This month I would like to discuss the concept of phenology. Have you ever been with a grower and heard them talking about phenology or growing degree days and wondered to yourself what they were talking about? Well here’s your answer.

First let’s take a quick trip back to high school biology class! Remember when we learned that plants, insects, and many disease pathogens depend on sunlight as a way to regulate their internal temperatures, which in turn drives their metabolism? Depending on how cool or warm a region is will determine how quickly nature gets moving in the spring.

This spring is a perfect example, there have been many clear sunny days and warmer than usual temperatures in most of the Eastern US, and in these areas plants, insects, and diseases are already active. Phenology is a measurement of this, of how Mother Nature is progressing based upon the daily temperatures.

A growing degree day (GDD) is a measurement of heat units. All plants and pests need to accumulate a certain amount of these growing degree days before they reach different lifestages in their development. For example most Lacebug species begin their developmental process in the spring at about 450 GDD and the lifecycle is complete at around 620 GDDs.

So again, the temperature of a given region determines how fast this lifecycle takes; cooler=slower, while warmer=faster. Having access to this type of data allows growers to be better informed about when to apply certain pesticides, allowing the chemistry to be as effective as possible. So how do we calculate a GDD?

Each crop or pest has its own requirement for how many GDDs it takes to complete its lifecycle, but all development usually stops around 55⁰F. This number is critical because it will serve as the lower threshold of development. Each organism has a lower threshold (50⁰F for most air dwelling species) and an upper threshold, where temperatures become too warm and development stops, also known as diapause in insects.

Here in Maryland we start to monitor our GDDs historically on March 1st, because that is when we usually start to reach temperatures of around 55⁰F. This is referred to as the Biofix date. This date will be different for each region and should also be available through your local extension agency.

So on March 1st I place out a high/low thermometer and start recording the high and low data sets for each day. Once I have a couple of days’ worth of information I sit down and plug them into this easy calculation:

For example if I had a high temperature of 72⁰F and a low of 50⁰F, here’s what my calculation would look like:

72⁰F + 50⁰F = 122    and   122 /2 = 61 (X)
then 61 (X) – 50 = 11 GDDs…  So on this day I would have accumulated a total of 11 growing degree days.

A phenometer is a tool that looks like a fancy thermometer. This device tracks the daily high and low temperatures and accumulates them. This makes it very easy for the grower to track GDDs, as the calculations are done for them and the device only needs to be checked once or twice a week. With the push of a button the user can see how many GDDs they are currently at for their growing location.

Another source for this information is your local extension agency. Most local agencies track this information and make it available to growers on their websites or in their publications.

Again, this information helps growers to make better educated decisions on when to apply pesticides and is a vital tool for a sound IPM program.  We at Harrell’s are working to get more of this phenology and GDD information up on our MyHarrells website. Stay tuned for more information!

Marshall Horsman is a Technical Manager for Harrell’s, specializing in tropical horticulture. He has been studying palms and horticulture since the age of 13, when he began traveling to remote areas of Latin America and the Caribbean with his father to collect rare palm seeds and orchids. He studied Ornamental Horticulture at the University of Florida and then spent 16 years as a Horticulture Consultant with A&L Labs. He has consulted numerous nurseries and Caribbean resorts, including the Atlantis Resort. He has maintained palms in Africa, the Bahamas, Costa Rica, the Caribbean, South Florida and other locations. His passion is his 80 acre palm arboretum in Southern Costa Rica, where he has over 200 species of palms.

Dr. Snyder has been the Research and Development Manager of Harrell’s, LLC since 2007. Dr. Snyder is a graduate of the University of Florida where he received his Ph.D. in Soil Science specializing in Soil Fertility and Fertilizers. Dr. Snyder is responsible for investigating new product opportunities, proprietary product development, and technical sales support.

Nutrients covered include nitrogen, potassium, magnesium, manganese, iron and boron.

Marshall Horsman is a Technical Manager for Harrell’s, specializing in tropical horticulture. He has been studying palms and horticulture since the age of 13, when he began traveling to remote areas of Latin America and the Caribbean with his father to collect rare palm seeds and orchids. He studied Ornamental Horticulture at the University of Florida and then spent 16 years as a Horticulture Consultant with A&L Labs. He has consulted numerous nurseries and Caribbean resorts, including the Atlantis Resort. He has maintained palms in Africa, the Bahamas, Costa Rica, the Caribbean, South Florida and other locations. His passion is his 80 acre palm arboretum in Southern Costa Rica, where he has over 200 species of palms.

