PS 20-16 - Impacts of Eucalyptus sp. on common agricultural crops of the Sichuan Province, China

Abstract: Native to Australia, Eucalyptus sp. were transplanted and cultivated across the world as an important timber crop used for a variety of purposes. Eucalyptus sp. are economically important especially to small plot farmers globally but may have an adverse impact on nearby crops due to suspected allelochemicals released by the Eucalyptus sp. For this study, leaves from two species of Eucalyptus were collected from the Sichuan province of China to be used for greenhouse experiments to test the effects of the leaf litter on common agricultural products. The agricultural crops selected included two introduced but common crops, tomato and hot pepper, and one native crop, bok choy. The selected seeds were germinated and grown in different concentrations of leaf litter mixed with soil. The plants were measured each week and the dry weights were taken after the growing period. In addition, seed germination was tested using an aqueous 1% and 10% Eucalyptus solution applied directly to the seeds. The plant growth experiment looked at the plant height, germination rate, and plant weight. The germination study looked at germination rates at different concentrations for the different seed types. Results indicate the allelochemicals in Eucalyptus do inhibit both growth and germination in the agricultural crops studied, with the indigenous plants having the largest inhibition of growth and germination rates. This could have an important impact on the way Eucalyptus species are cultivated and where they are plotted in relation to food crop production. Improving farmer knowledge of the impacts of potential allelochemical inhibition on crop yields could improve overall crop planning and protection and thus increase the producers yields and income.