Short Hort Notes^TM
August 24, 2004

*Surfing: While looking for some information on fruit trees on the net the other day, I ran across this tree identification key. It is on the National Arbor Day Foundation web site at www.arborday.org. In the left-hand menu, click on “Online Tree ID Guide” and then click on “Western Tree Identification”. It is not all-inclusive, but it may help you get to at least the genus of a particular unknown tree. There’s also a great “Tree ID Animation” feature that you can follow to learn the basics. Check it out!

*Tips for Digital Diagnostic or ID Photos: Many of you send pictures of plants either for diagnosing plant problems or for plant identification. Here are a few tips to increase chances of us making a reasonable diagnosis or identification.

Þ      Take a photo or two of the plant in its environment. Oftentimes if we can see the whole plant and its surroundings we can tell a lot more than by verbal description.

Þ      Then zero in and take a photo or two of the affected plant part(s).

Þ      Try to take pictures in the field. In transit to the office plants may wilt and end up in poor condition. To be on the safe side, take samples back to the office but try to do the photography on location.

Þ      Please check each photo before sending. We have received many that were not in focus or did not show the problem very well. A poor quality photo will almost always result in an answer such as “we can’t tell from the picture”.

Þ      For plant identification, it is imperative that flowers be included. Sometimes we can tell from other plant parts, but the only way to definitively key out a plant is by its flowers.

Þ      For identification purposes, take a good, in-focus close-up shot of the flowers and also another photo of the whole plant. It’s also helpful to have a picture of the foliage and stem as a check.

Þ      Give us some sense of size or scale. Using a coin, ruler, or other everyday item as a gauge will help infinitely.

Þ      Whether for problem diagnosis or plant identification, information on the area, growing conditions, etc., is always helpful.

Thanks.

*Crash Course in Seed Testing for Viability: During the American Society for Horticultural Sciences, one of the speakers, Annette Miller (USDA/ARS National Center for Genetic

Resources Preservation, Fort Collins, Colorado), talked about tetrazolium testing. Tetrazolium testing (or TZ) is a very common method to determine the viability of a seed –

whether or not the embryo is alive and “viable.” It actually detects metabolic activity (respiration) in seeds.

        The process goes like this:

Þ      Seeds are hydrated. This starts respiration.

Þ      Seeds are exposed to tetrazolium chloride which is colorless when it is in solution.

Þ      If the embryo is living, the tissue is stained red. If not, there is no color change.

Þ      The seed analyst then checks each seed for color change.

Þ      The report states the percent of the seeds tested that were viable, or were stained.

This is greatly simplified and results often vary and frequently are not clear-cut. This is where a trained seed analyst is invaluable.

Did you know that the Association of Official Seed Analysts (AOSA) certifies analysts? They are called Certified Seed Analysts or CSA. AOSA also formulates and updates the AOSA Rules for Testing Seeds.

Did you also know that the Society of Commercial Seed Technologists (SCST) certifies Registered Seed Technologists (RST) and Registered Genetic Technologists (RGT)?

How about the International Seed Testing Association (ISTA)? ISTA formulates and updates ISTA Rules for Testing Seeds and also monitors laboratories.

These are all in addition to the Federal Seed Act and State seed laws.

*Blossom End Rot: This seems to be the tomato topic of the week. Anything new as a remedy? No, because there is no magical cure for the problem. It is a physiological/ nutritional phenomenon that involves uptake of calcium (which is usually present in sufficient quantities in our soils). Calcium is taken up and distributed through the plant with the transpiration stream. With lower humidity in the air around the plant and sufficient moisture in the soil, the plant is actively transpiring and moving water, and calcium, from the roots through to foliage and fruit. With erratic irrigation, higher humidity, cool soil, or cool temperatures (or any combination of these) the plant isn’t transpiring and thus isn’t taking up calcium. Blossom end rot on tomato fruit is the result.

