Desempenho de Agrocybe aegerita em função do substrato de cultivo

Abstract

The present study aimed at developing a cultivation technology for the edible mushroom Agrocybe aegerita in Brazil, addressing various aspects such as the type of base substrate, supplement type, and pH conditioners. The first trial was conducted as a double factorial, consisting of 7 treatments x 3 managements techniques (full opening of the cultivation bag surface; 3 cuts; 6 cuts). The substrates used were sawdust, bean straw, coffee parchment, brachiaria hay, sugarcane bagasse, all supplemented with 10% wheat bran and 2% calcitic limestone. Three control treatments were tested: bean straw, brachiaria hay, and parchment, with only 2% calcitic limestone. The produced blocks were pasteurized at 80ºC for 12 hours + 4 hours of autoclaving, inoculated with 3% inoculum in a laminar flow chamber. The second experiment aimed at validating the data from the first experiment, using only one management technique. The substrates were again evaluated: sawdust, sugarcane bagasse, and brachiaria hay, all with 10% wheat bran + 2% calcitic limestone, pasteurized at 80ºC for 24 hours + 2 hours of autoclaving. Sawdust blocks were inoculated with 4% inoculum, while the others were inoculated with 3%. The third trial evaluated 4 supplements to be used in cultivation: wheat bran (FT), rice bran (FA), cornmeal (F), and FT+FA+F. The fourth trial assessed the effect of gypsum and calcitic limestone levels (0.5%; 1%; 2%) on cultivation. Blocks from the third and fourth trials were autoclaved for 4 hours and inoculated with 3% inoculum. Blocks from all trials were incubated at 25ºC and cultivated in a room at 25ºC with air conditioning, misting system, and humidity above 80%. The experimental design used was randomized blocks, and mushroom harvest data were analyzed using the mean test and treated with the Tukey test at a 5% probability level, with the option of transformation: square root of Y + 0.5 - SQRT(Y+0.5), using the statistical program Sisvar. Brachiaria has achieved the highest biological efficiency (BE) of 10.09% and highest productivity (P) of 3.49% in the first trial with management technique 2, although the differences were not significant. In the second experiment, bean straw was selected as the base substrate due to the best results obtained: 5.81% (P) and 16.60% (BE). The complete removal of the cultivation bag was chosen as the management technique to induce mushroom formation. The use of wheat bran as a supplement in the cultivation substrate yielded the best results in the third trial: 4.78% (P) and 17.32% (BE), while 1% gypsum showed the best results as a substrate conditioner in the fourth trial: 2.36% (P) and 8.94% (BE). The results of this study clearly demonstrated that the performance of A. aegerita mushrooms is strongly influenced by the chemical and physical characteristics of the substrate. However, this performance is likely to be significantly influenced by intrinsic genetic factors of the species as well, which necessitates future work in selecting more suitable strains for cultivating this mushroom in Brazil.