A free online tool has been launched to help producers select maize varieties that are best suited to their location and prevent problems associated with delayed maturation.
Using Met Office data, LG Seeds‘ tool maps the average Ontario Heat Units (OHU) accumulated during the past 10 years using a five-kilometre grid. Armed with actual OHU data for their postcode, producers will then be able to select varieties that will mature within the OHU available. The LG Seeds maize heat map can be accessed here.
Identify the maturity class
“OHUs are the internationally recognised system to show if maize can be grown successfully in a particular location,“ explains LG Seeds‘ Tim Richmond. “Using the online system, producers can identify the maturity class that they should opt for more accurately. And this will help to manage the risk when selecting varieties.“
Risk of damage to soil structure
He says that if there are too few OHUs, crops will struggle to mature. „And this can lead to a number of problems. A delayed harvest will potentially lead to harvesting in more difficult conditions and increasing the risk of damage to soil structure.
„It will also reduce the opportunity to establish a successor crop, leading to stubbles being over-wintered with a greater risk of soil run-off. From a herd point of view, a delayed harvest will mean maize silage is later going into the diet.
Mr Richmond adds that varieties differ in the number of OHUs they require to mature and this is why it is important to choose varieties that will mature within the heat units typically achieved in the locality. „Very early varieties require between 2,500 and 2,750 OHU. Early varieties need between 2,750 and 2,900 OHU and late varieties require more than 2,900 OHU.