Two decision procedures for irrigating cotton were compared. One procedure applied water when canopy temperature exceeded 29C (TKW) and the other procedure replenished stored soil water (1.7 a depth) to field capacity (SWR). The TKW procedure resulted in earlier, more frequent, and smaller quantity irrigations than the SWR procedure. Stored soil water was greater in the SWR treatment during the period when both procedures were applying irrigation, but late in the growing season TKW and SWP soil water levels were similar. Canopy temperature in the M treatment was cooler than that of the SWR treatment. Irrigating the TKW treatment when canopy temperature exceeded 29 C enabled plants to maintain canopy temperature below 31 C.

Early vegetative growth and fruiting was higher in the TKW treatment than in the SWR treatment. Final lint yields from the TKW and SWR procedures were similar. The TKW procedure has the potential of simplifying the decision of applying irrigation by monitoring only canopy temperature.