As I sit and write at the end of the growing season it’s interesting to reflect on the year just gone.
The crops and the quality of what goes in to store will be the best reflection of what the season has bought us. In general the excessively wet June and early July, followed by very little rain and then record-breaking temperatures in September, have dictated what we are seeing, not just in potatoes but across a whole range of cropping.
Going back to the early part of the year, most of the seed inspections did not cause too many alarms and planting conditions were pretty good – if a little truncated.
Crops emerged well and levels of weed control achieved were generally pretty good, although questions continue around how much longer we will have linuron available
Then came the blight. The first warning arrived through the Dacom system on May 12, which was before most crops were out of the ground. BlightWatch alerts also showed full Smith periods were recorded at the same time. There was active blight in Cornwall – but they always get it even in a normal year – so the cool start to spring didn’t send alarm bells ringing as they had done in 2014. Inoculum levels were low to start the season but this weather stimulated some blight build up, so the next warnings really grabbed the attention.
May 30 saw the next big risk period and the onslaught of the 2016 blight epidemic began. Interestingly, we only recorded one more full Smith Period (on June 13) in all of that atrocious weather, with the next one not being seen until September. However, the more sensitive Dacom system remained pretty much red throughout June and intermittently in July. We manged to get one or two robust treatments into the canopy (even though some were only just emerging) before intervals became stretched too much and blight started to show. Even though there was a lot of inoculum blowing around in the wind, overall, with the programme of blight fungicides used, we did not fare too badly.
It was surprising that, despite all the press and the widely held belief that the newer blight strains are more aggressive, we heard of so many problems arising from the use of lax programmes and weak products. Where sprayers physically just couldn’t travel over the ground then it’s acceptable, but where poor decisions were made it’s less so.
I really believe this is the new landscape in which we should consider the threat from blight. We must take this seriously and use robust treatments, even if the crop is very small or just emerging if it coincides with high-risk weather. The difference in cost between a robust and a weak blight programme isn’t huge when compared with the overall cost of production and potential loss if it all goes wrong. All the serious, major blight epidemics in recent years have all started early in the season but still not all of the industry has recognised this and changed practice.
Blackleg once again reared its ugly head and I don’t think we have heard the last of it now that lifting conditions have turned wet. It would help if we could manage the weather but ambient stores are once again faced with warm, humid air being drawn in – let’s hope for some cooler and drier weather soon. The processing store managers will have a difficult time on their hands managing some of these crops and that, combined with the new rules on CIPC, only make the job even more challenging.