Improvement of sweet potato. II. Harvest of fruit and germination of seed

Abstract

The Crops and Genetics Section of the Instituto de Pesquisas e Experimentação Agropecuárias do Centro-Sul (IPEACS) renewed its work on improvement of sweet potato (Ipomoea batatas (L.) Lam.) in 1965. Fruit resulting from open pollination of 38 cultivars were harvested from the collection of the Agricultural Climatology Section of IPEACS. The number of fruit harvested from the collection was 4,841 from which were obtained 6,675 seeds. The average number of seeds per fruit was 1.37. The seed of sweet potato is hard and requires scarification for improving germination. Unscarified seed had a germination of 11.3%. The more effective method used for improving germination consisted of removal of small portion of the seed integument with a knife. A germination of 90.5% was obtained by using this treatment. A modest improvement in germination was obtained by scarification with emery paper, through which a level of 29.8% germination was reached.