Morphological and mechanical characteristics of sweet potato seedlings transplanted mechanically

Abstract.

The morphological and mechanical characteristics of sweet potato seedlings in suitable transplanting period have great impact on the structure and design parameters of sweet potato transplanting machinery. In order to study its morphological and mechanical characteristics, sweet potato seedlings named "Longshu 9" were in nurture 35 days and cut as test materials, and then seedlings were measured and tested with a universal material testing machine. The results showed sweet potato seedlings varied in length from 19cm to 35cm, and the moisture content averaged 90.96%. The diameter varied in across the length of seedlings, and average diameters measured in three locations (root, middle and bottom) were 4.16mm, 3.84mm and 1.49mm, respectively. AS a result of different internal fibers, seedlings near the bottom were broken easily in tension test, and breaking force averaged 1.37N. Most of seedlings were shear off with the load more than 0.96N, and the crushing force averaged 8.07N when seedlings near the root were completely crushed. In conclude, the research on morphological and mechanical characteristics of sweet potato seedlings provides useful guidance for the design and optimization of sweep potato transplanter.