OH no, not again! After a fortnight of glorious weather and just as the combines started to roll, down came the rain and little prospect of improvement this week.

Most of Yorkshire had seen no rain for two weeks and has had temperatures more like those you would expect in Spain. The very warm and dry conditions had seen half of lowland winter barley crops harvested with winter oilseed rape not far behind. Winter wheat and spring barley crops are maturing quickly. Sugar beet and unirrigated potatoes which were wilting have had a reprieve.

Winter barley yields are rather light, with few crops topping 7.5 t/ha. At High Mowthorpe, the winter barley trial yields were dominated by the six-row varieties.

In the south of the country a start has been made on winter wheat and spring barley. Locally, most crops are still maybe two or three weeks off harvest, although the speed at which strobilurin-treated crops can switch from green to senesced make it easy to over-estimate the length of time to harvest. The yield and specific weight from these first-cut crops farther south have been relatively disappointing, suggesting they have been poorly-rooted and finished prematurely due to the hot weather.

Rape harvest has also been slow during the last week, about a quarter of the crop has been cleared. Early yield reports suggest a poorish start to the harvest with few crops over 3 t/ha (25 cwt/acre). Hopefully, yields will improve as we get into the better crops. We probably should be expecting moderate yields, as oilseed rape does not like 'wet feet', and although it has considerable powers of compensation, poor rooting on some soils, clinical and sub-clinical sulphur deficiency and late drought have all added to the potential variability of yield.

In the haste to get land ready after the combine, there has been quite a lot of ploughing of OSR stubbles straight after combining. This can add considerably to the problems with volunteer rape in following crops. As oilseed rape is encouraged into dormancy by early burial, ploughing after the combine adds new volunteers when the land is ploughed back up. This may not be a problem in cereal-oilseed rape rotations but where potatoes, sugar beet, peas and beans form part of the rotation, control of volunteer rape can be both difficult and expensive.

Winter beans are starting to show pod senescence and spring beans are at the green pod stage. Rust has increased very rapidly over the last two weeks and has caused general bronzing of the remaining foliage. Treatment is no longer cost-effective.

Peas have senesced very quickly during the last week and some forward crops will be desiccated in the next few days. Crops are often very variable, with poorer parts of fields having just two or three trusses of pods and better areas in the same field six or seven trusses.

Beet crops have coped well with the dry weather and have continued to grow rapidly, gradually making up for the slow start to the season. Weed beet is now easy to see and should be dealt with as soon as possible. Crops are weedier than in recent years with fat hen, redshank and knotgrass making a number of crops look increasingly untidy.

Potato prices have fallen recently, due mainly to an excess of old crop appearing on the market. There are plenty of potatoes in the ground and it looks like a prolonged drought or difficult harvest will be required to lift prices. There looks like being plenty of poor-quality potatoes available but not so many with good skin quality. Only the best land is able to produce quality potatoes without irrigation.

No blight has been reported in the region as yet and there have been no Smith periods in the last two weeks. The low risk of blight in recent weeks has meant that growers using inexpensive mancozeb have kept the cost of blight control down. It should be remembered that spray interval is more important than product choice and that when the blight risk is low, expensive fungicides are quite unnecessary.

This column is supplied by Derek Knight on (01430) 861988, a consultant for ADAS in East and North Yorkshire.

Updated: 10:06 Thursday, August 09, 2001