http://hdl.handle.net/10150/209669 Thu, 12 Mar 2026 12:59:48 GMT 2026-03-12T12:59:48Z http://hdl.handle.net/10150/211150 Suppression of Plant Parasitic Nematodes in Cotton Using the Antomopathogenic Nematode Steinernema Riobravis (Cabanillas, Poinar, and Raulston) (Rhabditida: Steinernematidae) Gouge, D. H.; Smith, K. A.; Payne, C.; Lee, L. L.; Van Berkum, J. R.; Henneberry, T. J. Silvertooth, Jeff Cotton fields were treated with the entomopathogenic nematode, Steinernema riobravis, and Vydate® L for the control of plant parasitic nematodes. Short staple cotton grown near Coolidge, Arizona, was treated at a rate of 1 billion and 2 billion S. riobravis nematodes per acre, and 0.5 lb a.i. Vydate® L per acre. Untreated cotton received an application of water only. Treatments were applied through a subterranean drip system with 12 inch spaced outlets. Applications were made in the daily irrigation cycle of 0.33 inches of water, normal irrigation cycles followed Products were uniformly distributed over the treated fields. Entomopathogenic nematodes persisted throughout the 6 week experimental period at the 1 billion per acre rate. However, nematodes applied at 2 billion per acre rate disappeared rapidly. Populations of various plant parasitic nematode species were monitored subsequent to treatment application. Nematodes were extracted using a standard sugar flotation technique and counted in I ml slide samples. Both Meloidogyne incognita and Tylenchorhynchus spp. populations were reduced by S. riobravis applied at 1 billion per acre rate. Phytoparasitic nematodes were reduced following application of Vydate® L, but control was not sustained beyond one week. Sat, 01 Mar 1997 00:00:00 GMT http://hdl.handle.net/10150/211150 1997-03-01T00:00:00Z http://hdl.handle.net/10150/211149 Telone II® Following Grain Rotation for Nematode Control? Husman, S. H.; McClure, M. A. Silvertooth, Jeff Six field trials were conducted between 1994 and 1996 in Buckeye and Gila Bend, Arizona to determine the effect of soil fumigation with Telone II on the yield of cotton following rotation with Durham wheat. Telone was shank injected at two or more rates (0, 3, or 5 gal/acre) in fields previously maintained with a cotton-wheat-summer/winter fallow rotation. Five fields were planted to Upland and one field to Pima cotton. Four of the six trials resulted in an average lint yield increase of 180 lint lbs/ac compared to the untreated controls. In one trial where all three rates were compared, yield at the 5 gallon rate was increased 141 lint lbs/ac compared to the 3 gallon rate and the control. In two of the trials none of the treatments differed significantly. Sat, 01 Mar 1997 00:00:00 GMT http://hdl.handle.net/10150/211149 1997-03-01T00:00:00Z http://hdl.handle.net/10150/211132 Aflatoxin Contamination of Bt Cottonseed Cotty, P. J.; Howell, D. R.; Bock, C.; Tellez, A. Silvertooth, Jeff Transgenic Bt cotton may have reduced susceptibility to aflatoxin contamination as a result of pink bollworm resistance. During 1995 and 1996, Bt cottonseed from several commercial fields in Arizona contained aflatoxin levels unacceptable for dairy use. Comparison of cottonseed with and without BGYF (bright-green-yellow fluorescence) from one highly contaminated (> 6,000 ppb aflatoxin Bj) Bt seed lot indicated that most contamination probably resulted from exposure of mature cotton to high humidity. Seed exhibiting BGYF was repeatedly detected in Bt cottonseed lots but, pink bollworm exit holes were not observed in the field. A field plot test in 1996 demonstrated high resistance among Bt cultivars to both pink bollworm damage and formation of BGYF seed cotton. These observations suggest that resistance to pink bollworm will result in reduced aflaaoxin contamination when pink bollworm pressure coincides with conditions conducive to Aspergillus flavus infection. However, Bt cultivars are not resistant to aflatoxin increases occurring after boll opening and large quantities aflatoxin can form during this period. If insect control provided by Bt cultivars leads growers to hold crops in the field longer, most advantages of Bt cotton in aflatoxin management may be lost. Combined use of Bt cultivars and atoxigenic strains of A. flavus may result in the most reliable control of aflatoxin contamination. Sat, 01 Mar 1997 00:00:00 GMT http://hdl.handle.net/10150/211132 1997-03-01T00:00:00Z http://hdl.handle.net/10150/211131 1996 Seed Treatment Evaluations Norton, E. R.; Silvertooth, J. C. Silvertooth, Jeff Cottonseed was treated with several fungicide treatments in an effort to protect the seed and seedling from disease. Seed germination and vigor was evaluated in two Arizona locations; Maricopa and Marana. Stand counts were taken on two separate dates after emergence at both Maricopa and Marana and percent emergence was calculated. Significant differences in percent emergence due to treatment were observed in the first sample date at Marana with the treatment combination of NuFlow ND and Maxim having the highest percent emergence. Results from the second sample date at Marana were statistically significant but similar treatment ranking was observed. Results at Maricopa showed no statistically significant differences due to treatment for either sample date. Sat, 01 Mar 1997 00:00:00 GMT http://hdl.handle.net/10150/211131 1997-03-01T00:00:00Z