The Effect of Irrigation during Cotton Squaring on Lint Yield and Plant Growth Characterisitics

It is commonly accepted that water is typically the most limiting input facing agricultural production.  However, environmental conditions such as episodic drought and unpredictable rainfall place a strain on the large irrigation systems located throughout south Georgia to deliver adequate water at critical periods of crop development.  An increase in the regulation of agricultural water use has also placed additional focus on increasing irrigation efficiency to maximize crop yield.  In cotton, the flowering period has been the subject of several studies and is typically regarded as the most critical crop stage to supply adequate water to avoid stress and optimize yields.  The effect of water supply on yield during the pre-bloom period, and the squaring stage in particular, has been studied to a lesser extent, and there are varying reports on the yield response to water supply during this period.  Cultivar maturity also can have an influence on the response to water supply at particular growth stages and the resulting impact on yield.  This experiment was conducted in three cotton growing seasons, 2012 through 2014, to determine the impact of irrigation during squaring on the yield of both early and late maturing cotton cultivars.  The results suggest that when periods of drought occur during squaring, adequate irrigation during this stage can improve yields compared to cotton grown in conditions where irrigation is withheld during squaring but irrigated normally during the bloom period.  Increasing irrigation rates above recommended rates during squaring did not result in increased yields.