THE EFFECT OF INTERCROPPING WINTER OATS AND PEAS ON POWDERY MILDEW CONTROL AS A PROTECTIVE STRATEGY IN ORGANIC FARMING
Authors:   University of Priština, temporary settled in Kosovska Mitrovica, Faculty of Agriculture, Lešak, Kosovo and Metohia, Serbia, Grčak Milosav , Grčak Dragan ,   University of Priština, temporary settled in Kosovska Mitrovica, Faculty of Agriculture, Lešak, Kosovo and Metohia, Serbia, Knežević Desimir ,   University of Priština, temporary settled in Kosovska Mitrovica, Faculty of Agriculture, Lešak, Kosovo and Metohia, Serbia, Jevtić Radivoje ,   Institute of Field and Vegetable Crops Novi Sad, National Institute of the Republic of Serbia, Novi Sad, Serbia, Župunski Vesna ,   Institute of Field and Vegetable Crops Novi Sad, National Institute of the Republic of Serbia, Novi Sad, Serbia, Orbović Branka ,   Institute of Field and Vegetable Crops Novi Sad, National Institute of the Republic of Serbia, Novi Sad, Serbia
Published: February 2025

: Intercropping cereals and legumes offers a sustainable and effective strategy for improving the health of organic farming systems. By combining cereal crops with legumes, this practice enhances biodiversity and promotes natural disease control, reducing the reliance on chemical pesticides and disrupts pest and disease cycles, ultimately leading to fewer outbreaks. Furthermore, legumes, such as peas, fix nitrogen in the soil, improving soil fertility and reducing the need for synthetic fertilizers. This study aimed to evaluate the variation in disease indices (DI) of powdery mildew in monocropping and intercropping systems with peas under different environmental conditions across two growing seasons. The field experiment was conducted over two consecutive seasons (2017/2018 and 2018/2019) at the Institute of Field and Vegetable Crops in Novi Sad. The experiment was set up in a randomized complete block design (RCBD) with four replications. A winter oat variety, Jadar, was used, while the intercropping legume was the winter pea variety, Kosmaj. Leaf infection percentages were assessed using the modified Cobb scale, and DI was calculated according to the standard formula. Statistical analyses, including ANOVA, Tukey pairwise comparisons, and two-sample t-tests, were used to determine significant differences in DI between oat plants across seasons and cultivation systems. The results of the Two-Sample T-test revealed a statistically significant difference between oats grown in different cultivation systems (P-Value = 0.000). Disease indices (DI) were significantly lower in oats grown in a mixture with peas (3.21) compared to oats grown as a monocrop (12.79). Tukey Pairwise Comparisons indicated that the DI of the stand-alone crop in the first growing season (14.92) was significantly higher than that of oats in the mixture during both the first (3.91) and second (2.50) growing seasons. Additionally, the DI of oats in the stand-alone crop in the second growing season (10.67) was significantly higher than that of oats in the oat-pea mixture in both growing seasons. No significant difference was found between the DI values of the stand-alone crops in the two seasons. Overall, the results suggest that intercropping winter oats with peas can reduce powdery mildew disease indices under varying climatic conditions.