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Charles E. Barrett, Xin Zhao, and Robert McSorley

that grafting onto resistant rootstocks can reduce nematode galling incidence. Tomato hybrid and interspecific tomato hybrid rootstocks were compared with respect to their influence on nematode resistance, crop vigor, and fruit yield. Materials and

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Wenjing Guan, Xin Zhao, Donald W. Dickson, Maria L. Mendes, and Judy Thies

because of their wide host range and the lack of highly effective management strategies. The use of soil solarization, cover crops, soil amendment, and biological control for disease and nematode management often yields only moderate results ( Oka et al

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Susan L.F. Meyer, Inga A. Zasada, Shannon M. Rupprecht, Mark J. VanGessel, Cerruti R.R. Hooks, Matthew J. Morra, and Kathryne L. Everts

, 2005 ; Hansson et al., 2008 ; Rothlisberger et al., 2012 ; Vaughn et al., 2006 ). Root-knot nematodes ( Meloidogyne sp.) are among the pathogens that can be suppressed by incorporation of mustard seed meals into soil. Application of ethiopian

Open access

J. N. Corgan, D. L. Lindsey, and R. Delgado

Abstract

The effects of the root-knot nematode [Meloidogyne incognita (Kofoid and White)] Chitwood ‘Race 3’, on ‘Utah Yellow Sweet Spanish’ onion were investigated in microplots containing a sandy loam. Inoculum levels of M. incognita ranged from 0 to 20,900 eggs and juveniles/500 cm3 soil. Onion growth and yield were suppressed severely in all nematode infested plots. Bulb weight/plant in the nematode infested plots was 24% of that in the root-knot nematode free plots. Symptoms of plants infected with M. incognita included numerous small galls on the roots, retarded growth, light foliage color, and leaf tip burn. The data indicated that M. incognita densities greater than 250 eggs and juveniles/500 cm3 soil can cause significant yield loss in onions in sandy loam.

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Mary Ann D. Maquilan, Dominick C. Padilla, Donald W. Dickson, and Bala Rathinasabapathi

Plant-parasitic root-knot nematodes (RKNs; Meloidogyne spp.) can cause severe damage to their hosts, leading to reductions in crop yield and quality ( Taylor and Sasser, 1978 ). These pathogens become problematic, especially in warmer weather in

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Perry E. Nugent and P.D. Dukes

The southern root-knot nematode, Meloidogyne incognita [(Kofoid & White) Chitwood], causes serious economic losses to melon (Cucumis melo L.) production in the United States. The present study was conducted to determine if separable differences in nematode resistance of Cucumis melo could be found at some inoculum level. Five C. melo lines were compared with Cucumis metuliferus Naud. (C701A), a highly resistant species, for root necrosis, galling, egg mass production, and reproduction when inoculated at 0, 500, 1000, 2000, or 5000 nematode eggs per plant. Using these criteria, melon line C880 inoculated with 1000 eggs per plant was highly susceptible, while PI140471, PI 183311, and the cultivars Chilton, Georgia 47, Gulf Coast, Planters Jumbo, and Southland were less susceptible. In greenhouse tests with an inoculum level of 1000 eggs per plant, low levels of resistance were evident. A thorough screening of the available germplasm against M. incognita may identify higher levels of root-knot nematode resistance for incorporation into improved melon cultivars.

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Francesco Di Gioia, Monica Ozores-Hampton, Jason Hong, Nancy Kokalis-Burelle, Joseph Albano, Xin Zhao, Zack Black, Zhifeng Gao, Chris Wilson, John Thomas, Kelly Moore, Marilyn Swisher, Haichao Guo, and Erin N. Rosskopf

Soilborne fungal pathogens, nematodes, and weeds represent some of the most important biotic factors limiting vegetable crop production and profitability in the world. After the phaseout of methyl bromide, although other chemical soil fumigants (CSF

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T.C. Vrain, Hugh A. Daubeny, J.W. Hall, R.M. DeYoung, and A.K. Anderson

The inheritance of resistance to the root lesion nematode [Pratylenchus penetrans (Cobb) Filip. and Stek.] in red raspberry (Rubus idaeus L.) was studied in a four-member half diallel, involving two resistant genotypes and two susceptible genotypes. Estimates of general and specific combining abilities (GCA and SCA, respectively) were determined for nematode densities in roots alone and soil alone, nematode densities per plant, and plant root and foliage biomass. GCA were significant for nematodes in soil and for root and foliage biomass; SCA were significant for nematodes in the soil and for root biomass. Neither GCA nor SCA was significant for number of nematodes in the roots or per plant.

Open access

Wayne B. Sherman, Paul M. Lyrene, and Paul E. Hansche

Abstract

A new root-knot nematode (Meloidogyne sp.) of peach which occurs in Florida overcomes the resistance of Okinawa and Nemaguard rootstocks (Prunus spp.). Resistance to this new nematode obtained from crosses and open-pollinated seedlings of Okinawa, Chico II, and P. davidiana has a heritability (narrow sense) of 0.31 ± .04. Two selections, Fla. 14-11 and Fla. 9-4, combine the nematode resistance of Okinawa and Nemaguard with resistance to the new nematode.

Open access

C. D. McCarty, W. P. Bitters, and S. D. Van Gundy

Abstract

No significant difference in root or top weight of 25 citrus rootstock seedlings grown in the greenhouse for 15 months was attributable to infestation of the citrus nematode, Tylenchulus semipenetrans (Cobb). Many nematodes were found on the roots of most of the cultivars tested regardless of nematode biotype, with the exception of trifoliate orange and some hybrids where one parent was trifoliate orange.