Gas Exchange Characteristics of Apple and Peach Leaves Infested by European Red Mite and Twospotted Spider Mite

Abstract

<jats:p>Greenhouse-grown `Imperial Delicious' apple <jats:italic>(Malus domestics</jats:italic> Borkh.) and `Redhaven' peach <jats:italic>(Prunus persica</jats:italic> Batsch.) trees were inoculated during the summer with three densities of European red mite (ERM) <jats:italic>(Panonychus ulmi</jats:italic> Koch) and twospotted spider mite (TSM) <jats:italic>(Tetranychus urticae</jats:italic> Koch). As ERM- and TSM-days increased, net photosynthesis (Pn), transpiration (Tr), and total chlorophyll content (TCHL) of apple leaves decreased linearly. At similar densities, TSM was more damaging than ERM to apple leaf gas exchange. Water-use efficiency (WUE) of apple declined similarly with increasing mite-days for both mite species. Specific leaf weight (SLW) of apple increased with TSM-days. Pn, Tr, TCHL, and WUE of peach declined linearly with increasing ERM- and TSM-days, and the rates of decline were similar for both mite species. Mites did not affect peach SLW. These results indicate that greenhouse-grown peach is more tolerant than apple to mite feeding.</jats:p>

Photosynthesis and transpiration of “Riesling × Sylvaner” grapevine leaves as affected by European red mite (Panonychus ulmi Koch) (Acari, Tetranychidae) feeding

“…These comparisons show that T. urticue is a much more harmful pest to the grapevine than P. ulmi. This is in agreement with MOBLEY and MARINI (1990). They found on apple that, at the same mite-load, the photosynthesis reduction caused by T. urticue feeding was twofold that of P. ulmi.…”

Patch Dynamics of a Phytophagous Mite Population: Effect of Number of Subpopulations

“…Arrows indicate dates when all 179 trees were sampled and ERM identified to stage. ERM damages apple trees by feeding on the leaves, reducing transpiration, chlorophyll levels, and net photosynthetic rates (Mobley and Marini 1990), resulting in lower production of apples. ERM passes through 3-5 generations per season in the study area (Herbert 1970).…”

Influence of European Red Mite on Leaf and Whole-canopy Carbon Dioxide Exchange, Yield, Fruit Size, Quality, and Return Cropping in `Starkrimson Delicious' Apple Trees

“…This is due to the combination of ubiquity, importance and manageability of ERM compared with the other foliar pests. Some of the reported effects of mites and other foliar feeders on apples are reductions in 1) leaf net CO 2 exchange rates (NCER) (Avery, 1963;Ferree and Hall, 1980;Mobley and Marini, 1990;Welter, 1989); 2) yield due to reduc-tions in fruit size and/or fruit numbers; 3) fruit quality via poor color; reduced sugar concentrations or delayed maturity or earlier fruit abscission; and 4) subsequent year crops due to poor return bloom (Ames et al, 1984;Chapman et al, 1952;Lienk et al, 1956;Lienk and Minns, 1980;Zwick et al, 1976) . The results, however, have been extremely variable.…”