Influence of Transpiration Suppressants, Sprinkler Irrigation and Moisture Levels on Transpiration and Evapotranspiration

摘要

Light sprinkler cooling water applications and white acrylic paint were applied to leaf canopies of tomatoes and citrus to attempt to reduce evapotranspiration. Moisture use, yields, and microclimatic data were determined. Estimates of influences of treatments on transpiration were evaluated with thermoelectric sensors. Tomato and citrus plant parts were analyzed for chemical effects of treatment. Diurnal changes in citrus tree trunks and fruits were monitored with linear variable displacement transducers. In 1968, the effects of treatments on water use were small and inconclusive. The white reflective treatment reduced water use by tomatoes by 10%, but reduced yields by 30% in 1969. Evaporative cooling increased yields of tomatoes in 1968 and 1969. In 1968, evaporative cooling increased total citrus yields and increased the tonnage of fruits which could be sold to fresh market. Evaporative cooling was effective in influencing fruit quality and size, and offers the promises of increasing the yield of quality produce and of making more efficient use of water. (WRSIC abstract).