2008 Annual Report
1a.Objectives (from AD-416)
Develop pest management technologies that reduce the dependence on conventional synthetic pesticides by integrating new biocontrol and alternative and environmentally benign insect control programs into the tree fruit production systems. Develop knowledge and strategies to improve nutrient and water use efficiencies of production systems. Characterize the physiological basis of environmental and genotypic interactions for fruit bud initiation and root plasticity. Develop systems that integrate traditional management of the tree and soil with novel techniques to manage fruit, shoot and root growth and minimize pest damage. Develop automation systems for production and post harvest practices of deciduous tree fruits to improve fruit quality, labor productivity, and reduce costs.
1b.Approach (from AD-416)
Orchard management practices will be altered to increase biological and bio-based control of pests and ensure sustainable production. Particle film and other developing technologies will be incorporated into production system to reduce the use of synthetic pesticides and mitigate the effects of environmental stresses. Natural products will be evaluated for pest control. Establish an insect rearing facility for natural and beneficial insect predators. Develop means of dispersing beneficial insects. Study insect behavior to develop attract and kill strategies, biological control, and the use of natural environmentally benign substances for integration into an orchard ecosystem. Different green and organic mulches will enhance the habitat for predatory and parasitic arthropods, manage weeds, modify root growth and distribution, and improve nutrient and water use efficiency, and fruit quality. Sod, shading, and reflective ground covers will be used to regulate carbon allocation to fruit bud development. Root distribution and morphology, phytohormone levels, and response to competition will be measured in apple and peach cultivars. Carbon allocation will be modeled in fruit bud and root tissues. Senor and sensor systems will be developed to determine fruit location in a canopy and differentiate fruit quality. Fruit quality is defined as either maturity or defect aspects. Developed sensors will be utilized in automated harvesting and post harvest sorting systems that will lead to consistent and uniform fruit quality and will allow to improve labor productivity and reduce costs.
During 2008, progress was made to optimize carbon assimilation in orchard systems and manage carbon partitioning to improve cropping and fruit quality. Two reflective groundcovers increased bloom and canopy volume on young apple trees. However, much of the resulting fruit was produced on one-year-old wood and often smaller than fruit produced from bloom on older spurs. To improve fruit size and quality, new chemical and mechanical thinning techniques were investigated. The essential oil, eugenol, applied at low concentrations thinned the bloom and increased fruit size on both peach and apple trees. A rod-drum shaker was used to thin green peach fruits which reduced follow-up hand thinning time by 50% and increased harvested fruit size. The net economic benefit of mechanical thinning versus hand thinning alone ranged from $71-$796 per acre. Additional research included initiation of five training systems with novel peach tree growth habits (pillar and upright) to determine the best management approach for growth, productivity, and adaptation to mechanized culture. The biological basis for size-controlling effects of apple rootstocks was partially characterized in greenhouse experiments using size-controlling rootstocks from the USDA apple rootstock breeding program. Differences among the rootstocks in hydraulic conductivity, hormone concentrations, and anatomy suggested that xylem development influenced scion growth.
Fruit bud initiation in peach decreases with shading from excessive vegetative growth. Sod competition reduced excessive growth in peach trees, and field experiments indicated less pruning would be needed to maintain yield when sod competition is used to control vegetative growth. In field experiments, the combination of kaolin-based particle films (PF) and irrigation maintained maximum photosynthesis rates at midday, a time when photosynthesis is often reduced. The use of PF may be an effective substitute for evaporative cooling not only to reduce fruit solar injury, but to improve apple quality through increased fruit weight in hot and dry climates.
Biological control within orchards was increased by adding food resources for natural enemies of aphids. The ratio of herbivores to predators was negatively correlated with pest control inputs suggesting this ratio might be used to measure potential sustainability of pest management in orchards. An orchard planting scheme was developed and published that incorporated all aspects of conservation biological control, including compost mulch, interplanting nectar-producing peach trees into apple orchards and planting companion flowering plants. Effective monitoring tools have been developed for dogwood borer based on identification of the female sex pheromone and for stink bugs using baited pyramin traps deployed within the canopy of fruit trees. This research project addresses NP305 Crop Production, Component 1: Integrated Sustainable Crop Production Systems, Problem Statements 1B.1,1B.2,and 1B.3.
