Biological effectiveness of a new multifunctional biopesticide in the protection of organic potatoes from diseases

Abstract

Crop disease control is of particular importance in organic crop production, as the use of chemical pesticides is prohibited there. A new multifunctional biofungicide Kartofin was selected and used to optimize the phytosanitary state of organic potatoes ecosystems. Previously of studies indicated the prospects of using the biofungicide to control numerous fungal and bacterial diseases during the potato growing season and storage of tubers. The crop rotation field experiment was carried out in 2017–2020 at the Experimental Station of the IEEP - BRANCH OF FSAC VIM near Saint-Petersburg (59°65 N and 30°38 E). The soil of experimental plots is sod-podzolic light loamy. In the potatoes (variety Udacha) field, a 2-factor field experiment was established which studied:  the action of biofungicide Kartofin;  the effect of the compost. The experiment was established on the plots with the size 61.6 m2 each. The experiment had four replications. Three doses of the compost were used which corresponded to different levels of the potato productivity. Potatoes were treated with biofungicide at the time of planting and by foliar spray during the growing season. The combined use of compost at a dose of 4 t ha-1 and biofungcide made it possible to achieve the yield of standard tubers of 27.3–28.2 t ha-1 with their low incidence of fungal diseases. The biological effectiveness of the biofungicide Kartofin in reducing the prevalence and development of a complex of fungal diseases (alternariosis, late blight, stem form of rhizoctoniosis) on potato plants of the Udacha variety reached 82.2–89.9%.