Grapevine leaf gas exchange, plant growth, yield, fruit quality and carbohydrate reserves influenced by the grape leafhopper, Empoasca vitis

Abstract

The impact of the grape leafhopper, Empoasca vitis, on leaf gas exchange, plant growth, yield, fruit quality and carbohydrate reserves of the grapevines, Vitis vinifera L., was studied. Gas exchange was measured on the discolored (red) and the green parts of infested main leaves and on leaves from uninfested vines. Photosynthesis and mesophyll conductance were severely reduced on main leaves showing leafhopper feeding symptoms. The stomatal conductance of the red leaf section of infested main leaves was lower than on undamaged control leaves. Additionally, the red leaf section of infested main leaves showed lower transpiration rates when compared to the green parts of the same leaves and to undamaged control leaves. Gas exchange processes of lateral leaves were not affected by leafhopper feeding. Leafhopper‐load on main leaves was correlated to visual damage symptoms. At 71.8 leafhopper‐days per leaf up to 40% of the main leaf area of the infested plants was discolored from the borders towards the center. Lateral leaves showed no feeding symptoms. Shoot diameter, pruning weight and carbohydrate reserves in the wood were not affected by leafhoppers. Lateral leaf area growth was significantly stimulated on plants infested by leafhoppers. No decrease in yield and fruit quality with leafhopper‐loads up to 71.8 leafhopper‐days per leaf were observed.

Effects of sap-feeding insect herbivores on growth and reproduction of woody plants: a meta-analysis of experimental studies

“…Plants infested by sap-feeders often suVer from chlorosis, leading to premature foliage loss; other symptoms include leaf-rolling, shoot distortion, growth reduction, and decrease in yield (Parry 1974;Rummel and Quisenberry 1979;Zwolinski 1990;CandolW et al 1993). The siphoning of large amounts of carbohydrates from plants by sap-suckers depletes carbohydrate reserves and Fig.…”

Spatial and temporal distribution of Empoasca vitis within a vineyard

“…Adults and nymphs feed on phloem sap, and punctures provoke leaf necrosis (hopperburn: Backus et al , 2005 ) that result in delayed maturity and reduced sugar content ( Vidano et al , 1987;Candolfi et al , 1993;Delbac et al , 1996 ). Insecticide intervention on nymph populations is sometimes required for summer generations, and intervention thresholds vary from 0.5 to 4 -5 nymphs per leaf according to authors and regions (Corino et al , 1992;Baillod et al , 1993;Candolfi et al , 1993;Rousseau, 1994;Delbac et al , 1996 ).…”

Volatiles from non‐host aromatic plants repel tea green leafhopper Empoasca vitis

“…The tea green leafhopper, Empoasca vitis G€ othe (Hemiptera: Cicadellidae), is a serious pest of the tea plant, Camellia sinensis (L.) O. Kuntze (Theaceae), in tea-producing countries in Asia, e.g., China, Japan, India, and Vietnam (Hazarika et al, 2009;Jin et al, 2012a). This piercing-sucking herbivore is also an important grapevine pest in southern Europe, including France, Switzerland, Italy, and Greece (Candolfi et al, 1993;Decante & van Helden, 2008;Pavan & Picotti, 2009). In Chinese tea plantations, E. vitis adults and nymphs feed solely on the young tea shoots and generally occur in 9-11 overlapping generations throughout the growing season of the tea plants (Feng et al, 2004;Pu et al, 2005).…”