2010 Annual Report
The brown marmorated stink bug is a recently introduced invasive pest into eastern North America that has begun to cause economic damage and is a household nuisance. It was shown that early season damage was greater than 20% in apple and 50% in peach in both unsprayed and sprayed orchards. Based on stink bug population studies that were conducted this year, specified growth rate models can be used to predict appropriate scheduling for pest management.
Research continued on the role of plant growth regulators on tree architecture and their effect on stress resistance. The DNA sequences of genes that may be important components of hormone regulation of branching were compared in herbaceous and vine species. This comparison allowed PCR primers to be developed which were used this year to demonstrate that similar genes were present in peach and apple. Cloning and sequencing of the gene DNA sequence from apple and peach enabled the development of a quantitative RT-PCR technique that will be used to compare gene expression in fruit trees with different growth characteristics.
In the greenhouse, applications of the amino acid DL-ß-aminobutyric acid (BABA) and the hormone abscisic acid provided dehydration protection to young apple trees.
Research progressed to develop techniques that improve crop load management which is necessary to attain marketable size fruit. A woven white reflective mulch material increased shoot growth in young apple trees and in one cultivar, blossom production was increased. In mature trees, applications of 1% eugenol, a natural essential oil, reduced crop load about 50% in peach indicating that eugenol can effectively reduce the time required for follow-up hand thinning. Multiple sprays of the ethylene generating bioregulator, ethephon, were effective at reducing the problem of biennial crop production in mature apple trees.
Progress was made in the development of machines for thinning peach bloom or green fruit. A new single spiked-drum shaker was designed and developed following previous tests with a double-drum unit. The new shaker is smaller, lighter weight and more readily adapted to forklift machines commonly found in commercial orchards. Field tests in 2010 demonstrated removal rates ranging from 10% to over 50% of the green fruit (about 35 days after full bloom) depending on shaker frequency. Work continued on techniques to create a three-dimensional model of a leafless apple tree for the eventual purposes of mechanized pruning. Cameras were used to acquire images of the tree, and those images were used as input to a computer program that is under development to create the three-dimensional model.
Brown, M.W., Mathews, C.R. 2009. Biology of Oedophrys hilleri (Faust) (Coleoptera: Curculionidae): A Potential New Pest of Peach in the Eastern United States. Entomological News. 120:185-193.
Tworkoski, T., Scorza, R., Glenn, D.M. 2009. Leaf N and P in different growth habits of peach: effects of root system morphology and transpiration. Journal of Applied Horticulture. 11(2):95-98.
Bergh, J.C., Leskey, T.C., Walgenbach, J.F., Klingeman, W.E., Kain, D.P., Zhang, A. 2009. Dogwood borer (lepidoptera: sesiidae) abundance and seasonal flight activity in apple orchards, urban landscapes and woodlands in five eastern states. Environmental Entomology. 38:530-538. Available www.bioone.org/doi/pdf/10.1603/022/038/0304.
Glenn, D.M. 2010. Canopy gas exchange and water use efficiency of 'Empire' apple in response to particle film, irrigation, and microclimatic factors. Journal of the American Society for Horticultural Science. 135(1):25-32.
Frank, D., Leskey, T.C., Bergh, C. 2009. Post-mating behavior of female dogwood borer (lepidoptera: sesiidae) in apple orchards. Environmental Entomology. 38(4):1219-1225.
Boiteau, G., Vincent, C., Meloche, F., Leskey, T.C. 2010. Harmonic radar: assessing the impact of tag weight on walking behavior of Colorado potato beetle, plum curculio and corn rootworm. Journal of Economic Entomology. 103(1):63-69.
Leskey, T.C., Wright, S.E., Glenn, D.M., Puterka, G.J. 2010. Effect of surround WP on behavior and mortality of the apple maggot (Diptera: Tephritidae). Journal of Economic Entomology. 103(2):394-401.
Frank, D., Leskey, T.C., Bergh, J. 2010. Development of a rearing methodology for the dogwood borer (Lepidoptera: Sesiidae). Annals of the Entomological Society of America. 103(1):50-56.
Leskey, T.C., Short, B.D., Wright, S.E., Brown, M.W. 2009. Diagnosis and variation in appearance of brown stink bug (Hemiptera: Pentatomidae) injury on apple. Journal of Entomological Science. 44:1-10.
Leskey, T.C., Hancock, T., Wright, S.E. 2010. Host tree-related differences in foragaing and electroantennogram activity for the plum curculio, Conotrachelus nenuphar (Herbst.) (Coleoptera: Curculionidae). The Canadian Entomologist. 142:284-293.
Miller, S.S., Tworkoski, T. 2010. Blossom thinning in apple and peach with an essential oil. HortScience. 45(8):1218-1225.
Brown, M.W., Short, B.D. 2010. Factors affecting appearance of stink bug (Hemiptera: Pentatomidae) injury on apple. Environmental Entomology. 39:134-139.