The Beneficial Effects of Insect Pollination and Biochar Seed Coating on Okra (<i>Abelmoschus esculentus</i>) Seed Quality at Varying Temperature Conditions

Abstract

Underutilized crops, such as okra, have the potential to alleviate stress on crop production imposed by climate change and farming conditions, but their production is greatly hindered by poor seed quality. Insect pollination and seed coating with organic substances (biochar) may improve okra’s seed performance, but the beneficial effects of biochar seed coating and pollination on the seed quality of okra grown under stressful conditions is unknown. We examined the impact of pollination and biochar seed coating on okra seed performance under varying temperatures. Seeds were obtained from plants grown under complete insect pollination and exclusion. A factorial experiment was conducted in growth chambers with three factors: seed type, seed coating and temperature conditions. Insect-pollinated seeds with biochar coating had the highest chlorophyll content, seedling vigour index, shoot, and root growth and the heaviest seedling mass, but with a reduced speed of germination and emergence. The insect-pollinated seed without biochar coating had a lighter seedling mass (33% lower) than insect-pollinated, coated seed. Low temperature conditions during germination were ameliorated by biochar seed coating but biochar coating could not alleviate high temperature (35/30 °C) stress. Harnessing the pollinator’s benefits and biochar seed coating are possible sustainable solutions to enhance seed quality.

Keywords

• biochar
• germination
• pollinated seed
• temperature
• vigour