Emergence and Seedling Growth of Okra Genotypes at Low Temperatures

Abstract

Seedling emergence and growth of 39 genotypes of okra [ Abelmoschus esculentus (L.) Moench] were studied at several temperatures. Seeds were evaluated in two separate studies. One was a 3-year early planting field evaluation where air temperatures ranged from -2 to 29C. The other was a study at controlled temperatures of 10/10, 14/10, 15/15, 20/10, and 20/20C day/night. Okra genotypes showed variation in seedling emergence in the field, but the results fluctuated over years. Seedlings emerged at all the controlled temperatures, although the percentage of emergence reached only 13% at 10/10C. All temperature regimes produced some degree of leaf chlorosis, the severity of which was greatest at the lower temperatures. Leaves of none of the okra seedlings of any of the genotypes grew at 10/10, 14/10, or 15/15C. Genotypic variation in emergence was observed with the controlled temperatures.