| Popis: |
Pest-resistant peanut (Arachis hypogaea L.) cultivars are critically important to reduce the increasing cost of production. Current pesticides used in the U.S. are effective but very expensive. The objective of this study was to evaluate several advanced Georgia breeding lines when grown without nematicides, fungicides, or insecticides. Preliminary yield trials without pesticides were conducted for 3 yr (1996-98) at the Univ. of Georgia, Coastal Plain Exp. Sta. under irrigation. However, preplant and occasionally post-applied herbicides were used for weed control. Thrips damage was noticeably uniform and severe early in the growing season each year, but plants seemingly recovered by midseason. Probably the most endemic diseases in the Southeast are both early and late leaf spots [Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton, respectively] and tomato spotted wilt virus (TSWV). Results from replicated field tests strongly suggest that it would be economically feasible to significantly reduce pesticide cost by growing multiple pest-resistant advanced Georgia breeding lines as compared to the five check cultivars Florunner, GK-7, Southern Runner, Florida MDR 98, and Georgia Browne. However, dollar values were variable and low with no pesticides because of the overall reduction in yield. An alternative approach for greater net returns possibly may be achieved by only reducing currently recommended input costs rather than eliminating pesticides with pest resistant cultivars. |
