Drought and Fertilizer: How Two Mainstays of Summer Bring in the Bugs

In the middle of the hot summer, insect populations build to increasingly damaging levels. Pest control becomes harder this time of the season, and two key little-known issues arise for herbivorous insect control.

Drought: Plant stress due to heat and drought can lead to higher herbivore numbers, especially if that stress is intermittent. For example, let’s say you have a shrub, and aphids really like that shrub. You do not water it regularly, and the plant lives outside in the heat of the summer. The weather has stayed dry for a while, and your shrub is starting to stress. Sap feeders like aphids do not usually respond well to drought, because plant sap is powered by turgor pressure, and the sap must move for them to eat. No rain, no food. However, leafy plants produce more nitrogen in times of stress. Your dry, stressed plant produces tons of nitrogen and then (viola!) it rains. The aphids suddenly have everything they need to produce tons of baby aphids.

Fertilizers: Nitrogen fertilizers are generally applied to improve plant growth and help them cope with biotic and abiotic stresses. However, although maintaining plant health is the first line of defense against herbivore attack, trees that are over fertilized are often more vulnerable. This occurs by improving plant nutrition for herbivores. Just as nitrogen is essential for plant growth, it also increases herbivore growth. Therefore, plant tissue that is high in nitrogen due to fertilization makes herbivorous pests grow faster and reproduce more. Fertilizer also benefits herbivores by reducing plant defenses. This happens because nitrogen stimulates rapid plant growth which requires all the carbon fixed through photo-synthesis to be used for plant tissue instead of defensive chemicals. Therefore, plants do not build chemicals toxic to herbivores or chemicals that attract natural enemies such as parasitoids to help defend themselves. Therefore, be sure to calibrate fertilizer application equipment, and do not apply more fertilizer than is recommended or necessary to maintain plant quality.

From: Steve Frank, NCSU Extension Entomologist

Drought Monitor Update

The North Carolina Drought Advisory issued by the Drought Management Advisory Council has been updated to reflect drought conditions on May 24, 2011 indicated on the weekly U.S. Drought Monitor of North Carolina. Luckily, western North Carolina has not been included in the recommendations to implement drought response actions. Click here for more info on areas included in the update.

Take the 40 Gallon Challenge

The 40 Gallon Challenge is a call for residents and businesses to reduce our region's water use on average by 40 gallons per person, per day. The challenge began in 2011 as a voluntary campaign to increase water conservation.

The 40 Gallon Challenge encourages people to save a minimum of 40 gallons a day by adopting new water-saving techniques. The pledge card outlines water-saving practices and the daily water-savings to expect. You can use the pledge to review the water-saving practices that you or your family currently puts to use. By pledging new practices, you will see the total daily savings expected for your household.

The 40 Gallon Challenge also provides maps and charts to see pledge activities in your state and across the United States. For more information click here.

Mandatory Water Restrictions

As the Mills River continues to drop in flow, the City of Hendersonville is implementing mandatory water restrictions to ensure our ability to meet the core water needs of our customers. By declaring a Phase II water shortage condition, the City and County will enforce restrictions on a number of uses, and violators may be subject to disconnection of their water service or a fine of up to $500.

Until mandatory restrictions are lifted, the following restrictions are in place:

• Watering of lawns, shrubs, trees and flowers is prohibited
• Vegetable gardens may only be watered once a week up to one inch of water
• New or existing pools may not be filled
• Washing of sidewalks, decks, driveways, patios, or homes or buildings is prohibited
• Washing cars is prohibited, unless at a commercial car wash which recycles water
• Operation or filling of ornamental fountains, pools or ponds is prohibited
• Drinking water at restaurants shall not be served unless requested by the patron
• Operation of water-cooled air conditioners is prohibited, unless the water is recycled
• Any other unnecessary use or intentional wasting of water is prohibited

Residents can help with the City’s enforcement effort by reporting violations or problems to the City’s Drought Response Hotline at 828-233-3215. A coalition of Hendersonville water and sewer employees, city code inspectors, city police and county sheriff deputies will be used to enforce the Phase II water restrictions.

