Frost Affect on Round-up Trans-Orb
Guidelines
Mild Frost (0 to -4oC)
Perennial weeds should not be seriously impacted. The cool evenings
should have conditioned Canada Thistle, Dandelion and Quackgrass to the cool
temperatures.
Continue applying, just begin later in the morning or early afternoon,
when the air temperatures are 5 to 7oC range and expected daytime
minimums are 7 to 8oC.
If cool evening is forecast (below -8oC), quit spraying to allow for 1.5
to 2 hours of sunlight on plants to ensure uptake.
Note: Frost signals a dormancy response in Quackgrass, encouraging
them to move nutrients to the roots, which can enhance control!
Heavy Frost (-5 to -10oC)
Canada Thistle can quickly show heavy damage, with the leaves
turning brown to black (crunchy) within 12 hours.
Quackgrass takes 24 hours to show symptoms.
Dandelion can be more tolerant to frost, and may not be affected.
It is best to wait and see what impact the heavy frost had on these
weeds. If the weeds are 60% green (after waiting) and still actively
growing acceptable performance can be achieved. With Quackgrass, three
days, of frost free weather, after application is best. With Canada
Thistle, three to five days, of frost free weather is best. A killing
frost can reduce some control.
You can check out the
Monsanto website for more
details.
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Inputs
Management Agro Inc.
