Beneficial Effects of Solid Matrix Chemo-priming in Okra

Area of Science:

• Agricultural Science
• Plant Pathology
• Horticulture

Background:

• Okra (Abelmoschus esculentus) is susceptible to damping-off disease caused by Pythium ultimum.
• Seed priming techniques are explored to improve seedling establishment and reduce disease incidence.
• Pythium ultimum is identified as a primary pathogen affecting okra seedling emergence in field conditions.

Purpose of the Study:

• To evaluate the efficacy of solid matrix priming techniques on okra seedling emergence and damping-off.
• To assess the combined effects of priming and fungicide seed treatment against Pythium ultimum.
• To compare chemo-priming and biological seed treatments with untreated and CMC-treated controls.

Main Methods:

• Field trials conducted at Stillwater and Bixby, OK, using okra seeds subjected to chemo-priming (thiram + carboxin), biological seed treatment (Trichoderma harzianum), untreated seed, and 1% carboxymethylcellulose (CMC) control.
• Evaluation of seedling emergence rates, vigor, and damping-off incidence in soil naturally infested with Pythium ultimum.
• Laboratory pathogenicity tests comparing isolates of Pythium ultimum with other soilborne fungi.

Main Results:

• Chemo-primed seeds exhibited more uniform and faster emergence compared to untreated seeds.
• Chemo-primed seeds demonstrated significantly greater vigor than fungicide-treated or priming-alone treatments.
• No significant differences in crop yield were observed among any of the evaluated treatments.

Conclusions:

• Solid matrix chemo-priming effectively enhances okra seedling emergence and vigor in Pythium ultimum-infested soils.
• While priming improves early-stage growth, it did not translate to increased final yield under the tested conditions.
• Pythium ultimum is a significant pathogen of okra, exhibiting higher pathogenicity than other isolated fungi.