Author : G. Abdel, Caser
WATER RELATION IN ONIONS: 1- INFLUENCE OF PLANT POPULATIONS AND INTERVAL OF FLOWERING STALK ERADICATIONS ON GROWTH AND YIELD OF GREEN AND DRY BULBS OF ONIONS (Allium cepa L. cv. Local Red) GROWN UNDER RAINFALLS AND SUPPLEMENTARY IRRIGATION
journal of kerbala university,
Volume 2, Issue 3, Pages 105-112
This experiment was carried out during the growing season of 2001-2002 and repeated in 2003-2004 in Mosul to investigate the effects of plant populations and intervals of flowering stalk removal on growth , dry bulbs and green yields of onions grown under irrigated and non-irrigated cultivations. The results of 2001-2002 growing season showed that supplementary irrigated onions significantly increased leaf fresh weight (14.4%), root dry matter percentage (7%), as compared to these of rainfalls. Low onion plant population (18 plants.m‾²) was superior over high onion plant population (36 plants. m‾²), as it substantially increased leaf numbers per plant (27.3%), leaf fresh weight (19.7%), fresh weight of dry bulb (25.9%), and yield of dry bulbs (62%). Moreover, this population significantly exceeded high population in 2003-2004 growing season in leaf fresh weight per plant (27.2%), bulb: leaves ratio (7.7%), and fresh weight of individual plant (6.7%). Weekly eradication of flowering stalks in 2001-2002 growing season appeared to be the most potent treatment, as it highly increased leaf numbers per plant (28.6%), bulb: leaves ratio (219%), bulb fresh weight (265%), yield of dry bulbs (263%), and root fresh weight (15.1%), in relation to that of no flowering stalk elimination which resulted in profound dry bulb yield reductions. On the other hand in 2003-2004 growing season, treatment of no flowering stalk eradication was superior on others, particularly on weekly eradication of flowering stalks, as it significantly increased the plant height (6.9%), leaf fresh weight (52.6%), and green onion yield (26.3%). The highest dry onion bulb yield (3.1 kg.m‾²) and green onion yield (6.64 kg.m‾²) were obtained from supplementary irrigated high onion population of weekly flowering stalk eradication, respectively, during 2001-2002 and 2003-2004 growing seasons.