Drought concerns have re-emerged in Australia's biggest grain-growing state, after "very dry and hot conditions" in some areas set summer records, farm officials have warned.

Rainfall rankings in other parts of the state, Western Australia, made the summer among the driest 10%, with only southern areas seeing significant rain last month.

A continuation of the dry conditions into the southern hemisphere autumn "could see progressive cutbacks" in the areas of grain sown for the 2010-11 harvest, a report from the state's farm ministry said.

"Apart from southern areas near the coast, there has been insufficient summer rain in most of the wheat-belt to build stored soil moisture."

Moisture factor 

The area eventually sown would be "heavily responsive" to soil moisture levels, the ministry said, noting that farmers, for whom fertilizer costs as well as grain prices have fallen, had been hoping to plant similar acreages to last year.

Abare, Australia's national commodities bureau, pegged the Western Australia wheat crop at 8.25m tonnes, approaching 40% of the country's total production.

In 2006-07, during the last nationwide drought, production fell to 5.1m tonnes.

'Wind, rain, hail and fires'

The dearth of winter rain, in a period dogged by the occurrence of an El Nino weather pattern, had brought the central area of Merredin its hottest January ever, with temperatures hitting 44 degrees Celsius.

Further south, Katanning received, in one thunderstorm, 97% of the rain it received all month.

"Wind, rain, hail and fires have all adversely affected parts of the region," the report said.

The upside to the dry spell was a reduction to "low levels" in populations of pests such as weed web moths and aphids.