Abstract

BIODIVERSITY OF NEMATODES IN TOMATO CROP OF RANGAREDDY DISTRICT HYDERABAD, TELANGANA STATE. INDIA. (2011-2012)

B. Kavitha and Prof. V. Vanita Das

Abstract

Nematode population was studied in tomato crop in Nagole and L.B Nagar, Rangareddy District. Nematode species of field crops Plant parasitic nematodes are microscopic and identification of nematode species based on morphology. Nematodes associated with tomato crops are Rotylenchus, Pratylenchus, helicotylenchus, hoplolaimus. The symptoms caused by these nematodes are some what similar to nutrient deficiency symptoms such as stunting and yellowing of plants. At the site of infection of hoplolaimus species many lateral roots may emerge giving the root system a bushy appearance. White females of cyst nematodes can be seen as small, white, pear-like bodies on the roots. Environmental factors such as soil type, temperature, moisture and nutrient level play a major role in the expression of nematode –induced symptoms. Options for management of these nematodes have been developed. In the world, tomato is cultivated in almost all regions. Tomato is the world’s largest vegetable after potato and sweet potato, but it tops the list of vegetables. As far as the area under this crop is concerned, China stands first followed by India, Turkey, Egypt, U.S.A., Iran, Italy, Mexico, Spain, Brazil and others. In terms of production also, China is the leading producer followed by U.S.A., Turkey, India, Egypt, Italy, Spain, Iran, Mexico and others (Sasser et al., 1983) Tomato (Solanum lycopersicum L.) is consumed nearly in every household in Ghana and it accounts for 38% of the total vegetable expenditure (Wolff, 1999). Beside being tasty, tomatoes also contribute to a healthy diet being a source of vitamins A, B and C and also containing good amounts of potassium, iron, and phosphorus (Wener, 2000). According to Hornaet al. (2006), in Ghana during the dry season, local production is not able to meet the domestic high demand and tomatoes are often imported, mainly from Burkina Faso. This can be attributed to several reasons, and most important among these is the vulnerability of tomato crop to various diseases including fungal, viral, bacterial and nematode diseases (Sasser et al., 1983). An estimated amount of US$500 million is spent on nematode control globally (Keren - Zur et al., 2000). Yield losses of between 73 - 100% were reported in Northern Ghana due to root-knot nematode (Hemeng, 1981). They cause serious damage to tomatoes, impacting both the quantity and quality of marketable yields (Peacook, 1957).

Keywords: Tomato, nematodes, symptoms, history.