Effect of the fertilization and growth promoting microrganisms on Schizolobium parahyba

Abstract

The objective of this work was to evaluate the effect of the chemical and biological fertilizing on the development of two varieties of Schizolobium parahyba, paricá and guapuruvú. The chemical fertilizer NPK 20-05-20 and the plant growth promoting microorganisms, Rhizobium sp. (Rhi) and Rhizophagus clarus (Arbuscular Mycorrhizal Fungus - AMF). The experimental design was a randomized complete block with five replicates and eight treatments. Forty-six day old seedlings of each variety were planted in pits containing hydroretent gel. Then the treatments were added: 1. Control; 2. Rhi; 3. AMF; 4. NPK; 5. Rhi + NPK; 6. Rhi + AMF; 7. AMF + NPK; 8. Rhi + AMF + NPK. Plant length, stem diameter and survival in the environment were evaluated. The ANOVA followed by the Duncan test (? = 0,05) was used to compare the means of the treatments. In the four evaluated periods (37, 111, 250 and 360 days), both varieties had a positive effect on height, diameter and survival when applied to NPK treatments. The interaction AMF and Rhizobium sp. favored the growth in diameter of the guapuruvú. For paricá variety that same treatment provided higher growth in height, however, AMF impaired development in diameter of this variety. Thus, it was observed that under low fertility conditions, the interaction AMF + Rhi favored a greater resistance of guapuruvú to abiotic stress compared to treatment 3, and the presence of grasses in the experimental area may have contributed to the reduction on the development of S. parahyba.