IRRIGATION MANAGEMENT FOR DOUBLE-CROPPED FRESH-MARKET TOMATOES ON A HIGH-WATER-TABLE SOIL

Two tomato (Lycopersicon esculentum, Mill.) experiments were conducted for two years on a southeastern Coastal Plain soil that has a high, f luctuating water table. In one experiment, two methods for managing mi croirrigation were compared to a treatment that received only rainfall by measuring marketable fruit yields for spring and fall cropping sea sons. Irrigation increased yields for both seasons in the second year because of low rainfall. Measurements among seven shallow wells on the site showed no consistent differences for either water table depth or gradient between adjacent wells. Two cultivars were evaluated in the second year, primarily because frost severely damaged the tomato plant s about three weeks after transplanting. In the second experiment, two excessively irrigated treatments were evaluated in an effort to induc e a "soft-fruit" storage and shipping problem experienced by many grow ers in this region. Although extremely large quantities of irrigation water were applied, these symptoms were not observed in this study. Th ere were no differences in fruit yield between the two water managemen t treatments in either spring or fall. Fruit quality measurements show ed no significant differences. The 'Sunny' cultivar performed better t han 'Walter' during the fall season for the extremely wet soil conditi on. A double-crop, microirrigation management system has higher input costs but provides increased profitability for fresh-market tomato pro duction, particularly where markets are available for both spring and fall crops.