acknowledge the assistance of Debbie Estrada, Tricia Swanson, Bill Barnett, Nick Dokoozlian, and Richard Rice in conducting this study. Portions of the study were supported by the California Table Grape Commission and the California Tree Fruit Agreement. Nick
Charles G. Summers, Albert S. Newton Jr. and Kyle R. Hansen
Katie Ellis, Tara Auxt Baugher and Karen Lewis
Although automated and precision agriculture initially took off in agronomic crops, it has remarkable value for horticultural specialty crops such as tree fruit ( Roberson, 2000 ). High crop value per unit area and crop response to environmental
D.M. Glenn, G. Puterka, T. Baugher, T. Unruh and S. Drake
Hydrophobic particle film technology (HPF) is a developing pest control system for tree fruit production systems. Studies were established in Chile, and Washington, Pennsylvania, and West Virginia in the United States, to evaluate the effect of HPF technology on tree fruit yield and quality. Studies in Chile, Washington, and West Virginia demonstrated increased photosynthetic rate at the leaf level. Yield was increased in peaches (Chile) and apples (West Virginia), and fruit size was increased in apples (Washington and Pennsylvania). Increased red color in apple was demonstrated at all sites with reduced russetting and `Stayman' cracking in Pennsylvania. HPF technology appears to be an effective tool in reducing water and heat stress in tree fruit resulting in increased fruit quality.
The genetically available range in tree fruit architecture has not been fully utilized for tree fruit breeding or production. Higher planting densities, new training systems, high coats of pruning, the need to eliminate ladders in the orchard, and mechanized harvesting require a re-evaluation of tree architecture. Dwarf, semidwarf, columnar, and spur-type trees may be more efficient than standard tree forms, especially when combined with specific production systems. Studies of the growth of novel tree types and elucidation of the inheritance of growth habit components may allow breeders to combine canopy growth characteristics to produce trees tailored to evolving production systems.
Paul Tvergyak and Mark K. Mullinix
To address the acute need of Washington's tree fruit industry for professional horticulturists, the Agriculture Sciences Department at Wenatchee Valley College and the Department of Horticulture and Landscape Architecture at Washington State University have developed and implemented a unique undergraduate degree program. This program represents a new way of addressing the need for professional horticultural positions in Washington's tree fruit industry amidst tradition, reductions in state higher education budgets, and eroding confidence in the public education system. This program is not a credit transfer program but a fully articulated agreement. We established a small working team that represented the partners. Their goal was to discuss and develop a concept framework that has three parts: administrative, curriculum and industry support. The objectives of the program are to address the need of Washington's tree fruit industry for entry level horticulturists who could assume more responsibility earlier in their career, to make the fruit industry and integral partner, to prepare students for graduate study as well as industry professionals and to capitalize on the respective strengths of the partners.
Curt R. Rom, R. Andy Allen and Bryan Blackburn
The Arkansas tree fruit research program has a history of involvement in rootstock development. The elements of rootstock development are rootstock cultivar testing and rootstock breeding and evaluation. Research is focused on apple and peach rootstocks. Rootstock testing is done in conjunction with the NC-140 cooperative uniform rootstock research project. Currently, there are 10 NC-140 trials in progress for apples, peaches, pears, and cherry rootstocks in Arkansas. The Arkansas rootstock breeding projects were established in the early 1970s as components of the fruit breeding program. The objectives are to develop apple and peach rootstocks which are adaptable to the Arkansas edaphic and adaphic conditions, have size control, have some degree of pest resistance, and are efficient in production. To date, 92 apple rootstock selections have been made and 41 are still in early evaluation for propagation and growth characteristics, while 56 peach rootstocks have been selected and are in early evaluation. Arkansas apple rootstocks selections are sequentially numbered with numbers preceded by AAR (ex: AAR-92). Peach rootstocks selections are numbered with numbers preceded by APR. Data from 2 NC-140 apple rootstock trials were presented and discussed.
Fenton E Larsen and Stewart S. Higgins
Many tree fruit nurseries are limited to fall digging of deciduous nursery stock. Since trees may not defoliate naturally for timely digging, these nurseries may wish to defoliate chemically, which would be less expensive than hand-stripping and may more closely simulate natural leaf abscission. Consequently, test chemicals were applied with hand sprayers at commercial nurseries in central Washington State using single or double applications 1 wk apart. In 1992 on 7 apple cultivars and one pear, 500 ppm NPA + 150 ppm Ethrel significantly enhanced defoliation. Defoliation at 1000 ppm NPA was not superior to that at 500 ppm, and two applications were generally no better than one. However, in 1993, two applications were often more effective than one, and the addition of Ethrel to NPA generally enhanced defoliation if the combination of NPA + Ethrel was applied twice. Alanap and NPA were generally equally effective as defoliants. The addition of Ethrel to Alanap enhanced defoliation in only 3 of 9 cultivars, and then generally only when sprayed twice. Alanap + Ethrel was as effective with Alanap at 300 ppm as with Alanap at 500 ppm Ethrel by itself seldom increased defoliation.
Frank J. Peryea
Boron (B) is an essential micronutrient that is often in inadequate supply in many deciduous tree fruit orchards and must therefore be added as fertilizer. It can also occur at phytotoxic levels because of over-fertilization, use of high-B irrigation water, or naturally in arid soils that are natively high in B. Tree B status is usually characterized by leaf analysis although other diagnostic criteria are being evaluated. Several tests are used to characterize soil B status. Symptoms of B deficiency include blossom blast, poor fruit set and development, shortened internodes, terminal bud death, and shoot dieback. To ameliorate deficiency, B fertilizer may be broadcast or sprayed over the soil surface or sprayed on tree canopies. In some regions, maintenance applications of B fertilizer are made to prevent development of B deficiency. Sodium borates or orthoboric acid are usually used. Fertilizer rates and timing vary with location and farming practices. Symptoms of B excess include reduced or no yield, impaired fruit quality, leaf marginal chlorosis and necrosis, defoliation, and shoot dieback. Boron toxicity is alleviated by leaching B-enriched soil to move B below the root zone.
Gregory A. Lang
the tunnel trees. Fruit that ripened in the tunnel exhibited less wind-bruising than those in the unprotected plot. In 2006 and 2007 at CHES, flowers not damaged by frosts or freezes tended to set very well, and the tunnels were covered from budswell
Mark K. Mullinix and Paul Tvergyak
Horticulture departments have been experiencing a decline of students studying pomology and the tree fruit industry suffers from a shortage of horticulturists. Wenatchee Valley College responded to the tree fruit industry's request to develop an undergraduate pomology program. The program has an industry advisory committee, is industry oriented and emphasizes the art and the science of deciduous tree fruit production. Industry and field-based instruction is a significant component of the curriculum. The fruit industry funded the development of two laboratory orchards totaling 53 acres. Industry satisfaction and student placement is high. Wenatchee Valley College's success motivated the industry to encourage the Washington State University Dept. of Horticulture and Wenatchee Valley College to join in an educational partnership. The Washington Tree Fruit Program was implemented in 1993. It is the state's first educational program cooperatively developed by two state institutions of higher education and boasts 55 degree-seeking students. The articulated curriculum has many innovations and represents a significant departure from traditional undergraduate pomology curricula.