Drought Information

While we have received some precipitation over the past several weeks, the drought conditions in North Carolina still exists. I received an email today with a couple of websites that may be of help as you deal with the ongoing drought conditions. I hope you find these sites useful.

http://www.cals.ncsu.edu/agcomm/difference/drought/

http://www.drought.unl.edu/dm/DM_state.htm?NC,SE

Burn Ban Reinstated

The North Carolina Division of Forest Resources has stated that due to severe drought conditions in North Carolina, all outdoor open burning has been banned until further notice. Burning permits previously issued are invalid. This statement was posted at 1:00pm on October 15, 2007.

Canker Diseases Follow Drought

Sharpen your pruners to remove dead branches on woody ornamentals due to a two punch combination of drought and fungal pathogens such as Botryosphaeria and Seiridium. The long term effects of this summer’s drought are becoming visible in landscapes throughout the Southeast. Much of this dieback has appeared in the last month. Drought stress has predisposed many of our woody plants to infection by fungal pathogens and in some cases wood boring insects. Rhododendron and Leyland cypress are two common hosts for these diseases, but you may see similar dieback on laurel, viburnum, holly and some juniper species.

Chemical treatments are not effective for the control of most fungal canker diseases. The best preventive strategy is drip irrigation during dry periods. Once dieback has occurred, diseased branches should be pruned out below the canker; below discolored wood in the stems.

Taken from article written by Alan Windham, Ornamental Pest and Disease Update, 9/07
Photo of Seiridium canker on Leyland Cypress, credit to J. Williams-Woodward, UGA

Burn Ban Lifted

RALEIGH – Recent rains across the state have allowed the N.C. Division of Forest Resources to lift its ban on open burning for all 100 counties in North Carolina.

The statewide ban on open burning, which was implemented Aug. 21, is canceled effective at noon Tuesday Sept. 18th.

Officials with the Division of Forest Resources decided to lift the burning ban because of Friday’s storm that dumped several inches of rain across the state. While recent rainfall and lower temperatures have reduced the fire danger, this small amount of precipitation has not ended drought conditions the state is facing. Residents should be especially careful as meteorological conditions could cause North Carolina to continue having warmer temperatures and below normal rainfall during the upcoming fire season. Officials are warning that if the drought continues, and there is an increase in the number of wildfires, the ban on open burning could be reinstated.

For more information, click here for the full article from NC Department of Forest Resources.

Free Water Conservation Help

Water conservation is everyone’s business, especially as the drought in NC worsens. Through a cooperative effort between the Department of Crop Science and the State Climate Office of North Carolina at NC State University an internet based decision-aide entitled the Turf Irrigation Management System (TIMS) has been developed and is now available to the citizens of North Carolina. This simple to use system can be utilized by anyone from the dedicated turf professional to the homeowner to help make irrigation management decisions.

First, it guides you through your account set-up by asking a few simple questions about the type of grass, soil and irrigation system you have. After set-up, it calculates the amount of irrigation you need and keeps track of when and how much water you actually use. Once you have entered your address, climate information is read from the closest weather station which is part of the NC Climate Retrieval and Observations Network Of the Southeast (CRONOS) and the irrigation needed by your turf is calculated based on recent weather conditions including precipitation and evaporation.

This system will help you practice better water conservation for your lawn, landscape or other turfgrass areas in this critical time for water resources. It is free to the public in NC and can be accessed at the following URL:

www.TurfFiles.ncsu.edu/TIMS

The State Climate Office of North Carolina is a public-service center and extension of the UNC system housed at NC State University and the primary source for climate data and expertise in North Carolina. The mission of the State Climate Office is to provide climate related services to the state, local and federal agencies, businesses and citizens of North Carolina.

