Manejo da murcha de esclerócio (Sclerotium rolfsii Sacc) em pimentão e seleção de acessos de Capsicum Sp. Resistentes

Abstract

The sclerotium wilt, caused by the fungus Sclerotium rolfsii Sacc. is a difficult disease to control, causing high losses in crops and chili peppers in the State of Amazonas and fundamental knowledge of the pathogen, for the establishment of disease management strategies and provide support for studies of resistance. This work aimed at evaluating the resistance of 20 genotypes of Capsicum sp to isolate, and performed a pretest aggressively ten isolates from different localities. We also evaluated the effect of Silicon, Glyphosate and nettle extract on the mycelial growth of the pathogen in vitro and in vivo. To assess aggression used the isolated IRB02 and experimental design in factorial randomized block with three replicates 1x20, containing a plant inoculated with three disks of mycelium of the pathogen witnesses absent from each genotype containing pathogen. In evaluating the effect of Si, Gliz and extract the design was completely randomized in a factorial 1x3x3, evaluating the Index mycelial growth in vitro with ten replicates, acada board an experimental unit, and a control containing only PDA medium for growth pathogen. To evaluate the effect of Si, and Gliz Extract in greenhouse was used in a completely randomized factorial 2x3x4 with five replicates, each constituted by a plant and the witnesses containing plants without application of products and evaluated the incidence and severity of disease for 30 days. Data were subjected to analysis of variance and means were compared by Tukey test at 5% probability using the program ASSISTAT 7.6 Beta. The isolated IR02 showed more aggressiveness average, being selected for the remaining stages of the study. Genotypes BC16, MA34; ATN01; ATN02; MA03; LA02; TBT01; MA18, MA43; BC01; ATN04; MA31; IRB02 showed greater resistance to the pathogen under study. The sources of Si 15.0 and 24.0 g / L-1, Gliz 4.0 mL / L-1 and Nettle Extract 10%, 20% and 50% used in the experiment had to be efficient in controlling the pathogen in vitro. These same sources were effective against the pathogen in the farming and Nathalie Tiberius in all volumes used, compared to the control. Given the results obtained, the isolated IRB02 can be used to assess the genotype resistance of Capsicum sp. The genotypes showed that resistance to the pathogen present with potential for studies of breeding and chili peppers for resistance to the pathogen under study and the products used can be better evaluated in relation to the volume to be used for possible disease control crops of peppers and chili.