Effect of different soil water available levels on the development of young plants of “erva-mate”

Abstract

The influence of different levels of soil water availability on the development of young plants of “erva-mate” (Ilex paraguariensis St. Hil.) was studied under controlled conditions. The plants were cultivated during the period from January to November, a total of 45 weeks. The foreseen treatments corresponded to 3 water available levels for plants: treatment 1 (T-1): soil moisture at 0.3 atm of tension, treatment 2 (T-2): soil moisture at 80% of water quantity used in T-1, and treatment 3 (T-3): soil moisture at 65% of water quantity used in T-1. The height of the plants, the number of the leaves, and the total leaf area were evaluated. The best results, with significant increment of the values of the studied parameters, were verified in treatment T-2 in relation to T-1 and T-3. In the treatment T-1, it seems that was an excess of water in the soil, limiting the availability of O₂ for the roots, depressing the development of the aerial part. On the other hand, in T-3, the expression of the development was limited by the water deficiency in the soil. In an “erva-mate” seedling production system, the irrigation process should be controlled.