Long spells of wet weather are normal in the winter months, so take the chance to spray when it comes.
Well it seems long, drawn-out spells of wet weather in the final months of the year are becoming something of the norm and if you do not go while you can it seems you face the consequences, especially on heavy ground. Many growers have spray recommendations left over from the autumn, as they are unable to travel and having retired the sprayer to the shed; they are left rather disheartened by the weather.
Unlike last year, luckily most cereal crops went in well and came up quickly, with most crops being drilled in late-September. These crops are now coming to the end of the BYDV protection window which Deter (clothianidin) dressed seed offers, so recommendations of cypermethrin have been made on those earliest sown crops, but as already pointed out, the percentage of applications actually made are rather low. Aphid numbers in the field are low, as the population of aphids is low in our area.
Oilseed rape is looking extremely vigorous in the field, with many undergoing growth regulation with metconazole before an application of Proline (prothioconazole) for light leaf spot (LLS) protection and phoma control.
LLS will be assessed again in February and if necessary an application of tebuconazole will be applied to keep the disease at bay, this is likely if conditions have remained mild throughout December and January. Application rates of tebuconazole may be increased to give additional growth regulation if necessary.
Many Proline applications were mixed with Kerb (propyzamide) once the soil temperatures dipped to below 10degC at the end of November to finish off the black-grass which the Centurion Max (clethodim) did not control. If black-grass is still present, and growers were unable to travel before Christmas, Kerb can be applied up until the end of January and Crawler (carbetamide) can be applied to the end of February.
There are the usual charlock populations to contend with, some Fox (bifenox) applications were made after we had a couple of frosts at the end of November, while others are holding off, waiting for some proper old fashioned minus temperatures which should put a stop to bolted plants. Fertiliser applications to oilseed rape crops often begin in February, but with such forward crops, these early applications may not be needed and we will be taking green leaf area measurements to assess the crop requirements.
Black-grass and brome control in cereals will be carried out when the weather warms up in early spring and as good growing conditions will aid efficacy. These applications will also take out any broad-leaved weeds which have come through since pre/early post-emergence sprays were applied in the autumn. Some applications were made during the mild temperatures of October, in situations where black-grass plants had not taken up residual herbicides due to dry conditions during or just after drilling and the weeds had started tillering.
On stubble ground, with the mild conditions, black-grass, brome and rye-grass populations have become established early. Stale seedbeds are important to start off with a ‘clean slate’ for spring-sown crops, so ground will be getting two or three litres/hectare of glyphosate depending on weeds present.
Barley crops are looking a little anaemic which is largely due to waterlogging and some residual chemical uptake, but they should grow away from this well in the spring and some early nitrogen could help.
Often, if the weather allows, we will begin to see the first crops of spring beans planted in February, so recommendations will be made for pre-emergence herbicides, which prove to be a vital part of the herbicide strategy for spring beans due to the lack of cost-effective post-emergence options.