YIELD AND EGGPLANT FRUIT QUALITY (Solanum melongena L.) DEPENDENT ON PLANT TRAINING AND NITROGEN FERTLIZATION

Studies upon the influence of varied forms and doses of nitrogen fertilizers as well as plant training on yields and eggplant fruit quality were carried out at The University of Life Sciences in Lublin in 2004- 2005. Plants were trained in their natural form as well as for 3 carrying shoots. Following nitrogen nutrition forms were applied: ammonium (NH4+ - in a form of (NH4)(2)SO4 20.5 % N), nitrate (NO3- in a form of Ca(NO3) 2 13.5 % N), and amide (NH2 in a form of CO(NH2)(2) 46 % N), at following doses per 1 plant: 5, 10, 15 g N. Yields and number of fruits, as well as contents of dry matter, vitamin C and reducing sugars were determined. It was found that the plant training method did not determine the size of eggplant fruit commercial yield, nor their number. Instead, it was observed that varied nitrogen rates significantly affected the yield size and fruit number. The highest yield was achieved when the highest nitrogen dose was applied (15 g N . plant(-1) - 4.76 kg . m(-2)), while the lowest yields were obtained after the lowest dose application (5 g N . plant(-1) - 3.22 kg . m(-2)). The average fruit number ranged to 17.7 fruits . m(-2) and 11.7 fruits . m(2), respectively. Achieved results referring to selected elements of fruit chemical composition indicated that the type of plant training did not influence on eggplant fruit quality. Varied nitrogen fertilization significantly affected the dry matter, ascorbic acid, and reducing sugars contents. Considering the yield size, fruit number, and reducing sugars contents, nitrate(V) form of nitrogen nutrition appeared to be the most favorable. Moreover, eggplant showed to have great requirements for nitrogen (15 g N . plant(-1)).