Influence of Fungal Strain, Temperature, and Wetness Duration on Infection of Grapevine Inflorescences and Young Berry Clusters byBotrytis cinerea

Abstract

The effect of temperature and wetness duration on infection of Vitis vinifera inflorescences (from "inflorescence clearly visible" to "end of flowering" stages) and young berry clusters (at "fruit swelling" and "berries groat-sized" stages) by Botrytis cinerea was investigated. Artificial inoculations were carried out using conidial suspensions of eight B. cinerea strains belonging to the transposon genotypes transposa and vacuma. Infection incidence was significantly affected by strain but not by transposon genotype (transposon genotype accounted for only 6.5% of the variance). Infection incidence was also affected by the interaction between strain and growth stage of the inflorescence or berry cluster (overall accounting for approximately 57% of the experimental variance). Thus, under our experimental conditions, the ability to cause infection was a strain rather than a transposon genotype attribute. Across all strains, infection incidence was lowest when inflorescences were clearly visible or fully developed, highest at flowering (from beginning to end of flowering), and intermediate at the postflowering fruit stages (fruit swelling and berries groat-sized). One transposa strain, however, was highly virulent on all grapevine growth stages tested. The effects of temperature and wetness duration on infection incidence were similar for all fungal strains and grapevine growth stages; infection incidence was highest at 20°C and lowest at 30°C, and was also low at 5°C. Similar results were obtained for mycelial growth and conidial germination. Based on the pooled data for all strains and grapevine growth stages, an equation was developed that accounted for the combined effects of temperature and wetness duration on relative infection incidence. This equation should be useful for developing decision-making systems concerning B. cinerea control at early grapevine growth stages.

Fungal Diseases in Two North-West Spain Vineyards: Relationship with Meteorological Conditions and Predictive Aerobiological Model

“…Some authors indicated that Botrytis conidia germination could occur at 13 • C [10], which explains the early infections that we detected during leaf development (S-1) at both vineyards in 2017. However, we detected that the highest Botrytis spore concentrations coincided with higher temperatures, around 20 • C and slightly rainy days, therefore within the optimal temperature range for infection development [45,55,56].…”

Environmental effects on the production ofBotrytis cinereaconidia on different media, grape bunch trash, and mature berries

“…In the absence of inoculum, predicting disease occurrence based on infection periods would be ineffective and may result in excessive control applications if conditions do not favour other components (Madden and Ellis ). Therefore, when combined with predictive models for infection (Ciliberti et al , ) our equations could contribute to the development of an effective disease prediction system.…”

A network meta‐analysis provides new insight into fungicide scheduling for the control of Botrytis cinerea in vineyards

“…In Italy and Spain, most of the regional public sanitary services recommend spraying in B rather than in A to their viticulturists . On the other hand, some recent papers emphasize the importance of spraying at timing A rather than B …”

“…The biology of B. cinerea and its epidemiology on vine crops have been studied in detail, and multiple infection pathways have been identified that occur in two periods: from flowering to young cluster development, and after veraison. In the early season, B. cinerea infects inflorescences and young berries, resulting in (i) inflorescence and blossom blight, (ii) latent infections of berries, and (iii) saprophytic colonization of grape bunch trash . After veraison, latent infections may become visible as rotted berries, and the colonized bunch trash may serve as a source of inoculum inside the bunches.…”