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Monilinia spp. is the main pathogen that affects stone fruit, causing significant production losses, especially in seasons with favorable climatic conditions for disease development. Currently, the standard practices for controlling this disease are by means of spray programs of synthetic fungicides. Fungicide applications using treatment schedules imply an increase in the number of applications; however, the applications are justified considering the real risk of Monilinia spp. infection. Consequently, fruit surface contains a higher number and concentration of residues, but not better control of the disease. From previous studies, the epidemiology of Monilinia spp. was deeply studied in one of the main stone fruit regions of Europe, the ‘Valle del Ebro’, and an epidemiological model was developed to describe the brown rot epidemic pattern in this area. After that, a warning system for fungicide applications in the field was elaborated that included the main factors to be considered as fruit susceptibility, the presence of inoculum in the field, and climatological factors (temperature, leaf wetness, rainfall, or their interaction). In the present study, we present data of the warning system validation during six seasons in 38 fields of peaches and nectarines of the ‘Valle del Ebro’. The results indicated that the incidence of disease caused by Monilinia spp., recorded in the field and postharvest, was similar in both plot evaluations and the calendar and warning systems. However, the disease level was higher in late varieties (3.2% and 9.3% of infected fruit recorded in the field and in postharvest, respectively) in comparison with earlier varieties (0.6% and 3.1% of infected fruit recorded in the field and in postharvest, respectively). In general, the strategy applied (the calendar or warning system) did not affect the disease level recorded. However, when fungicide treatments were applied following the warning system, the treatment reductions were higher than 50

In the last years, our research has focused on the study of brown rot on stone fruit caused by Monilinia spp. in the ‘Valle del Ebro’ (Spain). The epidemiology of this disease was thoroughly investigated in the field and one of the main outcomes was the development of a prediction model that indicates the risk of infection. Furthermore, the epidemiology was also studied in the postharvest phase, providing a lot of information regarding the relevance of the main postharvest handling operations, the identification of fungal population in packing houses, the fruit infection risks and the influence of temperature and humidity on conidia survival. Additionally, many efforts have been orientated to the development of control strategies for both pre and postharvest periods. Traditionally, chemical fungicides have been used to preserve fruit quality over extended periods of storage or transportation. However, the growing public concern over health and environmental hazards associated with high levels of pesticides has resulted in restrictions imposed by legislation and also by distribution companies. In this context, our main goal has been the development of environmentally friendly alternative strategies to synthetic fungicides in order to control brown rot on stone fruit. Although many studies have demonstrated the efficacy of these alternative treatments, only a few of them are currently applied under commercial conditions. Biocontrol agents, natural compounds from different origins and physical means are the main approaches which have been studied, with different success levels. There are several reasons for the limited success of these treatments, such as the inconsistency of results, variability of the efficacy under commercial conditions, low persistence, a narrow spectrum range of activity, the difficulties in developing a shelf-stable formulated product that retains efficacy (in the case of biocontrol agents), and economical and regulatory limitations. Generally, i

Apple is characterized by its high adaptation to diverse growing environments. However, little is still known about how different environments can regulate at the metabolic or molecular level specific apple quality traits such as the yellow fruit peel color. In this study, changes in carotenoids and chlorophylls, antioxidants as well as differences in the transcriptome were investigated by comparing the peel of “Golden Reinders” apples grown at different valley and mountain orchards. Mountain environment favored the development of yellow color, which was not caused by an enhanced accumulation of carotenoids but rather by a decrease in the chlorophyll content. The yellow phenotype was also associated to higher expression of genes related to chloroplast functions and oxidative stress. Time-course analysis over the last stages of apple development and ripening, in fruit from both locations, further revealed that the environment differentially modulated isoprenoids and phenylpropanoid metabolism and pointed out a key role for H2O2 in triggering apple peel degreening. Overall, the results presented herein provide new insights into how different environmental conditions regulate pigment and antioxidant metabolism in apple leading to noticeable differences in the apple peel color.

Apple is characterized by its high adaptation to diverse growing environments. However, little is still known about how different environments can regulate at the metabolic or molecular level specific apple quality traits such as the yellow fruit peel color. In this study, changes in carotenoids and chlorophylls, antioxidants as well as differences in the transcriptome were investigated by comparing the peel of “Golden Reinders” apples grown at different valley and mountain orchards. Mountain environment favored the development of yellow color, which was not caused by an enhanced accumulation of carotenoids but rather by a decrease in the chlorophyll content. The yellow phenotype was also associated to higher expression of genes related to chloroplast functions and oxidative stress. Time-course analysis over the last stages of apple development and ripening, in fruit from both locations, further revealed that the environment differentially modulated isoprenoids and phenylpropanoid metabolism and pointed out a key role for H2O2 in triggering apple peel degreening. Overall, the results presented herein provide new insights into how different environmental conditions regulate pigment and antioxidant metabolism in apple leading to noticeable differences in the apple peel color.