Hot, dry days in the Mallee are stripping subsoil moisture from crops desperate for rain.
Farmers have everything crossed that rain forecast for Thursday will fall and get their season back on track.
Agronomist Dale Boyd, from the Department of Environment and Primary Industries, says it's been a devastating start to spring for crops, with 30-degree days.
"With the recent dry weather, with a bit of heat in it, we are finding...(wheat) is extracting moisture quite quickly from all depths but especially starting to deplete it from depths like 60, 70 and 80cms," he said.
Mr Boyd says it's crucial crops receive rain in the weeks ahead.
"Due to the crop stage where it is at now, going through booting, pushing the head up, pretty soon some of those crops will be flowering," he said.
"It would be ideal not to have some of the stresses on that plant, one of them being moisture stress and some of it being heat stress as well."
© ABC 2013
14:05 EST Heavy rain has stranded about 40 people at William Creek in the South Australian outback due to flooded roads and low cloud has grounded aircraft.