Sustenance of Seed Germination Potential of Two Okra (<em>Abelmoschus esculentus</em> L. Moench) Varieties under Different Environmental Conditions in Sri Lanka

Abstract

Okra (Abelmoschus esculentus L. Moench) is a popular vegetable grown in most parts of Sri Lanka. Farmers and home gardeners purchase seeds in packed-form from retail outlets. However, quality problems are frequently reported, especially claiming low field germination even with the laboratory-tested and certified seeds. Quality parameters namely, percentage germination, moisture, field emergence and vigour index analysis were used to determine the effect of different storage environmental conditions on seed longevity of two okra varieties during a two-year storage period, from March 2016 to March 2018. Seeds in triple-laminated packets stored in four contrasting environments, namely, low temperature storage conditions (17°C and 60-65% RH); three geoenvironmental conditions namely; Gannoruwa (Mid Country Wet Zone), Kundasale (Mid Country Intermediate Zone), and MahaIlluppallama (Low Country Dry Zone) displayed varied behavior in seed quality parameters respective of the variety. It was apparent that germination test alone does not represent the full potential of field emergence. Results of the present study revealed that when field emergence and vigour are also taken in to account, both varieties of okra seed (with initial germination and moisture of ca. 94% and ca. 10%) can be stored under ambient conditions at Gannoruwa, Kundasale or MahaIlluppallama for a maximum period of 12 months, without compromising the seed quality. The seeds stored under low temperature conditions (i.e. 17°C), maintained the seed germination over 75% for a period of 24 months.

Keywords

• field emergence, germination, seed survival, storage conditions, vigour index