The Effect of Soil Moisture Conditions on Some Quantity and Palatability Traits of Opuntia ficus indica L. in Dasht-e-Zahab

Fodder plants are the most important crops in the world, because these plants provide fodder for millions of livestock in the world, which in turn feeds millions of people. In order to evaluate the effect of drought stress on some agronomic traits and forage palatability of cuctus, an experiment was carried out on the basis of a randomized complete block design consisted of four treatments; the supply of water based on 56, 24, 15 and zero percent of the plant dry matter (rain-fed farming condition) with three replications in Research farm of Dasht-e-Zahab (2017-2018). The results showed that there is not a significant difference between the drought stress (23.34 and 18.28, respectively) and normal irrigation (23.17 and 20.18, respectively) in terms of length and width of pad in moderate drought. The maximum fresh yield was obtained in years of 2017 (65.46 t.ha-1) and 2018 (64.88 t.ha-1) in the no-stress treatment. The fresh yield was 60.04 t.ha-1 in the moderate-stress treatment. Also, the maximum dry yield was obtained in the first year of no-stress treatment which did not have a significant difference with the moderate-stress treatment. The ratio of elements concentration in the young pads to the 1- and 2-year pads were respectively 33.43 and 23.4 percent for P, 0.14 and 21.48 percent for K, 2.47 and 21.55 percent for Ca and 66.01 for Na. The results showed that the deficit irrigation increased nutrition accumulation and forage palatability of the crop. Also, dry and wet forage showed a positive significant correlation with the length and width of pad and forage palatability. Therefore, it is possible to achieve similar forage with normal irrigation treatment by applying moderate drought stress. Cactus pear with its high efficiency in converting water to dry matter, produces significant forage and helps to revive vegetation in drought conditions.