Adjusted yields from root samples taken from farms participating in Bayer’s #Beet150 initiative suggest the impact of this summer’s heatwave on crop potential has been profound with those furthest east likely to be most heavily affected.
Plant counts taken in August revealed that populations fell within the normal range and showed crop potential. It was less apparent however, how the impact of moisture deficits arising from the driest summer for more than 40 years would affect root growth. With root dig surveys completed on the same 15 farms that participated in the plant count surveys, the extent of the dry summer can now be seen. These root digs took 10 roots from each field and were analysed for weight and sugar content in the commercial tare house.
Across all participating farms the average adjusted biological yield for crops sampled on the 4th and 5th of September is 65t/ha. As with all averages however, it conceals a wide range and were it not for the exceptional crop in Yorkshire where the drought was less severe, the average would be below 60t/ha. This is 10-15% down on where crops could be expected to be in a typical year and healthy crops will have continued to build yield in the weeks since. However, the rate of increase begins to fall gradually from late September before eventually settling at roughly 1% per day from the end of October. Sequential lift data indicates that between early September and late October, crops can add roughly 25t/ha to fresh weight yields though such growth requires favourable weather during this time.
At 157t/ha the Yorkshire crop would be considered impressive in any year, but after the later start to the season caused by ‘the beast from the East’ and the drought that followed, it is simply exceptional.
Unfortunately, others have fared less well. Even where crops established well in good seedbed conditions in many cases they did not get the moisture once established to push on and bulk up. Unsurprisingly this is particularly pronounced on light, free-draining soils where in some crops the outer leaves wilted and died off. Crops look good now and will grow on but yield has been severely impacted.
Potential yields from samples from unirrigated crops in Norfolk ranged from 27t/ha to 61t/ha. Less than one in 10 growers irrigates sugar beet, but where it was available this season it was highly worthwhile. It is not by chance that the highest adjusted yield for samples taken in Norfolk – 89t/ha – is from an irrigated crop.
Bayer root crop campaign manager Ed Hagues said the results, while likely to disappoint many, were not unexpected, but nor should they overshadow the fact there were still many crops in excellent condition.
“Last year was an exceptional season, but the principal difference between it and 2018 is that 2017 was a wet summer. This year was always going to struggle to match 2017. The mild weather and regular showers seen in September will have enabled many crops to continue building yield, but the stark reality is that it is too little, too late. For many, the damage to potential was done in June and July. It is important to note however, that there are many good crops this year.
“The significance of soil type is apparent. The deep silty soils over peat farmed by the grower in Yorkshire supported crop growth better than the light, sandy soils typical of farms in Norfolk. This combined with the very little rain received in the east means crops across much of the region were always going to struggle,” says Mr Hagues.
He adds: “Where crops are suitably protected from disease with two full-rate applications of Escolta (cyproconazole + trifloxystrobin) applied about four weeks apart, there is every chance of them continuing to bulk up and take advantage of the important yield growth on offer through the autumn.”
Unirrigated sugar beet in Essex (left) and Norfolk (middle) contrasts with that from the irrigated crop in North Norfolk (right).
As with many growers this season, #Beet150 entrant Tony Pointer has endured a difficult and protracted drilling period that has seen him finish drilling later than ever before.
The implications of a late spring and a hot, dry summer are yet to be fully understood by sugar beet growers, but while moisture is in short supply, plant populations are largely on target.