Potency to use aqueous extractions of pesticidal plants to manage termites in the sugarcane ecosystem of Sri Lanka

Abstract

Termites caused major economic damage to sugarcane plantations. An experiment was conducted at the Sugarcane Research Institute (SRI), Uda Walawe, Sri Lanka, with the objective of determining potential plant extracts that have insecticide properties to manage termites during germination and the early plant growth phases of sugarcane. Three plant species that are available in the sugarcane ecosystem were selected for the field study, i.e., Leucaena leucocephala (Ipil-Ipil) pods and leaves, Gliricidia sepium (Gliricidia), and Lantana camara (Gandapana). The immature pods and mature leaves of the pesticidal plants were used for the experiment. Filtrate of blended withered plant parts was used for sett treatment at planting. Three pretermite infested plots with six rows of 5 m length and 1.37 m row spacing were established with three nodal setts of variety SL 96 128. Twenty seed setts were planted in each row according to the recommended practices. Data on plant characteristics (germination, plant height, length of the third leaf, width of the third leaf, root mass), and damage were observed four weeks after planting. All the plant extracts had significantly less sett damage compared to the non-treated control. Among them, the lowest sugarcane sett damage was recorded on G. sepium leaf extract treated sugarcane setts (9.33± 2.85) followed by L. camara treated setts (11 ± 2.89). Germination and plant characters were not significantly affected by extractions compared to the non-treated control. The highest germination was recorded on Fipronil treated sugarcane setts (19 ± 2). The highest leaf number was recorded on the non-treated control (4.47 ± 0.32). The highest plant height was recorded on L. leucocephala pod treated sugarcane setts (9.16 ± 1.49). Moreover, , L. leucocephala leaf extract treated sugarcane setts showed the highest root weight (1.38 ± 0.79). Therefore, aqueous extracts of Gliricidia sepium leaf and Lantana camara leaf are effective in managing termite damage in sugarcane setts at the planting and early growth stages.