Ornamental Crops IPM E-newsletter, 2009

Don’t get in Too Deep: Planting Depth Tips for Trees and Shrubs

Brian Eshenaur, NYSIPM,  bce1@cornell.edu

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Within the first couple of years too many newly planted trees or shrubs struggle and eventually die. Many factors can cause this problem, but one that is often overlooked but very common is a planting depth that is too deep. I have seen it with plugs and seedlings in greenhouses, with liner stock in nurseries, and seedlings in Christmas tree farms, as well as larger trees and shrubs in landscape and street tree plantings.

There are many reasons deep planting can happen. Often I think the person doing the planting feels like they are “going the extra mile” by getting the plant down a little further. They know it can work for tomato transplants but aren’t aware it can be lethal to woody plants.

In the case of nurseries, it can occur gradually. Where cultivation is used to control weeds, soil is often thrown against the trunk in the process and builds up over time. Also, while digging trees to be balled and burlapped, extra soil often ends up with on top of the root ball, then at planting the hole is dug to the level of the burlap and not the root flare.

Reasons Deep Planting is a Problem:

• Lack of oxygen and build up of carbon dioxide. The fine fibrous roots normally near the surface need to use oxygen to do their work of making water and nutrients available to the rest of the plant. The oxygen content of soils declines as the soil depth increases so if the plant goes in too deep the roots will not be able to breath. In fact on heavy textured or compacted soils the rate of gaseous movement (diffusion of O2 into the soil and CO2 out) drops off very rapidly so root growth is hindered and eventually ceases at these depths where the oxygen levels are too low.
• Higher moisture at deeper in the soil. Not only will water occupy pore spaces and displace oxygen rich air, it can also help the spread of disease organisms. Some fungi like Pythium and Phytophthora require higher levels of soil water for their spores to move. Others diseases are better able to attack plants weakened from water logged roots.
• The difference between trunks and roots. Stem and bark tissue, unlike roots, is not designed to withstand soil contact. When soil is packed around stems or trunks, the protective tissue can become saturated and weakened so it loses its defensive properties. Deteriorated bark and stems inhibit the growth of the plant and can allow certain insects or diseases to feed on the vital pipework of the plant just inside the bark layer.
• Future problem with girdling roots. If the trunk is below the soil level it is vulnerable to girdling roots. These start as roots that grow near, and often around, the trunk, then as both the tree and roots increase in girth the vascular tissue of the trunk can be constricted. Girdling roots can increase the chance of a storm blow-over, branch dieback and even the death of the tree.

To get the planting depth right, simply make sure that the root flare or the top most roots are planted at the surface. This may require removing some soil from the trunk to find the root flare. If a balled and burlapped tree or shrub is planted so the burlap is level with the soil surface it will often be in too deep. Careful attention to planting depth is an important first step to increase plant vigor and resistance to insects and diseases.

Maybe it IS Easy Being Green: Suggestions for Promoting Sustainability in Greenhouses and Nurseries

Betsy Lamb, NYS IPM  eml38@cornell.edu

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There’s a lot about sustainability in trade journals and your local newspapers at the moment – maybe even enough to make you wonder what it is all about and whether there’s some advantage to finding out more. Your customers are probably also hearing about it, which provides you an opportunity to show them how sustainable the green industry is and to sneak in a little marketing at the same time.

The longwinded definition of sustainability is “the ability to meet the needs of the present without compromising the ability of future generations to meet their own needs.” (Bruntland, G. (ed.), 1987, Our common future: The World Commission on Environment and Development.

Oxford, Oxford University Press). But what it really comes down to is the 3 E’s – economy, environment, and employees (and the community). Practices that preserve the environment while benefiting the human component and resulting in a profitable business are sustainable. And once you start thinking about it, you’ll be surprised how many you already use.

Environment

Reduce pesticide use (but maintain quality)

• Use integrated pest management (IPM) practices like scouting and sanitation to control pests without pesticides. Consider using biological control.
• Promote resistant varieties where they are available. Provide information to customers on which varieties have resistance and make sure you have some to sell them.

Be more energy efficient.

• Check your thermostats and replace them if they don’t work. Check your heating system to find any leaks. Have an energy audit done to find out where your heating dollars are going.
• Promote local products. That’s what you are growing anyway so make the most of it! The ‘buy local’ movement is very popular for food crops so remind your customers that they can buy locally grown ornamentals, too.

Consider water and fertilizer use

• Group plants by water needs if possible so you are only watering what needs it.
• Check pH and salt levels in your media to make sure you are not overfertilizing.
• Think about where the water goes after it leaves the pots to prevent contamination of waterways.

Reduce waste

• Recycle pots and flats where possible without danger of spreading soilborne diseases.
• Compost plant materials and use or sell the compost. This takes some thought, organization and space so the compost you are producing is good quality but there are some ornamental businesses doing this already.
• Reduce shrink. Well, you are trying to do that anyway, aren’t you?
• Reduce packaging. The green industry is better on this one than food processors but keep it in mind.

Employees (and the community)

• Educate your employees on sustainability and ask them for suggestions.
• Create a customer pot recycling program. You may need to work with your local recycling system as ag plastic recycling is not yet common.
• Get involved with your community in some way. I’ve seen a lot of good ideas for community involvement by local greenhouses and nurseries – festivals, America in Bloom, plants provided for Habitat for Humanity houses, etc. I bet you can think of one that works for you, too.

