CROPS have grown more in the last week than in the whole of the previous month. The windy and increasingly showery conditions have limited crop spraying at a time when everything wants some treatment.

Ears are starting to appear on September-drilled wheat crops (GS 51-55), whilst October- and November-drilled crops have flag leaves emerged. Most winter barley crops are flowering, with forward crops at the end of flowering and at the start of grain-fill. Spring barley is very variable, depending upon sowing date and the dryness of seedbeds; most are around GS 30/31 with advanced crops at GS 31 and by the time you read this, the flag leaf will be there on early crops.

With wheat crops seemingly clean and an apparently short interval since T1 fungicide application, it is easy to believe there is plenty of time for T2 applications. But the rapid growth and belts of showery weather crossing the country mean the last - and most vital leaves for grain production - will now have been exposed to Septoria infection. A strobilurin plus good quality triazole should be applied as soon as possible, Landmark, or Twist plus Opus, or Amistar plus Opus are the best options. The very rapid crop growth will inevitably mean that many forward crops will be in ear by the time the T2 spray is applied. In these situations, a T3 spay will not be required.

Many winter barley crops have now had, or will shortly receive, their T2 fungicides. These should aim to prevent rhynchosporium development, particularly on susceptible varieties like Vertige, and provide effective protection against brown rust. The latter, although presently only at low levels, often develops quickly through June and July during grain-filling period, especially on the wolds where early morning dews can last for several hours.

This season there may well be scope for a single fungicide regime on some spring barley, but each crop must be assessed individually. Rhynchosporium (particularly on Optic) can build up extremely rapidly and lack of any protection can be judged a risky strategy when there have been relatively high levels around earlier in the season. The recent warm and drier weather and T1 sprays have slowed rhynchosporium on the winter crop, but the forecast showery weather could reawaken the disease, particularly where there were low level early infections on spring crops.

The majority of winter oilseed rape crops are rapidly approaching the end of flowering. Many crops have shown signs of sulphur deficiency, with very pale or almost white flowers. If you have seen this, it probably means you will have to apply sulphur to next year's crop, it is too late to remedy this year's crop.

With continued dry conditions, petal sticking has not occurred and the risk of sclerotinia must be very low this year, except on farms where there is a history of the disease. There are still Phoma and light leaf spot lesions at the mid-plant level, but lower leaves are senescing rapidly or have already been lost. Alternaria levels remain very low. Despite recent warm, sunny conditions, seed weevil numbers have not increased further, only at High Mowthorpe, which seems to have its own resident population of weevils was a threshold requiring spraying reached.

Warm, sunny conditions have continued to favour flea beetle activity in spring oilseed rape crops. Vigilance will be needed, as is often the case with spring rape as crops approach the susceptible green to yellow bud stages when serious attacks of pollen beetle can occur.

Most winter bean crops are at early- to mid-flowering. A lot of crops are quite open and, while this may benefit disease control, weed suppression is less and excessive weed growth will increase the requirement for desiccation later in the season. Disease levels are generally very low in both winter and spring beans.

Pea crops have made rapid growth, with both adequate moisture and warmth. Plant populations are generally good, despite strong land seedbeds being very dry and cloddy. Check the need for post-emergence weed treatments and spray when the crop is well waxed and before flower buds are visible. There is little or no disease in peas at present and the need to spray will only arise if we have a return to showery weather.

The warmer dryer conditions have brought some cheer as crops and price prospects continue to improve.

This column was supplied by Derek Knight, a consultant for ADAS in East and North Yorkshire, who can be contacted on (01430) 861988.

Updated: 09:26 Thursday, June 07, 2001