Some growers may have left it too late to harvest maize silage

“The optimum time to harvest maize is when it reaches 32% dry matter (DM) but analyses of this year’s crop are showing a high proportion of silages at 38 to 40% DM,” said Dr Simon Pope, Wynnstay crop protection manager.

“The DM of maize alters very little during the ensiling process, so the DM% shown on silage analysis is usually the DM% of the crop at harvest. Given that maize dries down at a rate of 2% to 3% per week leading up to harvest, analyses indicate that some crops should have been chopped at least two to three weeks sooner.”

Reflecting on the 2017 season, Dr Pope explains that many early maturing varieties had reached target DM by the first week of October.

“Cobs took longer to ripen compared to 2016, due to the cooler weather in September, and cob maturity often coincided with very rapid stover senescence. This was because the weather conditions during ripening were ideal for eyespot and fusarium stem rot to develop rapidly.”

He said that despite being ready, some crops were not harvested until much later. Weather and ground conditions were certainly responsible for at least some of the delays.

“A situation developed where growers had over-mature maize crops, with much higher than normal eyespot and fusarium stem rot, both factors which predispose the crop to lodging and brackling. Then ex-hurricane Ophelia hit the country on 16 October causing lodging over wide areas.”

“The combination of this extreme weather event and an over-mature crop, led to a challenging harvest for some growers. Lodging and brackling became an issue, and this didn’t appear to be variety specific, with winds so strong the effects were indiscriminate.”

Dr Pope said that while overall the season appears to have been a success for the majority of growers, the problems experienced by some highlight the risks of delaying harvest.

“With a lot of time, effort and money invested in growing the crop, growers want to ensure optimum feed value is realised and ensuring maize is harvested and clamped when it reaches target DM, is fundamental to achieving this.

“While 2017 has not been a typical year, it highlights the importance of keeping your eye on the ball when crops are nearing maturity. When there’s a window of opportunity, it’s important to harvest the crop, and if anything, it’s better to harvest a little bit early than a little bit late.”