Effect of some compounds on the decay of strawberry fruits caused by Botrytis cinerea Pers.
Field experiments were conducted in the years 1997-2000 to determine the effect of various sprayings strawberry plants on the percentage of infected fruits caused by Botrytis cinerea Pers. The effect of garlic's extract at concentration 1%, water solution of microcrystalline chitosan (3% polymer content) at concentration 0.2% and iprodione (255 g active form in 1000 cm3 of water) was estimated. The experiment was conducted on cultivar Senga-Sengana. During the growing season strawberry plants were sprayed three times--at the beginning of blooming, during full blooming and at the end of blooming. Ripped fruits were stored for 24 hours in a cooling chamber. Then the strawberry fruits were weighted and the percentage of infected fruits was estimated. In the first year of cultivation there was found no effect of used plant protection on the decay of strawberry fruits. Intensification of the disease was very low because of the lack of rainfalls and good weather. These conditions did not propitious the infection. In the second and in the third year of cultivation the best efficacy in control grey mould had iprodione which limited decay of strawberry fruits to 9% (in the second year) and 11.1% (in the third year). In the second year the chitosan water solution had protective effect and the decay of strawberry fruits was diminished to 15%. The highest development of infection was in combination where garlic extract was used for spraying both in the second 23% and in the third year 32.5% as well.