Economic and Weed Control Assessment of Double-Crop and Relay-Intercropping Systems of Peanut with Wheat.

The climatic conditions of the southeastern U.S. may allow multiple cropping systems of peanut (Arachis hypogaea) with wheat (Triticum aestivum) to be a sustainable approach towards crop production. The objectives of this project were to determine the most economically viable cropping systems to maximize wheat and peanut yield potential and the system effect on weed control. A split-plot design was used with eight cropping systems including variations of double-crop (DC), relay-intercrop (RI) and monocropping (MC) as main-plots and three sub-plot effects of peanut cultivars. Studies were conducted in Tifton, GA in 2009 and Plains, GA in 2010. Visual weed ratings in 2009 determined both RI treatments (54-65%) were least effective in controlling crowfootgrass (Dactyloctenium aegyptium), while control of smallflower morningglory (Jacquemontia tamnifolia) was lowest in one RI treatment (70%). Wheat yields within the RI (1300-3100 kg ha^-1) plots were consistently lower than the DC (4065-4250 kg ha^-1) treatments in both years. In 2009, peanut yields in RI (3500-3715 kg ha^-1) and DC (3550-3970 kg ha^-1) treatments were significantly lower than the majority of MC treatments. Peanut yields in 2010 were significantly higher in one MC (4920 kg ha^-1) treatment than all other treatments (3590-4190 kg ha^-1) except for the DC (4335-4710 kg ha^-1) plots. In 2009, the income above variable cost (IAVC) for one MC ($1390 ha^-1) treatment was significantly higher than all other treatments ($376-895 ha^-1). The IAVC for 2010 showed both DC ($1042-1141 ha^-1) plots being significantly greater than all other treatments ($294-756 ha^‑1). At this time, double cropped peanut after wheat does provide an economic advantage and has shown to provide better weed control over relay-intercropping of peanut with wheat. Additional research is needed to improve management of relay-intercrop systems to fully realize the benefits that such systems can provide.