irrigation is all about stress management

Irrigation...It's All About Timing

Craig Bednarz
Lubbock, Texas

For me, irrigation is all about stress management (for the crop, not the producer). Too little irrigation may reduce yield while too much irrigation may delay crop maturity and reduce fiber quality. To maximize profit per unit of irrigation water applied, we need to monitor (or at least predict with some degree of accuracy) crop water deficit stress.  This is where we find the large void in irrigation management. We cannot manage something we cannot monitor.

Several technologies have been developed to help us monitor or predict crop water deficit stress. I would be willing to bet with a few clicks of a mouse any producer can find daily potential evapotranspiration (ET) for his or her region.  Potential ET is a mathematical model based on daily climatic conditions. There are many variants of this model.  While they all tend to be very accurate in predicting daily potential ET, they do not tell us anything about crop water deficit stress.

source : cottonfarming