Irrigation water management of wheat crop under sowing dates at fayoum

الملخص EN

A field experiment was conducted at Kom Osheem Agric., Res., Station, Fayoum, Egypt during 2003/2004 and 2004/2005 seasons to study the effect of three sowing dates, i.e.

D1: 22 Nov., D2: 2 Dec., and D3:12 Dec.

and irrigation water managements, i.e.

irrigation at I1:30%, I2:55% and I3 : 80% available soil moisture depletion (ASMD) on yield, yield components and some water relations of wheat crop (Giza 168 cv.).

A split-plot design with four replications was used in both seasons.

The main obtained results were as follows: 1.

Planting wheat on 22 Nov., and irrigation at 30% ASMD gave the highest averages of plant height, spike number/m2, grain weight/ m?,1000 – grain weight, grain yield/fed.

(1566.0 and 1656.0 kg), and straw yield (3625.9 and 3824.4 kg/fed.) in the two successive seasons.

The lowest averages of yield and its components were obtained from sowing on 12 Dec.

and irrigation at 80% ASMD in both seasons. 2.

Delaying sowing date from 22 Nov.

to 12 Dec., significantly decreased all yield components, grain yield/fed by 12.7% and 12.4% and straw yield/fed by 24.7% and 25.6% in 2003/2004 and 2004/2005 seasons, respectively.

However, increasing the ASMD from 30% to 80% significantly decreased yield components, grain yield/fed by 29.7% and 24.5%and straw yield/fed by 11.9% and 13.4% in the two successive seasons.

3.

Seasonal consumptive use (ETc), as a function of the different treatments averaged 40.40 and 39.70 cm in 2003/2004 and 2004/2005 seasons, respectively.

Delaying sowing date from 22 Nov.

to 12 Dec., and increasing ASMD from 30% to 80% decreased seasonal Etc from 46.18 and 45.43 cm to 35.35 and 34.85 cm in the two successive seasons. 4.

Daily ETc rates were low during Nov.

and Dec., then increased during Jan.

and Feb., to reach its maximum values during March and declined again at April till harvesting.

The values of daily ETc decreased with delaying sowing date than 22 Nov.

and increasing ASMD than 30% in the two growing seasons months.

The crop coefficient (Kc) values were 0.51, 0.59, 0.67, 0.80, 0.95, 0.69 and 0.49 (averages of the two seasons) for, Nov., Dec., Jan., Feb., Mar., Apr.

and May, respectively. 5.

The highest water use efficiency values were 0.871 and 0.936 kg grains/m3 water consumed were obtained from D3I2 treatment in 2003/2004 season and D2I2 treatment in 2004/2005 season, respectively.