[Thayer]

http://people.morrisville.edu/~khana/Canoladiseasesjd.ppt#18

I found it interesting, I am trying to work on more research as to proper rotations.

 

[Hoytshooter]

Thayer...
Any idea if those diseases attack and can be problems with any/all brassicas or are they specific to the conola varieties?

 

[rat]

Sclerotinia is a pretty common fungal pathogen and many kinds of vegetable and forage crops are susceptible including brassica sp. common to wildlife food plots like chickory, turnip, rapes ect. It is usually a concern for large-scale vegetable growers and canola (oilseed rape in the north), and sugarbeet farmers. Normally, they are using fungicides to control in these situations but there are some rotational cropping strategies that have been known to minimize the infestations.

Problem is that it is persistent in the soil for quite a few years. Fungicides are only preventative and not curative so if you already have it, its too late to apply a fungicide to help, save for maybe minimizing some spread to some unaffected areas or tissue. Fungicides also will have no effect on sclerotial bodies that are in your soil, so its not like you can sterilize the soil with these products. Fungicides can be expensive too.. just ask any grower that is using them to save themselves from soybean rust nowadays.

I would say if you havent had a problem with it, you arent likely to. If you have seen it, just ask a local county extension agent what your options are.

 

[doepee]

That's a lot of good info. Thanks.

 

[Thayer]

Good stuff rat! Can you eliminate the diseases by rotating the brassicas every two years or does limiting the brassica crops to two year cycles prevent the disease from starting??? There is not a whole bunch of info out there on why the rotation is important and what it does.

 

[rat]

Rotational strategies usually involve rotating to a less susceptible species but small story vegetables seem to be the most sensitive to the infection. Not usually a problem in soybean/corn rotation because both of those species seem to be fairly tolerant.

We are talking foodplots here and usually most of the species used for this purpose can be sensitive to this pathogen. I would say again that if you havent had the problem, you shouldnt spend a lot of time worrying about it. You would have to have a pretty severe infestation to lose an appreciable amount of the crop so you might just tolerate if you have small patches of blight. Total elimination prolly is not practical...

I did not mention before, but there are conditions that this bug likes... seems like I remember that cooler, moist conditions are prime for the infection to proliferate and spread. You can prolly help yourself by watering only once every so often and deeply when you do so. Frequent small amounts of water can cause a humid understory and set you up for trouble. Avoid the temptation of watering too often and rely more on good ol mother nature for your moisture source. Low areas that hold water are also good spots for this condition, so avoid planting in areas that do not have good drainage.

Now.. fugicides are pretty effective if you know you will have trouble. Be sure to apply BEFORE you notice symptoms. Also, the county extension service will have pathogen id services if you think you have a problem. They are usually very helpful folks and willing to give expert advice where needed.

 

[henry]

So basically , your saying the best bet is to have a rotation program in place before it starts. And if it does start, try and live with it??? Would you say rotating with soybeans every other year is a good approach to prevention??? (beans are also an excellent source for nitrogen for the following years brassicas)

:cheers::cheers:

 

[rat]

Rotation will certainly help. Continuous cropping programs can have other problems as well.

Beans (and other legumes, for that matter) will fix nitrogen in the soil and will certainly be beneficial.

I'm not saying "just live with it"... there are measures for control if it happens. I am admittedly not a pathologist but I work with a few people who are. Tell you what... I will have a speak with some of the folks who are experts and re-visit this thread. My experience comes mostly from commercial row-crop agriculture and turf managemnent. I have only a limited knowledge of spore-borne fungal pathogens but I have access to many resources of info in this area
Generally speaking of course, fungal pathogens, whether they be in commercial ag situations or turf, have many universal properties that can be managed in much the same way. My recommendations for best management practices (such as watering considerations, humidity, use of fungicides, low-lying areas ect.) are generalities and come from a basic understanding in how these thing attack living plants of many types. White mold, or sclerotinia, certainly falls into this category. Make sense??

 

[henry]

Makes sense to me. When you refer to them as" spore born" I wonder if the problem is a bigger concern in the warmer southern climates where the spores have a longer season. I think I read that the soybean sudden death problem was spore born, and not near the threat here as it is in warmer climates.

:cheers::cheers:

 

[rat]

Originally posted by henry
Makes sense to me. When you refer to them as" spore born" I wonder if the problem is a bigger concern in the warmer southern climates where the spores have a longer season. I think I read that the soybean sudden death problem was spore born, and not near the threat here as it is in warmer climates.

:cheers::cheers:

Right on Henry.. Soybean rust overwinters in the southern climates and is drifted into northern climes during the growing season. Active colonies of this fungus have been noted year-round on kudzu in Florida. Certain companies (which I will not name) that have an extensive catalog of fungicides are putting the fear into soybean growers about rust and its not always warranted. Not to minimize the potential problem, but it is a clever marketing tactic.

Problem with white mold, as I understand it, is that it can overwinter in the soil here in the transition zone. It has root and shoot activity and if conditions are right in your area, it can propagate quickly.