AS AN early maize harvest gets underway, growers are being urged to carefully assess cob maturity before deciding when to chop.

Dr Simon Pope,Wynnstay’s crop protection manager, said "A neighbouring farm's maize harvest may have begun but that doesn't mean your crop is ready too.

“There are a range of factors which influence crop maturity including variety, management and the weather, and while in general maize has matured earlier this year, it’s important to assess individual crops to ensure optimum harvest timing.”

He says harvesting at the correct stage of maturity is key to securing a high-quality crop. The target should be a total crop dry matter (DM) of 32 percent, with at least 30 percent starch content, so he advises growers to continuously monitor crops to determine if they are ready to be chopped.

Dr Pope said: “It’s easy to tell when a cob is ready. Simply snap the cob in half, break off a kernel and squeeze it. If milky liquid squirts from the kernel, or if any liquid remains at all, the crop needs more time to ripen. If there’s no ‘milk’ in the kernel, and the starch is cheesy, it’s ready.

“Also, consider how green the stems and leaves are. Avoid leaving the crop in the field so long that the leaves die and the grain becomes bullet hard. Equally, the crop should not be harvested before the cobs are fully mature and while the stover remains green and sappy.”

He said if growers can harvest maize crops early, there’s a good opportunity to establish a cover crop to avoid leaving the ground bare over the winter period.

“Re-seeding with grass or sowing a forage rye catch crop soon after harvesting maize should be considered. Alongside improving the soil structure, reducing the risk of surface water run-off and the amount of leached nutrients, it will provide additional forage options in the spring.

“Growers should check which herbicides were applied to the maize crop since some, such as nicosulfuron, have following crop restrictions, which preclude ryegrass as a following crop. In this situation, forage rye would still be an option.

“However, the priority must be to harvest maize when it is ready, rather than to compromise yield and quality by chopping it too early in order to sow a following crop,” said Dr Pope.