Daily high soil temperatures at the 2-inch depth are consistently getting into the 60s°F. Yesterday, temperatures in sunny locations reached into the upper 60s. This means that the warm-season species are, or will be soon waking from winter slumber.
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Winter’s Continuing Legacy
Despite a winter we all want to forget, it never ends if you are a pathologist. Everywhere I look there is plant damage due to the extreme winter. Broad-leaved evergreens seemed to take it hard again this year, particularly some of the hybrid hollies. Frozen roots and heavy winds, along with the need to transpire on sunny winter days, left them in shambles. The injury was visible early and often.
Gettin’ Over The Winter Blues
The Plant Diagnostic Laboratory is in recovery from SAD – not seasonal affective disorder – but sample affected disorder! Snow cover equals very few sample submissions, so with the exception of our talk show circuit, life in a plant diagnostic facility is pretty quiet in the winter. While it is certainly a pleasure to see everybody at the winter meetings, I would much rather sit in the lab looking at dead stuff than stand in front of everybody talking about it. Fortunately, as the weather improves from week to week, the samples are starting to roll in.
Looks Like Grass… But It Isn’t
Other than today and yesterday, soil temperatures in New Brunswick have been reaching into the lower 50s°F during the last week or so. And you see the effects, some plants are finally awakening from winter slumber. Cool-season turfgrasses are slowly greening up. Tree buds are swelling, some are flowering. Forsythia is just starting to bloom. And prostrate knotweed, one of the earliest germinating summer annual weeds, is emerging.
[Read more…]
Don’t Get Them ‘Angry’: Insecticide Resistance in AWB
The annual bluegrass weevil (ABW) is an insect that can get very ‘angry’: insecticide resistant that is. Surveys have indicated that resistance in this insect is wide spread. Dealing with insecticide resistant ABW can quickly become a nightmare. The best thing to do, if you still can, is to not get the weevils ‘angry’ in the first place. Once they are resistant, there may be no feasible way of getting them susceptible again. There are no silver bullets out there and none in development.
Resistance is Sneaky
I estimate that any golf course that has tried to intensively control ABW for at least 5 years will have some level of insecticide resistance. With intensively I mean multiple applications per year over large proportions of the golf course. Resistance tends to sneak up on people. First there are some small problems here and there that will be excused by ‘missing spots’, ‘timing off’, ‘poor weather conditions’, etc. Unfortunately, the typical reaction is to ratchet up the spraying activity. [Read more…]
Winterkill on Annual Bluegrass: Don’t Skip the K
We lost the ice cover on our Poa annua trials two weekends ago (March 7-8th) and initially the turf looked okay. But now… it doesn’t. And it will probably get worse, if we are reading the symptoms correctly.
Last Friday (March 13), my graduate student, Chas Schmid, informed me that I needed to look at his potassium trial on our Poa annua turf. There was a huge difference between no‑K and K fertilized plots. The no-K plots have steadily lost green color and become very blotchy. Plants taken from those plots are water-soaked and feel mushy when squeezed (How is that for a scientific description?). Dr. Lindsay Hoffman has a lot of experience with winterkill on Poa annua in Massachusetts and she is convinced that many of the plants are dead. And it smells like it – silage on a dairy farm!
Take home for me – don’t let your Poa annua turf become potassium deficient! Chas’ data for suppressing anthracnose severity indicates that a soil test (Mehlich 3) ≥50 ppm K and a tissue level of ≥2% K in the clippings are indicators that the K level is good. And winterkill in March 2015 hasn’t changed my mind about that data!
Looks like this might be the end of this Poa annua field. Dr. William Meyer said, “Good riddance.”