Boron helps aid the transport of sugars made through photosynthesis. However, its main role is that it is involved in the movement of calcium to formulate cell walls. Therefore, areas of “new growth”, such as root tips or meristematic tissue that makes new leaves, flowers or even fruit need it most. And despite how little is needed, (often put in fertilizer mixes at .03%) deficiencies of boron are not uncommon.

One of the reasons for this deficiency is that boron leaches out of soil, unlike the rest of the minors. In the tropics, where rainfall is a daily occurrence, boron levels are frequently void. Coffee growers will often have 1% boron put in their mixes. As it aids calcium in cell wall formation, a deficiency of boron will stunt or cause necrosis (dead tissue) in tips of stems.

In sandy areas of Florida, several palm varieties will show boron deficiency as a distorted new bud or  “hook leaf” , including Foxtails, Phoenix varieties, and Montgomery palms. As the sand has little CEC, the boron leaches away. In foliage crops, like Spathyphyllum boron deficiency is shown as rippling of new leaves.

Source: http://flrec.ifas.ufl.edu/palm_prod/palm-key-photos/Fig-10_B%20def-royal1L.jpg

This being said, there is a fine line between boron deficiency and boron toxicity. Because of the potential liability, many fertilizer mixes have NO boron. Boron toxicity can cause a severe tip burn and take a great deal of time to grow out of. Dracaenas ‘Janet Craig’, ‘Warneckii’ and ‘Massangeana’ and Calatheas are very boron sensitive. Bromeliads and orchids even worse!

Some palm growers have upped their boron levels in their fertilizer mixes by 3-4X. This should be done at their own risk, as there is no room for error. Boron will accumulate in leaf tissue and will cause burn once it reaches a critical threshold. It is best to leave the rate in fertilizer bag at .03%.

For palms showing boron deficiency, our Harrell’s MAX® Tropical Mix plus Boron sprayed at 1 Qt. per 100 gallons of water has literally performed miracles. It might be a little strong on Spathyphyllum crops so a recommendation of 2 ounces Solubor per 100 gallons once a month is good.

Use tissue analysis first to determine if a crop is boron deficient. If soils are too high in boron, remember leaching will help this. Sometimes boron can be high in reclaimed water as sewage (and sludge) often have high amounts. So this nutrient is a little tricky and needs scrutiny when dealing with it; I really only recommend boron on crops that historically show deficiencies and have a leaf analysis to substantiate it.

And yes, despite how little a plant needs, next month’s Nutrient will be Molybdenum!

Photo by Michael Berger

Trees, shrubs, and herbaceous ornamentals benefit greatly from proper fertilization.  Fertilizing with the proper complete fertilizer early in the year promotes the development of healthy landscape plants that can withstand stresses associated with the growing season.  Proper fertilization also promotes highly desirable aesthetic qualities such as flowering and blooms which result in beautiful landscape appearances.

Woody ornamental fertility requirements are determined by geographic location, maturity stage, and desired plant growth.  One application of a complete fertilizer may be sufficient on mature plants, while three to five may be necessary for younger plants.  In general, three to five pounds of nitrogen (N) per 1,000 sq ft per year is sufficient for most locations.  Southern regions may require up to three applications of three to five pounds of N per 1000 sq ft.  The use of a controlled-release fertilizer containing both macro- and micronutrients is highly desirable as nutrients in many landscapes are subject to leaching losses resulting from irrigation and heavy summer rainfall.  Finally, be sure to check soil pH at least once a year to confirm proper pH for each specific woody ornamental species.

Herbaceous ornamentals such as annuals and perennials are fertilized at the time of planting and at six to eight week intervals during the growing season depending on the specific type of plant species.  As with woody ornamentals, the use of a controlled-release fertilizer containing macro and micronutrients maximizes plant responses and minimizes undesired nutrient leaching losses.  Furthermore, the use of controlled-release fertilizers helps to reduce the chances of fertilizer burn.  In general, the application of a complete, controlled-release fertilizer at one to two pounds of N per 1000 sq ft per growing season is sufficient.  Again, remember to check soil pH yearly to confirm desirable pH conditions.

Image from deerticks.com

Dr. Richard S. Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Millbrook, NY warns of a potential high 2012 tick population and higher public risk of Lyme Disease.

