NEMATODE COMMUNITY ASSOCIATED TO MELON CROP IN A FIELD OF RIO GRANDE DO NORTE STATE, REACTION OF CUCURBIT GENOTIPES TO Rotylenchulus reniformis, CARACTERIZATION AND SURVIVAL OF THE PARASITE

Abstract

The center of fruticulture of Rio Grande do Norte State, Brazil, is located inAssu–Mossoró belt wich account 92% of brazilian melon exports. Theintensive melon growing has resulted in increase of incidence and severityof plant diseases and plant parasitic nematodes of Meloidogyne and Rotylenchulusgenera are the main pathogens threating commercial melon crop in Assu andMossoró municipalities. Nematodes of Rotylenchulus genus are sedentaryectoparasitic of roots and R. reniformis is economically the most importantspecies with wide geographic distribution and host range. It survives todessecation better than the majority of plant parasitic nematode species. Thereare references related to resistance sources in Cucumis genus to root–knotnematodes, but there is a lack of informations about reaction of melongenotypes to R. reniformis. The melon growing in Rio Grande do Norte iscarried out during dry season and wet season other crops are grown or fallowis applied. Geostatistical techniques allow to define areas infested by plantparasitic nematodes making available to control them only to certain cropareas where the target nematode damage threshold has been exceeded. Despiteof economical importance of melon crop to Rio Grande do Norte State,there is a lack of informations related to pathosystem reniform nematode –melon crop in the semi–arid area of this State.