The final round of crop visits are under way as the spraying season draws to a close. Fungicide performance has been good despite the challenging spraying conditions. Winter oilseed rape crops look promising, with heavy canopies and good pod distribution evident on many crops.
It is remarkable how crops recovered from the ravaging the pigeons inflicted in the spring time. Sclerotinia stem rot is evident on some crops, with prematurely ripened plants notable in the crop standing out as the most obvious issue. The stem, when split, will reveal the hard black sclerotinia in the stem cavity, which fall to the ground or are combined with the seed.
I have noted some pod midge larval damage, with pods white and shredded, a result of an earlier visit from the brassica pod midge.
Winter barley will be ready for the combine in the next couple of weeks. The crops are generally disease free with a lot of green area on the flag leaves and awns still visible. Six-row crops look particularly promising on the heavier soils and lodging problems are minimal.
Crows are active on field margins and need to be controlled.
Winter wheat crops are in grain-filling mode, with the final T3 applications mainly completed. While the general consensus is that disease levels were low this season, if unsprayed areas around poles, for example, are examined the real levels of disease pressure can be assessed. The T3 fungicide should include a strong triazole with septoria and fusarium control and a strobilurin to enhance grain colour, prolong the green tissue, control head moulds and maintain straw quality.
Spring barley crops are variable, late sown crops are going through the growth stage motions but remain thin and short with poor to moderate yield potential. Rhynchosporium remains the most obvious disease with small patches of infection scattered in some crops. Mildew levels are minimal mainly on the stems and lower leaves.
Occasional yellow flag leaves point towards a mild form of Barley Yellow Dwarf Virus, but I have not seen bad infections on any crop, particularly following ploughed grass.
Fully headed winter oats are clean and again showed remarkable recovery. Disease control has been easy, particularly where the preventative mildewcides have been applied. White threads are evident on the heads amongst the grains on the oat panicle. It is a condition known as blast due to sterile florets linked to stress factors such as frost or moisture stress. The spring oats have just headed and have varying levels of mildew present and have been treated with morpholines and tebuconazole/stobilurine combinations.
Bean crops remain relatively disease free with some lesions of chocolate spot on the bottom leaves. The recent blight weather also favours the development of chocolate spot and untreated crops would definitely benefit from a systemic/contact fungicide application. Crop height will be an issue in some crops for spraying.
Spring oilseed rape crops are in full flower with some fields showing very uneven flowering patterns as a result of the variable spring germination. Weeds like redshank and fat-hen are problematic where crop cover was poor.
Disease level is low, with occasional leaf-spot present. A triazole/insecticide application at petal drop should be planned. I still have pigeon attack on some crops despite the abundance of grassland with swards of clover which should be the preferred option for pigeons in late June.
It is a good time to assess the performance of crop inputs when the crops are pre-harvest, fungicides and herbicides. I have noticed poor cleaver control in a number of crops requiring repeated herbicide applications, possibly a combination of spring dry soils, weather hardened cleavers and dodgy spraying weather! Chickweed in some fields continues to resist the effect of SU herbicides, with similar problems emerging with knotgrass and other polygonums.
Combines will be geared up in the next couple of weeks and hopefully the yield potential will become a reality.
Gerry Bird is a crop consultant and member of the ITCA. Email: email@example.com