Seed fortification with calcium sulphate enhances germination indices, growth and nutrient concentrations in Rhodesgrass (Chloris Gayana Kunth.)

A laboratory experiment was conducted to evaluate the effect of Ca seed fortification on germination, seedling establishment and tissue nutrient concentrations in rhodesgrass. Calcium sulphate (CaSO4) seed coating (SC) and seed priming (SP) were the two nutrient seed fortification (NSF) methods. The treatments (in g CaSO4 kg−1 seed) for seed coating were 0 (control), 1, 2, 3, and 4 (referred to as SC-rate). The priming treatments (in per cent CaSO4 in the priming solution) were 0 (hydro-primed), 0.25, 0.5, 0.75, and 1.0% (referred to as SP-rate). Seed coating at 2 g CaSO4 kg−1 seed (SC-2) improved germination percentage (15.4%), germination index (19.7%), seedling emergence percentage (17.6%), seedling vigour index (53.2%), root dry weight (20.8%) and shoot dry weight (30.8%) when compared with control (SC-0). The Ca and sulphur (S) concentrations in seedlings were also improved (36.5% and 52.2% respectively) in SC-2. The CaSO4 seed priming showed minimal effect on root and shoot length while the rest of the parameters were not affected. The study reveals that calcium seed fortification through seed coating at 2 g CaSO4 kg−1 seed improves early plant establishment and enhances tissue nutrient concentrations (Ca, S) in rhodesgrass.