Abstract
Phytosanitary monitoring of diseases in organically grown potatoes cultivated in mixed crops with peas, common beans, garlic, savory, dill, and basil was conducted on the territory of the Maritsa Vegetable Crops Research Institute, Plovdiv, during the period 2023–2025. It was observed that potatoes grown in mixed crops are susceptible to the same diseases as those grown as a monocrop. The main diseases diagnosed during the growing season included potato late blight (Phytophthora infestans) and early blight (Alternaria solani), while post-harvest diseases included Fusarium wilt (Fusarium spp.) and black scab (Phoma exigua). Infection of tubers produced in organic systems with seed-borne fungal pathogens was confirmed. It was established that disease development in potatoes grown in mixed cropping systems primarily depends on the quality of the seed material, the timing of sowing and transplanting, and fertilization rates. The companion crops did not significantly influence the incidence or severity of fungal diseases in potato plants. The inclusion of garlic and common beans in mixed cropping with potatoes reduced the development of potato late blight by over 67%, whereas the highest incidence of late blight was recorded in mixed crops of potatoes and peas. The results of the study will support the control of diseases in vegetable crops grown using organic technology.
Keywords: allelopathic effect, intercropping, organic production, phytosanitary monitoring, Solanum tuberosum