Location: Soil Dynamics ResearchTitle: Effects of fertilization, tillage, and phorate on thrips and TSWV incidence in early planted peanuts Author
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/8/2013
Publication Date: 7/8/2013
Citation: Tubbs, R.S., Balkcom, K.S., Toews, M.D., Srinivasan, R. 2013. Effects of fertilization, tillage, and phorate on thrips and TSWV incidence in early planted peanuts [abstract]. In: Proceedings of the American Peanut Research and Education Society. p. 34. Interpretive Summary:
Technical Abstract: Thrips feeding is usually more prevalent in early planted peanuts (Arachis hypogaea L.), which often directly results in higher incidence of tomato spotted wilt virus (TSWV). Several management tools are available to reduce thrips feeding and/or the threat of TSWV in early planted peanuts, including fertilization which could help plants grow out of thrips damage more rapidly, tillage method (surface residues in reduced tillage systems disrupt thrips feeding on peanut foliage), and use of phorate insecticide. However, current peanut cultivars exhibiting excellent field resistance/tolerance to TSWV may not require thorough management of thrips for control of TSWV as in the past when more susceptible cultivars were being grown and TSWV pressure was more severe. Trials were established in Tifton, GA and Headland, AL in 2011 to assess early season thrips populations and whether they were viruliferous or not, TSWV incidence, and yield potential for Georgia-06G peanut planted in late April using factorial combinations of starter fertilizer (16.7 L/ha 10-34-0 vs. none), tillage (conventional deep-turn vs. strip-till), and phorate (5.6 kg/ha vs. none). Starter fertilizer had no effect on yield, grade, thrips numbers, or TSWV incidence. Conventional tillage resulted in approximately twice as many adult tobacco thrips (Frankliniella fusca) than strip-till management at 21 days after planting (DAP) and four times as many immature thrips at 28 DAP in both locations. There was likewise more than twice as much TSWV in conventional till plots as a result of heavier feeding. However, this did not adversely affect production, as conventional tillage had 7% higher yield and 1.2% improved grade over strip till. The inclusion of phorate reduced adult thrips by 50% at 14 and 21 DAP at both locations, and there were approximately 75% fewer immatures with phorate than without the treatment at 28 DAP in both locations. There was likewise a resulting 15% increase in yield where phorate was used. Management decisions including tillage and/or phorate in-furrow have a much more significant effect on thrips management and peanut production than starter fertilizer.