Water Relations in Fruit Cracking of Single-Truss Tomato Plants.

Abstract

We investigated water relations of fruit cracking in single-truss tomato (Lycopersicon esculentum Mill.) plants grown hydroponically in a greenhouse. At 24 d after anthesis, the water potential of the culture solution was changed from -0.06 MPa (control plants) to -0.36 MPa (stressed plants) . The water status of the culture solution and plant tissues was measured with an isopiestic thermocouple psychrometer. Fruit cracking decreased from>80% of fruit in the control to <30% in the stressed plants. The water potential gradient between fruit flesh and water source was greater in the control plants than in the stressed plants. Between predawn and morning, turgor increased in the fruit flesh in the control plants but not in the stressed ones. The hardness of the fruit skin was not different between stressed and control plants. These results indicate that the water potential gradient and increased turgor in the tissues might trigger fruit cracking in single-truss tomato plants.