THE BEST sowing date for first wheats could be up to five weeks earlier than that for second wheats, according to the latest information from ProCam‘s 4cast predictive agronomy system.

First wheats achieved the highest yield when sown in the first week of September, while second wheats performed best when sown in the first week of October, the results showed.

“The results point to the fact that the agronomic requirements for optimum yield in second wheats are greater than many people realise,” said ProCam technical director Dr David Ellerton.

“Across the board, first wheats yielded 0.98t/ha more than second wheats over the five year period.”

He found that first wheat yields fell by 0.2t/ha for each week after the September 12 optimum sowing date.

By comparison, sowing second wheats earlier than the optimum October 2 drilling date – the first week of September for example – lead to a 0.5t/ha yield deficit.

“It is this sort of fine tuning that can make all the difference between profit and loss.”

Compared to first wheats, spending on herbicides was about £2/ha more for second wheats at £47.70/ha, Dr Ellerton added.

If you have to grow successive wheats, paying attention to drill dates and herbicide management will always pay dividends he concluded.