Winter crop walks at Southern Farming Systems branches at Geelong, Streatham, Hamilton and Gippsland have focused on research and key topics of the season.
Hamilton’s crop walk, held last week, centred on managing potash deficiencies in canola and wheat and blackleg infection in canola.
Dr Robert Norton, from the International Plant Nutrition Institute in Horsham, told about 15 producers they could typically pick a potassium deficiency when they saw better crop growth in the previous crops’ windrows and header tracks.
“The better the crop, the more potassium it removes,” he said.
Wheat and canola are potassium rate responsive at differing levels, depending on plants demand versus supply available.
The trial site at Glenthompson had canola and wheat with various rates of muriate of potash (MOP), either drilled side by side with the seed or top dressed.
“Plants use potassium through a supply versus demand process, we will apply urea to push the plants along and see what response that may occur in the spring,” Dr Norton said.
Unlike other fertilisers, potassium is relatively immobile in the soil and does not move unless a root comes into direct contact or it is immobilised into the soil solution. It can’t be lost into the atmosphere like nitrogen.
“IPNI have developed an app called the Crop Nutrient Removal Calculator to help producers calculate nutrient removal of nitrogen, phosphorus, potassium and sulphur for differing crops,” Dr Norton said.
The group also travelled to the SFS Hamilton branch site at Lake Linlithgow, where variety trials are being conducted. Steve Marcroft, of Marcroft Grains Pathology discussed the current situation with blackleg disease in canola. Reasons behind the disease being an issue this season include:
- Overall increased canola production
- Genetic resistance to group A varieties
- Increased fungicide resistance levels, with some resistance forming to the seed treatment Jockey
- More rainfall days, causing continual leaf wetness and allowing the disease to reproduce and travel
“Know your blackleg ratings, monitor the crop and use seed treatment fungicides,” Dr Marcroft said.
“Don’t continually crop canola after canola, use the GRDC blackleg management guide updated each year to help with decision making.”
Southern Farming Systems’ major field day, Agrifocus, is at the Westmere trial site on October 12 and 13. Details: www.sfs.org.au
