Guidelines have been issued for growers contemplating re-drilling sugar beet that has failed to germinate during the cold spring.
British Sugar says 98% of the UK crop had been sown by the start of the week, while only about 1000ha had been re-drilled. The company was urging growers to think hard before doing so as time went on.
“It really has to be a catastrophic crop to be thinking about drilling in May,” said agricultural development manager Robin Limb.
Crops poorly and unevenly established with fewer than 50,000 plants a hectare might be worth re-sowing, the BBRO guidelines suggested.
Much depended on how evenly distributed the plants were, the cost of re-drilling and how well re-sown crops might establish. Only poor areas were likely to justify the exercise, and the later it was done the less likely it was to reward.
Despite good seed-beds for early drilling the cold weather has caused some germination problems for sugar beet growers
Yield potential was cut by about 3t/ha for every week that drilling was delayed. Late-harvested crops stood to benefit slightly more than those intended for early lifting.
Growers re-drilling should use the same seed spacing as originally used and avoid the temptation to cut seed rates, as it was false economy.
“To rip up a crop because there are too few plants and to replace it with another where there are too few seeds is nonsensical,” the guidelines stated.
The main problem was determining what the final establishment of crops already sown was likely to be. Any plants under a capped surface for more than a week would be weak and might not survive. Those with severe “pinch points” on the underground hypercotyls were unlikely to do so.
* The number of beet per chain is almost the same number as thousands of plants a hectare (ie 50/chain = 50,000/ha).
For more info visit the UK Sugar Beet website.
Q: How many plants a hectare have I?
A: It is very seldom worth re-drilling an area with more than 50,000 and not always worth doing so where the count is 40,000.*
Q: How many plants a hectare will I get from re-drilling?
A: Late sowings are prone to Aphanomyces (blackleg) and more tempting for aphids, so don’t cut down on aphid control treatments.
Q: How much will re-drilling cost?
A: The equivalent of 10-12t/ha of beet.
Q: Will I gain enough extra yield to pay for it?
A: Unlikely if you already have 50,000 plants a hectare – probably if you have only 30,000. The later you re-sow the less likely you are to gain.