Diagnosis

Field diagnosis can be difficult due to the rapid death of infected trees. Early symptoms may be reduced vigor, fading green color, and yellowing throughout the entire tree. Symptoms often begin from the top of the tree and progress downward. Trees begin to die in midsummer and can die within weeks of the initial infection leaving brown, dead needles still attached to the branches. It is helpful to scout for infection centers the previous year or during the off-season.

Management Strategy

Pinetect™ is a tree injection product that is used to preventively treat pines that are susceptible to pine wilt nematode. Optimal results occur when Pinetect is applied in the spring of the year prior to adult flight of the pine sawyer beetle, which vectors the nematode. Any refillable injection device that is capable of injecting pine can be used to apply the product. Rainbow distributes the Pine Infuser injection system that can be used to apply Pinetect. Pinetect is the only labeled product that follows the application procedures and dosage rates developed by Kansas State University.

 

Pine wilt symptoms on Scots pines

Susceptible tree species, listed most to least susceptible: Scots, Austrian/Black, Aleppo, Japanese black, Japanese red, Mugo, Pitch, Swiss stone, Shortleaf, Virginia, Lodgepole, Jack, Red, Loblolly, Monterey

Distribution: Midwest USA including IA, IL, MO, KS, NE, KY

Pathogen: Bursaphelenchus xylophilus

Symptoms: Rapid death, yellow needles turning brown in a few weeks, random distribution in the landscape. The disease affects healthy and stressed trees equally regardless of tree size

Signs: None visible

Distinguish from look-alikes: Rapid death – herbicides or mechanical injury are other agents that kill as quickly.

Salt damage will cause needles to die from the tip back, pine wilt nematode kills whole needle quickly.

Needlecast diseases display symptoms either on newly formed needles or on older needles and will cause needle loss and decline over several years. PWN usually kills pines in one season.

Product: Pinetect™

Dose: Use 5 ml of Pinetect per inch of DBH for the first 6 DBH inches and 15 ml for each additional DBH inch.

Example: 12 DBH inch tree would require 120 ml of Pinetect.

Timing: Treat only on a preventive basis. Optimal results are obtained when injections are made in the spring of the year.

Retreatments: A single treatment will prevent pine wilt nematode infection for two growing seasons. Retreat every other spring with Pinetect.

Application Overview: refer to Pine Infuser application guide for details

1. Pinetect can be applied using any refillable injection device. Rainbow recommends using the Pine Infuser.
2. Shake the Pinetect concentrate bottle vigorously prior to dispensing the Pinetect into each Pine Infuser.
3. Determine the amount of Pinetect to use by measuring the diameter of the tree 4’ 6” above the soil line. Follow the above dosing guidelines to determine total volume for the tree.
4. To determine the number of Pine Infusers, divide the total dose for the tree by 20. Fill each infuser with up to 20ml of Pinetect. Fill the infuser only after they have been seated in the tree.
5. When using multiple refillable injection devices for each tree, it is important to drill the hole only for that device, seat the device, and start the injection process immediately prior to drilling and seating the next device. This limits the amount of resin buildup, which can slow down the uptake time of Pinetect.

Expectations:

Pinetect will provide two years of protection from pine wilt nematode.

Other Treatment Practices:

• Preventive trunk and limb sprays with Onyx or Covert to control the pine sawyer beetle and other pine bark beetles
• Preventive applications of Xytect for control of sawfly and other insects
• Promptly remove and burn infected trees
• DO NOT transport woodchips from infected trees
• Cover firewood from infected trees for at least a year to prevent emergence of beetles
• Plant resistant native pines and 5-needle pines