Seed Quality Status of Polymer-Coated Bt Cotton (Gossypium sp.) During Storage Under Coastal Environment

Abstract

An experiment was conducted during 2009 at Karaikal Dist., Puducherry (UT) to evaluate the seed quality status and storability of polymer-coated seeds of Bt cotton NHH 44. The seeds were coated with synthetic polymer (Polykote at the rate 3 ml/kg diluted in 5 ml of water kg⁻¹ seed) alone or in combination with fungicide (Flowable Thiram (Royal flow)) at the rate 2.5 g kg⁻¹ seed) or insecticide (Imidachloprid at the rate 6 ml kg⁻¹ of seed) or both and stored in 700 gauge polythene bags and cloth bags for 4 months. Besides the above mentioned, Vitavax 200 at the rate 2 g kg⁻¹ seed and seeds primed and dried to original moisture content and primed seed treated with polymer along with Flowable Thiram and Imidachloprid were also included as treatments. Observations on percentage seed germination, seed moisture content and seed infection were recorded at bimonthly intervals up to 4 months. The results of standard germination test on treated and untreated stored seeds indicated that seeds treated with Royal flow + Imidachloprid (90 %) were on par with Vitavax 200 (88.5 %) and Flowable Thiram alone (89 %) excelled other treatments irrespective of containers and period of storage. The increase in seed moisture content was gradual in the case of polythene bag when compared to cloth bag-stored seeds. The results on seed health status indicated that among the treatments, Polykote-coated seeds were highly susceptible to seed infection. Seed coating with Polykote coupled with Royal flow and Imidachloprid and seeds coated with Vitavax 200 effectively contained the seed infection. Between containers, seeds stored in 700 gauge polythene bags excelled cloth bag by maintaining higher germination and less seed infection during storage.