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United States Department of Agriculture

Agricultural Research Service


Location: Application Technology Research

2009 Annual Report

1a. Objectives (from AD-416)
The objective of this project is to enhance food and ornamental production through improved means for delivering agrochemicals such that utilization of the materials is maximized while losses from leaching, drift, or off-target loss are minimized. These methods will provide abundant, safe food and ornamental crops. These discoveries will minimize environmental impact, reduce production costs, and reduce worker exposure. The specific objectives for the next five years include: Objective 1: Develop new or enhanced delivery technologies that provide the most efficacious application of production materials, including nutrients and pest management materials. Sub-objectives: Identify application factors affecting distribution and quality of deposits of pest management materials applied to nursery, floricultural, vegetable, fruit, and field crops, and to integrate findings with Drift Reduction Technology (DRT) research into crop production programs. Develop automated or mechanized chemical delivery technologies for greenhouse production systems based on pest population information and/or plant development and plant stress information. Objective 2: Improve understanding of substrate chemical, physical, and biological properties to improve container crop production while minimizing agrichemical leaching. Sub-objectives: Evaluate the use of regional agricultural/forest byproducts and synthetic materials for use as a substrate in nursery containers. Determine the effects of irrigation parameters and hydraulic properties of soilless substrates on nutrient and pesticide leaching from pot-in-pot production systems.

1b. Approach (from AD-416)
Application systems will be evaluated by examining deposition patterns on artificial targets and plant tissue, atomization characteristics, and off-target spray movement on passive ground and airborne collectors. The effect of air and travel speed and their interaction with droplet size on deposition patterns on artificial targets placed within different field crop canopies will be examined in field trials. Full assessment of the potential benefits of any DRT will be measured in the field under varying canopy conditions. The effect of air speed and its interaction with droplet size on deposition patterns on artificial targets placed within different field crop with horizontal and vertical target surfaces will be examined in field trials. Droplet size distributions and droplet velocities from atomizers will be determined using a particle/droplet laser image analysis system. Granular delivery systems will be evaluated for their ability to apply herbicides to potted surfaces. Pneumatic and mechanical means for aiding in movement through canopies will be incorporated into the delivery systems. The effectiveness of the delivery systems will be evaluated by examining the deposition granule patterns on the target surface as well as measurement of the amount of active ingredient. To improve safety, reduce production costs, and to put spray only where needed, a carrier system will be evaluated to automate spray delivery in greenhouse and sheltered environments. First studies will utilize a wheeled, hand-cart to evaluate technology to target spray delivery. Air-assist and electrostatic technology appropriate to a greenhouse production system will be evaluated. One or more synthetic materials and one or more agricultural materials will be compared with conventional pine bark for production of nursery plants. Polyethylene terephthalate (PET) is a synthetic material currently used for many applications that has potential as a substrate component. Another strategy will be to grow the substrate. Agricultural crops which produce large amounts of biomass will be grown, harvested, and processed into a substrate. PET, switchgrass chips and willow chips will be the first candidates tested for suitability as substrates. To determine the effects of irrigation parameters and hydraulic properties of soilless substrates on nutrient and pesticide leaching from pot-in-pot production systems a commercial pot-in-pot (PIP) system will be used. Pine bark will be amended with peat at three rates and irrigation will be applied either with a timer or automatically activated according to soil moisture readings from a neutron probe irrigation sensor. A complete fertilizer package and an insecticide will be incorporated into the substrate during the mixing process. A preemergence herbicide will be applied to the substrate surface of all containers after they are filled and planted. All production inputs and all climactic inputs will be recorded by data loggers. Leachates will be collected weekly and analyzed for all macro- and micro-nutrients using ICP analysis; insecticide and herbicide concentration in the leachates and plant tissue will be quantified with GC-MS analysis.

