Influence of reduced N-fertilizer application on foliar chemicals and functional qualities of tea plants under Toxoptera aurantii infestation

Abstract

Background The tea aphid, Toxoptera aurantii (Boyer de Fonscolombe) is a polyphagous pest predominant in tea orchards and has become the most pernicious pest deteriorating tea quality. Nitrogen (N) is essential to plant growth improvement, and it can significantly impact plant defensive ability against aphid infestation. This study was designed to quantify the influence of reduced N-fertilizer application on foliar chemicals and functional quality parameters of tea plants against the infestation of T. aurantii. In this study, the tea seedlings (cv. Longjing43) were applied with normal level (NL) of N-fertilizer (240 kg N ha−1) along with reduced N-fertilizer levels (70%NL and 50%NL), and with and without T. aurantii infestation. Results The results showed that N-fertilizer application significantly affected plant biomass and photosynthetic indexes, foliar soluble nutrients and polyphenols, tea catechins, caffeine, essential amino acids, volatile organic compounds of tea seedlings, and the population dynamics of T. aurantii. Compared with the normal N-fertilizer level, the reduced N-fertilizer application (70%NL and 50%NL) significantly decreased all the foliar functional quality components of tea seedlings without aphid infestation, while these components were increased in tea seedlings with aphid infestation. Moreover, the transcript expression levels of foliar functional genes (including CsTCS, CsTs1, and CsGT1) were significantly higher in the NL, and significantly lower in the 50%NL for tea seedlings without aphid infestation, while the transcript expression levels were significantly higher in 50%NL in aphid inoculated tea seedlings. Conclusion The results demonstrated that the reduced N-fertilizer application could enhance foliar chemicals and functional quality parameters of tea plants especially with T. aurantii infestation, which can relieve soil nitrogen pressure and reduce pesticide use for control of tea aphid infestation in tea plantations.

Rapid Identification of Aphid Species by Headspace GC-MS and Discriminant Analysis

“…Saturated alkanes (C13-C28) were also reported in previous studies as aphid cuticular hydrocarbons) from A. craccivora [52], Brevicoryne brassicae, Hyalopterus pruni [53], and Aphis fabae [54]). Decane (detected in E. lanigerum and A. punicae), 9-eicosene, and 8-heptadecene (detected in E. lanigerum) were detected in the headspace hydrocarbons (Figure 2, Table S2) and were also found by Muñoz, Argandoña [55], Ahmed, Agarwal [56], by Pokharel, Zhong [57] in aphid-infested plants, and by Ali, Morgan [58] in Leptothorax ants. Among Me-Alk, dimethyl alkanes were detected in the headspace of crushed aphids (Figure 2, Table S2), i.e., 3,8-dimethyl undecane, 4,7-dimethyl undecane, 4,5-dimethyl, nonane, and 4,6-dimethyl dodecane.…”

Intercropped Flemingia macrophylla successfully traps tea aphid (Toxoptera aurantia) and alters associated networks to enhance tea quality

“…[31][32][33] Until now, studies have focused on the individual components of tea aphids, ants, or natural enemies rather than examining the intricate interactions within the community. 34,26 A prior field study revealed that intercropped F. macrophylla significantly alleviated arthropod damages in a tea plantation. 35 Analyzing the potential effects of F. macrophylla as a trap plant on the networks associated with tea aphids would provide valuable insights into the complex dynamics of the arthropod community, leading to improved effectiveness of this strategy in tea plantations.…”

“…22,23 The tea aphid, Toxoptera aurantia, is a destructive and widespread pest in tea plantations. [24][25][26] It is estimated to cause more than 30% economic reduction in tea plantations in Zhejiang province, China. 25 Traditional treatments for tea aphids predominantly rely on chemical pesticides, exacerbating 3R issues (resistance, residue, and resurgence).…”

“…The tea aphid, Toxoptera aurantia , is a destructive and widespread pest in tea plantations 24–26 . It is estimated to cause more than 30% economic reduction in tea plantations in Zhejiang province, China 25 .…”

“…In addition, there are competitive interactions between attending ants and natural enemies that ants drive away predators to protect aphids 31–33 . Until now, studies have focused on the individual components of tea aphids, ants, or natural enemies rather than examining the intricate interactions within the community 34,26 . A prior field study revealed that intercropped F. macrophylla significantly alleviated arthropod damages in a tea plantation 35 .…”