Sclerotia of Sclerotinia sclerotiorum production and powdery mildew severity in pea cultivars under different water depths

The effect of water depth on the number of sclerotia produced by Sclerotinia sclerotiorum, oidium severity caused by Erysiphe pisi, and top plant dry matter of dry pea (Pisum sativum L.) was studied under soil and climate conditions of Central Brazil. It was used a randomized complete block design with four replications (cultivar as a factor and a split plot on water depth). Water depths, applied through a single irrigation sprinkler line, varied from 125 to 499 mm, and the cultivars studied were Maria, Luiza, Marina, Mikado, Triofin, Viçosa, Amélia and Kodama. Top plant dry matter did not vary among cultivars; however, it increased with total water depth applied. Number of sclerotia produced in infected plants increased significantly as water applied increased and did not differ for semi-leafless and normal leaf cultivars. Cultivars Marina, Mikado and Luiza showed a significant reduced number of sclerotia in comparison with cv. Triofin. Water depth and cultivar interacted significantly for oidium severity evalueted 70 days after planting. Increasing water depth applied to the crop reduced oidium severity on the susceptible cultivars Amélia and Mikado. Cultivars Maria and Marina showed good potential for use in areas infected with Sclerotinia.

Pisum sativum L; Erysiphe pisi; irrigation management; disease; control