18 September 1998

Hopes of maincrop potato growers rest on a bulking boost

By Andrew Blake

GOOD late bulking in the first half of the month could offset some of the maincrop potato yield lost from late planting.

But only one-third of crops are still green enough to make the most of any further sunshine, says David Hudson, technical director for Sutton Bridge, Lincs. And unexpected differences in progress showing between those the overall yield is now bound to be lower than last year, he believes.

The companys growers have about 2200ha (5500 acres) of potatoes from Essex to Yorks and across into Hereford.

"Two or three weeks ago I was thinking it would be 10-14% down. Some crops have bulked up very nicely recently, with the odd one putting on 2t/acre in a week. But there are not enough of them to make a big difference and I still believe we could be up to 10% down on last years very big crop.

Much depends on the canopy remaining. "There is a huge proportion of tired looking crops out there now. I estimate that one-third have now had it, another third could do a bit more and another third still have good potential." But cooler weather will undermine that, Mr Hudson notes.

Meanwhile, some crops of Maris Piper with reasonably good canopies are still bulking while apparently similar fields are standing still. Compaction or June flooding could be to blame, he speculates.

Foliar blight flared up again recently in moist, warm weather but has by and large been contained, says Mr Hudson. "We have been on very tight spraying intervals. I know of only one site with tuber blight. The main quality problems are going to be tuber shape and lack of bakers simply because of size."

On the plus side dry matters which reached an unusually high 23-24% have begun to slip recently. That should ease bruising risks, he explains. "They are getting back to 21-22% which is a bit more comfortable. On some sites bruising remains frustratingly high despite careful management and tuber handling." &#42

MAINCROPPOTATOES

&#8226 One-third still bulking.

&#8226 Yield 10% less than 1997?

&#8226 Minimal tuber blight.

&#8226 Dry matters easing.

Yield prospects

"Maincrop yields arent going to reach the 48t/ha we saw overall last year," confirms BPC spokesman Rob Burrow. Many crops for storage have already been burned off, he notes. "Tuber numbers are also quite low in a number of areas, particularly Scotland. But dry matters are surprisingly good considering all the moisture we have had. "There are some big variations between crops, but we still estimate the average yield will be 2-3t/ha lower than last year."