Excess irrigation water was provided to spring crops of bag-grown greenhouse
tomatoes (Lycopersicon esculentum Mill.) to test the effect on radial fruit cracking. Varied
numbers of emitters were placed in bags filled with soilless medium to provide different
amounts of irrigation water. In 1990, all emitters provided water containing nutrient
solution, but in 1992, the extra water added in one treatment did not contain nutrient
solution. In both years, the percentage of cracked fruit was 20 percentage points higher in
the treatments receiving more water. The increase in cracking was similar whether or not
nutrient solution was added to the extra water. There also were some effects of the extra
water on yield. Fruit count per plant was slightly higher (9.5%) when extra water was
provided without nutrient solution, but was the same when nutrient solution was added to
the extra water. Fruit weights per plant were 18.6% higher in 1990 when watering was
increased. In 1992, fruit weights were similar, except for the treatment where the extra
water provided did not contain nutrient solution. Fruit weight in this treatment was 19.7%
higher than in the other treatments. In both crops, the percentage of cracking increased
as linear and quadratic functions of cluster positions, i.e., there was more cracking in the
upper clusters. In greenhouse situations, growers should consider water reduction when
experiencing high levels of fruit cracking and as a precautionary measure when harvesting
from the upper clusters. Providing excess water to greenhouse-grown tomatoes may be a
viable technique for screening cultivars or for conducting research on practices to reduce
cracking