This week we have started spraying in earnest; pre-emergence sprays on spring cropping and clopyralid based sprays (e.g. Galera) on the rapeseed are close to completion. Mesosulfuron + iodosulfuron (e.g. Atlantis) applications on wheat have also begun in ideal conditions.
On cereals, disease development over winter has been slow due to the cold conditions. However, septoria is present on the lower leaves of all varieties; its rate of development during the season will depend on varietal resistance, temperatures and rainfall especially during April to June.
We are finding yellow rust in Oakley crops. On wheat’s scheduled T0 sprays can begin soon, ideally these will be timed 2-3 weeks ahead of the T1 fungicide timing (leaf 3 50-75% emerged, usually the 2nd -3rd week of April).
In many cases these will be applied with the first split of chlormequat. Thinner, later drilled crops can receive a single chlormequat application at the T1 fungicide timing.
Chlormequat applications can be applied at the onset of stem development (ear at 1cm) as these aim to strengthen the tiller by shortening the distance between the lower stem internodes. Chlormequat works best following warmer nights (above 6C) and humid days.
Winter barley T1 fungicides and early plant growth regulators should be applied at early stem extension. Spring herbicide control in barley should be completed before the crop meets in the row and shades the target weeds.
Warming temperatures, light rains and the recently “washed in” nitrogen have accelerated growth, whilst increasing day length drives crop development forward. In general winter sown crops are looking very healthy and even, perhaps with the exception of an occasional late drilled or rabbit damaged cereal but even these are now growing well.
Symptoms of manganese deficiency have been widespread this season, often exacerbated by the frosts; Puffy soils prone to manganese deficiency should be rolled before stem extension and generous doses of manganese should be applied to correct any deficiencies as soon as possible.