CANOLA SWATHING TIME
The majority of canola fields in south-central North Dakota
are nearing or are at the stage for swathing. A sign of canola being very near
the swathing stage is the natural yellowing and senescence of leaves and leaf
drop. When canola plants consist only of stems, stem branches and pods, the
crop is probably very near the optimum time for swathing.
Canola swathing should be initiated when a minimum of 15-30 percent of seeds, contained in pods located on the main stem, have started to turn color. Seed color change is from green to light yellow, or reddish brown, brown, or black, depending on the cultivar. Seeds with only small patches of color should be counted as color changed. Seeds will begin maturing at the lower portion of the plant and will continue upward. Another rule-of-thumb for timing canola swathing is that the majority of seeds should have changed color in pods contained on the lower third of the main stem while seeds present in the upper third of the main stem will still be green but firm when pressed between your finger and thumb.
Plant
and seed inspection should be performed throughout the field. Also, when
scouting a canola field it is best to disregard plants infected with
sclerotinia (white mold) and determine swathing time based on development of
healthy (productive) plants.
Details on timing the swathing operation may be obtained from
the NDSU Extension Service circular A-1171 ''.
WHEAT DISEASE UPDATE
The NDSU Extension Service small grain disease survey
continues for south-central North Dakota. Thirty-four hard red spring and durum
wheat fields in dough stages of growth were checked in Emmons, McIntosh,
Dickey, Logan, LaMoure, Burleigh, Kidder, Stutsman, Barnes, and Foster counties
during July 20-26. Tan spot, Septoria leaf blotch, and leaf rust were found on
flag leaves in 94-97% of the fields surveyed. Septoria glume blotch was found
on main stem heads in 65% of the fields. Scab (Fusarium head blight) was found
in 94% of the fields surveyed with incidences of infected main stem heads
ranging from 0 to 36%.
SEPTORIA LEAF SPOT IN SUNFLOWER
As you scout your early-bloom sunflower for seed weevils,
banded sunflower moth, sunflower beetles, and rust you may detect another pest.
Septoria leaf spot, a fungus disease, can be found in area sunflower fields.
The disease first develops on the lower leaves and later may spread to the
upper leaves. The spots begin as water-soaked areas (greasy green in
appearance). The spots are somewhat diamond shaped, brown on the upper surface
and a lighter grey-brown on the lower surface. A narrow yellow halo often
surrounds newly-developed spots. Mature leaf spots may contain tiny, indistinct
dark-brown specks called pycnidia, which are visible with a hand lens.
Moderately high temperatures and abundant rainfall are required for rapid
disease development. The disease develops more rapidly after flowering.
Fortunately, this disease rarely is severe enough to cause economic loss and
currently fungicide treatment is not recommended.