Summer crop planting windows discussed at AgQuip grains breakfast

Speaking at the Grains Research Development Corporation (GRDC) and NSW Department of Primary Industries (DPI) annual grains industry breakfast at Commonwealth Bank AgQuip, summer crop research lead, Loretta Serafin said while soil temperatures at Breeza were only about six degrees, other areas were slightly higher and rising. 

“Soil temperatures are rising, but not rising as fast as I would like,” she said

Ms Serafin said the general recommendation for planting maize and sunflowers was 12 deg and rising, while sorghum required about sixteen.

“We will have to wait a bit on the plains to start some of these summer crop options,” she said. 

Ms Serafin said her team had carried out work last year looking at how early sorghum could be planted, sowing from the 6^th of August through to September with soil temperatures ranging from ten degrees to sixteen.

“Ten degrees is too early, we had plants still emerging seven weeks later, only half the seeds we put in the ground ever came up, we had massive establishment losses and a patchy plant stand,” she said. 

“Closer to eleven degrees, things came out of the ground much more rapidly, but it was still very slow. 

“Sixteen degrees, no surprises, everything came out of the ground.

“If you sow too early you also result in patchy stands and that is an opportunity for weeds,” she said.

However, while higher risk, in two out of three sites sowing early still resulted in higher yield, despite reduced plant stands. 

Ms Serafin said in this particular years data, crops planted later in spring  suffered from extreme heat during flowering, drastically reducing yields. 

“While early sowing meant low establishment and patchy stands, high compensation ability from sorghum meant last year it yielded more,” he said.

“It is not my suggestion you plant at 10 to 12 degrees.

“We are trialling it again this year, we may be able to prove some small gains at moving the window forward.

“But we need more work to know if it will work reliably because of the risk of frost.”

“Surprisingly there was no significant difference between varieties of sorghum in the trials.” 

Ms Serafin said while maize had a lower temperature requirement at 12 degrees, it was important to ensure the temperature was rising.

“We planted at nine and everything established well,” she said. 

“The question is though, what happens when you have a cracking frost on those small plants.”

Ms Serafin said soil moisture for a summer crop was scarce, though there were areas in northern NSW with some profile.

“I sowed early sorghum, for early season trials at Moree two weeks ago,” she said. 

“Over the next six months, before the summer crop planting window closes, there is a 90 per cent chance of 50 millimetres rain in a seven day period. 

“I think there is a lot of hope that we could have a sowing opportunity.”