Spring has arrived and a welcome change in the weather allows wheels to roll. A good forecast this week should enable seed-bed preparation for the spring crops; in wet situations there is still time to allow patience for the right conditions.
Top dressing has begun in earnest and crops are already responding to their first dose of nitrogen. Even the yellow, washed out barleys are starting to green up and moving quickly to the beginning of stem extension. These barleys will soon be ready for their plant growth regulation and 1st fungicide. Spring herbicide control in barley should be completed before the crop meets in the row and shades the target weeds.
Rapeseed is moving quickly, on some forward crops there may only be time for a two way split of solid fertiliser before the crop becomes too tall. Many crops will receive a plant growth regulator (PGR) this season between green and yellow bud. On the biggest canopies I will be using some Caryx (mepiquat + metconazole), however, straight tebuconazole or metconazole still offer good growth regulation.
Whilst field walking last week there was an obvious increase in the severity of yellow rust infection, particularly on later drilled susceptible wheats e.g. Santiago and Conqueror. If not already sprayed, susceptible crops should receive a rust active triazole at the soonest opportunity.
Early to mid-sown wheats have recently arrived at early stem extension (GS 30) and are ready for the first stage of a robust PGR programme and the T0 fungicide (triazole + chlorothalonil). As disease pressure is high (and in the case of yellow rust less discriminating than current Recommended List ratings suggest) all crops will need a robust early fungicide treatment tailored to the varietal susceptibility. Fungicide doses at T0 & T1 will be higher than in recent years to combat the high disease pressure and the shift in sensitivity of septoria to the triazoles, which is now evident in the field.
Those of you that have noticed a slip in poppy control from sulfonylureas would be advised to consider a change in the early herbicide strategy. Florasulam-based products are still giving good control.
Winter beans should be monitored for leaf notching by adult pea and bean weevils. In dry conditions, slow growing spring crops are at greatest risk.
As I continue to walk this spring it seems that in general the pre-emergence herbicides have worked remarkably well, even in some high population situations. But then you can stumble on a surprising example of poor control from autumn residuals and Atlantis (applied in good conditions). Finding one of these can chill you to the bone, a reminder that cultural control is ever more important!