Application of nitrogen, phosphorus, potassium, manure and dolomitic lime as related to seed production of Paspalum notatum Flugge in a Dark Red Latosol

Abstract

Seed production of Paspalum notatum was compared with or without addition of 4 g/m² of N (as ammonium sulphate), 50 g/m² of P2O5, 15 g/m² of K2O (as potassium chloride), 10 l/m² of horse manure and 200 g/m² of dolomitic lime in a Dark Red Latosol. Seed production was evaluated through number of spikes, total weight, weight of pure seeds, relation between weight of pure seeds and total weight, weight of 1000 pure seeds, total weight per spike, weight of pure seeds per spike, seed germination percentage and seedlings emergence speed. Levels of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn in leaves and seeds dry matter were determined. Quality and quantity of seeds were affected by mineral nutrition. The highest values of C% in soil were the best for seed yield and quality. The best seed production correspondend to the lowest levels of P, K, Ca and Zn in leaves. The relations N/P, P/Ca, P/Mg, P/S, P/Zn, K/Ca, K/Mg, K/B, Ca/Mg, Ca/B, Fe/Mn, Zn/Cu, ZN/Fe and Zn/Mn in plants dry matter were important. The highest seed yields corresponded to the lowest seed levels of N, B and Cu, and to the highest seed levels of Ca. The best seeds presented the highest levels of Zn, and the lowest levels of B. Seed production was not significantly improved by fertilizers or dolomitic lime application.