Economy

• Market your sustainability. You can have a full-blown advertising program or provide information around the greenhouse or nursery to point out those things that you doing that make you ‘green’. A simple pamphlet near the register describing sustainability and what you are doing might be just enough to get a dedicated customer. And add new sustainable practices so customers see you are dedicated to the concept.
• Market sustainable products. Plants are pretty environmentally friendly themselves but you might add compostable pots or environmentally friendly pest control products. Just watch out for ‘greenwashing’ – products that say they are sustainable or ‘green’ with nothing to back up their claims.

And what about standards and certification? You may have heard about Veriflora certification for cut flowers and potted plants and about the development of sustainability standards for all of agriculture. Most operations become certified because it is required by their customers, although some have done it because of a commitment to sustainability. If you would like more information on Veriflora certification you can check their website at the Veriflora website. The sustainability standards aren’t in place yet but you can read more about them at the Leonardo Acadamy.

Greenhouse IPM: Making the Transition

Gary Couch, NYSIPM, gjc15@cornell.edu

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Integrated Pest Management (IPM) programs have benefited apple growers for over three decades and generated programs for other fruit, numerous vegetables and many other agricultural crops. In comparison, Greenhouse IPM doesn’t have this long history but is gaining in use. Still, many greenhouse growers question how they can make the transition with the least trauma and risk.

Typical pest control, particularly for insects, has fallen into two categories; Calendar systems, with scheduled periodic treatments meant to prevent problems and Crisis systems, where control is started when damage becomes obvious. The first is costly in terms of labor time, materials, and all the problems associated with high pesticide usage, and does not always prevent losses from occurring. The second is costly in terms of plant losses and the disruption of production due to the unscheduled time demand of the drastic measures needed to get an outbreak back under control.

IPM programs take advantage of the best features of each while avoiding their shortcomings. Simply put, the IPM approach is designed to give the security of a calendar system with the savings and fringe benefits of reduced pesticide usage. This is achieved by replacing the one-size fits-all calendar and crisis type approaches with one that is custom tailored to the exact conditions in your ranges, your labor situation, and your production and marketing schemes.

IPM replaces the automatic treatments of a calendar system with pest monitoring. Calendar systems assume the need for treatment periods at a set interval regardless of the actual conditions in the range. Monitoring allows you to confirm or deny that need, generally resulting in fewer treatments with the same level of protection or better as properly timed treatments are more effective.

The major greenhouse insects, whitefly, thrips, aphids, fungus gnats, shore flies, and leafminers can be easily monitored through the proper use of yellow sticky cards. By periodic examination of the cards, you can easily detect upswings in insect levels, pinpoint “hotspots” which can be spot treated, and gauge the effectiveness of any control effort. As the cards will capture insect pests long before they’re abundant enough to be obvious, damage and loses can be reduced. Timing sprays to coincide with the exact rebound period of the pest rather than at predetermined intervals will often reduce the number of applications during the production cycle, saving both time and materials. Discovering and treating small “hotspots” of insect build-up with portable spray equipment can reduce the need of blanket treatments and the inconvenience of using large sprayers, again saving on labor time and material. Post treatment sticky card counts readily indicate the effectiveness of the treatment and can reveal problems with equipment, technique, or the material used, which can prevent waste.

To use sticky cards as an aid they should be placed 2 to 4 inches above the foliage. While the exact number needed for good coverage is difficult to determine, one 3” by 5” card for every twenty feet of bench is a good rule of thumb. Obviously, the less you use the less accurate you’ll be, but, too many is economically wasteful. The cards should be dated and replaced after a treatment if they’re too full to judge any changes. The yellow sticky cards can be checked at a glance during normal greenhouse activity or records can be kept if it’s a large operation with more than one person responsible for pest control. Combined with hand-held spray equipment for spot treatments, both monitoring and management can be done in minimal time. While not actually providing control, trap captures of egg-laying adults can further delay the rebound period. Keep in mind that non-flying pests such as mites, mealybugs, scales, and diseases must still be monitored by visually checking plants closely.

The increasing incidence of resistant pests such as western flower thrips and sweet potato whitefly, more stringent pesticide regulations and enforcement, fewer materials available and at higher costs, less available labor, and growing concerns about groundwater protection and other environmental and health issues, need not be viewed as problems for the industry. They can be opportunities and incentives for providing effective plant protection with less pesticide input. Lowering costs while maintaining quality is just good business. By starting a monitoring program you can immediately reap some benefits and will be in a better position for adapting to other IPM advancements, such as incorporating biological controls, as they come along.

Yellow Sticky Card in use.

Branching Out for 2009

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Emerald Ash Borer, Asian Longhorned Beetle and Oak Wilt are a few of the pests that call for a close eye by New York landscape and nursery professionals in 2009. Branching Out, an IPM Newsletter for Trees and Shrubs can help with reliable field reports and up-to-date management recommendations. Faculty and staff at Cornell in cooperation with Cornell Cooperative Extension educators across the state, gather information for Branching Out via state-wide on-site scouting, and prepare the newsletter.

Each issue contains:

• an up-to-the-minute scouting report highlighting pest activity
• an in-depth feature article
• other items of interest to tree care professionals

Branching Out readers report:

• their pest management activities are based on better information
• they apply fewer pesticides
• those pesticides they do apply are better directed at truly damaging pests (and at the appropriate time to control those pests).

All subscriptions run April through September. Back issues are sent to late subscribers.

Check them out at their web site to see a sample of Branching Out.

Cost and Ordering Information:

The cost of Branching Out is $40 for the 2009 season (if postmarked by March 15, the cost is only $35). To subscribe, just send your name, address, phone number and email address along with a check or money order payable to Cornell University, to:

Branching Out
Department of Plant Pathology
Cornell University
334 Plant Science Building
Ithaca, NY 14853 4203