Abstract The present work evaluated the agronomic behavior of species and varieties of Pleurotus submitted or not to the scratching technique. The cultivated species/varieties were Pleurotus ostreatus and Pleurotus ostreatus var. Florida, and Pleurotus djamor, where half of the treatments were scratched before the first and second flushes, while the rest were only scratched before the second flush. Yield (%), biological efficiency (%), weight of mushroom (g) and number of mushrooms (uni) were evaluated. It was observed that scratching harmed the mushroom weight for P. ostreatus, where the treatment without scratching produced significantly higher values, in the first harvest flush. On the other hand, scratching favored yield and the number of mushrooms for P. djamor. When the species are compared, it is noted that P. ostreatus obtained a lower yield, which was also reflected in the biological efficiency. P. djamor stood out with a large number of mushrooms, statistically higher than the other species, on the other hand, producing mushrooms of low weight of mushroom. The use of the scratched technique is not recommended for the conditions used in the work, due to the increase in labor and loss of mushroom weight.

RESUMO O fungo Ceratocystis cacaofunesta é um dos principais problemas na cultura do cacaueiro no Brasil. Para o cacaueiro há poucas alternativas para o controle da doença, sendo que a indução de resistência vem sendo testada como uma possibilidade de controle. Neste trabalho foram utilizados três indutores de resistências em três concentrações diferentes visando a indução de resistência do cacaueiro atacado por Ceratocystis sendo elas: glicose (0,1M, 0,5M e 1M), sacarose (0,1M, 0,5M, 1M) e acibenzolar-s-metílico (1ppm, 100ppm e 1000ppm). Além disso, amostras das plantas tratadas foram coletadas e analisadas para verificar a presença de grãos de amido. O único tratamento que não apresentou nenhuma morte de planta foi o acibenzolar-s-metílico a 1 ppm. Foi observado grãos de amido em todas as plantas tratadas, porém em quantidades diferentes. São necessários estudos mais detalhados para confirmar a efetividade do produto na indução de resistência de plantas de cacaueiro ao fungo Ceratocistys.

ABSTRACT The fungus Ceratocystis cacaofunesta is one of the main problems in cacao culture in Brazil. For cocoa, there are few alternatives to control the disease, and induction of resistance has been tested as a possibility of control. In this study, three resistance inducers were used at three different concentrations with the aim of inducing resistance in the cacao tree attacked by Ceratocystis: glucose (0.1M, 0.5M and 1M), sucrose (0.1M, 0.5M, 1M) and acibenzolar-Î2-methyl (1ppm, 100ppm and 1000ppm). In addition, samples were collected from the treated plants and analyzed for the presence of starch grains. The only treatment that did not show any plant death was acibenzolar-s-methyl at a concentration of 1 ppm. Starch grains were observed in all treated plants, but in different amounts. More detailed studies are needed to confirm the effectiveness of the product in inducing resistance of cacao plants to the fungus Ceratocistys.

Abstract The aim of this research was to evaluate the efficiency of aqueous alkali-treated Brachiaria straw for the cultivation of appropriate species of oyster mushroom. The substrate used in the cultivation of various Pleurotus spp. was soaked for 20 min by using two different procedures: (i) 0.5–2.0% Ca(OH)2 in 100 L water, and (ii) 50–250 L water. As a result, 1% Ca(OH)2 dissolved in 100 L water and 3.5 kg of Brachiaria straw presented the best production. The most suitable species for the application of the present method were P. pulmonarius and P. sapidus. The success of this technique is directly related to the concentration of Ca(OH)2 and water, the species, and the origin and quality of raw material used as the substrate in the production of oyster mushroom.