Abstract:
In order to clarify the optimum planting density and suitable application amount of potassium fertilizer for Pushu 32, an interactive experiment of planting density (D) and application rate of potassium fertilizer (K) was set up to study the effects of the two on the agronomic traits and yield of Pushu 32 were studied. The D1, D2 and D3 were 40500, 45000 and 49500 plants·hm
-2, respectively, and the K1, K2, K3 and K4 were 0, 90, 180 and 270 kg·hm
-2, respectively. The results showed that under the same planting density, the number of branches, the longest vine length, the number of tubers per plant, the rate of large and medium tubers, the weight of tubers per plant, the yield of fresh tubers, the yield of dry tubers and the yield of stems and vines increased with the increase of the application rate of potassium fertilizer, while the T/R value decreased, and the application of potassium fertilizer within a certain range could promote the growth of sweet potato stems and leaves and increase the yield of sweet potato. Under the same potassium fertilizer level, with the increase of planting density, the number of branches and the longest vine length of sweet potato decreased, the rate of large and medium potato and the weight of potato per plant decreased, and the number of potato per plant, fresh potato yield, dried potato yield and stem and vine yield increased. The further analysis showed that under the conditions of high density, increasing the application amount of potassium fertilizer could not significantly increase the yield of fresh root yield and dry matter yield, and could not improve the production efficiency of sweet potato, but would increase the cost of fertilizer. In conclusion, the study recommended D3K3 treatment as the reasonable combination of planting density and potassium fertilizer application for Pushu 32 in Datian County, that is, the planting density was 49500 plants·hm
-2, and the application rate of potassium fertilizer (K
2O) was 180 kg·hm
-2. The results of this study could provide a useful reference for the high yield, high efficiency and high-quality cultivation of Pushu 32 in Datian County and other places.