Effects of Topping on Physiological Characteristics,Yield and NutrientAccumulation of Wuzhimaotao (Ficus hirta Vahl.) in the Rubber Tree//F. hirta Intercropping System

In order to understand the effect of topping on the physiological characteristics, yield and nutrient accumulation of Wuzhimaotao (Ficus hirta Vahl.) in rubber tree//F.hirta intercropping system, we set up 3 treatments, viz. topping without fertilization, topping with fertilization and fertilization without topping.The morphology, physiology, yield and nutrient accumulation of plants were investigated. The results showed that the topping significantly reduced plant high, stem diameter, root diameter, total dry weight, the dry weight of shoots and roots, SPAD value and nitrogen, phosphorus and potassium accumulation(P0.05), while topping significantly increased the dry weight ratio of root to shoot, water content of whole plant, shoots and roots(P0.05). There was no significant effect of topping on chlorophyll a, chlorophyll b and total chlorophyll content(P0.05). The plant height, aboveground biomass, roots biomass, total N, P and K of topped F. hirta decreased by 22.92%, 41.67%, 11.83%, 29.40%, 22.78% and 22.58%, respectively, compared with untopped F.hirta. These results indicated that topping could promote the dry matter accumulation and transfer to the underground part and increase the proportion of root yield, decrease the total N, P and K of F.hirta during the harvest period, and decrease the height of F.hirta. Topping recommendations for F.hirta intercropped in the mature rubber plantation which could promote the dry matter accumulation and transfer to the underground part and increase the proportion of root yield, decrease nutrient loss and decrease wind damage. These results provide a scientific basis for topping technology for the plants which grow under the high shaded and high nutrient competition conditions, and provide some theoretical guiding for the intercropping of F. hirta with mature rubber.