Espaçamento para mandioca ( Manihot esculenta ) em solos Fluminenses de baixa fertilidade

In four trials the spacing of 1.00, 1.20 and 1.40 m between rows and 0.50, 0.70 and 0.90 m between plants were studied in a randomized complete-block, split-plot design with 8 replicates in low fertility soils of three counties in the main cassava (Manihot esculenta Grantz) production area of the Rio de Janeiro State. It was concluded that there was no difference among spacing between rows for the total production of roots, independent of location, giving a yield of 15,400 kg/ha, approximately in all four trials. A 0.50 m spacing between plants produced the highest yield (16,184 kg/ha). The difference in production between the latter treatment and the other two was approximately 765 kg/ha. The roots were classified as commercial type (length from 0.20 to 0.40 m) and industrial type (0.30 to 0.50 m). The best spacing for both types of root was 1.40 m between rows which gave an increased production of 6.2% for the commercial type and 7.8% for the industrial type relative to the 1.00 m spacing. The best spacing between plants was 0.90 m which showed increased yield of 3.0 and 5.1% in comparison to 0.70 and 0.50 m respectively, for the commercial type. The increase in production for industrial type roots was 5.1 and 7.6% for the 0.90 m treatment in comparison to 0.70 and 0.50 in respectively.