[Photo: Australian Maize Association president Nick Hutchins (left) and grower Tony Sawers in the record-breaking crop.]
An Australian corn grower, Tony Sawers, from Boort in north-western Victoria, has set a new Australian record and broken through the 20 tonnes of grain per hectare barrier for the first time. The hybrid was Pioneer 3335, which yield-tested at 20.5t/ha when harvested in May.
Australian Maize Association president Nick Hutchins, of Darlington Point, NSW, who adjudicated the weigh-in, measured out a random 1.4-hectare section of field, from which grain was harvested and taken to a weighbridge at Boort.
Another field was also tested from a random one-hectare section of crop. The 3335 maize from this section yielded 20.55t/ha. The average yield of the two sections was 20.5 tonnes per hectare at 12 per cent moisture.
Mr Hutchins says the high yields were a combination of good soil type, excellent crop management, drip irrigation, hybrid choice and longer day lengths in Victoria. "The longer day lengths allow for more solar radiation, and the area generally has cooler summers than northern corn-growing areas," he says.
Mr Sawers says there were not many days over 35ºC last season, which helped set the record yields. This season he is expecting his yields to average around 19.2 tonnes over the 163ha planted to 3335.
The drip irrigation system was installed for tomatoes six years ago. Then 20 hectares of corn was trialled in 2000 to see how it would perform with the system. The success of the trial has resulted in corn being expanded to 300ha under drip irrigation on the farm.
The record-breaking crop was grown with two rows on every bed and drippers located about 25 centimetres underground at the centre of each bed. Row spacings of 84cm were used on the bed system, with a planting rate of 85,000 seeds per hectare.
Brothers Ronald and Wayne Bramley, who managed the corn, say the drip irrigation and soil moisture was monitored at least once a day. The blocks were given two to three hours of water each day and used an average of 6.67 megalitres per hectare. The crop was also helped by 70 millimetres of summer rain early in 2005, giving total water use, including rainfall, of 7.37mgL/ha. Mr Sawers says this was close to the previous season"s total water use of 7.41mgL/ha.
Ronald Bramley says each hectare received 370 kilograms of MAP, incorporated prior to sowing, and a further 400 units of nitrogen during the growing season, which was fed through the dripper system. The crop also received three litres a hectare of Primextra® and one litre a hectare of Dual® Gold for weed control. Two kilograms a hectare of Counter were applied for insect control. Mr Bramley says that apart from the commercial paddocks, Sawers Farms ran a number of trials on the property last season. These included variety testing of hybrids and plant population checks.