Growth and Production Response of Several Local Sweet Potatoes (Ipomoea batatas L.) Clones on Multiple Trimming Levels

Trimming is an effort to reduce plant parts to optimize plant parts that are important for growth and production, to increase crop productivity. This research aim was to determine the growth and production response of several local sweet potato clones on several trimming levels. This research used a randomized block design with two factors, local sweet potato clones (local clone of Dusun Bintang Meriah, Sirube-rube, Dolok Sinumbah) and several trimming levels (without trimming, trimmed after tendrils reach 50 cm long, 75 cm long, and 100 cm long).This research was carried out in Balai Penelitian Tanaman Sayur, Tongkoh Village, Berastagi, Karo Regency from July 2018 to January 2019. The results showed that the local sweet potato clones had a good growth and production response to several levels of trimming. Three local clones did not affect significantly in the length of tendrils, tuber weight per sample, number of tubers per sample, crown wet weight, and harvest index. Trimming levels did not significantly affect the length of tendrils, tuber weight per sample, number of tubers per sample, and canopy wet weight, but significantly affect the harvest index. The best level of trimming was trimmed after the length of the tendrils is 75 cm.