Studies on Intercropping Systems of Garlic and Green Onion to Potatoes and impact that on Growth, Yield, and Resistance Late Blight Disease

The study assessed the effect of intercropping Patterns on the performance of potato plants, i.e., vegetative growth, tuber quality and yield as well as potato late blight,Phytophthorainfestansdisease epidemiology. Trials were carried out under a greenhouse and open field in Moshtohor and Kaha, Qalyubia Governorate, Egypt,  respectively during three successive winter seasons of 2016/2017, 2017/2018 and 20178/2019. Potatowas intercropped with garlic or onion at the ratios of 1:1; 2:1 and 3:1 plant population. These treatments were compared with fungicide (Radomil gold) foliar spray and unsprayed monoculture potato plant with respect to disease development and potato tuber yield and quality. The results prevailed that, all potato-garlic ratios exhibited superior performance when compared to the fungicide unsprayed treatment. Among the proportions, 1 potato with 1 garlic intercropped plots showed significantly low disease development and high tuber yield. Moreover, at 1:1 combination of garlic (or onion) to potato, the land equivalent ratio (LER) was greater than 1 and the monetary values were high at both testing sites. The study also demonstrated that fungicide treatment provided significant low disease development and higher potato tuber yield when compared to the untreated monoculture control treatment. The findings of this study suggested garlic as a potential intercropping plant for the management of potato late blight disease under Egyptian condition. In winter growing season, the extracts of garlic or onion plants reduced the disease severity of late blight. The effect of competition among the two different Allium species in potato intercropping and the economic viability of intercropping potato with garlic or onion compared to its sole cropping were studied under natural late blight infestation. Generally, the present study concludes that intercropping of potato with garlic and onion may affect yield and disease resistance, competition between the 2 species (Solanumtuberosum and Allium spp.), and economics of mixtures as compared to monoculture of the same species. Although Allium crops had lower yield in mixture but are more expensive in markets, solitary planting of them would not reach the profitable level gained with potato under our trials condition