It has been a frustrating spring, especially for heavy land growers with large areas to drill. Drier weather last week did enable good progress and there is relief as at last we face the right direction. Good spring seed-beds have been difficult to achieve, with the most important tool being patience.
The forecast remains cool and with soil temperatures sitting around 10C, crop establishment is slow. During this time vulnerable crops should be monitored carefully for slug activity, with particular attention given to those in “difficult” seed-beds.
Many beet crops are relatively clean and the pre-emergence herbicide spend appears to have been worthwhile. However, some earlier drilled, light land fields are getting dirty, as the first post-emergence sprays have been delayed by wet conditions. Weed control on farm could be awkward where drilling is staggered, with fields requiring different herbicide timings and treatments. Early treatments should be relatively kind, then turn up the heat as the first true leaves appear.
In late September drilled wheats, final leaf 3 is approaching full emergence. Well timed, robust fungicide applications are paramount to ensure the top, yield building leaves stay clean. T1 fungicides are well underway; strong protection is important so I’m hoping treatment will be nearing completion by the time this is read.
Cooler temperatures should slow disease development, but the level of septoria inoculum on lower leaves is alarming – just look in the bottom of a susceptible crop on a damp morning. For all crops, timings between T1 and T2 must be tight (three weeks). Forward crops received T1 over a week ago and leaf 2 is now emerging. In cool conditions, flag leaf emergence may be slow and an interim spray (T1.5) based on chlorothalonil may be required to bridge the gap between T1 and the flag leaf spray (T2).
Rapeseed crops range from full flower (majority of crops) to green bud where pest damage has restricted early growth. Fungicide strategy and level of investment in disease protection, particularly sclerotinia, will depend on yield potential and the interaction between temperature and rainfall at flowering. So far risk models show that temperatures have been too cool for infection, but remember all treatments work in preventative way, so it is important to coat petals before they fall and catch in the leaf axials.
Winter beans are growing well. Ascochyta and cercospora are present in some crops, but the level of chocolate spot is low. Monitor disease levels and be ready to apply the first flowering spray as symptoms appear. It is early doors for spring beans; most of these are emerging well considering some of the seed-beds. Keep these protected from pea and bean Weevil, a foliar feed can improve plant health with the consequential benefit of increased ability to fend of disease, particularly downy mildew and perhaps saving more costly treatments later.