Much of the West is experiencing severe to exceptional drought exacerbated by extreme heat. These conditions cause enormous stress on even drought-tolerant trees. Drought-weakened trees risk increased attack by insects and diseases.
If you’ve scheduled an Arborjet Injection treatment to protect your customers’ trees, your help is essential as we optimize treatment timing and protocol to work around these ongoing weather extremes. Please see guidance below.
We suggest that your clients protect high-value trees with at least one deep watering weekly during these challenging weather conditions. It is important to follow local watering restrictions, but evapotranspiration averages 1.5” weekly, so slow, deep irrigation is preferred over frequent light watering.
Guide clients to “pre-water” trees that are to be injected, and to irrigate again after treatment. This assures effective movement of the treatment within the tree, and reduces risk of adverse reaction to treatment made during extreme weather conditions. Avoid trees with significant leaf drop, as these trees are showing significant reaction to the drought by reducing leaf surface area.
We advise that when high temperatures are expected, you alternatives might include treating in the early morning before temperatures reach the 90’s, delaying treatments where possible as indicated on the label, and requiring that your clients irrigate before you treat their trees.
Where allowed by label, consider using lower effective treatment rates coupled with the early morning treatments and irrigation as discussed above. Now would be an excellent time to look for irrigation heads and sprays which need adjustment, for watering cycles which need to be extended, or to make time of day changes to comply with restrictions. Many systems are set up for 20 minute zones, and in extreme drought, this is ineffective when irrigating trees.
If you have any questions, please call me to discuss how best to protect your clients’ trees from serious insect and disease pests while we work through this exceptional drought. While we can’t manage the weather, together we can better protect your clients’ highly valuable trees.
Western States Regional Technical Manager