Abstract
A study was carried out during the period from November 2000 to February 2004 with a view to developing improved production techniques of summer tomato for overcoming the deleterious effects of high temperature and rainfall on growth, flowering and yield. Six field experiments were conducted at RARS, Jessore. Of which, experiment 3 and 4 were repeated at BAU, Mymensingh. In experiment 1, twenty-five genotypes of summer tomato were evaluated. In experiment 2, twelve selected genotypes were planted at first week of each month from April to September. Three growth regulators each at three concentrations along with a control (water) were applied to two heat-tolerant varieties in the third experiment. In the fourth experiment, two summer tomato varieties were subjected to three mulching treatments. Three genotypes of tomato were grafted onto two eggplant rootstocks in the fifth experiment. In the experiment 6, four heat tolerant genotypes of tomato were grown with or without rain-shelter during first week of March, June and October 2003. Wide variability among the genotypes was recorded for plant, inflorescence, flower and fruit characters, yield components, yield and reaction to diseases. The genotypes ST002, ST004, ST005, ST006, ST008, ST014, ST015, ST016 and ST021 were found promising. April and September plantings were superior in respect of number and weight of fruits per plant, plant stand and yield. May planting performed the worst in these respects. Among the genotypes, the hybrid variety BARI Tomato-10 performed the best followed by ST021. Among the hormones, only 4-CPA was effective in fruit- set and development, GA3 induced profuse fruits but it was not effective in fruit development. The hormone 4-CPA @ 45 ppm had the highest yield, net return and BCR. Mulching with black polyethylene and black polyethylene + rice straw ameliorated soil conditions through stabilizing soil moisture and soil temperature at Jessore. BARI Tomato-10 with black polyethylene + rice straw mulch gave the highest yield and net return. But at Mymensingh black polyethylene mulch had adverse effect on soil moisture condition due to heavy rain. Solanum sisymbrifolium showed superiority in respect of success and compatibility of grafting with tomato genotypes, growth, fruiting, plant survival and yield. Tolerance to summer conditions and diseases was also improved with grafting onto the wild Solanum. Among the genotypes, BARI Tomato-10 performed the best in all these respects. Marketable and total yields, gross return, net return and BCR were maximum in the combination of BARI Tomato-10 onto S. sisymbrifolium. Open field crop yielded satisfactorily in March and October plantings. Rain-shelter protected crop performed well all over the season. June planted crop in the open field gave the poorest yields while October planted crop both inside and outside rain-shelter gave the highest yields. Economic analysis showed that open field crop in the early and late summer, and shelter-protected crop in the rainy season gave higher net return and BCR. It may be inferred from the above experiments that the hybrid variety BARI Tomato-10, hormone treatment 4-CPA @ 45 ppm, black polyethylene + rice straw mulch and grafting onto S. sisymbrifolium were found to be improved techniques for summer tomato production. Early (March and April plantings) and late (September and October plantings) summer crop produced higher economic yield even without rain-shelter.