Impact of Date Residues, Humic Acid and The Level of Irrigation in Growth and Yield of Onions (Allium cepa L.)

Abstract

A field experiment was carried out in Anbar Governorate, Heet city, during December 2018 to May 2019 in sandy clay loamy soil .The experiment included three factors : Date residues were added at two levels (0 and 5%) of soil weight mixed with the soil, Humic acids was added to the soil in three levels (0, 15 and 30 kg ha−1 ),The amount of irrigation 100 % and 50% of the net irrigation depth calculated from the measurements of the American type A evaporation basin were added. Study factors were distributed according to the split -split plot design within RCBD with three replications. The results showed that the study parameters had a significant effect on the values of plant height, fresh weight of leaves, number of leaves, average bulb weight and total bulbs yield. The highest values of plant height, number of tube leaves, average weight of bulb, and total bulbs yield were 78.3 cm, 25.0, 85.0 gm and 30.82 ton ha-1 respectively when adding 5% of date residues and the humic level was 15 kg ha-1 and irrigation water 100% compared to 27.1 cm and 3.0, 26.1 gm and 2.0 ton ha-1 when date residues are not added, and a humic level of 0 kg ha-1 and the amount of irrigation water 5 0%. The bilateral and triple interaction between the three factors also show a significant effect on some plant traits.