Ornamental Crops IPM E-newsletter
The purpose of this e-newsletter is to provide regular integrated pest management updates to commercial horticulture educators in the Cornell Extension system and others that are in the position to use and disseminate information. It is our intent that the content from these updates will be used in newsletters and programs that reach New York growers.
E-newsletters are sent out on a quarterly schedule (Spring, Summer, Fall and Winter). We welcome your feedback on the content and/or format of the information.
We would appreciate it if you would let us know when and where you are using the content. This will help us determine the types of information that are useful for you and your programs, and will give us some information on distribution of the information.
If you would like to be included on the email list, please email Brian Eshenaur and ask to be added to the list.
NYS IPM Program Saved by Stakeholders: Thanks to the efforts of concerned NY growers, the IPM Program was funded in the state budget that passed in early April. Thank you for your support!!
In this Issue:
- Swiss Needlecast
- What's in the Water? Alkalinity and growing conifers
- Annual Cornell Floriculture Field Day and IPM In-depth
- 2010 New York Greenhouse Production Figures
- Ornamental Crop Growers Opinions Needed
Brian Eshenaur, NYS IPM Program
Currently the biggest problem Douglas fir growers in NY are dealing with is Swiss needlecast. It has been more difficult to control than Rhabdocline and has caused some Christmas tree growers and landscapers to stop planting the customer favorite, Douglas fir.
Why Swiss? Swiss researchers noticed this needlecast disease on Douglas Fir trees established there in plantations in 1925. So, although the fungus that causes this disease is native to the Western US, where the Douglas fir grows naturally, it was first identified in Switzerland and the name stuck.
It's a fungus. Swiss needle cast is caused by the fungal pathogen Phaeocryptopus gaeumannii. It grows inside the needles and produces rows of tiny black specks on the undersides of the needles that may make infected needles look sooty. It is these black fruiting structures that produce the fungal spores.
Give it moisture and watch it spread. The majority of spores are released in the spring beginning in April but spore release can continue through September. The newly formed needles are the most susceptible and most infection takes place during wet spring weather. Damp rainy weather creates an environment where the spores can infect foliage so this disease is worse after unusually wet springs. It takes about a year before the infected needles produce the black fungal fruiting structures.
It's often there before you know it. Unlike Rhabdocline and most needlecast diseases, Swiss needlecast can sneak up on growers because infected needles can remain green and attached to the tree. In fact the diseased needles may produce spores for three seasons before they turn off-color and are finally shed. Eventually the needles will fall and in the most severely affected plantings, only the green needles at the tips of the branches are present. When infections reach this level, the tree's growth is severely stunted. It often makes sense to remove the most severely affected trees to reduce sources of the fungus.
Resistant trees and fungicides can help. Not surprisingly research found that tree seedlings originating from drier areas east of the Native Ranges in the Pacific Northwest were more susceptible to Swiss needlecast than seed collected from wet forests near the coast. However disease resistance can't be looked at without considering cold hardiness, postharvest needle retention and other characteristics of a quality tree. Even within a single seed source, growers can see natural variation in levels of susceptibility in the field.
Protecting the new foliage as it emerges with a fungicide can provide good control. The fungicides that are known to be effective include chlorothalonil, mancozeb, or Spectro 90 WDG. Treatments start when about 10% of the trees have broken bud and continue at three to four week intervals until July 1. Follow all product labels for specific instructions.
Elizabeth Lamb, NYS IPM Program
Most of us remember learning about pH in high school chemistry – acids and bases and what happens when you mix them together. That's right – pH is a measure of the concentration of positively charged hydrogen ions dissolved in the water. The higher the concentration, the more acid the water is. Alkalinity is also based on what is dissolved in the water, but in this case it is the concentration of alkalis – compounds like calcium carbonate – which when dissolved form negatively charged ions. So water with high alkalinity tends to neutralize acids and tends to have a basic pH.
Thanks for the chemistry lesson – why do I need to know this? Because the pH and alkalinity of your water can affect your conifers and any other plants you are growing.
All plant species have soil pH ranges that are optimal for growth. Often they match the conditions where the plants are native. Trying to grow a conifer out of its pH range can result in poor growth or yellowing of needles. Finding exact information on ranges can be difficult but the following table should help.
