NDSU Extension - Williams County


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July 1, 2015

Sclerotinia Risk

Once Canola is in bloom, it becomes susceptible to diseases. One disease that is one to watch out for is Sclerotinia, which is caused by Sclerotinia ascospores which can be found on the canola petals. Once this disease is found on the petals, it will quickly spread to the healthy green tissue and eventually will cause large yield-robbing lesions on the stems and branches. But this disease only occurs when conditions are favorable, which is adequate rainfall before flowering and cool to moderate temperatures with long wet periods during flowering. The past week has been warmer, but with the rain and temps in the 70s a few weeks ago, this disease could still show up. One way to monitor the spread of this disease is by using the Sclerotinia risk map and calculator www.ag.ndsu.edu/sclerotinia. This calculator uses the data that is collected from the NDAWN stations, North Dakota Agriculture Weather Network, other information from farmers can be added to this site to make it more accurate. If you know your fields received more rain than the closest NDAWN station, that field might be at higher risk. Most of Williams County shows to be in the high estimated risk area. This information was from the NDSU Crop and Pest Report, June 25th 2015.

Water for Livestock

Many people depend on surface water for their livestock during the summer pasture months. Using water from lakes, rivers, ponds, sloughs and dougouts normally has no consequences, but sometimes under specific environmental conditions there can be concerns. Problems seems to arise when there may be many naturally occurring harmless algae species but there are other that produce toxins which affect the nervous system or liver. Blue green algae is not the algae you see in stringy mats along the shore, the algae forms as large colonies of fine green particles which suspend near the surface. The particle appear blue as they die and dry on the surface. A veterinarian should necropsy dead animals to rule out causes of death, but they can’t likely find conclusive evidence that would lead to algae poisoning. When livestock are poisoned they may show signs when it is nervous system toxins such as; muscle tremors, decreased movement and difficult breathing. They often collapse and experience sudden death within a short distance of water. Animals affected by liver toxins become listless, weak, may have pale colored membranes, bloody diarrhea, or dark tar like stools, they may also sunburn on light pigmented area. Other dead animals, birds or small mammals, may indicate its presence. Hot dry calm sunny days stimulate the reproduction of blue green algae, which will further enhance the nutrient levels in the water. Algae poisoning is more likely in stagnant water following hot weather. This information was from John Dhuyvetter, Area Livestock Specialist.


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