North: Crops using up available nitrogen
Despite some cold nights earlier in the month the generally milder weather has allowed winter crops to grow on quietly. Winter barleys and some oilseed rape crops are starting to look as if they have used up all the currently available nitrogen.
However, with the NVZ start date passed and with the ground being on the whole fit to travel, there is an opportunity to apply the first top dressing of nitrogen plus s
Winter barleys, in addition to nutritional stress, are also carrying various levels of disease dependant on variety. Mildew, net blotch and rhyncosporium have all been spotted. A T0 spray will pay dividends. This need not be too complex as long as there is a mix of actives to counteract the possibility of fungicide resistance build up.
Light leaf spot is present in many oilseed rapes. However, those not sprayed in the autumn will have been treated in the past week or so. The next critical timing will be the “welly boot” spray when consideration may have to given to growth regulation in conjunction with a fungicide.
Green Area Index calculations in wheat have indicated that there appears to be sufficient nitrogen in most crops for the present and certainly they look that way for now.
As suggested last month attention to detail with growth regulation in wheat this season may be critical. Weeds in late sown, untreated wheat crops will be more of an issue right now. Most weeds, particularly annual meadow grass, will be past the stage of being controlled with residual herbicides and various mixtures of contact materials may have to be considered.