Double cropping of potatoes in a semi-arid environment: the association of ground cover with tuber yields

Summary The association of ground cover and ground cover duration with fresh- and dry-weight potato tuber yields in a semi-arid Mediterranean climate, was investigated. Cultivars of different maturity classes were tested under the contrasting climatological conditions of the spring and autumn seasons. The correlation coefficients of ground cover (GC) and ground cover duration (GCD) with fresh- and dry-weight tuber yields were lower for the autumn than for the spring season. In both seasons, high yields were positively correlated with high GCD. However, variation in tuber yields was evident in cultivars with similar GCD, indicating the involvement of factors other than ground cover and light interception in tuber yield. This investigation was supported by a grant from the Ministry of Foreign Affairs, Technical Assistance Department, Netherlands.