*4.3.5.3 Establishment and management of trees*

In systems where trees are promoted for on-farm planting or in agroforestry systems, challenges associated with tree–crop interactions, and likely competition such as that for nutrient and water resources, are sometimes experienced. Researchers, for instance, find below-ground competition to be a major problem in simultaneous agroforestry systems and a focus of much research in recent decades [64]. Considering that trees raised from seed may differ in their competitiveness from those raised from cuttings, studies have been conducted to evaluate differences in root system architecture of plants raised from seed, stem, or root cuttings and the relationships between the competitivity index (CI) and crop yield [62]. From such studies, more shallowly rooted cuttings than seedlings, higher competitivity indices, and a negative relationship between CI and crop yield in *Melia volkensii* under integrated land-use systems have been observed. Therefore, to reduce tree–crop competition, the use of seedlings rather than cuttings should be recommended when promoting the use of this species on dryland farms [62].