Thinning green peach fruits with a rod-drum shaker, a new approach for increasing fruit quality. Fruit trees produce excess bloom that can result in over-cropping and small, poor-quality fruit. Preliminary tests of a rod-drum shaker mechanism on upright, narrow canopy pillar peach trees 52 to 55 days after full bloom reduced crop load an average of 58%, follow-up hand thinning time by 50%, and increased fruit size by 9% at harvest compared to conventional hand thinned or non-thinned control trees. Large scale commercial orchard tests conducted in Pennsylvania showed similar results. The net economic impact of mechanical thinning versus hand thinning alone ranged from $71 to $796 per acre. The rod-drum shaker was as effective for bloom thinning peach trees as a commercial string thinner developed and used in Europe. Mechanical thinning appears to be a promising technique for supplementing hand thinning in peach trees. This research project addresses NP 305 Crop Production, Component I: Integrated Sustainable Crop Production Systems, Problem Statements 1B.1, Develop Integrated Strategies for the Management of Pests and Environmental Factors that Impact Yield, Quality, and Profitability of Perennial Crops; 1B.2, Develop Mechanization and Automation Practices that Increase Production Efficiency; and 1B.3, Develop Perennial Crop Production Systems that are Productive, Profitable, and Environmentally Acceptable.
Particle film materials reduce negative effect of heat and increase apple productivity. Heat is a limiting factor of plant productivity throughout the world, and kaolin-based particle films (PF) have demonstrated that the reflective nature of the resulting plant surface can increase plant productivity primarily by reducing temperature in fruit, leaf, and canopy, but the underlying plant responses are not clear. The study was conducted from 1998 to 2007 and demonstrated that the combination of PF and adequate water could maintain maximum photosynthesis rates at full sun levels during the midday period and minimize the midday depression of photosynthesis that is observed and reduce the daily carbon accumulation. The increased carbon accumulation in the PF treatments during the midday period was likely diverted to the fruit, since the PF treatments increased fruit weight in 8 of 10 years. The use of PF may be an effective substitute for evaporative cooling not only to reduce fruit solar injury, but to improve apple quality through increased fruit weight in hot and dry climates. This research project addresses NP 305 Crop Production, Component I: Integrated Sustainable Crop Production Systems, Problem Statements 1B.1, Develop Integrated Strategies for the Management of Pests and Environmental Factors that Impact Yield, Quality, and Profitability of Perennial Crops; 1B.2, Develop Mechanization and Automation Practices that Increase Production Efficiency; and 1B.3, Develop Perennial Crop Production Systems that are Productive, Profitable, and Environmentally Acceptable.
5.Significant Activities that Support Special Target Populations
|Number of Active CRADAs||1|
|Number of Non-Peer Reviewed Presentations and Proceedings||15|
|Number of Newspaper Articles and Other Presentations for Non-Science Audiences||1|
Tworkoski, T., Miller, S.S. 2007. Endogenous hormone concentrations and bud break response to exogenous BA in shoots of apple trees with two growth habits grown on three rootstocks. Journal of Horticultural Science and Biotechnology. 82(6):960-966.
Tworkoski, T., Takeda, F. 2007. Rooting response of shoot cuttings from three peach growth habits. Scientia Horticultureae. 115:98-100.
Brown, M.W., Mathews, C.R. 2007. Conservation biological control of rosy apple aphid, Dysaphis plantaginea (Passerini) in eastern North America. Environmental Entomology. 36(5):1131-1139.
Myers, C.T., Leskey, T.C., Forsline, P.L. 2007. Susceptibility of fruit from diverse apple and crabapple germplasm to attack from plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae). Journal of Economic Entomology. 100(5):1663-1671.
Brown, M.W., Matthews, C. 2008. Conservation biological control of spirea aphid, Aphis spiraecolia (Hemiptera: Aphididae), on apple by providing natural altervative food resources. European Journal of Entomology. 105:537-540.
Glenn, D.M., Wunsche, J., Mcivor, I., Nissen, R., George, A. 2008. Ultraviolet radiation effects on fruit surface respiration and chlorophyll fluorescence. Journal of Horticultural Science and Biotechnology. 83(1):43-50.
Glenn, D.M. 2008. Long-term effects of sod competition on irrigated peach yield. HortTechnology. 18:445-448.
Campostrini, E., Glenn, D.M. 2007. Ecophysiology of papaya Carica papaya L.: a review. Brazilian Journal of Plant Physiology. 19:83-94.
Shellie, K., Glenn, D.M. 2008. Wine grape response to foliar particle film under differing levels of preveraison water stress. HortScience. 43(5):1392-1397.
Leskey, T.C. 2008. Reproductive development of female plum curculio, conotrachelus nenuphar (Herbst) in the mid-atlantic: Presence of multivoltine populations. Journal of Entomological Science. 43(2):208-216.