VEGETABLE GROWTH PROMOTER MICROORGANISMS WITH AGRICULTURAL PLASTER ON POTATOES (Solanum tuberosum L.) UNDER SHADOW HOUSING

Abstract

As an alternative to the excessive use of synthetic fertilizers, farmers use microorganisms that promote growth in plants, to increase roots growth, strengthen natural mechanisms that react to diseases and insects and increase production. The objective of this study was to evaluate the potential of agricultural plaster combined with Bacillus cereus, B. subtilis, Pseudomonas fluorescens and Trichoderma harzianum as plant growth promoter. Its soil application will allow selecting the most productive combination, with higher quality and crop yield. The design was completely random, with three treatments applied to potatoes cultivation (Solanum tuberosum L.) in shaded house conditions and drip irrigation. The treatments were: control (T1), T. harzianum combined with 40 kg ha?1 calcium (T2), B. cereus, B. subtilis, P. fluorescens and T. harzianum combined with 40 kg ha?1 calcium (T3); the source of calcium in T2 and T3 was agricultural gypsum. The evaluated variables were plant height, chlorophyll content, numbers and nutritional composition of leaves, weight and volumetric weight of the tuber. The viability of the microorganisms in the rhizosphere was determined with selective agars for each type of microorganism. There were no statistical differences regard on chlorophyll between treatments; the control significantly exceeded in height compared to the plants from T2 to T4; the number of tubers (51.5 %) and yield (49.4 %) from T3 was significantly higher than T1. At the biocontrol in the tuber for Streptomyces T3 was better (9 %) than T1 (32.14 %). T3 had a higher yield and better standard quality.