Effect of different doses of NPK fertilizer on the abundance of termite (Glyptotermes dilatatus) in tea garden of the north-eastern part of Bangladesh

Abstract

Tea termite (Glyptotermes dilatatus) is a devastating pest of the tea garden. Fertilizer application is considered an important intercultural practice for proper growth and development of tea bushes. In this study, different doses of nitrogen-phosphorus-potassium (NPK) fertilizer were applied as 0 (Control), 10 (NPK10), 20 (NPK20) and 30 (NPK30) g per liter/plant in the Kewachara tea garden of Sylhet, Bangladesh. The abundance of termite and the infestation height were assessed at 0, 5, 10, 15, 20, 25, and 30 days after NPK application. A low number (0.07-0.13) of termite populations were observed with NPK10, NPK20, and NPK30 where there was no significant difference over control. The number was highest at 5 days after application of the dose NPK30. The infestation height was found highest (11 cm) with the doses of NPK20 and NPK30, which showed a significant difference over NPK10 and the control. The infestation height also altered with the days of sample collection. The mineral composition of termite-infested soil in stem and mound was examined, and it was discovered that the concentration of phosphorus (P) in mound soil is higher (45.6 g/g) than in stem soil (33.4 g/g). Moreover, sulphur, iron, and magnesium concentrations in mound soil were also recorded higher than in stem soil, which was 10.3 g/g and 13.4 g/g and 0.30 meq./100 g, respectively. In contrast, boron and calcium were found higher in stem soil compared with mound soil. However, the concentrations of nitrogen and potassium were similar in both soils; they were 0.04% and 0.13 meq./100g, respectively. Therefore, fertilizer application did not affect the overall termite population, however the infestation height and nutrient concentration of mound and stem soil were altered.