We’ve reached the time of year when spraying opportunities become few and far between. A marked difference in ability to travel fields can be seen depending on crop, cultivations, local rainfall and field drainage. Whilst some farms remain confident of being able to continue spraying, others are finding conditions preventing them from travelling land again until springtime. Therefore, planning recommendations and product requirements has necessarily become a far more flexible process over the past few weeks.
Wheat is a prime example; programmes range from tri-allate, an early residual spray and autumn blackgrass product all applied, to crops as yet un-treated. Where this is the case there is understandably concern about the increasing growth stage and size of weed populations in ongoing mild weather.
Where possible, and populations of blackgrass advanced, the window for application of Atlantis (iodosulfuron + mesosulfuron) and a residual tank mix partner is still open. This comes with several caveats: weather and soil temperatures must be monitored to ensure active weed growth at application, nozzle choice and water volumes discussed, and day to day decisions made as to suitability to spray a small target with a dry leaf. Increasing numbers of broad-leaved weeds such as speedwells on untreated fields have also come into consideration as autumn control is far more effective than waiting until spring.
Cereals – barleys in particular – are showing considerable yellowing, particularly to overlaps and waterlogged or compacted areas. As long as it is mild, barley yellow dwarf virus (BYDV) insecticide applications must continue – consider tank mixing a manganese nitrate product before winter, particularly to land prone to deficiency. Delayed spring applications due to poor weather can be too late for some crops, and an application now helps crops growing under stress. Diseases can be found at low levels in both wheat and barley. Crops need monitoring, but treatment will only be required where infection levels are high.
Whilst we are still able to consider at Atlantis on wheats, it is early for propyzamide applications to oilseed rape. The decision to spray has to be made taking into account the actives reduced half life in mild conditions versus its target blackgrass plants’ ever increasing size and strength.
Winter Beans are emerging well alongside blackgrass on prone land, even where several stale seed-beds were achieved pre-planting. Post-emergence carbetamide and graminicide mixes are another plan to add to the list of weather dependent spray jobs.