An extensive survey of root-knot nematodes (Meloidogyne spp.) in the North West Frontier province (NWFP) of Pakistan comprising of 74521 sq km area was conducted. A total of 494 positive samples of root and rhizopheric soil from 58 species of plants belonging to 15 families were collected form 164 localities grouped into 34 arbitrary regions in 14 districts/agencies of the province. Root-knot nematodes were identified on the basis of morphological characters as will as North Carolina Differential Host Test.
Four species of Meloidogyne viz. M. javanica (Treub,1885) chitwood, 1949, M. incognita (Kofoid & White, 1919) Chitwood, 1949, M arenaria (Neal, 1889)Chitwood, 1949 and M. hapla Chitwood, 1949 were found fairly well distributed throughout the province. Tow races of M. incognita (R-1,R-2) and both races of M. arenaria were identified. M. javanica ranked first, with respect to both geographical distribution (114 out of 164 localities) and natural host range (39 out of 58 plants) followed by M. incognita (27 out of 58 plants).
Of the 58 plant species with which root-knot nematodes were found associated, only three namely tomato (Lycopersicon esculentum Mill.), okra (Abelmoschus esculentus (L.) Moench) and egg plant (Solanum melongena L.) were found as hosts of all these four species of Meloidogyne. Plants which were hosts of any three species of meloidogyne were the following five: banana (Musa sapientum L.), chilli pepper (Capsicum annum L.), kidney bean (Plaseolus vuglaris L), potato (Solanum tuberosum L.), and sponge gourd (Luffa cylindrical L.), The 12 plants which were found as hosts of any two species were cabbage (Brassica oleracea L. cv capitata), carrot (Daucus carota L.), cucumber (Cucumis sativus L.), lettuce (Lactuca sativa L.) musk melon (Cucumis melo L.) peach (Prunus persica (L.) Batsch ) , pyrethrum (Chrysanthemum cinerariefolium L.), soybean (Glycine max (L.) Merr.), sugarbeeet (Betavuglaris L.), sugarcane (Saccharum officinarum L.), tobacco (Nicotiana tabacum L.) and watermelon (Citrullus lanatus (Thunb.) Matsum & Naki) Thirty plants were found hosts of any one of the above mentioned Meloidogyne species, These were almond (Prunus amygdalus Batsch.), apricot (Prunus armeniaca L.), basil (ocimum basilicum L.) black night-shade (Solanum nigrum L.) bottle gourd (Lagenaria siceraria (Mol.)Standl), broad bean (Vicia faba L.), cauliflower (Brassicaa oleracea L. cv. Botrytis), chenopodium (Chenopodium album L.), chery (Prunus avium L.), chickpea (Cicer arietinum L.), cotton (Gossypium hirsutum L.), garden pea (Pisum sativum L.), garlic (Allium sativum L.), grape vine (Vitis vinifera L.), kenaf (Hibiscus cannabinus L.), lentil (Lens esculentus L.), maize (Zea mays L.) maize (Zea mays L.), lentil (Lens esculentus L.), onion (Allium cepa L.) peanut (Arachis hypogaea L.), plum (prunus domestica L.), pumpkin squash (Cucurbita moschata (Duch.) Poir.), radish (Raphanus sativum L.0, red colver (trifolium pretense L.), rice (oryza stiva.), spinach (Spinacia oleracea L.) squash (Cucurbita pepo L,), sunflower (Hilianthus annus L.), sweet orange (Citrus sinensis (L.) osbeck), and sweet potato (Ipomoea battas Lam.) Eight plants were found host of and unidentified species alone. These were alfalfa (Medicago sativa L),cosmos (Cosmos bippinnatus Cab.), guava (Psidium guajava L.), pear (pyrus communis L.), The plants where one or more unidentified concomitant Meloidogyne species were found associated with any of the four most common Meloidogyne species were found associated with any of the four most common Meloidogyne species were the following eight; broad been (Vicia faba L.), chenopodium (Chenopodium album L.) grape vine (Vitis vinifera L.), lentil (Lens esculentus L.), pyrethrum (Chrysanthemum cinerariefolium L.), spinach (Spinacia oleracea L.), tomato (Lycopersicon esculentum Mill,) and watermelon (Citrullus lanatus (Thunb.), Matsum & Naki). M. javanica was found to parasitize the following 39 plants; apricot, banana, basil, kidney been, cabbage, carrot, cauliflower, chenopodium, cherry, chillipepper, chickpea, cotton, cucumber, egg plant, garlic, grapevine, kenaf, lentil, lettuce, maize, muskmelon, okra, onion, peach, peanut, plum potato, pyrethrum, soybean, spinach sponge gourd, sugarbeet, sugarcane, sunflower, sweet orange, sweet potato, tobacco, tomato and watermelon.
M. javanica, M. arenaria and several ectoparasitic nematodes were found on peach roots and soil, collected from 34 places. Except in one instance where the M. javanica galling index was 5, low to moderate infestation was found on peach roots. In the experiment of varietal susceptibility using 18 peach cultivars, seven viz. Golden jubilee, El berta, Meadow lark, NJ 238, Spring dust, Carmen and 3A gave galling index of 3 indicating moderate susceptibility to M. javanica. Cultivars 6A, Babcock, NJ 241, Summer set, Triumph, Wiggin and South heaven showed galling index of 2 while the remaining viz. Robbin early, Flordasel, Loring and Red French an index of 1 and both of these categories (galling index 2 and 1) were considered resistant to M. javanica.
Seasonal fluctuations of M. javanica population associated with peach were studied for 24 months (March 1983 to February 1985). Highest galling (31 galls/ plant) was observed during the month of September, 1984 followed by September, 1983 July, 1984 and August, 1984 (29 galls/plant) whereas lowest galling (2 galls/plant) was noted in the month of January, 1984 followed by December, 1983 and January, 1985 (6 galls/ plant). The distribution and occurrence of nematodes in the province was found correlated with irrigation system, temperature and soil fabric, More root-knot nematodes were found in the irrigated areas than the rain-fed areas where minimum temperature did not fall below 10° C. The soils where clay portion was more than 30% resulted in less root-knot nematode infestation. No correlation could be established between nematode occurrence and rainfall, altitude, electric conductivity, pH, presence of salts (P2 O5,K2O and Caco3) and organic matter.
Two crops viz, tobacco Nicotiana tabacum and okra Abelmoschus esculentus were used for control experiment in which four chemicals (carbofuran, aldicarb, phenamiphos and tenekil) and five organic amendments (mustard (Brassica compestris) oil cake, saw dust, tobacco (Nicotiana tabacum) dust and mazri (Mannohops ritchieana) leaf liquor were tested. In case of tobacco data about leaf yield and in case of okra about fruit yield were collected and in both cases mustard oil cake ranked first followed by cotton oil cake. However, when galling index of all the treatments was worked out, carbofuran ranked first followed by aldicarb.