http://localhost:80/xmlui/handle/123456789/16873 2026-04-07T11:12:06Z http://localhost:80/xmlui/handle/123456789/17609 Title: RELATIONSHIP OF NEMATODES TO YIELD OF MAIZE GROWN UNDER DIFFERENT CULTIVATION REGIMES Authors: MAHFOUZ M; ABD-ELGAWAD Abstract: Relationships between population densities of different nematode species at harvest and yield of maize were examined for 4 cropping sequences on sandy loam soil in Ismailia, Egypt. Correlations calculated between the total plant-parasitic nematode population densities and yield were not significant for individual cropping sequences tested; whereas among the individual genera, population densities of Helicotylenchus pseudorobustus only had significant (P=0.05) negative correlation with yield in two cropping sequences. Log-transformed nematode densities, however, revealed additional negative correlation between maize yield and density of Heterodera zeae. The general relationship was described by Y = 409.1283 - 1.2113 X1 - -0.7330 X2 + 0.2430 X3 + 0.2429X4 where Y = yield or ear weight (g/plant), X1, X2, X3 and X4 nematode population densities of Helicotylenchus pseudorobustus, Heterodera zeae juveniles, Pratylenchus brachyurus and Tylenchorhynchus latusper 100 cm3 soil at harvest; respectively (P = 0.0628). Accordingly, maize yield loss estimate caused by the nematodes was 63 g/plant. At harvest, no significant correlations were found between population densities of the different nematode species in each site including a cropping sequence. Yield components of individual maize cv. Giza 2 plants were more than that produced by cv. Double hybrid 202. 1990-07-11T00:00:00Z http://localhost:80/xmlui/handle/123456789/17606 Title: SEARCH FOR RESISTANCE TO ROOT-KNOT (MELOIDOGYNE INCOGNITA AND M. JAVANICA) AND RENIFORM (ROTYLENCHULUS RENIFORMIS) NEMATODES IN COWPEA Authors: PATEL, B.A.; CHAVDA, J.C.; PATEL, D.J. Abstract: Cowpea (Vigna unguiculata) is severely affected by root-knot nematodes, Meloidogyne spp., (Swarup, 1962) and by Rotylenchulus reniformis Linford & Oliveria, 1940 (Seshadri, 1970). R. reniformis causes 13% loss in cowpea yield from farmer’s point of view (Reddy & Singh, 1981). Growing resistant variety is the least expensive way of managing nematode diseases. Several workers have tried to locate resistance source through screening of germplasm in cowpea. Variety V-16 has been reported to be resistant to R. reniformis (Thakar & Patel, 1984). Cowpea varieties C-152 (Patelet al., 1977) and 82-1B (Patel et al., 1984) have been also identified as root-knot resistant cultivars. To further locate the sources of resistance to nematodes, 37 cowpea lines were tested separately against root-knot (mix population of M. incognita and M. javanica) and reniform (R. reniformis) nematodes in 10 cm diameter earthen pots filled with steamed soil. Completely randomized design with 5 replications was used. Variety Pusa falguni, a known susceptible cultivar, was used a check. Single seed of each line was seeded/pot. On attaining 2-3 cm height, 500 second stage juveniles of root-knot and 200 pre-adult larvae of reniform nematodes were inoculated in the rhizosphere of each plant in each set. Plants under root-knot inoculations were examined after 45 days of incubation and roots scaled for root-knot intensity using 0-5 (0=Free, 5-Maximum root galling) rating scale. In case of reniform nematode, 12 days after inoculation, each plant was carefully removed and washed free of soil. Roots were stained in0.05% acid fuchsin lactophenol. Finally the reaction of susceptibility to nematode infection for each variety was given on the basis of maximum gall index for root-knot nematodes and maximum number of females penetrated in the roots for reniform nematode. 1990-07-10T00:00:00Z http://localhost:80/xmlui/handle/123456789/17602 Title: INFLUENCE OF SALINITY STRESSES ON HATCHING AND JUVENILE MORTALITY OF ROOT-KNOT NEMATODES, MELOIDOGYNE INCOGNITA (RACE 2) AND MELOIDOGYNE JAVANICA Authors: KHAN, ABRAR AHMAD; KHAN, M. WAJID Abstract: Effect of different soil salinity levels (ECe) of NaCl and NaHCO3 on hatching and mortality of juveniles (J2) or root-knot nematodes, Meloidogyne incognita (race 2) and M. javanica were studied in artificial treatment. A direct correlation in hatching and salinity levels were recorded. Inhibition in hatching and juvenile mortality were highest in 5.0 mmhos/cm. At all the salinity levels, per cent mortality increased with an increase in exposure period. Hatching inhibition and mortality percentage of M. javanica were slightly greater than M. incognita (race 2). Sodium chloride showed a greater effect than NaHCO3 for both the nematodes. 1990-07-09T00:00:00Z http://localhost:80/xmlui/handle/123456789/17599 Title: EFFICACY OF CERTAIN VITAMINS IN CONTROLLING THE ROOT KNOT NEMATODE, MELOIDOGYNE INCOGNITA ON TOMATO Authors: S.A. MONTASSER Abstract: The efficacy of 3 vitamins applied as foliar sprays in controlling the rootknot nematode,Meloidogyne incognita, were evaluated under greenhouse conditions. All concentrations of ascorbic acid, riboflavin and nicotinic acid reduced the number of galls and nematode reproduction over untreated plants. Ascorbic acid and riboflavin gave the best nematode control and plant growth. 1990-07-08T00:00:00Z