gezira Research Station, Gezira,
Sudan, to study the effect of extended irrigation intervals at different
growth stages on growth and yield of cotton (Gossypium barbadense L.)
variety Barakat 90. The experiment was laid out in a complete block
design with four replications. The treatments were irrigation every two
weeks (standard) and extended irrigation intervals of one month during
predetermined stages of cotton growth. These stages were early vegetative
growth, late vegetative growth, early flowering, late flowering, early fruit
opening and late fruit opening. The results indicated that growth and yield
of cotton were adversely affected by extending the irrigation interval to
one month throughout the growing season as well as when the irrigation
interval was extended during the early flowering stage. The magnitude of
this reduction was significant, and the levels of yield exhibited wide
seasonal variation. The extended watering intervals had significant and
substantial adverse effects on yield, associated with shorter plant height
and reduced shoot dry weight and forced early 50% flowering and bolling
compared with standard irrigation. The three components of cotton yield,
i.e., lint index, seed index and ginning-out turn, were not affected
significantly, because they are genetically controlled.