EFFECT OF PLANTING DATE AND PHOSPHATE FERTILIZATION ON GROWTH AND YIELD OF BROCCOLI PLANTED IN SOUTHERN IRAQ

Abstract

The experiment was conducted during the winter season 2017-2018 on broccoli variety Paraiso under desert conditions in southern Iraq, as it nine factorial treatments in which three planting dates interacted (1/9, 15/9 and 1/10) and three levels of phosphate fertilization (0, 400 and 800 kg ha-1) added once after two weeks of transplanting, to find out the best date and level of fertilization that will affect growth, increase production and improve its quality, the results showed that plants grown on the first date, as well as plants fertilized at the level of 800 kg ha-1 were significantly higher in vegetative growth indicators represented by plant height, number of leaves, leaf area and fresh and dry weights of the total vegetative growth, and yield indicators that included weight (666.15, 552.75 g) and curd diameter, number and weight of lateral curds, yield of a plant (0.789, 0.656 kg) and total productivity (17.36, 14.44 ton ha-1) and the qualitative and chemical characteristics that included crud total chlorophyll concentration (4.17, 3.96 mg 100 g-1 fresh weight), percentage of total soluble solids (9.60, 8.75%), vitamin C ( 87.23, 79.77 mg 100 g-1 fresh weight), total soluble carbohydrates ( 28.95, 25.32 mg g-1 dry weight) and the percentage of total nitrogen, phosphorous, potassium and sulfur. Only the first date plants exceeded in stem diameter, while first and second dates and plants fertilized at the level of 800 kg ha-1 significantly exceeded in the percentige of dry matter. The bilateral interaction between the experiment factors achieved a significant effect on some of the characteristics under study.