Holding of Cut-sprouts in Sweet Potato (Ipomoea batatas Lam.) : IV. Effect of holding on rooting under low soil temperature or moisture

[摘要] We investigated the effect of holding of cut-sprouts for 5-10 days on the rooting under low soil temperature or moisture in sweet potato using cv. Koganesengan. The holding treatments were carried out under 16°C, 85% relative humidity and a weak light condition. The soil temperature was controlled at 20°C and 30°C. The soil moisture was adjusted to 30% and 70% of field capacity. Under the favorable conditions (30°C soil temperature or 70% soil moisture) the number of roots was decreased by the holding. However, the elongation of roots was accelerated and the total length of roots was increased about 10% by the holding. The rooting of cut-sprouts was restricted by the low soil temperature or moisture. The degree of restriction was smaller in the held cut-sprouts than in the non-held ones. At the low soil temperature the holding increased the number of roots by about 30%, the total length about 3 times, and the average root length and root dry weight about 2 times. Under low soil moisture the number of roots, the total length of roots, the average root length and root dry weight were also increased by holding about 50%, 3 times, 2 times and 2 times, respectively.

[学科分类] 农业科学（综合）

[关键词] Cut-sprout;サツマイモ;Holding;地温;Rooting;土壌水分;Soil moisture;取り置き;Soil temperature;è‹—;Sweet potato;発根