Temporal progress of web blight in three common bean genotypes on the central coast of Ecuador

Abstract

Web blight caused by Rhizoctonia solani Kuhn is one of the main common beans (Phaseolus vulgaris L.) diseases of the Ecuadorian central coast. Thus, the present study aimed to evaluate the progress of web blight incidence using nonlinear models in promising genotypes SER 03 and SER 08, using the commercial cultivar INIAP 473 as a control. This study was carried out between the 2010 and 2012 seasons in Quevedo, Ecuador. Epidemiological parameters such as initial disease (y0), disease progress rate (r), final incidence and the area under the disease progress curve were estimated using the Exponential, Logistic, and Gompertz models. In general, progress curves, epidemiological parameters and other evaluated plant health variables were lower in the INIAP 473 cultivar than the other genotypes in 2011 and 2012, especially in the last season when higher y0 and r were observed in the commercial cultivar. It seems that soil and seeds inoculum and temperature play an important role in standard bean crop disease progress. While the response of genotypes and each location conditions influenced the epidemic modeling, the Logistic model better described the web blight progress under these conditions.

Cercospora leaf spot management with nitrogenous fertilizers in cotton is dependent on the disease amount in the plant canopies

“…Across all canopy layers, poultry manure and urea collectively reduced Y0 by an average of 35%, standing out against the other two organic options. Epidemiological parameters of leaf diseases can be affected by cultivar genetics, cultural practices such as strip tillage, and other factors (Cantonwine et al, 2007;Fischer et al, 2021;Chávez-García et al, 2022). However, some organic or inorganic fertilizers and doses in cotton plants can also reduce Y0 and r parameters of diseases, such as Ramularia leaf spot (Palma-Zambrano et al, 2022).…”

Impact of Web Blight on Photosynthetic Performance of an Elite Common Bean Line in the Western Amazon Region of Colombia

“…The specific adaptation level of a bean genotype depends on its physiological responses and its degree of susceptibility to a given stress condition [ 30 ]. In our study, tropical climatic conditions (higher values of air humidity, rainfall, and air temperature) in the Amazon region are favorable for the frequent development of WB [ 73 , 74 ]. During the initial stages of infection (scale scores of 1 and 2), the elite bean line (BFS 10) faced the combined stress situation (pathogen infection and higher values of PAR) that increases the dissipation of regulated energy and induces a significant reduction in PSII efficiency, while keeping the ETR intact, thus entering into a dynamic state of photoinhibition [ 63 , 75 ].…”