Morsy, M.G. and K.M. Abd El- Latif ( 2012). Evaluating the effect of irrigation number on growth, yield, storability and water productivity of some onion varietiesFayoum J. Agric. Res. & Dev., Vol. 26, No.2, July,
Abstract: Field experiments were conducted during 2008/2009, 2009/2010 and 2010/2011 seasons at Sids Agric. Res. Station, Bani-Swief Governorate, Egypt. These trials aimed at investigate the effect of irrigation number, i.e. I1: transplanting irrigation (TPI), I2: TPI + Live irrigation (LI), I3: TPI + LI + 2nd irrigations and I4: TPI+ LI+ 2nd +3rd + 4th irrigations on vegetative growth, bulb yield, storability and water productivity of three onion varieties namely V1: Giza 6 Mohassan, V2: Giza 20 and V3: Giza Red. A split-plot design with four replicates was used. The most important results could be summarized as follows:-
1- Plant height, leaves number /plant and bulb diameter were significantly increased with increasing irrigation to 5 irrigation (I4) in the three seasons. Giza Red variety significantly surpassed Giza 6 Mohassan and Giza 20 in these growth characters in all seasons. Growth attributes were significantly affected by the interaction between irrigation and varieties except for plant height in the 1st and 3rd seasons and bulb diameter in the 2nd season.
2- Irrigation treatments and varieties significantly affected bulb weight, dry matter presentage, days to maturity, marketable yield, culls and total yield in the three season. The higher values of marketable yield, i.e. 12.60, 13.06 and 13.45 t/fed., as well as total yield, i.e. 15.74, 15.37 and 16.10 t/fed. In 2008/2009, 2009/2010 and 2010/2011 seasons, respectively were detected from I4 irrigation treatment and Giza Red variety. However, the dry matter (%) decreased with increasing irrigation number in all seasons.
3- Water consumptive use values over irrigation treatments and varieties were 767.46, 813.92 and 792.1 m3/fed. in 2008/2009, 2009/2010 and 2010/2011 seasons, respectively, including the transplanting irrigation. Irrigation Giza 20 variety at 5 irrigation (I4) gave the highest consumptive use values, i.e. 1317, 1331.3 and 1316.3 m3/fed in the three successive seasons.
4- Increasing irrigation number applied resulted in lower water productivity for all varieties. Giza red variety irrigated one irrigation (I1) was the more efficient variety in water utilization than Giza 6 Mohassan and Giza 20 varieties. These results were found to be true for water productivity. The highest water use efficiency, i.e. 16.88, 14.91 and 16.12 kg/m3 water consumed in irrigated according to irrigation treatment (I4), exhibited highest water consumptive use values as compared in 2008/2009, 2009/2010 and 2010/2011 seasons, respectively were observed from irrigating Giza red variety one irrigation only.
5- In the three seasons, lower values of bulb weight losses (%) were obtained under the irrigation treatments, I3 after two and four months storage periods, whereas after six months, I4 irrigation treatment exhibited the lowest value. Also, lower values of bulb weight losses (%) were recorded by Giza 6 mohassan as compared with Giza 20 or Giza Red varieties
Keywords: (Onion yield, irrigation level, water productivity, onion varieties, storability)