Statewide burning ban now in effect

The N.C. Division of Forest Resources has initiated a statewide ban on all open burning and canceled all burning permits effective at noon on August 21st. The ban on open burning will be in effect until further notice. The ban on open burning is necessary because of the dry weather conditions and an increase in fire activity statewide. Currently more than 100 firefighters are battling 130 wildfires in Robeson County alone. Yesterday there were 46 new wildfires affecting more than 370 acres across North Carolina.

By North Carolina law, the ban prohibits all open burning statewide, regardless of whether a permit was issued. Open burning includes burning leaves, branches and other plant material. In all cases, it is illegal to burn trash, lumber, tires, newspapers, plastics or other non-vegetative materials. The ban will be enforced by local law enforcement agents, county fire marshals and the N.C. Division of Forest Resources, an agency within the Department of Environment and Natural Resources. The open burning ban means that all burning is prohibited if it is 100 feet or more from an occupied dwelling. An occupied dwelling is a home or residence that someone lives in.

For more information, contact Chris Carlson at (919) 733-2162 ext. 262 or cell (919) 210-5013, or Brian Haines at cell (919) 218-9728. Residents can also contact a county ranger with the Division of Forest Resources or the local county fire marshal's office.

Taken from Asheville Citizen Times - 8-21-2007

North Carolina Drought Advisory

Until further notice, the North Carolina Drought Management Advisory Council is strongly urges the implementation of drought response actions, for all Henderson and Haywood County water users located in or dependent on water resources from the areas of the state experiencing the following drought conditions. See map and key to see that Henderson and Haywood Counties are both listed as level D3.

• (D3) Extreme drought conditions. (Red)
• (D2) Severe drought conditions. (Tan)
  
• (D1) Moderate drought conditions. (Peach)
  
• (DO) Impending drought conditions. (Yellow)

Dealing with Extreme Drought (D3) conditions means we should be following these precautions until further notice:

• All water users are advised to follow the water shortage response guidelines set forth by the Water Use during Drought Rules effective March 19, 2007. Water users without a written plan are advised to follow the applicable default water use reduction standards outlined in Section .0613 of the Rules during extreme drought designations.
• Stay informed on drought conditions and advisories (www.ncdrought.org).
• Participate in regional and local coordination for the management of water resources.
• Reduce socially and economically important water uses to ensure the availability of water for critical needs (e.g. firefighting, health and safety, etc.).
• Revisit and/or explore, if not already accomplished, alternative water sources and reuse options.

Become a Water Wise Gardener

This spring has started out extremly dry across WNC. Our lawns are beginning to look and sound crispy as we walk across them. You may be wondering if you should be watering your garden, and if so, how much should you apply? My advice is to follow these tips below. Remember that if you do begin to water, you should continue to water until the dry period is over.

Water-wise tips for gardeners and homeowners:

• Utilize highly-efficient watering systems such as soaker hoses and drip irrigation systems. These allow water to go directly to the plant roots and not be lost through evaporation. These methods also encourage plants to develop strong root systems by thoroughly soaking into the soil.

• Water efficiently. Monitor soil conditions to determine how often you should water. A standard recommendation is to apply one inch of water every 7-10 days.
• If you have a sprinkler system, check it thoroughly for leaks that can result in water loss. Sprinkler systems can be outfitted with rain sensor devices to prevent them from coming on when they are not needed. Some sprinkler systems can be retrofitted to include drip irrigation for plant beds.
• Set sprinkler systems to appropriate setting of no more than one inch of water a week for most landscapes and gardens.
• Water plants in the evening or early morning when less evaporation occurs. However, morning watering will prevent most plant diseases.
  
• Mow grass to the most appropriate height for the weather conditions. Leaving grass slightly higher in drier weather allows the soil to retain more moisture. It is also important to keep mower blades sharp especially during drier periods.
• Utilize mulch and compost in plant beds to help retain moisture. Mulch can also help reduce weeds, which will compete with plants for moisture.
• Collect rain in rain barrels to use for watering as a supplement during dry periods.

For more information on garden irrigation, see this publication.