Spring fungicide and herbicide treatment recommendations are a priority for our agronomists this month
Spring fungicide and herbicide treatment recommendations are a priority for our agronomists this month as crop growth continues apace in the mild conditions experienced so far this year. Dominic Kilburn writes. North Yorkshire
Yorkshire Arable Advice and AICC agronomist, Andrew Fisher says that his region fared OK in terms of winter rainfall which he estimates was 40 per cent above normal and while fields have been too wet for spring work until recently, winter crops are looking in very good condition. The only slight concern, he notes (speaking in mid-March), is with some oilseed rape crops that are already knee height and with reports of snow arriving by the end of the month, there is concern. Snow has been mentioned as potentially arriving before the end of the month which could knock over a lot of crops already at an advanced growth stage. It happened to us about 15 years ago and I dont want it to happen again, he stressed. Andrew says that he is trying BASFs new plant growth regulator, Caryx (metconazole + mepiquat chloride) for the first time this season on oilseed rape. Most of the forward crops will benefit from being held back a bit, he suggests, adding that levels of phoma and light leaf spot are generally low at the moment. With soil N mineralisation taking place for most of the winter due to the mild conditions, wheat and oilseed rape have taken up sufficient quantities of nitrogen to date. As a result, well be holding off with the N applications as long as possible, he added. Andrew says that T0 fungicides applications to wheat are to begin towards the end of March Cherokee (chlorothalonil + cyproconazole + propiconazole) the choice in the majority of cases, with Poraz (prochloraz) in the mix for eyespot-susceptible varieties. Theres a little bit of yellow rust showing in Robigus but not in Oakley as yet, and Cherokee will deal with that, Andrew suggests. Looking to later fungicide programmes on wheat, Andrew says that he is not 100 per cent convinced that there is a place for SDHI chemistry at the T1 slot in April, although certainly at the T2 timing if the disease pressure dictates. There is a cost factor with SDHIs but also I would prefer to use them sparingly where I can careful not to over use them initially. With spring cropping in full swing, spring beans have gone in the ground this month with a pre-emergence herbicide spray to get them off to a clean start, while some grassy stubbles are being sprayed off in preparation for spring barley. Were also doing some tidying up with herbicides on about 10 per cent of fields which were mostly late planted with wheat and where we havent been able to get on the land until now. Meadow grass, some brome and black-grass are being targeted with either Atlantis (mesosulfuron + iodosulfuron) or Othello (mesosulfuron + iodosulfuron + DFF). *Andrew Fisher can be contacted via email: [email protected] or tel: 07836 711918. East Midlands Spring drilling is well underway in the East Midlands, said Arable Alliance and AICC agronomist Andrew Wells (left), with good progress having been made with spring barley, sugar beet and spring beans recently. Looking back at the winter months, and as was the case further north, above average rainfall occurred but not to excessive levels. Andrew commented that patience was required when working some of the heavier soils in preparation for spring crops over the past few weeks, and that some min-tilled land has been a little tighter to work than normal because of a lack of frosts during the winter. Aside from that, soils are in good condition, he claimed. Andrew noted that both oilseed rape and winter wheat continued to grow throughout winter with some of the wheats now very green and well tillered, while there are oilseed rape crops with very large canopies. I will be looking to hold back on early nitrogen dressings in OSR, but, because of the forward state of many crops, we are having to make the decision to apply nitrogen earlier than we would like as we are running out of time in terms of getting the disc spreaders through the crops. PGR programmes are on-going in oilseed rape on the more forward crops; tebuconazole has been applied for growth regulation and light leaf spot control, and this will continue as crops reach the rapid stage of stem extension, explained Andrew. Five-spray strategy Speaking earlier this month, he said that he was writing spray recommendations for rust control in wheat for T -1 mid-March applications onwards, using cyproconazole or tebuconazole for rust control and adding manganese as required. In early April a T0 application will include chlorothalonil in a triazole mix, while, looking further ahead, a T1 is planned to follow at the end of April, or even in early May. Im planning a five-spray fungicide programme this season on rust susceptible wheats, of which there are many, and Im committed to ensuring there are no gaps between the timings as thats when the problems occur. The T -1 wont cost any more than 5/ha but it does mean that if T0 is delayed, or there are difficult spraying conditions, then crops wont be a mess come April. Andrew pointed out that yellow rust was very prevalent in crops during March. Pre-emergence herbicides for black-grass control are also being applied to recently drilled crops such as spring wheat, with Andrew seeing more use of Avadex (tri-allate) in some situations; one advantage being its increased efficacy compared with alternatives should prolonged dry weather occur.