Objective To explore the agronomic, economic, and pest/disease control effects of the intercropping pattern between Kadsura coccinea and sweet potato (Ipomoea batatas), aiming to improve the utilization efficiency and economic benefits of non-grain farmland in mountainous areas.

Method Taking K. coccinea variety 'Fenhong 1' and sweet potato variety 'Yanshu 25' as materials, three treatments were set up: K. coccinea monocropping (T1), K. coccinea intercropped with sweet potato (T2), and sweet potato monocropping (T3). A large-area experiment was conducted to analyze data such as agronomic traits, yield, and occurrence of diseases, pests, and weeds of K. coccinea and sweet potato.

Result In the intercropping pattern, there were no significant differences in stem diameter, stem length, and leaf area of K. coccinea compared with the monocropping pattern, while the average internode length at maturity significantly increased by 11.91%. The proportion of large fruits of K. coccinea in the intercropping pattern was 34.34%, which was 4.21 percentage points higher than that in the monocropping pattern; the proportion of large and medium fruits was 71.5%, which was 6.25 percentage points higher than that in the monocropping pattern, among which the increase in the proportion of large and medium fruits reached a significant level. The fruit drop rates in the monocropping and intercropping patterns were 67.60% and 62.00%, respectively. The yields of K. coccinea in the monocropping and intercropping patterns were 8 070 kg/hm² and 7 935 kg/hm² respectively, with no significant difference between the two. For sweet potato in the intercropping pattern, except for the significant difference in the increase of vine length compared with the monocropping pattern, the growth ranges of other agronomic traits were similar to those in the monocropping pattern, and the yield decreased slightly but not significantly. Intercropping significantly inhibited field diseases, pests, and weeds of K. coccinea. The field weed coverage in the intercropping pattern was 1.23%, which was significantly 52.5 percentage points lower than that in the monocropping pattern. The fresh weight control effect, dry weight control effect, plant control effect, and height control effect reached 89.2%, 93.45%, 21.51%, and 69.2%, respectively. The prevalence rate of leaf spot disease of K. coccinea in the intercropping pattern was 17.54%, which was 7.77 percentage points lower than that in the monocropping pattern; the prevalence rate of leaf blight was 18.69%, which was 4.44 percentage points lower than that in the monocropping pattern. The intercropping pattern of K. coccinea and sweet potato significantly improved the comprehensive economic benefits, achieving an additional income of 83 235.4 yuan/hm² in the intercropping field compared with the K. coccinea monocropping field, with a land equivalent ratio of 1.97.

Conclusion The intercropping pattern of K. coccinea and sweet potato is feasible, which can improve land utilization efficiency and economic benefits, inhibit diseases, pests, and weeds, increase grain yield, and has popularization value.