Effect of Plant Density on Bark Yield of Cinnamon Intercropped Under Mature Rubber

Abstract

Possibilities for intercropping cinnamon (Cinnamomum verum J.Pres) under rubber (Hevea brasiliensis Muell. Arg.) were investigated. In one experiment, the 9.1 m inter row space of a 15 year old rubber plantation was intercropped with cinnamon. The effect of four cinnamon densities (17,500 bushes ha−1, 8,260 bushes ha−1, 7,980 bushes ha−1 and 3,980 bushes ha−1) and four levels of fertilizer (60 g bush−1, 120 g bush−1, 180 g bush−1 and 240 g bush−1) on cinnamon bark yield and yield components were tested in a split plot experiment. Interception of light by the rubber canopy, R:FR ratio of transmitted light under the rubber canopy and the fine root length density in the inter row was uniform in all treatments throughout the whole experimental period. R:FR ratio of light under cinnamon was significantly lower under the highest cinnamon plant density of 17,500 bushes ha−1. Bushes in the highest plant density treatment (D1) produced longer shoots than those in the lowest density treatment (D4), where the weight of bark cm−1 was greater. As a result there were no significant effects of plant density on cinnamon bark yield at the individual bush level. This also resulted in significantly greater weight of bark per ha in the highest density treatment (D1) indicating the possibility of increasing cinnamon plant density for obtaining greater bark yield from intercropping systems under considerable shade and root competition. Increasing the level of added fertilizer even up to four times the standard did not have any advantage on bark yield or its components.