Nursery practices increase seedling performance on nutrient-poor soils in Swietenia humilis

Swietenia humilis is a valued tree species for its high-quality wood, among other commercial interests. Attempts to plant the species in southwest Mexico have often failed due to poor quality seedlings combined with low soil fertility and dry environments. Nursery top-pruning and fertilization are practices previously reported to improve seedling quality, and facilitate rapid establishment under poor site conditions. In the present study, the effects of three top-pruning intensities (0%, 25%, and 50%), and two fertilizer regimes (traditional and exponential) on several S. humilis seedling morphological and physiological indices were tested in the nursery, and a quality test trial on nutrient-poor soils was conducted. Significant interactions between the above two treatments were not detected. Top pruning at 25% and 50% intensity did not improve S. humilis seedling quality. However, exponential nutrient supply exhibited favorable effects on seedling growth. Results of the quality test trial revealed exponential fertilization promoted satisfactory seedling performance when low nutrient availability was a limiting factor