Response of Allium Cepa (L.) for irrigation quantity and potassium fertilization

Abstract

A two-year experiment on onion cv Giza 20 was carried out during 2005/06 and 2006/07 at Agric Res. Sta. (ARC), at Gemmiza, Gharbia governorate, Egypt. The trail included two factors, viz. irrigation at (80, 60 and 40% available soil moisture, ASM) and potassium (K) rate at (120, 100 and 80 K2O/fed.). The treatment combinations were arranged in a split plot design with three replicates. Irrigation levels were randomly distributed at the main plots, meanwhile the sub ones were devoted to potassium levels. Six traits, correlation among them, efficiencies of the use of water and K as well as some relations were studied. The results showed that the studied two factors and their interactions significantly affected all studied traits as well as use efficiency of both water and potassium. The pronounced products with all respects, either traits or efficiencies, were given by applying I-60, K100 and their interaction (I-60 × K100) for water use efficiency (W.U.E). Meanwhile for potassium use efficiency (K.U.E) the treatments were I-60, K80 and (I-60 × K80). Highest bulb yields were 19.80 and 18.33 ton/fed. in the first and second season respectively. Correlation coefficient was, in most cases, positive and highly significant. Without any exception, correlations of bulb yield with all traits were positive. The corresponding ones of total soluble solid (T.S.S) were insignificant in both seasons. Water use efficiency was 11.41 and 10.57 Kg/m3 in the two respective seasons. The corresponding values of potassium use efficiency were 197.95 2 and 183.25 Kg/Kg K O, respectively. The curve analysis showed that the relation between bulb yield and both water consumptive use and potassium rate was a quadratic one in both seasons. © 2009, INSInet Publication.