Scientist: Integrated Orchard Management for Deciduous Tree Fruit Crops 

Professional biographical information: 

B.S. cum laude  in Botany  from Ft. Lewis College (1972).

M.A. in Plant Ecology from University of Colorado (1974).

M.S. in Production Agronomy from Colorado State University (1977).

Ph.D. in Crop Science from Oregon State University (1981).

Description of research projects:

The area of research is soil-water management and soil-plant-water relations in fruit production.  The research focuses on the response of fruit and shoot growth to chemical and physical changes in the plant environment.  The research will develop (1) management systems that more efficiently utilize the environmental resources (2) production systems that minimize pesticide usage.

Developed and patented a pest control system based on particle film technology that controls a wide range of diseases and insect pests. The particle film also reduces heat and water stress in plants and improves production efficiency.  The USDA-ARS Technology Transfer Award was presented for this work in 1999 and the Federal Laboratory Consortium Technology Transfer Award was presented in 2000.  Dr. Glenn received the "Outstanding Senior Scientist of the Year 2001" award for the conception, development, and transfer of particle film technology.  This technology is under commercialization by Engelhard Corp.

Particle Film Technology consists of the development and application of aqueous formulations of chemically inert mineral particles that have been specifically formulated to coat agricultural and consumer crops with protective films. The physical properties of the film reduce damage from insects and plant pathogens, while enhancing photosynthesis and yield of horticultural product. Drs. Glenn and Puterka initiated their work on Particle Film Technology when they realized that the behavior of insects on such films would be profoundly altered from their behavior on natural plant surfaces. Particle films prevent insect infestation by coating plants with a physical barrier that deters insect infestation, and impedes insect movement, feeding, and egg-laying (Glenn et. al. 1999; Puterka et. al. 2000). The physical barrier formed by particle film technology also acts to prevent contact between pathogenic microbial inocula and plant surfaces, thereby reducing infection and disease (Glenn et.al. 2000a); Puterka et.al. 2000). As applied, the particle film transmits 90-98%of photosynthetically active radiation, while its reflective properties reduce heat build-up, ultraviolet radiation damage and heat stress in plant canopies. These properties ultimately produce more efficient photosynthesis, and increase the amount of assimilate available for fruit development (Glenn et. al. 1999, 2000b).

Field research demonstrated that this technology effectively provides a safe replacement for some uses of organophosphate and carbamate insecticides in a wide range of crops, including apple, pear, grape, blackberry, tomato, peach, and nectarine. Particle film technological development was expedited by the involvement of large numbers of collaborators, and the use of both northern and southern hemisphere sites, permitting year-round data collection. The field collaborations involved 26 U. S. scientists, including scientists at 7 USDA Agricultural Research Service locations; scientists from Argentina, Australia, Brazil, Chile, Italy, Israel, Germany, New Zealand, the Netherlands, and South Africa; and 18 U. S. apple, peach, and pear growers.

The US Environmental Protection Agency (EPA) registration process "fast-tracked" this material to make it available in the 2000 growing season due to the formulations' low toxicity and safe handling properties. The formulations contained only compounds on the Food and Drug Administration's "Generally Recognized as Safe" list.  Additionally, the safe and natural basis of this material justified the Organic Materials Review Institute's (OMRI) approval of kaolin formulations for year 2000 organic certification in the United States.

Importance and Impact of Particle Film Technology

Particle Film Technology is currently having major impact on key insect pests and environmental stresses in the U. S. apple, pear and grape production industry, on consumers of these products, and on the environment. The basic principles of the underlying particle film concept make it applicable to numerous crops. The enthusiasm generated by international field trials and by its initial commercialization indicates that the technology will soon have global impact. Technologies such as particle film are needed to help implement national policies, including the Food Quality Protection Act, that are aimed at regulating conventional chemical pesticides in food production, as a means to reduce the pesticide load in the environment, This, in turn, will improve agricultural worker safety, and insure a safer food supply for the U.S. consumers.

Another benefit is that the underlying mechanisms of this technology make it improbable that insects will develop resistance; thus, particle films will be useful in resistance management programs. Particle films create a physical barrier that repels insects so there is no toxic selection pressure. The international adoption of particle film-based insect control programs will reduce chemical pesticide use at the global level and insure that the American consumer will have produce available with reduced levels of pesticides. Commercialization of the technology under the name Surround-WP™ Crop Protectant has resulted in the effective control of insecticide-resistant pear psylla in Washington and Oregon. This specific commercial application was solicited directly by fruit growers in the affected area, based on their awareness of previous field trials. Particle film technology has also been shown to be effective against codling moth, leafroller, leafhopper, plum curculio, spirea aphid, and thrips. Perspective for the economic impact of particle film technology can be gained from the fact that $185,000,000 were spent in 1997 on insecticides for deciduous tree fruits, nuts, citrus and grapes, and that commodities with a 1999 US farm gate value of $14,300,000,000 are directly impacted by the technology.

In organic agriculture, particle film technology represents the first broad utility material that provides effective insect control and high produce quality in organic fruits and vegetables. Its adoption by organic growers will further increase the growth of this expanding industry in the US and globally. Surround-WP has been certified by OMRI as an organic material that can be used by registered organic farms in the U.S. In 2000, the Michigan Organic Board recommended Surround as its foundation pest control system.

Particle film technology represents the first effective means of combating insect vectored diseases. As a highly effective insect repellent, particle film technology deters insects from feeding, thus preventing transmission of disease agents. This concept has been demonstrated for leafhopper-transmitted diseases such as variegated chlorosis in citrus, and Pierce's disease in grapes. The high level of leafhopper control (Glenn et.al. 1999; Puterka et.al. 2000; and unpublished data) is a breakthrough for insect management and control of leafhopper vectored diseases. Trials of particle film-based control of the glassy-winged sharpshooter in grapes are presently underway in the Temecula valley and Kern county in southern California. Successful control of this insect will prevent the spread of Pierce's disease, which is a serious threat to the $2.8 billion California table and wine grape industry.

Sunburn control of fruits currently relies on the extensive use of irrigation water for evaporative cooling of sensitive fruit. 'Surround Crop Protectant' is the first material to provide effective suppression of high heat damage and sunburn without the use of evaporative cooling. The impact of particle film technology will be to reduce the dependence of agriculture on irrigation water sources to mitigate heat stress. Particle film technology will become a key component of heat damage control as water shortages and conservation measures become key environmental issues. The color of fruits and vegetables is a key criteria in high quality, particularly in the export market. The technology has demonstrated that the reduction of infrared and ultraviolet light as well as the redistribution of photosynthetically active radiation results in improved red color development in apple.

Particle film technology, while still in its infancy, represents a broadly-based insect control system whose impact could be similar to the development of the first synthetic insecticides but without the adverse environment and food-chain characteristics. In addition, particle film technology provides agriculture with the first sunburn and heat management tool that can manipulate ultraviolet, photosynthetically active radiation, and infrared radiation. The multifaceted aspects of particle film technology for agriculture makes it likely that it will have a global impact on many aspects of the U.S. and world agricultural production systems.

Particle Film Technology Presentation!  Particle Film Technology in Agriculture to Reduce Heat Stress and Sunburn.  Click here for details.

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