Species Identification and Occurrence Investigation of Vegetable Root-Knot Nematodes under Protected Cultivation in Shandong Province

During 2001～2003, systemic investigation on occurrence and damage of vegetable root-knot nematode diseases under protected cultivation was conducted in Shandong province. The results showed that vegetable root-knot nematode diseases in protected field existed universally. Nematode-infected plants were found in 67.6% greenhouses and the rate of totally diseased plants was 50%. In four or more years old of cucumber or tomato greenhouses, the rates of greenhouse and plant were even up to 95% and 66%, respectively. Identification host and perineal pattern techniques were used to identify the root-knot nematode species in the samples which were collected from infected fields. Meloidogyne incognita was the dominant species occurring under protected cultivation vegetable field in Shandong province. M. incognita populations were found in 97.94% samples, while M. arenaria race 1 populations were found in 7.73% samples. Moreover, most of the M. arenaria infected samples were co-infected with M. incognita, with only one exception.