Averting Crop Catastrophe30-Jun-2014

A NASTY part of crop production is that in terms of risk management, it is perennially a potential case of out of the frying pan and into the fire.

Plant too late, and you run the ever-increasing risk of heat shock from hot conditions in late spring, but go too early and you are a prime candidate for frost damage. This year, after years of the best crops being those early sown, farmers are seeing evidence of the latter, with frost touching up crops in parts of South Australia, NSW and Victoria in particular.

Speaking last month at a Grains Research and Development Corporation (GRDC) farm business update in Horsham, Victoria, Tim McClelland of Birchip Cropping Group (BCG), said there was no single way to avoid catastrophic events, whether it be a run of 35-degree plus days in October or this year’s run of frosts in August that caused widespread stem frost in cereal crops.

Instead, he said the best way to ensure some sort of a return from these difficult seasons was to spread the risk.

“No single strategy will alleviate the risk associated with a catastrophic event, so multiple solutions are required.”
He said these disastrous events stretched beyond climate. “We see disease events like this year’s outbreak of beet western yellow virus (BWYV) or pests such as mice or locusts, both of which have been major problems in the past decade.”

Unprecedented events

The common theme with these events, according to Mr McClelland, is that it is often something unprecedented, making decision making difficult.

“This makes these events virtually impossible to plan for.” Mr McClelland said the use of decision support tools, such as BCG’s own Yield Prophet could give growers some projected data to assist with making their minds up with what to do with struggling crops.
This example is being borne out this year with stem frost affected crops in Victoria.

There are different schools of thoughts as what the best options are for growers, and vastly differing circumstances.

Mr McClelland said some growers with moisture underneath, such as in Victoria’s north-east, would be best to leave crops and see how new tillers emerge, but said in the drier areas it may be best to cut crops for hay. GRDC southern panel member Rob Sonogan had a different interpretation, saying even with poor crops, unless farmers had their own equipment the costs of fodder production and the uncertain market there may mean they are best off taking the chance of letting crops go through to grain.

Mr McClelland said this showed the benefit of punching in data specific to an individual farm.

“Each case is different and figuring out what is best for your own circumstances is critical as there is no one size fits all answer.”

Mr McClelland said farmers needed to think through their problems and then act. “It’s another tough one, you’ve got to act quickly, but not rush in without thinking it through.”

Planning for climate stress

 
Moving forward, he said farmers would increasingly have to plan for climate stress on crops.

“The incidence of frost is increasing, and the frost window has broadened, which is paradoxical, given our climate is warming.”

He said farmers needed not to over-react to the conditions of the season before. “The temptation now, with the frosts during August, would be to push sowing back, but you need to look at the data and see cereal crops lose more yield from heat shock than they do from frost.
“We need to stagger our sowing dates to ensure there is a range of maturities there, but it would be dangerous to react to the frosts and simply push all the planting back.”

“We get these serious frost events one year in 20, maybe one year in 10, but heat shock has an impact nearly every year.

“What we have found is that having multiple varieties over a broad sowing window, with staggered growth stages, is the best bet.
“This doesn’t mean sowing your long season varieties, then the medium and then short, so they are all at the most vulnerable growth stages at the same time.”

He said logistically it was difficult to chop and change between sowing different varieties at planting, but said growers should try and mix things up as much as possible to spread the risk.

“Spread your sowing dates around so you’ve got some crop planted either side of the optimum sowing date.”

Farmonline

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