‘This is not because of the unusually warm winter, however,’ says Ostenfeld.  ‘There is no rigorous evidence supporting a positive correlation between winter temperatures at a site and overwinter survival or subsequent spring/summer density of ticks.  The reason we’re expecting a bad 2012 is that heavy acorn masting in 2010 in the northeast led to very high densities of white-footed mice and eastern chipmunks in 2011.  Both these species but especially mice are highly competent reservoirs for the Lyme disease spirochete and also good-quality hosts for larval ticks.  In our 20-year dataset, the summer after a high-mouse year almost always sees unusually high abundance of infected nymphal blacklegged ticks.’ Read more about Dr. Ostfeld’s prediction

Harrell’s recommends Talstar by FMC for deer tick control. Take a few minutes to read FMC’s Best Management Practices for Deer Ticks.

Lakeland, Florida, April 20, 2012

“Turf & Landscape is a natural fit between our existing Horticulture and Golf divisions”, says Matt Shook, vice president of sales and marketing for the turf and landscape division. “For the past year we have been developing business in Florida and Indiana with landscape professionals, parks and recreation facilities, cemeteries, amusement parks and athletic fields. We have found customers in these markets are looking for a reliable, knowledgeable partner for their turf and ornamental challenges. Our Turf & Landscape representatives fit that niche and fill that need.”

Harrell’s is pleased to welcome the following six territory managers to the southeastern region:

Chris Weigand – North Georgia

Chris was previously with John Deere Landscapes in the Atlanta market, before joining Harrell’s late last fall.  Chris has been working in the turfgrass industry for over 18 years in sales as well as working on golf courses.  Chris is a graduate of Abraham Baldwin Agricultural College.  Chris and his wife Abi have 2 daughters and reside in Gainesville, GA.

Matt Marlow – Northern North Carolina

Matt joined Harrell’s late last fall. Prior to that, he was with John Deere Golf as well as Smith Turf and Irrigation.  Matt has worked in the turfgrass industry for over 9 years in both the golf and landscape markets.  Matt is a graduate of North Carolina State University.  Matt resides in Knightdale, NC.

Rodney Moulin – Southern North Carolina and South Carolina

Rod was previously with Super Sod in the Charlotte market.  Rod has been involved in the turfgrass industry for many years working as a golf course superintendent for over 20 years as well as working in equipment sales.   Rod is a graduate of Ohio State University.  Rod and his wife Laurie have 4 children and reside in Indian Land, SC.

James Bartley – Alabama, NW Florida and parts of the Gulf Coast

James is the current president of the Alabama Turfgrass Association and trustee with the Alabama Turfgrass Research Foundation.  James was previously employed with Southern Lawns for 34 years. James is a graduate of Auburn University with a B.S. in agronomy.   James has been married to his wife Donna for over 30 years and resides in Auburn, AL.

Mickey Lovett – Tennessee and Arkansas

Mickey has been working in the turfgrass industry of over 25 years.  Mickey has worked with Syngenta, Ciba-Geigy and Zeneca.  Mickey is a graduate of the University of Tennessee at Martin with a degree in Agriculture.  He and his wife, Dixie, have been married for 30 years and have 3 daughters and 2 grandchildren.  Mickey will be opening new markets for Harrell’s in the newly formed Turf & Landscape division.  Mickey resides in Paris, TN.

Waldo Terrell – Southeastern Sports Turf Specialist

Waldo was previously with Southern Athletic Fields in the south eastern US.  Waldo has worked in the turfgrass industry for over 13 years in both sales and field maintenance.  Waldo will be opening up new markets for Harrell’s in the newly formed Turf & Landscape division as an athletic field specialist.  Waldo attended the University of Georgia in Athens and managed the athletic fields.  Waldo and his wife Jenny have 2 children and reside in Athens, GA.

Harrell’s is pleased to announce the appointment of Travis Shaddox, PhD. as the designated technical advisor for the Turf & Landscape Division.

The Harrell’s team consists of several technical experts for the Horticulture and Golf Divisions and the devoted Turf & Landscape technical expert, Travis Shaddox, PhD., will be the point person working to troubleshoot and solve customer agronomic challenges in the T&L market. Travis received his Master’s and Ph.D. in soil fertility and turfgrass nutrition from the University of Florida. He has experience as an account manager for Valleycrest Companies where he maintained athletic turf and for the past five years he has held a sales manager role for Harrell’s.  Travis will also assist with customer education and product development.

