Seedball technology counterbalances the effect of small seed-size and low soil nutrients on early pearl millet seedling performance

In the African Sahel region, pearl millet (Pennisetum glaucum (L). R. Brown) is often produced in low-nutrient soils. Seed weight could vary between 4 and 44 mg per seed. Evidence shows chemically infertile soil and small seed size significantly reduce seedling establishment and, in turn, cause low grain yield. Seedball technology can potentially counterbalance this effect. Therefore, the objective of this study was to investigate the influence of seedball on pearl millet seedling establishment. Conventionally sown and seedball-derived pearl millet seedlings of a local and an improved varieties were grown for 29 days from small and large seed sizes, in low- and medium-nutrient soils at a greenhouse of University of Hohenheim, Germany. Results showed that under low-nutrient conditions and with small seed sizes produced biomass was generally inferior to the other factor combinations. Seedball technology significantly enhanced seedling vigour, leaf number, plant height, dry matter, root length as well as fine root development, and nutrient uptake irrespective of soil nutrient level and seed size. These enhancement effects were more obvious in the local variety. A previous study revealed “early nutrient release in the seedling root zone” as seedball pearl millet seedling enhancement mechanism. The released nutrients presumably compensated for nutrient deficiency in low-nutrient soil and small seed seedlings. In the Sahelian pearl millet production system where (i) low soil nutrients, (ii) small seed sizes and (iii) local seed varieties are rampant, the application of the seedball technology under these conditions is proven effective for increased seedling vigour and is therefore recommended.