When is it too late to drill oilseed rape?
8th September 2025
Given the season, many oilseed rape growers drilled in August, or even as early as late July. However, others are holding back, noting that later drilling into September has its advantages, said an NPZ UK expert.
Michel Shuldham of NPZ UK explained that there are a number of provisos for successful late drilling.
“Most important is to say it is advisable only for hybrid varieties with their vigorous development. And as late-sown oilseed rape crops are more at risk to phoma, a good phoma rating is important.
“As part of our trials into late drilling, we have analysed daily temperatures at our headquarters in Impington, close to Cambridge, over two autumns.
“If we want to reach the 8-leaf stage with a robust plant based on an 8 mm root neck diameter and a tap root of more than 8cm before winter, we have to accumulate 150°C for germination and around 120-150°C per leaf pair.”
Mr Shuldham said that between the beginning of September and the end of November in the two autumns the team analysed, they received 1,131°C and 1,163°C. That is more than enough for sufficient development of the crop, the expert added.
When to consider late sowing?
He continued: “Calculating both figures together, we need a minimum of 800°C for sufficient development before winter, and based on the temperature data from Impington, we can still reach that stage.
“Varieties such as our hybrids Maverick and Murray, with their vigorous growth habit and exceptional RlmS Phoma resistance, are good examples of varieties that should be suited to late drilling while, as always, taking into account farm location and modifying key factors such as the sowing rate.”
The NPZ UK expert said that it is certainly worthwhile considering late sowing if your temperature data is comparable with the one from Impington.
“And with many growers having their own weather station – such as the Sencrop – you can look at your own historic information as well as our data to make an informed decision,” Mr Shuldham concluded.
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