(M4) SOYBEAN: Glycine max (L.) Merr. Terutaka Niide and Bonnie B. Pendleton Division of Agriculture P.O. Box 60998 West Texas A&M University Canyon, TX 79016-0001 Phone: (806) 651-2505 Fax: (806) 651-2938 E-mail: firstname.lastname@example.org Robert Bowling Texas Cooperative Extension Moore and Sherman counties st 310 1 Street Dumas, TX Phone: (806) 935-2594 Fax: (806) 934-9765 E-mail: email@example.com Dectes borer: Dectes texanus texanus LeConte It has been reported soybeans resistant to soybean cyst nematode were less infested by Dectes borer. Eleven varieties of soybeans in maturity groups III to V were evaluated for abundance of and damage by Dectes borer in a field at the Texas A&M Research Field near Etter, TX. Varieties were selected based on reports of resistance to soybean cyst nematode in Kansas and Tennessee . Each plot was 4 rows × 21 m long, and 76 cm apart. The experimental design was a RCB with four replications. Soybean seeds were planted 296,526 per hectare on 29 May in a field adjacent to sunflower residue infested with Dectes borer. The soybean field was irrigated with 10.4, 11.6, 12.9, and 11.2 cm of water on 8 May, 22 Jul, 13 Aug, and 28 Aug, respectively. Twenty consecutive soybean plants from one of the center two rows of each plot were pulled up and brought to a laboratory on 11 Sep. Petioles and stems were split and examined for tunneling by Dectes borer. The length and width of each tunnel were measured with a micrometer caliper calibrated to 0.1 mm. Damaged stems were examined for girdling. The outside diameter of the stem, number of side shoots, number of petioles, numbers of infested petioles and stems, width and length of each tunnel in infested plants, number of larvae, and whether the stem was girdled or not were recorded. PROC MIXED was used to analyze data (P ≤ 0.05). Soybean variety did not significantly affect the percentage of stems, petioles, side shoots or girdled plants infested by Dectes borer. Soybean cyst nematode-resistant varieties of soybean did not confer resistance to Dectes borer in this study, contrary to findings of others. It is possible that lack of Dectes borer in previous studies might have been a behavioral response such as antixenosis by adult Dectes during oviposition. Assessment of adult Dectes behavior and laboratory assays to determine mechanisms of resistance in soybean are needed to determine factors that influence ovipositional preference by Dectes to soybean hosts. Resistance to Percentage per plot Soybean soybean cyst variety nematode Stems infested Petioles infested Side shoots infested Stems girdled 'DKB38-52' Unknown 3.8 2.5 0 0 'AG3702' R - 3, MR - 14 6.3 6.3 0 1.3 '93B85' R - 3, 5, 14 7.5 2.5 1.3 2.5 'AG3703' R - 3 11.3 3.8 0 0 'AG3905' R - 3, 14 2.5 7.5 3.8 0 'AG3701' MR - 3 12.5 10.0 1.3 0 'DKB46-51' R - 3, 14 17.5 10.0 0 1.3 'DKB38-51' R - 3, 14 21.3 3.8 1.3 1.3 'AG3903' Unknown 20.0 7.5 1.3 1.3 'DK5995' Unknown 22.5 12.5 1.3 1.3 'AG4301' R - 3 27.5 22.5 0 0 Means in a column are not significantly different (P > 0.05). R = resistant and MR = moderately resistant to soybean cyst nematode; the number indicates the race of soybean cyst nematode.
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 2005