Roots, Shoots, Fruits & Flowers: Satsuma Stem Canker, Blueberry Planting & Blue Wildflower

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Satsuma spot. Photo by Robbie Hutchins, LSU AgCenter.

An extension agent in Rapides Parish shared this email with several extension agents, “I took these pictures today of this satsuma tree in Alexandria. The homeowner said that last week there was a white spot on the tree and now the tree looks like this with the bark falling off and some holes in the tree.

There is almost a 0% chance this is mechanical damage since I had to crawl on the ground under the limbs just to take the picture.

I did go by in the late spring / early summer of 2018 to give the landowner advice about proper pruning. At that time his trees had suffered some minor freeze damage after the 14 degree weeks in 2018. That damage was in the south/southwest parts of the trees and this is on the east side of the trunk.

I’m sure I am overlooking something here but I just can’t figure it out. Any advice would be greatly appreciated.”

Dr. Raj Singh, a plant disease specialist with the AgCenter, shared his brief comment, “[I see] signs of phytophthora stem canker (PSC). [PSC is] different from foot rot. I would need some bark tissue to confirm it.” Your local AgCenter office can assist gardeners with sending specimens to the Plant Diagnostic Lab for diagnosis of plant ailments. The cost is $25.

If PSC is confirmed in a plant, then suggested treatment would include Monterey Agri-Fos Systemic Fungicide. Read the label for using a soil drench as a treatment.

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Blueberry plant with blueberries. Photo by LSU AgCenter.

Barry recently saw an article from the AgCenter about blueberry plants and sent this email, “I successfully grow them here at the house in Pineville and now, I would like to grow Rabbiteye Blueberries at the farm [in Avoyelles Parish]. Our soil there is alluvial Red River riversand, and the pH is about a perfect 7. Is there a way that I could acidify the soil (on a small scale and around the individual bushes) so that I could grow blueberries? How would I do that?”

According to the AgCenter publication, Home Blueberry Production in Louisiana, “Blueberries require a soil pH of 4.0 to 5.3 for best growth. The primary material recommended for lowering soil pH is finely ground wettable sulfur. Since sulfur reacts slowly and must be converted by soil bacteria, the change in soil pH is brought about slowly. Therefore, sulfur should be added to the soil and mixed thoroughly several months to a year prior to planting….

Sulfur also can be applied after planting to the soil surface but not mixed with the soil. Rates of up to 7/10 pound per 100 square feet can be used yearly, if needed.”

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Blue Waterleaf. Photo by Joe Pacholik.

Joe shared an email and an image of a beautiful flower, “I noticed this flower growing around a friend’s pond. They say it is a wild flower, and do not know what it is. I have a wet area I’d like to plant these in, as they appear to like wet feet. I was wondering if you knew what they are…”

Mr. Robert Turley, AgCenter Horticulture Agent, assisted with the identification of this attractive flower. It is Blue Waterleaf or Skyflower (Hydrolea ovata) Hydrophyllaceae Family). According to the University of Florida, this plant can be propagated by seed, or “by cuttings, by division, or by removing and potting up the numerous suckers produced by the species.”

Finally, blue waterleaf has spines so please handle this plant carefully.

If you want to contact Roots, Shoots, Fruits and Flowers, please send your questions and pictures to Keith Hawkins, Area Horticulture Agent, 337-463-7006 or Also, you can be on the “green thumbs” email list by emailing your request to the address above.

“This work has been supported, in part, by the USDA National Institute of Food and Agriculture, Renewable Resources Extension Act Award, Accession Number 1011417.”

8/21/2019 3:59:50 PM
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