black knot


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black knot

[¦blak ‚nät]
(plant pathology)
A fungus disease of certain fruit and nut trees that is characterized by black excrescences on the branches; destructive to plum, cherry, gooseberry, filbert, and hazel.
References in periodicals archive ?
The more advanced systems were able to detect and geometrically locate, at least partially, mineral streak, discoloration, sound knots, black knots, burl pocket, decay, blue stain, wane, split ([greater than or equal to] 0.
In yellow-birch, sound and black knots are not the most important defects, as one might find in softwoods.
The ATB Blank-Spectra system, being the most budget-minded, is capable of reliably detecting sound knots, black knots, and bark pockets.
This grade will not permit black knots larger than 1/4 in.
This grade will permit any size or number of round red knots (splits within the knot are acceptable and splits around the knot are acceptable up to two-thirds of the circumference of the knot); small black knots which are tight and not over 1/32 in.
Occasional small black knots if they are tight and not over 1/4" (6.