Home / Canola Watch / Diseases / Page 37
-
A long fall provides a few extra weeks to look back on the year that was — to reassess plant stands, fertilizer rates and disease levels. A long fall also gives growers an opportunity to control weeds and distribute residue in fields planned for canola in 2013…
-
High levels of blackleg have been found in some canola fields this year. Quite likely blackleg was present the last time canola was grown on these fields but went undetected based on a lack of obvious yield losses. Just before or while swathing are the best times to check plants for blackleg and other diseases. Uninfected parts of the plant…
-
Growers and agronomists may be able to find clues to explain lower yields by looking at the plants, pods and seeds. Did the pods form? Did pods fill properly? Are seeds there but small or shriveled? Read more to see what these may mean, and what can be done to reduce these losses next year…
-
Pre-harvest is a good time to scout for disease severity. The photo above shows severe sclerotinia infection. This article includes sclerotinia and various other diseases to look for…
-
When doing their own disease surveys, growers may find it easier to check crops while swathing. Stop at five random spots in the field while swathing and check 20 standing plants at each spot. This will give you a good idea how much of the field actually had sclerotinia or blackleg or clubroot, for example…
-
Pre-harvest is a good time to scout for disease severity. Fields with lots of diseased plants may also be poorer candidates for straight cutting due to the increased shattering risk. Read more for tips on how to identify blackleg, sclerotinia and alternaria…
-
If infection rates are high, determine where most of the yield is. If it’s in the healthy plants, then make harvest decisions based on what’s best for the healthy plants. That means swathing at 50% to 60% seed colour change for ideal yield and quality. If most of the yield is in the infected plants, then earlier swathing — at…
-
Late or mild infections of aster yellows could lead to poor seed set in normal-looking pods. Stress from aster yellows can also sometimes lead to purpling or may aggravate sunscald…
-
It is not surprising that sclerotinia stem rot disease levels differ from field to field even if fields are in close proximity. Sclerotinia disease level is very dependent on the microclimate within the field. Moist growing conditions (ie. frequent rainfall or high humidity or heavy dews) promote disease development but factors that result in moisture-laden canopies can…