Potatoes making good progress despite late start – Farmers Guardian

Planting finished about a month later than normal for many growers following the wet spring. but on the upside, residual weed control has been very effective given adequate soil moisture.

Some crops may require an additional graminicide for the likes of couch control, although seed growers are limited in the products they can use – cycloxydim is one option that is approved.

This season, there have been some emergence issues in a few crops, with initial assessments. suggesting chronological ageing of seed could be a factor, rather than any problems with seed treatments.

Warmer weather last season meant there were almost two flushes of tubers within the same crop. When tubers came out of the cold store this season, those from the initial flush were ready to go, whereas some later-season tubers could have still been dormant. If the eyes are not g open when tubers are planted. crops are slower to emerge.

Generally, early planted crops had reached rosette stage by the time of writing in mid-June, with late blight programmes just beginning, while later crops are about seven to 10 days behind.

For growers just starting blight programmes, recognise that although crops are smaller than normal for this stage in the year, they could still face higher blight risk given warmer conditions.

After a late start, the warming soils and plenty of moisture have helped crops establish quickly, rewarding growers who were patient enough to wait for soil conditions to improve, rather than forcing crops into poor seedbeds.

Many crops are now at row closure, although there is quite a range across the region, with the most advanced at tuber initiation, versus some only planted at the beginning of June.

As elsewhere, residual chemistry has worked well in moist soils. with very little need for any post- emergence follow-up, especially as crops are advancing so quickly.

Blight programmes are well underway on most farms, and although cool, wet conditions through May and into June were not conducive to blight in this area, this is changing with expanding canopies and warmer weather.

Indeed, several blight infections have been confirmed up and down the country.

With limits on certain chemistry and the ongoing threat of fungicide resistance, it is important to plan blight programmes carefully so chemistry and modes of action can be alternated, while still targeting the most suitable products. to the optimum timing.

It also avoids heavy reliance on any one product, or running out of options as the season progresses.

Plans should be adapted as the season unfolds, utilising decision support tools and crop monitoring to help tailor fungicide choices and partner products as required.

Mancozeb, for example, is a cost-effective partner that provides added protection going into higher- risk situations, plus background effects on alternaria, while cymoxanil offers some curative kick-back where blight risk may have increased prior to application.

Do not forget, if blight is seen, it is worth sending samples for analysis as part of the Fight Against Blight campaign, to help identify the genotypes present in the UK.