Yield loss and physicochemical changes in fresh tea leaves caused by Polyphagotarsonemus latus (banks) attack in different tea clones

Abstract

The overall goal of this work was to determine the effects of Polyphagotarsonemus latus (Banks) (Trombidiformes: Tarsonemidae) infestation on the physicochemical contents of fresh tea leaves and tea yield under field conditions in Rize province (Black Sea Coast, Turkey). The study was carried out on Muradiye-10, Pazar-20, and Tuglali-10 tea clones. Water extract, dry matter, caffeine, total polyphenol, crude cellulose, and total ash were analyzed as physicochemical parameters in the fresh tea leaves. The findings indicated that the yield of Muradiye-10 was significantly reduced with the increase in infestation of P. latus. Dry matter content in all clones showed a reduction when the shoots were infested by P. latus. Although the water extract values generally remained unchanged, the infested leaves of Pazar-20 had a higher amount of water extract than the uninfested leaves. On the other hand, the polyphenol content was not affected by mite feeding. The total ash, crude cellulose, and caffeine contents showed unsteady changes. Their values either increased, decreased, or remained unchanged considering the years, clones, and mite densities. We conclude that the infestation of P. latus generally deteriorated the physicochemical contents of fresh tea leaves as well as fresh tea yield, although it changes over the years, clones, and mite densities.