Link to home

Beneficial Effects of Solid Matrix Chemo-priming in Okra

May 2001 , Volume 85 , Number  5
Pages  535 - 537

K. E. Conway and R. Mereddy , Department of Entomology and Plant Pathology ; B. A. Kahn and Y. Wu , Department of Horticulture and Landscape Architecture ; and S. W. Hallgren and L. Wu , Department of Forestry, Oklahoma State University, Stillwater 74078

Go to article:
Accepted for publication 2 February 2001.

Two field trials at Stillwater and Bixby, OK, evaluated the efficacy of solid matrix priming techniques, alone or in combination with fungicide seed treatment on seedling emergence and reduction of damping-off of okra in field soil naturally infested with Pythium ultimum. The following treatments were evaluated: thiram + carboxin (chemo-primed) (commercially applied), biological seed treatment (bio-primed) (Trichoderma harzianum isolate OK-110, 1 g suspended in 1% carboxymethylcellulose [CMC]), untreated seed (control), and a 1% CMC control. Chemo-primed seeds had a more uniform and faster emergence compared with untreated seeds at both field sites. Within 3 days, 92 and 78% of chemo-primed seeds had emerged at Stillwater and Bixby, respectively, compared with 84 and 71% emergence in the untreated control. Mean emergence of chemo-primed seeds was lower (P ≤ 0.05) than the untreated control. Chemo-primed seeds had greater vigor (P≤ 0.05) at both locations compared with either fungicide-treated or priming alone, at both locations. There were no differences (P ≤ 0.05) in yield among treatments at both locations. P. ultimum was consistently isolated from damped-off seedlings and surrounding soil at both locations. Isolates of P. ultimum were more pathogenic on okra in laboratory tests than isolates of Rhizoctonia spp., Fusarium spp., and other Pythium spp. also isolated from seed or soil.

Additional keywords: bio-priming, emergence rate, seed vigor

© 2001 The American Phytopathological Society