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), I1: TPI + Live
irrigation (LI), I3: TPI + LI + 2nd irrigations and I4: TPI+ LT+ 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 I4 treatments 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, culb 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 766.88, 798.7 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. 1310.0, 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, 25.20 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.