A Newsletter for Professionals Growing Greenhouse Crops in the Rocky Mountain Region

Contents

• Biological Control in Ornamental Greenhouses
• Root rots of Annuals and Perennials: The rest of the story
• Rocky Mountain Greenhouse Short Course
• FREE EPA Worker Protection Standard Training

Biological Control in Ornamental Greenhouses

This summer, I am working on an exciting project. Koppert Biological Systems of Holland and Adams County have jointly funded an internship position. Koppert is a company that specializes in providing beneficial insects to combat greenhouse pests. In The Netherlands, biological control is utilized in a variety of greenhouses, including vegetable, cut flower and bedding plant operations. In the United States, however, the merits of this pest control strategy are just beginning to be realized. At this time, biological control using beneficial insects is basically limited to vegetable greenhouses. However, this may soon change.

Our summer intern, Tami Moon, a student at Wayne State University, is working with a number of area greenhouses growing ornamental crops. The crops include: cut flowers, plugs and bedding plants. We are working in conjunction with Priola Greenhouse, Welby Gardens, Tagawa Greenhouse and Gulley Greenhouse. The overall strategy is to develop Integrated Pest Management Strategies for floriculture greenhouses. We are also evaluating biological control programs in bedding plant and plug crops. Tami is visiting each greenhouse weekly, to examine plants for the presence of insects. She is also counting the numbers of pests trapped on yellow sticky cards. We expect to obtain useful data related to fluctuating pest populations over time, and to correlate this with control measures employed (including biological control), to determine the efficacy and cost-effectiveness of a variety of pest control strategies.

One of the really exciting developments of this project is the creation of digital images and video clips of insect pests and natural enemies. Tami is collecting insects that we are photographing under the microscope. We have made high-resolution photographs of thrips and aphids. In addition, we have made video clips of thrips laying eggs in leaf and flower tissue!

To see the video, click here

This catalog of digital images and video clips will be very useful on the Commercial Greenhouse webpage. More importantly, the high quality images will be useful in both the Certified Greenhouse Professional Manual and a new publication that I am writing. Currently, I am working on an IPM guide for greenhouses. This will be a bilingual publication, which gives an overview of greenhouse pests, and various control measures, including beneficial insects. I expect this to be a valuable tool for greenhouse managers. The book will assist in educating greenhouse employees regarding pest control. It is crucial to educate employees regarding pest management. It is not possible for a greenhouse manager to inspect the entire crop every day. However, greenhouse laborers observe 100% of the crop, every single day. By training them to recognize certain insects, they will be able to help you prevent pest problems while they are still at a manageable level.

I would like to take the time to thank Koppert B.V., Adams County, and the greenhouse operations for their valuable contributions toward this exciting project.

No endorsement of products mentioned is intended nor is criticism implied of products not mentioned. As always, before using any pesticide, consult the label.

Chris Freeman
Area Specialist Commercial Greenhouse
Adams County

Root Rots of Annuals and Perennials: The Rest of the Story.

Root rot diseases are indeed, the most common problems growers encounter on annual and perennial plug or pot production. They are also the problems most over looked and ignored by growers. Several different fungi can cause root and stem rots on a variety of plants, however, Rhizoctonia is the most common fungus we find associated with problems in Colorado. The most common management strategy used is a fungicide when a root or crown rot is diagnosed. But fungicides don't totally solve the problem in an overwhelming majority of cases. Why????

Plant production is a complex field. Plant varieties, nutrition, temperature regimes, and business practices are often the focus. There are other factors, however, that exert as much of an influence over plant health as nutrition and temperature. These include planting depth, cleanliness of the greenhouse, and air circulation; and unfortunately they are frequently overlooked. When a disease problem arises, it's human nature for us to concentrate on a tangible "culprit" or the fungus involved. However, a large portion of the disease problem is due to something that stresses the plant. If fungicide applications are not solving your plant production problems check for these "other pieces of the puzzle":

1. Planting depth. We often find herbaceous plants at a depth of ½ - 1 inch lower than they should be. Even if you have good quality help, it's a great idea to periodically check this end of your plant production program. All of us, when under a time crunch, tend to get sloppy in this area. When any plant (woody or herbaceous) is planted too deeply, the physiological relationship between roots, soil and water changes dramatically. Oxygen exchange rates are hindered and the plant becomes weakened. Opportunistic pathogens such as Rhizoctonia take advantage of the situation.
2. Soil and water debris on bench tops and floors. Puddles on the floor, plant debris and soil/media on bench tops or floors are a significant pathogen source.
3. Air movement and plant spacing. The closer pots or plants are spaced the less likely air is able to move as freely among the plants. Decreased air movement means increased humidity and favoritism for opportunistic pathogens.
4. Watering. Watering too frequently will deplete oxygen levels in the media and favor root and crown rotting fungi.

Good sanitation practices are essential in helping manage or minimize root and crown rot disease problems. The following should be used in prevention as well as in conjunction with fungicide applications when root diseases appear:

No endorsement of products mentioned is intended nor is criticism implied of products not mentioned. As always, before using any pesticide, consult the label.

Laura Pottoff
Extension Pathology Agent
Jefferson County

Colorado State University Cooperative Extension and the Colorado Greenhouse Growers Association is pleased to announce the 2000 Annual Rocky Mountain Greenhouse Short Course.

October 18-19, 2000 at the
Arvada Center for Arts and Humanities
6901 Wadsworth Blvd., Arvada, Colorado

The topic for the program this year is Understanding Greenhouse Nutrition and Media Technology. We have four top speakers who will be providing the material. Contact Bob Briggs at the CGGA Office for more information or download the brochure by clicking on the link below.

Download the Brochure
requires Acrobat Reader

Plan to attend the CGGA 75th Anniversary Gala
Wednesday 18 October, 2000
Keynote speaker will be Paul Ecke, III
Paul Ecke Ranch

Contact the CGGA Office for details

Steven E. Newman, Ph.D.
Greenhouse Crops Extension Specialist
Horticulture and Landscape Architecture

FREE EPA Worker Protection Standard Training

As most of you already know, greenhouses must comply with the EPA Worker Protection Standard (WPS) if they use pesticides with labels that refer to the WPS (40 CFR Part 170). Specific training is required for "handlers" of pesticides, and "workers" who may be exposed to pesticides, according to the 1995 EPA WPS. It is believed that WPS training can help prevent greenhouse employees from being accidentally poisoned by pesticides.

Meeting the training requirements of the standard may be difficult for some employers. New employees need to have WPS training within the first five days on the job if they enter areas treated with pesticides. Employees expected to "handle" pesticides need to have their WPS training before they take on any tasks that require handling. "Workers" and "handlers" need to be retrained according to the WPS every 5 years.

The High Plains Intermountain Center for Agricultural Health and Safety (HI-CAHS) has teamed up with AmeriCorps to provide free training this summer to help producers comply with the EPA WPS. Training can be given in English or Spanish, as needed. Producers/employers can schedule a training session by contacting the HI-CAHS office (CSU in Ft. Collins) at (800) 622-8673 or (970) 491-6151. It is our intention to help make your operation safer and more productive. HI-CAHS services are confidential! Please do not hesitate to call with questions if you are unsure about whether your business or operation needs to comply with the EPA Worker Protection Standard.

Tina Daniels
HICAHS Safety & Health Consultant and
Extension Farm Safety Specialist
CSUCE Agriculture Health and Safety