1a. Objectives (from AD-416)
1. Develop and integrate sustainable pest control technologies into deciduous tree fruit production systems. 2. Develop and integrate new horticultural technologies and strategies into deciduous tree fruit production systems to improve apple and peach fruit quality. 3. Develop and integrate new automation and mechanization technologies into deciduous tree fruit production systems to improve apple and peach production efficiency.
1b. Approach (from AD-416)
This project proposes the development and integration of entomological, horticultural, and engineering technology to solve major problems affecting temperate tree fruit production, the sustainability and environmental impact of tree fruit production, and consumer acceptance of tree fruits. Novel arthropod management techniques will be developed through the evaluation of insect behavioral manipulation strategies, identification of insect-resistant fruit tree accessions, and manipulation of the orchard floor vegetation to encourage beneficial insects and arthropods. Improved light, water, and pest management will be developed through new irrigation and vegetation manipulation of the orchard floor and through improved understanding of hormones and growth habit on carbon partitioning, tree development, and water use efficiency. Novel crop load management will be developed through new chemical and mechanization approaches. Future mechanization of orchard operations will be facilitated by newly developed tree management systems to improve light penetration in novel tree growth habits and by computerized visualization of tree branches and fruit. The broad base of expertise in the research program will integrate the most appropriate technologies to solve the key problems of tree fruit production. Productive and sustainable tree fruit production systems will benefit both consumers and global competitiveness of U.S. growers.
3. Progress Report
During 2010, progress was made toward the management of plum curculio, and a potentially significant insect threat to fruit, the brown marmorated stink bug, was evaluated. The synthetic chemical, trans-2-hexenal, was identified as a reliable standard for use in behavioral studies that monitor electro-physiological responses of plum curculio. This new standard will enable the discovery of biologically active signals for plum curculio management with physiochemical techniques. 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.
1. New and efficient mechanical thinning equipment for high-density peach production systems. Reducing the number of fruit per tree (thinning) is necessary to attain marketable size fruit, but thinning is a costly and labor intensive operation that could benefit from mechanization. A new single spiked-drum shaker was designed and developed by ARS scientists at Kearneysville, WV 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. This thinning device has drawn interest from peach grower groups in California, Washington, and South Carolina in addition to Pennsylvania where some tests were conducted.
2. Brown marmorated stink bug may cause significant damage to apple and peach. 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 by ARS scientists at Kearneysville, WV that early season damage to apple is greater than 20% and to peach is 50% in both unsprayed and sprayed orchards. The insect growth rate was also confirmed. Damage estimates and sampling will enable stink bug monitoring for determination of when damage levels to fruit are imminent. Application of these data to previously developed growth rate models can predict when this pest is at the proper growth stage to manage.
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.