“As a company we work to be a true partner to our customers. Our territory managers and technical experts work together to help our customers identify the best solution for their particular needs,” says Shook. “We have been fortunate to have a solid technical expert with a strong turf & landscape background who has been working for us for five years and we’re pleased to have Travis join us on the Turf & Landscape team.”

In addition to being one of the nation’s largest distributors of branded fungicides, herbicides and insecticides, Harrell’s produces top-quality, custom blended fertilizers, specialty liquids, and wetting agents for the golf course, sports turf, landscape management, and horticulture industries. Harrell’s guarantees stringent quality control procedures, tight manufacturing specifications and careful selection of raw materials for each product that carries the Harrell’s name.  They are also the exclusive eastern formulator and a leading world distributor of POLYON®, the industry’s superior controlled-release fertilizer technology.

Matthew Shultz, Technical Consultant, Harrell's LLC

Syngenta has released a technical bulletin for a new fungicide called Micora in the ornamental markets. The active ingredient, Mandipropamid, is in MOA class 40, the Carboxylic Acid Amides. This chemistry will have protectant and contact control and translaminar activity into the leaf cuticle. Micora provides long residual control of labeled diseases Phytophthora and Downy Mildew. Foliar and drench rates are a low 4-8 oz/100 gals. Low volatility and low to medium mobility in the soil will make this a good tool in controlling soil borne Phytophthora pathogens.

I also picked up a technical bulletin from Syngenta for their new insecticide called Enfold. Enfold is an insecticide that is highly effective against caterpillars, leafminers, spider mites and pear psylla. Enfold will be available in a soluble granule form, and is in the Avermectin or MOA Class 6 fungicide group. The active ingredient is Emamectin benzoate and can be applied at a low rate of 2.4-4.8 oz/100 gals. Enfold has some contact activity but works best after the insect ingests the active ingredient. Testing has indicated that Enfold is safe to use around many beneficial insects, and can be compatible with sound IPM practices.

Hurricane has been reformulated into a WDG (water dispersible granule). From personal previous use with the old water dispersible bags, this new formulation should help growers with ease of mixing and should also help to keep mixing dust to a minimum. Another great feature with the new WDG, is that growers are now no longer required to tank mix, so no more adding Medallion for soil drenches. New packaging comes in an 8 oz container and application rates are very low at 0.75oz/100 gallons on seedlings and up to 1.5oz/100 gals on cuttings and transplants. Hurricane still controls the same labeled diseases including Pythium, Phytophthora, and Rhizoctonia.

The SePro Corporation has announced the registration of its’ new biological insecticide Preferal. Preferal contains the natural occurring fungal strain, Isaria fumosoroseus which was first isolated by Dr. Lance Osborne at the U of FL. Preferal is effective at controlling aphids, whitefly, thrips and spider mites. This water dispersible granule has been used in IPM programs in Europe for some time now with good success, and is compatible with most beneficial insects.

Connecticut Environmental Council needs your immediate action on two legislative proposals currently under consideration by the Environment and the Planning & Development Committees.

 Support – HB 5155 in the Environment Committee

The Environment Committee is scheduled to vote on CTEC’s top legislative priority for the 2012 session HB 5155 which would remove the ban on pesticide use at schools K to 8. This legislation would permit pesticide use on all public and private schools K to12 if they adhere to Integrated Pest Management (IPM) program overseen by DEEP. Click here for position paper & committee list.

 Oppose – HB 5121 in the Planning & Development Committee

The Planning & Development Committee is scheduled to vote on this proposal, which seeks to ban pesticides use on all residential, municipal and commercial lawns (including public and private golf courses). This proposal would ban pesticides at all public and private schools as well as municipal recreation fields. In addition, this bill seeks to repeal the state’s longstanding oversight of pesticides thereby permitting municipalities to regulate the use of these products, which will most certainly lead to a patchwork of municipal regulations. Click here for position paper & committee list.

 Step 1:

By using your home and business addresses, use the attached list of members of the Environment Committee and Planning & Development Committee to determine if your state representative or state senator serves on either one or both of these committees.

 Step 2:

If your state representative or senator serves on these committees send them an email today. Use the attached position papers on each one of these bills to craft a short email to your legislators. Your action could mean the difference between success or failure on these two very important issues.

 Step 3:

Ask your employees, family and friends to contact their legislators on these committees.