Influence of storage conditions on viability and vigour of Sunflower (Helianthus annuus L.) seeds

Abstract

The storage experiment examined the effects of storage temperatures, seed moisture contents (SMC), and storage durations (SD) on the viability and vigour of sunflower seeds. Certified sunflower seeds were evaluated for seed germination, seedling vigour, and fungal infection. A 3x3x6 factorial experiment in Completely Randomized Design was set out in four replicates. The three factors were temperature (5, 20, 35 ºC), SMC (6,8,10%), and SD (15, 30, 45, 60, 75, 90Days After Storage, DAS). Before storage (0 DAS), the initial germination percentage (GP=94%), Germination index (GI=322), Seedling vigour index (SVI=2118), and fungal infection incidence (FII=52%) were determined and used as control. The lowest GP of 67%, GI (269.2), SVI (1295), and FII (78.0%), was found in seeds stored at a temperature of 35 ºC and SMC of 10% at 90DAS. Upon the interaction effect at the end of 90DAS, the temperature of 5 ºC with SMC of 6% followed by the temperature of 20 ºC with SMC of 6% recorded the greatest GP of 87.5 and 87.0%, GI of 304.3 and 296.8 SVI of 1910 and 1877 and fewer fungi incidence (%) of 61.5 and 63 respectively. The germination percentage was above the minimum certification standards of 85%, as per the Tanzania Official Seed Certification Institute. Conclusively, our results discovered that the optimum storage conditions-Temperature of 5 and 20 ºC with SMC of 6 and 8% could be suitable for maintaining the viability and vigour of sunflower seeds throughout the storage duration (90 DAS).