We’re seeing this show up no as night (and day) temperatures cool down. We’ve also seen a bit of precip lately which increases humidity and decreases plant transpiration.

An interesting “remedy” (thanks Jim for calling about this) being bandied about is using milk as a calcium source for tomatoes. We do not recommend this. Milk is expensive, it will sour, it will attract insects and animals, and there is usually enough calcium in our soils, it’s just not being taken up. Save the moo juice for yourselves!

*In the Panter Back Yard and Zoo: We started pulling out the pea plants, although a few are still producing. We’ve literally harvested pounds and pounds of these snow peas this summer, mostly because it has been cooler than usual. The tomatoes are ripening up (yes we too have some blossom end rot, although not a lot as we tend to keep the plants evenly moist) and the cabbage is heading out – finally. This wasn’t a great broccoli year, probably because of cooler temps. Carrots look like they are ready to harvest though.

Flower-wise things are winding down. The late-bloomers are showing their colors – things like Liatris, Rudbeckia, Echinacea, Phlox (tall garden type), Perovskia (Russian sage), Aster, Castilleja (Indian paintbrush), and a couple of others. The annuals are still looking pretty good, especially dianthus, zinnias, and petunias. The morning glories haven’t done much this year, not because they were planted late, but because it was so cool and wet early in the summer. They weren’t impressed.

With all the cool, wet weather lately, the lawn looks great. Wonderful powdery mildew in spots too.

Insects haven’t been bad this year either, although the prayer plants (Maranta leuconeura) inside ended up with some major league spider mites. Acephate took care of them, at least temporarily.

And the zoo? All the creatures - finned, four-legged, feathered, and eight-legged – seem to be happy and healthy.

*Upcoming Events

-International Bedding Plant Production Conference, September 20-23, 2004, Holiday Inn O’Hare International Airport, Rosemont, Illinois. Contact: 888-888-0013 or www.ballpublishing.com/conferences/.

-Society of American Florists Annual Convention, September 29 – October 2, 2004, Ritz-Carlton Kapalua, Maui, Hawaii. Contact: www.safnow.org or 800-336-4743.

-Association of Specialty Cut Flower Growers National Conference and Trade Show, November 2-5, 2004, Doubletree Hotel, Orlando, Florida. Contact: ASCFG at ascfg@oberlin.net or visit www.ascfg.org.

-Rocky Mountain Regional Turfgrass Association Conference and Trade Show, December 7-9, 2004, Holiday Inn – DIA (I-70 and Chambers Road), Denver, Colorado. Contact: RMRTA at 303-770-2220 or web site www.rmrta.org.

-ProGreen Expo, January 10-14, 2005, Colorado Convention Center, Denver. Contact: http://www.progreenexpo.com/index.htm.

-Wyoming Groundskeepers and Growers Association Conference, January 26-28, 2005, Parkway Plaza Hotel, Casper. Contact: WGGA at 307-234-7583, IIIwishes@msn.com, or www.wgga.org.

-National Agricultural Plastics Congress, March 5-8, 2005, Charleston, South Carolina. Contact: American Society for Plasticulture 814-238-7045 or info@plasticulture.org.

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Glen Whipple, Director, Cooperative Extension Service, University of Wyoming, Laramie, WY 82071.

Persons seeking admission, employment, or access to programs of the University of Wyoming shall be considered without regard to race, color, religion, sex, national origin, disability, age, political belief, veteran status, sexual orientation, or marital or familial status. Persons with disabilities who require alternative means for communication or program information (Braille, large print, audiotape, etc.) should contact their local UW CES office. To file a complaint, write the UW Employment Practices/Affirmative Action Office, University of Wyoming, P.O. Box 3434, Laramie, WY 82071-3434.

Where brand names are used, no endorsement is implied.

Karen L. Panter, Ph.D.
Extension Horticulture Specialist
Department of Plant Sciences
University of Wyoming