Management of white mold of soybean using winter cereal straw

Leandro André Feller,Marcelo Cruz Mendes,Carla Daiane Leite,Jessica Vanessa Wosniak Corrêa,Cacilda Márcia Duarte Rios Faria,Leandro Alvarenga Santos

doi:10.1590/0103-8478cr20190476

Abstract

ABSTRACT: The management of white mold (Sclerotinia sclerotiorum(Lib.) De Bary) has been one of the main production limitations faced by soybean (Glycine max L.) producers. Considering the complex management of this disease and resistance structure of the pathogen, the present study was conducted in the municipalities of Guarapuava and Palmas in Paraná with the objective of managing the white mold of soybean using straws of winter cereals, such as oat, rye, and triticale. Initially, the three winter cereals were cultivated simultaneously in both the study areas. Straw production, plant height, and shoot fresh and dry weight were evaluated. Subsequently, BMX Apollo soybean was cultivated on cereal straws, and the incidence and severity of white mold were evaluated. In the in vitro experiment, 20 sclerotia covered by a layer of cereal (oat, rye, and triticale) straws were added and carpogenic germination was observed only in the control treatment after 98 days. Regardless of the study site, rye presented greater height and fresh weight than the remaining two cereals. Soybean cultivation on winter cereal straw reduced the incidence and severity of white mold. Cultivation on rye straw reduced mold incidence by 77.7% and 76.6% in Palmas and Guarapuava, respectively.

Highlights

White mold, caused by the fungus Sclerotinia sclerotiorum (Lib.) De Bary, affects approximately 650 plant species, soybean (Glycine max L.)
Production of winter cereal straw The associations between cultivation sites (Guarapuava and Palmas) and winter cereal production were examined based on plant height and dry weight
Guarapuava, soybean cultivated on rye and triticale straws showed a lower white mold incidence at all stages (R5.1, R5.4, and R6).soybean cultivatedon oat straw showed the same white mold incidence as controls (Table 3)

Summary

Introduction

White mold, caused by the fungus Sclerotinia sclerotiorum (Lib.) De Bary, affects approximately 650 plant species, soybean (Glycine max L.). In Brazil, the incidence of soybean white mold has significantly reduced crop production (TUPICHET al., 2017). High humidity and temperatures between 10 °C and 21 °C favor carpogenic germination, which is characterized by the emission of apothecia containing asci and ascospores that are disseminated by the wind for 2 to 3 weeks. The management of soybean white mold generally involves an integrated program of measures including cultural practices, since chemical control alone is inefficient. The use of a physical barrier, derived from conventional crop remains, can affect the carpogenic germination of S. sclerotiorum sclerotia, thereby reducing the initial inoculum of the pathogen, in addition to improving chemical, physical, and biological characteristics of soil (VENTUROSO et al, 2013). The potential use of dead cover in the management of soil-dwelling pathogens has already

Objectives

Methods

Results

Conclusion