Wednesday, November 15, 2006
235-6

Response of Peanut Diseases in a Bahiagrass Rotation System and the Influence on Yield.

F.K Tsigbey1, T.W. Katsvairo2, J.J. Marois1, D.L. Wright2, J.R. Rich1, and P.J. Wiatrak1. (1) Univ of Florida, 155 Research Rd, Quincy, FL 32352, (2) Univ of Florida, 155 Research Rd, Quincy, FL 32352

Bahiagrass(Paspalum notatum) rotation was evaluated as an alternative peanut  (Arachis hypogaea) disease management strategy for the traditional peanut and cotton (Gossypium hirsutum L.) rotation between 2003-2005 in North Florida. In a four year rotation using Cotton-Bahiagrass-Bahiagrass-Peanut (CBBP), and Peanut-Cotton-Cotton-Peanut (PCCP), peanut diseases [Early (Cercospora arachidicola) and late (Cercosporidium personatum) leaf spots, tomato spotted wilt (TSW), and southern stem rot (Sclerotium rolfsii)] were consistently reduced in the CBBP rotation. Southern stem rot (Sclerotium rolfsii) incidence was higher at all scoring times for the peanut/cotton rotation compared to the bahiagrass rotated peanuts in 2003. The average TSW incidence was higher for the PCCP rotations (21.7%, 71%, 51.4%) compared to the CBBP rotation (10.2%, 32%, and 28.93%) in 2003, 2004, and 2005 respectively.  Number of thrips per peanut plant was lower for the CBBP rotation (8) and higher for the PCCP rotation (22) in 2005 and this corresponded with a higher percentage of peanut plants damaged by thrips feeding, 37.5% and 92.5% respectively. Bahiagrass rotation reduced Cercospora leaf spot progression and severity in all years with significant differences in the severity of peanut leaf spots between the two rotations. On the Florida scale of 1-10, leaf spot severity at harvest was 5.2 for CBBP rotation peanuts compared to 5.8 in the PCCP rotation in 2003; 6.1 and 7.5, 6.1 and 6.6 respectively in 2004, and 2005.  The CBBP rotation increased pod yield of peanut over the traditional PCCP rotation, 2,783kg/ha and 1,959kg/ha in 2003; 3,282kg/ha, and 2,415kg/ha in 2004; and 1,856kg/ha and 1,381kg/ha in 2005 respectively.  Pathogenic soil nematode population was lower in the CBBP rotation compared to the PCCP.

Handout (.pdf format, 213.0 kb)