Dry matter accumulation and potato productivity with green manure

摘要

Growth patterns and distribution of dry matter in different parts of potato plants (Solanum tuberosum, Solanaceae) with green manure can be positively influenced by the use of green manure. The aim was to evaluate the dry matter accumulation and pro-ductivity of potato with varying quantities of sunn hemp, Crotalaria juncea (Fabaceae) as a nitrogen source. The experiment used three different amounts of sunn hemp, equivalent to 100, 200 and 400 Kg ha-1 nitrogen (N), the recommended mineral N dose (250 Kg ha-1), and a treatment with zero N. Sampling was carried out at 35, 50, 65 and 80 days after planting, representing the subplots. The treatments were arranged in a randomized block design with split plot, the plot were enlarged fertilization and the small plot sampling dates. Four replications were used. Dry matter accumulation in the shoots of potato was greater with sunn hemp than with mineral nitrogen. The accumulation of dry matter in tubers and in the whole plant increased over time at higher rates of sunn hemp than with mineral fertilizer. Commercial and total potato productivity increased with sunn hemp quantity. Green manure at higher rates (400 and 200 Kg ha-1) increased the accumulation of dry matter in potato aboveground parts and in tubers. The commercial productivity of potato was 24% greater with green manure than with mineral fertilizers, indicating the potential of sunn hemp to provide adequate quantities of nitrogen for the growth and development of this crop.