Good and sustainable agronomic practices are needed in vegetable production to maintain high crop yield. As part of efforts to achieve this, two field experiments were carried out between 2008 and 2010 to evaluate the combined effects of age of transplant and NPK fertilizer on the growth, fruit yield and quality of Solanum melongena var.’ long purple’. Four levels of NPK fertilizer (0, 200, 300 and 400 kg NPK/ha) and three ages of transplanting (5, 6 and 7 weeks after sowing) in 12 factorial combinations were the treatments. These were laid out in randomized complete block design replicated thrice. Data collected were subjected to analysis of variance and significant means compared using least significant difference (LSD) at 5% probability level. All the growth parameters and fruit attributes assessed increased with increasing levels of NPK. Application of 300 kg NPK/ha produced the best growth while plants that received 200 kg NPK /ha and non-fertilized plants had least performance. The fruit and seed attributes such as fruit length and girth, number of fruits/plant, number of seeds/fruits, seed weight, and fruit yield were all significantly influenced by the fertilizer levels. The number of fruits/plant ranges from 4.3 in non- fertilized plants to 8.2 in 300kg NPK /ha treatment. There was no significant difference in fruit yield produced by 300 (26.88 t /ha) and 400 kg (28.78 t /ha) NPK /ha treatments. Transplanting of seedling at 6 weeks after sowing (WAS) produced significantly better plant growth, fruit attributes and fruit yield compared to plants transplanted at 5 and 7 WAS. It can be concluded that application of 300 kg NPK /ha in combination with transplanting of seedlings at 6 weeks are good agronomic practices that could ensure optimum performance of Solanum melongena. Key words: Solanum melongena, NPK fertilizer, age of transplant, growth, fruit yield
