Effects of Soaking Method and Soaking Time on Water Absorption and Seedling Growth of Cassava Stem
The long stems(1.8 m)of cassava variety'South China No.205'were selected for test materials.Two kinds of soaking methods were used,which were placed in the horizontal(completely soaking)and vertical(soaking within 10.0 cm base end)modes,and the 5 kind of soaking time were set up:0(CK),6,12,18,24 h.The change of water content of stem after different soaking treatments and the growth of seedlings after planting of short stem segments(15.0 cm)in base,middle and top parts were studied.The results showed that the long stem water absorption rate was significantly increased,but the long stem water absorption speed was significantly decreased with the extension of soaking time.The long stem water absorption content,water absorption rate and water absorption speed of the horizontal soaking mode were significantly increased by 0.53,3.65 and 0.29 percentage points compared with vertical soaking mode,respectively.The emergence rate,plant height,stem diameter,root diameter,fresh and dry weight of stem and leaf(S&L)per plant of the vertical soaking model were significantly higher than those of horizontal soaking model.The plant height,stem diameter,root number of cutting,weight of fresh and dry S&L per plant of soaking 12 h and CK were better than those of other soaking time.The plant height,stem diameter,leaves number,root number,root diameter,weight of fresh and dry S&L,proportion of bud number per cutting of the base and middle stem part were significantly higher than those of top stem part.It is recommended that the long stem of cassava should be in vertical soaking for 12 h,and the cuttings from the base and middle stem part should be planted.