Influence of different soil amendments on drought stress tolerance of Maclura pomifera

A factorial experiment in a completely randomized block design was performed to investigate the effects of different planting beds (soil, soil/vermicompost, soil/sheep manure and soil/sesame seed meal) on the growth of Maclura pomifera under different irrigation regimes (90%, 55% and 35% field capacity [FC]). Drought stress adversely affected plant characteristics while inclusion of soil amendments in the planting beds improved plant performance and promoted plant hardiness to the drought stress. The sesame seed meal showed to be the best amendment for improving the stem diameter and leaf areas as well as reducing the ion leakage. This soil amendment also efficiently improved the uptake of K and P from the soil and resulted in the highest content of these elements in the Osage orange leaves under water deficient. Severe water deficient decreased the activity of antioxidant enzymes, while application of soil amendments improved their activities. Sesame seed meal and vermicompost containing beds were highly effective for inducing activity of antioxidant enzymes and hence improved drought tolerance in Osage orang plants. Based on the results of this investigation, sesame seed meal is suggested as an efficient soil amendment, which is statistically better than sheep manure and vermicompost for minimizing water requirement and improving plant tolerance to the drought deficient in Osage orange. This is the first report representing the potential of sesame seed meal as an efficient soil amendment, which suggest new practical application for this oil extraction by-product in sustainable agriculture.