3. Progress Report
Significant progress was made on this project in the last year in the areas of pesticide application efficiency, drift management, substrate analysis, and nursery weed management. Field studies have identified improved methods to apply pesticides in crops of different architecture such as those with the primary structure components being broad leaves or vertical stems. Field research was initiated to estimate the amount of fungicide moving through the intended target and ending up on the ground. Air-assist sprayer parameters including droplet size and air speed were evaluated to determine the most effective means of treating abaxial leaf surfaces on mature poinsettias. Fields studies were conducted to assess the potential benefits of using towers on tree sprayers as a potential Drift Reduction Technology for orchard or shade tree pest management. Studies were initiated to evaluate the use of regional agricultural/forest byproducts and synthetic materials for use as a substrate in nursery containers. Three materials that could be used for a substitute for pine bark as a substrate material were used in short and long-term plant bioassay studies. Nursery production research studies modeled the impact of peat moss on the physical and hydraulic properties of pine bark substrates. At Kansas State University, work has been primarily purchasing equipment, expanding production areas to meet our research needs, and recruiting graduate students to work on the alternative substrates project. In 2008 a preliminary study with Eastern Red Cedar (Juniperus virginiana) as an alternative potting substrate for container-grown trees was conducted. This work was presented to nursery producers at The Wichita Area Nurseryman's Association Field Day. At Oregon State University, research was conducted to determine extent of nitrogen and phosphorus release from Controlled Release Fertilizers throughout fall and winter months in the Willamette Valley. In addition, we evaluated uptake of nitrogen and phosphorus of deciduous and evergreen plants and assessed environmental impact on experimental nursery sites. This work was published in abstract form at one science meeting and is being prepared for journal publication. It was also presented to nursery producers at four different nursery workshop events.

4. Accomplishments
1. Biofuel Crops Can Be Used as Nursery Potting Substrates Pine bark is the primary component of nursery potting substrates. Due to the energy and economic crises, pine bark availability has declined and price has increased dramatically, negatively impacting the ability of U.S. nursery growers to secure a reliable substrate for growing plants. Our research showed that several biofuel crops already grown in the U.S. (willow, switchgrass, and giant miscanthus) can be used as a substitute for pine bark. This will provide an additional market for biofuel crop producers, while reducing nursery grower dependency on pine bark.

2. Potentially devastating soybean disease could be kept in check with new information on application technology Asian Soybean Rust (ASR) is a potential devastating disease that could destroy much of the U.S. soybean crop. Current fungicide treatments can manage ASR if they can reach the lower part of a mature soybean canopy. Field studies demonstrated that small droplet applications designed to improve coverage can only effectively treat the target area if air-assistance is used to help provide extra energy to penetrate the canopy. These findings demonstrate the importance of matching the application equipment parameters with the pesticide choice to provide the most efficacious applications.

Review Publications
Altland, J.E., Buamscha, G., Sullivan, D., Horneck, D. 2008. Nitrogen Availability in Fresh and Aged Douglas Fir Bark. HortTechnology. 18(4):619-623.

Altland, J.E., Buamscha, G., Horneck, D. 2008. Substrate pH Affects Nutrient Availability in Fertilized Douglas Fir Bark Substrates. HortScience. 43:2171-2178.

Altland, J.E., Wehtje, G., Gilliam, C., Mckee, M. 2008. Liverwort (Marchantia polymorpha) Response to Quinoclamine in a Pine Bark Substrate. Weed Science. 56(5):762-766.

Derksen, R.C., Zhu, H., Ozkan, E., Hannond, R., Dorrance, A. 2008. Determining the Influence of Spray Quality, Nozzle Type, Spray Volume, and Air-Assisted Application Strategies on Deposition of Pesticides in Soybean Canopy. Transactions of the ASABE. 51(5):1529-1537.

Altland, J.E., Glenn, W., Gilliam, C. 2008. Interaction of Glyphosate and Diquat in Ready-To-Use Weed Control Products. Weed Technology. 22(3):472-476.

Altland, J.E. 2009. Preemergence Control of Black Cottonwood in Nursery Containers. Journal of Environmental Horticulture. 27(1):51–55.

Last Modified: 06/25/2017
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