Soil pH can also affect soil fertility. Some nutrients get tied up in compounds that can't be taken up by the tree's roots at certain pH levels. For example, nitrogen, potassium, calcium and magnesium all become less available to plants at pH's below 6. If you are growing your trees in low pH soils, you might need to take that into consideration when planning a fertilizer program. Different fertilizers also have different effects on soil pH so you may be able to match your soil pH to your fertilizer for best results. Ammonium and urea forms of nitrogen are acidic and nitrate forms are basic. Fertilizers may have a mix of types so check the label.
The pH and alkalinity of your water source can also affect your production. For example, alkaline water will reduce soil pH over time. Few field grown conifers grown in NY are irrigated, so this may not be a concern but for those grown in pot production, irrigation water may need to be acidified to maintain the low soil pH desired.
The pH and alkalinity of your water can also affect how your pesticide applications work. In some cases, high alkalinity causes the active ingredient to break down. Water pH over 7 can affect the efficacy of glyphosate (Roundup), paraquat (Gramoxone), bentazon (Basagran), clethodim (Envoy), sethoxydim (Poast), and 2,4-D (many products) (from Weed Management In Nursery Crops, Dr. James Altland, Oregon State University). The following table lists the optimum water pH of certain insecticides and miticides and comments from the Cornell Pest Management Guide for Commercial Production and Maintenance of Trees and Shrubs.
* Active Ingredient=Potassium salts of fatty acids
4th Annual IPM In-depth – Monday, July 18, 2011
Back again this year, the popular hands-on IPM In-depth where you get to be up close and personal with plants, insects, and diseases. NEW this year – a longer diagnostic session and lunch!
This year's topics are:
Various Viruses: Greenhouse virus diseases and their control
It's not supposed to be yellow, is it? Diagnosing Nutrient Disorders
9th Annual Cornell Floriculture Field Day to be held Tuesday July 19 2011.
Cornell University's annual Floriculture Field Day will be held Tuesday July 19, 2011 at the Cornell campus in Ithaca, NY. The morning program will center around a marketing theme. We will hear from several individuals that have found creative ways to wholesale, retail, and directly market their products.
Lunch and the afternoon program will take place outdoors at the Blue Grass Lane annual and perennial trials facility. Participants can attend guided tours of the trials or view the flower beds at their own leisure. The Kathy Pufahl Container Design competition will also be held in conjunction with Field Day. The afternoon will conclude with an ice cream social and announcement of the container design contest winners.
Rain or shine we'll see you there!
Field Day 2011 Schedule – July 19, 2011
8:30-8:45 Welcome: Neil Mattson, Cornell University
8:45-9:15 Todd Lighthouse: Marketing via Farmers' Markets and organic niche
9:15-9:45 Anna Steinkraus: Successfully selling in On-farm markets
9:45-10:15 Margaret Kelly: Update from NYS Ag and Markets (½ DEC credit)
10:45-11:45 Lloyd Traven and Stephanie Whitehouse (Peace Tree Farms): Marketing to retail/what are retailers looking for?
11:45-12:00 Lloyd Traven In Memoriam: Marketing lessons from Jack Williams
12:45 – 1:30 Lunch
1:30-1:45 Hot New Annuals: Melissa Kitchen
1:45-2:45 Walkabouts, guided garden tours, choose from:
2:45-3:00 Announcement of container contest winners
3:00-4:00 Ice cream social, Cool Jazz and Socializing
DEC pesticide credits will be available at Field Day and at the IPM In-depth. More information and registration forms will be posted shortly to Cornell Greenhouse Horticulture.
The most recent figures from the USDA Floriculture Crops 2010 Summary were released with the following postings:
It’s the busiest time of the year for many of you, but the IR-4 Ornamental Horticulture Program needs your input to prioritize pest, disease, weed and plant growth regulator (PGR) research issues. By providing information on your biggest pest and PGR problems, you can shape the IR-4 program’s two-year plan that will ultimately benefit our industry. The survey can be completed online and should take no more than five to seven minutes to complete.
The IR-4 Ornamental Program focuses on greenhouse, nursery, landscape, Christmas tree and forestry producers. The primary objectives of the program are to facilitate new product registrations and to place new diseases, insects and weeds, as well as new crops, on already registered ornamental horticulture product labels. Please complete this survey to identify your biggest challenges so that our industry can move forward to address those issues.
PS. The Northeast is ahead in submissions of this survey! Thanks to those of you who have already sent yours in or completed one at an IPM program.