Congratulations to the following researchers on their successful grant proposals in 2016. Research projects focus on agricultural engineering, environment and plant microclimate monitoring, entomology, plant pathology, soil science, horticulture, plant breeding and evaluation, new product evaluation, propagation, and water managemen. There are 5 funded projects for the year 2012 directed by researchers from the University of Georgia, and University of Florida.

The results of the research conducted at CANR benefit the entire industry. All results are published on the CANR website and presented at the Georgia Green Industry Trade Show in January.

The Center for Applied Nursery Research is open to all and presents a wonderful opportunity to observe new plant material and visually experience the projects in progress in addition to reading the final reports following project completion.

CANR is funded by special events and donations from industry and individuals. With continued support from the industry, the Center can continue to fund and provide a site for horticulture research in Georgia and the Southeast. For more information on how you can support CANR click_here

The 2016 Projects are:

Evaluating five improved genotypes of cotoneasters for container production in southeastern U.S.

Ryan Contreras

Over the past 15-20 years, production of cotoneasters has declined due to a variety of reasons, not the least of which has been a lack of breeding for improved varieties.  As Dirr points out, there are a number of problems with the genus including fire blight caused by Erwinia amylovora.  I have developed a number of selection that have proven resistant to fire blight in our greenhouse inoculation studies.  I have propagated these selections and grown them in limited numbers.  Industry input in Oregon on these selections has been extremely positive.  They root at high percentage (all >90%) and progress through production very fast; one selection in particular rooted and was transplanted into a #1 container in 1 month.  I believe these selections have potential to revive a “workhorse” genus and provide a crop for growers nationwide including areas where fire blight has limited their potential.  The objective of the proposed research is to grow these five selections alongside two industry cultivars and evaluate their production scheduling and resistance to disease (fire blight), insect (lace bug), and environmental stress (heat).

Longevity and efficacy of pre-emergent herbicides

Dr. Mark Czarnota

University of Georgia

There are many herbicide available to the nursery industry, but little scientific research has been performed to determine the longevity of the herbicide in soil-less media.  It is often thought that most preemergence herbicide provide approximately 30 to 40 days of control where weed seed growth is inhibited, and the additional month or two of weed control is just time that no weed infestation is present.  To determine the length of time that a herbicide provides weed free growth, replanting of weeds seed needs to occur weekly until no weed control is observed.  The objective of this study is to test the longevity of select herbicides on the control of select weeds, and determine the actual length of weed control that an individual herbicide can be expected to provide.

Automating leaching fraction measurements to improve water conservation, fertilizer efficiency, and plant growth during container nursery production

Amy Fulcher

Water is an essential input for container nursery crop production.  The threat of regulation, poor water quality, periodic drought, and competition for water make managing water resources a critical aspect of container nursery management.

Measuring leachate and calculating leaching fraction (leachate volume/total irrigation volume) is an effective way to determine irrigation volume and can be used to improve irrigation scheduling. Determining the leaching fraction of one plant during one irrigation cycle is typically done by manually capturing and measuring the irrigation water volume and the leachate coming out of the bottom of the container. Other methods include weighing the leachate and irrigation water, and aggregating leachate on a collection pad from multiple plants before measuring. However, manual methods of leachate measurement are time and labor intensive and therefore difficult to perform at a nursery on a scale suitable to capture day-to-day and plant-to-plant variation. Furthermore, these methods are only functional at a small scale; they would be difficult to adapt to a large-scale outdoor nursery environment under overhead irrigation.

Our objective is to design and develop automated leachate gauges that will function in an outdoor nursery setting with overhead irrigation and deliver accurate, real time data that can be used to schedule irrigation.  The proposed system will automatically adjust irrigation run time to maintain a leaching fraction of 10-20%.

Chemical fate of phosphorus in containerized nursery crop production

James Owen, Jake Shreckhise, and Alex Niemiera

Virgina Tech,

A complete fractionation of phosphorus (P) (i.e. total phosphorus, orthophosphate, dissolved phosphorus and insoluble phosphorus) in pore-water (i.e., solution residing in container substrate pores) of amended and non-amended soilless substrate has not yet been performed; furthermore, the determined fraction of total leachate phosphorus in the form of orthophosphate (plant available P) has been inconsistent between studies (Million et al. 2007; Ristvey et al., 2004). Fractioning pore-water phosphorus will provide insight on short-term quantity of plant available phosphorus in pore-water, as well as the immediate bioavailability of P leached from soilless substrate. We hypothesize that not all pore-water phosphorus is immediately plant available. Thus, our results would allow us to make fertilization recommendations based on plant available phosphorus rather than total phosphorus in pore-water. Additionally, determining the proportion of dissolved and insoluble phosphorus in leachate would aid in our understanding of the container nursery’s environmental impact due to phosphorus runoff. Therefore, our objectives are to determine (1) the concentration and form of phosphorus in pore-water of lime- and micronutrient-amended and non-amended pine bark when fertilized with controlled-release fertilizer containing nitrogen, phosphorus and potassium AND (2) the effect of pine bark source (i.e., supplier) on pore-water phosphorus form and concentration when fertilized with controlled-release fertilizer containing nitrogen, phosphorus and potassium. Preliminary experimentation at Virgina Tech in our laboratory has shown a dramatic effect of amendments on leached P fractions warranting a need for continued research described within this proposal.

Container Production Techniques of Syzygium buxifolium, An Alternative to Buxus

Donglin Zhang

University of Georgia,

Recently, boxwood blight, a devastating fungus disease (Cylindrocladium buxixola), has been reported in Georgia and 15 additional states and its alternatives are desperately needed. Syzygium buxifolium from central China shares similar ornamental features as boxwood, but is resistant to boxwood blight because it belongs to Myrtaceae. The objectives are 1) to evaluate Syzygium performance in container, 2) to investigate container production strategy for Syzygium, and 3) to address the production schedule of Syzygium as a potential new plant.