Growth and yield responses of rainy season field tomatoes to timing and splitting of fertilizer application

Growth and yield responses of eight (8) tomato cultivars (UN-83, Nsukka Local NHle-7-7-1, Roma VFN, Ronita, Ife 1, Rossol, and Ace VF) to different times and modes of NPK fertilizer application were studied in two field experiments under rainy season conditions in Nsukka, Nigeria. Plant height and number of branches and leaves were higher in Nsukka Local, Rossol and Ife-1 while stem diameter was higher in Roma VFN and Ronita. The attainment of reproductive growth stage as measured by number of days to 50% anthesis and 50% fruit-set was earlier with UN-83, Rossol and NHle-7-7-1 while truss capacity was higher in UN-83 and Nsukka Local. Total plant dry matter was similar in all the cultivars but dry matter partitioning to the reproductive organs was more in UN-83 and Rossol. Fertilizer application at transplanting time either in single full dose or in split increased the plant size attributes (Plant height, Stem diameter, Numbers of leaves and branches per plant) and enhanced earlier maturity of the crop. They also increased total plant dry matter and facilitated early dry matter partitioning to the reproductive organs, while fertilizer application at two weeks after transplanting or at flowering depressed total plant dry matter and accumulated most of the early dry matter in the stems and leaves. Total fruit yield (t ha-1) was higher in UN-83 and Nsukka local but time and mode of fertilizer application had no consistent effects on fruit yield. Keywords: Tomato, cultivar, NPK fertilizer, split application Agro-Science Vol. 5 (1) 2006: pp. 17-2