SYMPTOMS OF NUTRITIONAL DEFICIENCIES IN SEEDLINGS OF MAHOGANY GROWN IN NUTRITIVE SOLUTION

Abstract

Mahogany (Swietenia macrophylla) is one of the most expensive wood species in the world, but its uncontrolled exploration has reduced its natural reserves. Therefore, reforestation programs can be an alternative for the continuous use of its wood. However, little is known about its nutritional requirements and for this reason, this work aimed at diagnosing the symptoms of macro and micronutrients deficiencies in seedlings of mahogany in the missing element technique. The plants were cultivated in nutritive solution and the treatments consisted of the individual nutrients omission - N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn, and in complete nutritive solution. After 100 days from the beginning of the treatments, the symptoms were described and photographed; the plants were collected, washed, separated in roots and aerial parts, dried and weighed for dry mass determination. In general, the visual symptoms of nutrients deficiencies were easily characterized, except for the -S, -Zn, -Mg and P treatments, in the omission of the other nutrients there was a reduction in the production of total dry mass, especially in the N, K, Ca and Cu omission indicated larger demand of these nutrients in the initial phase of the plant development.