INFLUENCE OF SOIL TENSION ON TOMATO FRUIT CRACKING

Fruit cracking in tomatoes is a serious problem, particularly when trellis culture is used. Past studies indicate that fruit cracking is associated with fluctuating soil moisture levels. Soil moisture variations are influenced by irrigation practices, and an irrigation regime employing frequent applications of water will lessen variations in soil moisture. A field study was initiated to study the effect of trickle irrigation regime on fruit cracking in `Celebrity' tomatoes ( Lycopersicon esculentum Mill ). In the three treatments used, soil was allowed to dry to 10-20, 50-60, and 100-110 centibars of tension, respectively, between watering and then was irrigated to field capacity. These tension levels corresponded with soil moisture levels of field capacity (10-20 cb), 20% of available water depleted (50-60 cb), and 40% of available water depleted (100-110 cb). Yield measurements indicated that the driest treatment (100-110 cb) significantly reduced the percent of radially cracked fruit. This treatment also significantly lowered the total yield, in terms of both fruit number and weight. There was no significant effect, however, on marketable fruit yield due to irrigation treatments. Further field studies are required to determine the optimum irrigation program to reduce fruit cracking.