In vitro and In vivo Activity of Cyprodinil and Pyrimethanil on Botrytis cinerea Isolates Resistant to other Botryticides and Selection for Resistance to Pyrimethanil in a Greenhouse Population in Greece

No cross-resistance was observed between pyrimethanil or cyprodinil and the fungicides benomyl, iprodione or carbendazim + diethofencarb. In vitro, both anilinopyrimidine fungicides were effective against strains of Botrytis cinerea resistant to benzimidazoles and/or dicarboximides and against a wild type strain insensitive to diethofencarb (EC₅₀ values ranged between 0.03–0.19 and 0.006–0.054gml^–1 for pyrimethanil and cyprodinil, respectively). Preventive applications of anilinopyrimidines completely protected young cucumber plants and fruits that were inoculated with all strains of B. cinerea. The effectiveness of pyrimethanil against grey mould was studied in greenhouse grown tomatoes in relation to (a) the type of infection and the progress of the disease on different plant parts and (b) the response of the naturally occurring B. cinerea population to the selection pressure caused by eight successive applications of this fungicide. Pyrimethanil effectively controlled grey mould on leaves, fruits and stems but did not significantly reduce the number of dead plants and fruits with 'ghost spot' symptoms. The selection pressure caused by the consecutive applications of pyrimethanil resulted in reduction of its effectiveness on leaves that became apparent after the sixth application. This was correlated with a shift of the B. cinerea population (not previously exposed to anilinopyrimidines) towards reduced sensitivity, probably due to the development of a low level of resistance (R _L = 7.7). Pyrimethanil delayed the onset of the disease but it did not reduce the infection rate.     

Control of powdery mildew of grape in Greece using Sporodex® L and Milsana®

Journal of Plant Diseases and Protection - Six field trials were conducted in Greece to study the efficacy of two formulations of Reynoutria sachalinensis extract (Milsana® Vp 1999 &...     

Effect of variety choice, resistant rootstocks and chitin soil amendments on soil-borne diseases in soil-based, protected tomato production systems

Soil-borne diseases are the most significant crop protection problem in soil-based, low-input and especially organic glasshouse production systems in Europe. While chemical soil disinfestation has been the control method of choice in conventional farming systems, soil steaming has been the main strategy for the control of soil-borne diseases in organic production. Both methods are extremely expensive and have been increasingly restricted for environmental reasons by governments, and integrated and organic farming standard-setting bodies. The use of disease-tolerant varieties, grafting onto resistant rootstocks and chitin soil amendments were evaluated as potential replacements for soil steaming in organic and other low-input tomato production systems. When only Pyrenochaeta lycopersici and/or Meloidogyne spp. were present in soil, grafting and/or chitin soil amendment were found to be as effective in reducing root disease and/or increasing yield as soil steaming, but the efficacy of both treatments was reduced when Verticillum albo-atrum was also present in soil. No additive effects of combining grafting and chitin soil amendments could be detected. A more widespread use of grafting and/or chitin soil amendments may therefore allow significant reductions in the use of steam and chemical soil disinfestation in glasshouse crops. It will also allow integrated and organic farming standard-setting bodies to impose further restrictions on the use of soil disinfestation treatments.