Induced Volatile Emissions, Photosynthetic Characteristics, and Pigment Content in Juglans regia Leaves Infected with the Erineum-Forming Mite Aceria erinea

Persian walnut (Juglans regia L., Juglandaceae), one of the essential nut crops, is affected by different diseases, including mite attacks which result in gall and erineum formation. As proportion leaf area covered galls or typically relatively low, impact on tree photosynthetic productivity often considered minor, no pest control management usually suggested. However, effect erineum-forming mites photosynthesis might be disproportionately larger than can predicted from impacted. In present study, we studied how foliage characteristics, pigment contents, stress-induced volatile organic compounds scaled with severity infection varied 0% (control trees) to 9.9%, Aceria erinea J. regia. Both net assimilation rate (up 75% reduction) stomatal conductance 82%) decreased disproportionately, increasing severity. Leaf total chlorophyll β-carotene contents also severity, although reduction was less for characteristics (28% 25% β-carotene). The induced significant emissions green leaves volatiles ((Z)-3-hexenol, (E)-2-hexenal, (Z)-3-hexenyl acetate 1-hexanol), monoterpenes homoterpene 3-(E)-4,8-dimethyl-1,3,7-nonatriene, these positively percentage infected. These results collectively indicate that profound modifications physiological significantly productivity.