Utilization of Forage Crops as an Effective and Eco-friendly Method for Weed Growth Control and Distribution in an Immature Rubber Plantation

Rubber plantation, especially in the immature phase, is usually infested by various local weed species in the inter-row spaces of the rubber trees. This study aimed to evaluate the distribution of weed species and the growth and yield of forage crops for weed control and management in an immature rubber plantation. The field study was conducted with four treatments of forage crops. The first treatment was a control plot in which local weeds were growing naturally without forage crops. The plot was compared with the other three immature plots wherein native tropical carpet grass (Axonopus compressus), native whip grass (Hemarthria compressa) and high productive yield ruzi grass (Brachiaria ruziziensis) were planted, respectively, in the inter-row of the rubber trees. The study period was split into four seasons: S0 – January to June 2016; S1 – July to September 2016; S2 – October to December 2016; and S3 – January to March 2017. Results showed that three families of narrow-leaf and nine families of broad-leaf weeds were found in the study area. A large number of common weed families were observed more in the S3 than those in other seasons. Moreover, all forage crops were effective in suppressing weeds, with ruzi grass demonstrating the highest level of competitiveness and yield among the native forage crops reaching 1.50 Mg ha-1 in the S3. Therefore, implementing an indirect weed control approach using forage crops in rubber plantations could serve as a sustainable and environmentally friendly alternative to chemical herbicides.