Investigation of alternative control methods aganist lettuce white rot disease agent Sclerotinia sclerotiorum (Lib.) de Bary

There are some number of diseases which can lead to great crop loss for lettuce culture. The most important of them is called Sclerotinia sclerotiorum. It is the most polyphagous plant fungi among the pathogens and the most destructive pathogen. It is a soil borne fungal disease that can effect the planting and cultivation of lettuce (Lactuca sativa L.) This disease hold place near the root and can be identified as white, cotton like mold. Effected tissue has a soft rotten place. This disease causes root rot in the early stage of development. In the further stages it causes the root rot, stem rot and the leaf rot. The plant fades and dies. In this work, we demonstrated the effects of increasing the organic matter in the soil, biological preparations such as Pseudomanas flourescens and Trichoderma viridae and Hidroxyquinoline sulfat fungicide which is certified for controlling the disease. The results show that biological preparation containing Pseudomanas flourescens is succesfull on the control of the disease. Keywords: Lettuce, Sclerotinia sclerotiorum, Pseudomanas flourescens, White rot, Fungicide.