Entomology
Extension and Research Program at The West Virginia University
Experiment Farm in Kearneysville
Arthropod Pest Susceptibility of New Apple Cultivars
A CSRS regional project --
NE-183, Multidisciplinary Evaluation of New Apple Cultivars-- has
been initiated to evaluate new apple cultivars under a wide range
of edaphic and environmental conditions. In the spring of 1995,
replicated plantings of 26 new apple cultivars (five trees of
each cultivar) were planted at 28 sites in 14 states and 2
Canadian Provinces. Plantings were designated as either a
"horticultural" or "pest" planting depending
on whether the primary objective was to evaluate horticultural
qualities or pest susceptibility. One of each type of planting
was established at the Appalachian Fruit Research Station,
Kearneysville, WV, in April 1995. This paper summarizes pest
susceptibility data for the 1996 growing season.
Cultivar/Rootstock Combinations
Braeburn/M.9; Braeburn/MARK; Golden Delicious/M.9; Golden Delicious/MARK;Yataka/M.9; Yataka/MARK; Arlet/M.9; BC8M15-10/M.9; Cameo/M.9; Enterprise/M.9; Fuji Red Sport 2/M.9; Gala Supreme/M.9; Ginger Gold/M.9; Golden Supreme/M.9; Goldrush/M.9; Honeycrisp/M.9; Fortune/M.9; NY 75414-1/ M.9; Orin/M.9; Pristine/M.9; Sansa/M.9; Senshu/M.9; Shizuka/M.9; Suncrisp/M.9; Sunrise/M.9; PioneerMac/M.9.
Rosy Apple Aphid - Very low population on most cultivars, ranged from 0.2-1.4 infested terminals/tree. Most abundant on Enterprise, Fortune, and Pristine.
White Apple Leafhopper (1st generation in May) - Population ranged from 4.0-17.2 nymphs/25 leaves. Most abundant on Golden Supreme, Sansa, Ginger Gold, Senshu, and Gala Supreme. Least abundant on Pristine, Suncrisp, Arlet, Fortune, and BC8M15-10.
Spirea Aphid - Low population on most cultivars when data taken in mid-June, average rating ranged from 0.28-1. Probably would have had higher population by waiting another 1-2 weeks to take data. Most abundant on NY 75414-1. Least abundant on Goldrush.
Potato Leafhopper - Ranged from 8.6-35 nymphs/25 leaves. Most abundant on Gala Supreme, Senshu, Sunrise, Honeycrisp, and Pristine. Least abundant on Braeburn/M.9, Braeburn/MARK, NY 75414-1, Ginger Gold, and Golden Del/MARK.
Rose Leafhopper - Ranged from 2.8-18.2 nymphs/25 leaves. Most abundant on Gala Supreme, Fortune, Fuji Red Sport 2, PioneerMac, and Enterprise. Least abundant on Golden Del/MARK, Golden Del/M.9, Goldrush, Golden Supreme, and Arlet.
European Red Mite - Very low population on most cultivars, ranged from 0.3-1.0 motile stages/leaf. Most abundant on Ginger Gold, NY 75414-1 and Braeburn/M.9.
Japanese Beetle - Ranged from 28-96 percent of terminals damaged. Most damage on Honeycrisp, Orin, NY 75414-1, Golden Del/M.9, and Gala Supreme. Least damage on Sunrise, Golden Supreme, Suncrisp, PioneerMac, and Cameo.
White Apple Leafhopper and Rose Leafhopper (August) - Ranged from 3.6-22 nymphs/25 leaves. Most abundant on Cameo, Fortune, Sunrise, Suncrisp, and Gala Supreme. Least abundant on Goldrush, Golden Del/M.9, Pristine, Senshu, and Arlet.
Spotted Tentiform Leafminer - Very low population on most cultivars, with total mines at end of season ranging from 0.008-0.084 mines/leaf. Most abundant on Goldrush, Fuji Red Sport 2, NY 75414-1, Ginger Gold, and Golden Del/M.9. Least abundant on PioneerMac, Pristine, Enterprise, Golden Del/MARK, and Sansa.
Arthropod Pest Rating - Summing populations of all pests for each cultivar gave an overall rating that ranged from 85-206. Highest pest populations occurred on Gala Supreme, Honeycrisp, Orin, Senshu, and Enterprise. Lowest pest populations occurred on Golden Supreme, Suncrisp, Arlet, PioneerMac, and Sunrise.
Some data indicate that the level of damage from one pest could have influenced populations of subsequent pests. For example, 3 of the 5 cultivars with the least damage from Japanese beetles also had the highest population of white apple leafhoppers and rose leafhoppers in August. The fact that there was more foliage available (very low Japanese beetle damage) could have led to higher leafhopper populations.
H. W. Hogmire (November 1996)
