EFFECT OF BIO AND ORGANIC FERTILIZERS ON GROWTH, YIELD AND FRUIT QUALITY OF SUMMER SQUASH

The aim of this study, conducted at the Vegetable Research Farm, College of Agriculture, University of Dhok, Iraq during spring season of 2009, was to obtain high production with better quality of two summer squash cultivars (Mullah Ahmed No.1 and Sucheimie No. 2) by using a bio-fertilizer i.e. Azotobacter with a control treatment, and three levels (0, 1.5 and 3.0 t dunam^-1; 1 dunam equals 0.1 hectares) of an organic fertilizer i.e. heep residues, thus making a total of 12 treatments. The experiment was implicated in a Factorial Randomized Complete Block Design (F-RCBD) and replicated three times. Data were collected on vegetative parameters of summer squash plants including plant height (cm), number of branches plant-1, number of leaves plant^-1, fresh weight of the plants, dry weight of the plants, and total chlorophyll; and also on yield characteristics such as number of fruits plant^-1, fruit length (cm), fruit diameter (cm), percent TSS, early yield (kg plant^-1) and total yield (t dunam^-1). The results revealed that Azotobacter alone or in combination with sheep residues had significant effects on vegetative (shoot) parameters, and substantially improved the quantitative and qualitative traits of fruit yield of the two cultivars. The interaction effect of both the bio and organic fertilizers was also significant and resulted in best performance of both the summer squash cultivars in terms of vegetative as well as reproductive characteristics.