Abstract
Abstract: The objective of this work was to evaluate the relationship among Entomosporium severity, defoliation, and vegetative-reproductive variables of three European pear cultivars in Southern Brazil. The Packham’s Triumph, Abate Fetel, and Williams pear cultivars were assessed regarding Entomosporium severity, defoliation, and natural leaf fall every two weeks, from the appearance of the first symptoms at the beginning of January until the end of April, during the 2012/2013 and 2013/2014 crop seasons. The vegetative and reproductive variables were evaluated in July, during the dormant period. Data on Entomosporium severity were integrated over time and converted into the area under the disease progress curve (AUDPC). The coefficient of determination (R2) of the linear regression of Entomosporium severity versus defoliation was significant for all studied cultivars and crop seasons. Defoliation in trees affected by Entomosporium was significantly higher than natural leaf fall in the control trees protected by fungicides. A negative correlation was observed among defoliation, branch fertility index, and plant height, indicating that the higher the defoliation, the lower the development of the vegetative and reproductive variables plant height and vigor. Entomosporium severity differed significantly among cultivars when the AUDPC was considered the differentiating epidemiological variable. The Abate Fetel and Williams pear cultivars are the most susceptible and resistant to Entomosporium, respectively.
Highlights
Brazilian pear (Pyrus communis L.) production was approximately 15 thousand tons in 2015/2016 (IBGE, 2017b)
The initial symptoms of Entomosporium under natural infection processes were observed during the first half and at the beginning of January in the 2012/2013 and 2013/2014 crop seasons, respectively
The differences between the two crop seasons regarding the date when the first symptoms appeared and Entomosporium severity can be attributed to one or more unfavorable climatic factors related to the development of the disease, including: minimum, average, and maximum temperatures; relative humidity; and rainfall (Figure 1)
Summary
Brazilian pear (Pyrus communis L.) production was approximately 15 thousand tons in 2015/2016 (IBGE, 2017b). Associated with per capita consumption, there is a high potential for pear culture expansion, especially in Southern Brazil where climatic and soil conditions are favorable. In this region, the pear crop is an excellent alternative for temperate climate fruit diversification (IBGE, 2017a). In Southern Brazil, Entomosporium is a prominent disease that can drastically increase during plant growth, depending on microclimate, cultivar susceptibility, and primary inoculum liberation (Nunes et al, 2016), often causing early defoliation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
