Physiological response and yield of paclobutrazol treated tomato plants (Lycopersicon esculentum Mill.)

Experiments were conducted to study the physiological effect of the plant growth retardant paclobutrazol (PBZ) and its impact on the yield of tomato plants (cv. Precador). Seedlings were treated at the time of pricking out with soil and foliar applications of PBZ at concentrations of 1.0 and 25.0 mg l(-1) respectively. The results established that: The reduced height and the increased thickness of the young plant stem, as well as the accelerated root formation are a significant advantage of the PBZ treatment, contributing to the improvement of seedling quality at planting. Soil treatment (1 mg l(-1)) and foliar treatment (25 mg l(-1)) with PBZ improves the photosynthetic activity and water balance of tomato cv. Precador. PBZ accelerates fruit formation and increases early fruit yield. The concentrations of the retardant used and the mode of its application ensure the production of fruits without any residual retardant and harmless to human health from a phytosanitary point of view.