EFFECT OF PLANT GROWTH REGULATOR ON THE GROWTH AND YIELD OF HEAT TOLERANT TOMA TO (Lycopersicon esculentum Mill.)

Abstract

Tomato is one of the most important fruit vegetables that are cultivated throughout the year in Bangladesh. During warm seasons, tomatoes cultivated in high raised land areas are often planted under rain shelter. High temperature (both day and night), humidity, rainfall and light intensity are the basic limiting factors of the tomato production in summer season. High temperatures reduce fruit set and fruit production in tomato. During the summer season tomato is available in urban market at an exorbitant price. There is a great demand of tomato in summer-rainy season but there is no good variety for this season. Recently BARI has released some heat tolerant open pollinated and hybrid varieties with some limitations liking hormone application and smaller fruit size. Considering the factors. the experiment was under taken to evaluate the two heat tolerant varieties of tomato under polytunnel with and without plant growth regulator application during summer-rainy season. The experiment was conducted at the Research Farm of Olericulture Division under Horticulture Research Center of Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur during May 2006 to August 2006. The experiment was laid out in a RCBD (factorial) with three replications. Two heat tolerant tomato varieties BARI Toamto-4 and BARI I lybrid Toamto-4 with and without plant growth regulator applications were included in this experiment. The higher fruit set percentage (42.52%) was recorded from BARI I lybrid Tomato-4 which was also higher in case of pollen viability (42.75%), number of fruits per cluster (3.01), number of fruits per plant (12.70) and yield per plant ( 460 g). Better performance was observed in spraying of 4- CPA at 40 ppm concentration in respect of percent fruit set (45.38%), number of fruits per plant ( 16.45) and yield (39.39 t/ha) under high temperature condition. In combined treatment, BARI Hybrid Tomato-4 with 40 ppm 4-CPA performed a sigmficant role in number of fruits per cluster (3.41), number of fruus per plant (22.48), number of fruits per plot ( 144.00), yield per plant (62 I .68 g), yield per plot ( 15.23 kg) and above all fruit yield (50.57 t/ha).