Arable News

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Field Focus – October 2014

Crops are emerging well for our Field Focus agronomists.

Our three agronomists all agree that harvest was good, to very good, in places as autumn drilling and treatments get into full swing. Dominic Kilburn writes.

 Notts and LincsWinter wheat yields at harvest were outstanding, said Nottinghamshire-based AICC and Arable Alliance agronomist Andrew Wells. Those with free-draining soils on limestone or sand and gravel have probably had the best harvest in a decade, he commented.

Main varieties such as Santiago and JB Diego have performed much as expected, he noted, while others such as Evolution, which come with additional disease resistance, he hoped would take a larger share of the market for this autumn’s drilling.

Oilseed rape achieved a “good average”, winter barley yields were good but variable, and while spring beans were just above average in yield, their quality was exceptionally good, he said.

Speaking in mid-September, Andrew said that all oilseed rape drilling had been completed and most of the crop had established well. “As things are at the moment some oilseed rape crops need a bit of moisture, although that could have changed by the time this article lands on the doormat.”

Andrew said that monitoring for flea beetle will be a priority for the next few weeks, although his primary concern (due to the loss of neonicotinoids) is the threat from the aphid-spread virus turnip yellows (TuYV). “Numbers of aphids are also low at the moment and I’d rather not apply Plenum (pymetrozine) as it’s quite expensive, although it’s about the only option we’ve got if aphid numbers reach the required threshold for spraying.

“Even then it doesn’t offer long term protection of the crop,” he added.

Continuing with oilseed rape, Andrew said that it will be important to get good control of grass weeds in the crop this autumn. A Falcon (propaquizafop)-type product will be applied first to take out volunteer cereals and, then, for black-grass, Centurion Max (clethodim) will be considered when the crop and black-grass are at the (minimum) 4-leaf stage.

“Ahead of that application though I will want some moisture,” said Andrew. “I tried some clethodim quite early last year when conditions were dry and it was quite disappointing compared with later applications. There’s enough black-grass out there for it to be of concern and we’ve got to do a good job on it in oilseed rape this time around.”

Andrew admitted that one of the big challenges this autumn is trying to hold back growers from drilling their winter wheat too early. “In reality, they will look at the weather forecast and make a judgement on completing drilling while soil conditions are still good.

“However, for those that are drilling earlier, if the dry weather continues they will also have to make a judgement on when pre- and peri-emergence herbicide applications are made, on a day-by-day basis,” he suggested.

Ahead of the main winter wheat drilling programme, Andrew reminded growers that seedbed quality was a priority; both fine and firm seedbeds required to provide pre-em herbicides the best opportunity to be effective. In addition, when spraying, growers and sprayer operators must focus on detail such as reducing their forward speed, use of forward and backward facing nozzles (with a fine spray) and minimum water volumes of 150 litres/ha.Northamptonshire AICC and Indigro agronomist Damian McAuley advises growers in the east Midlands. Also speaking in mid-September, Damian said that, overall, cereal yields in the region had been excellent, despite the fact that black-grass had been a season-long concern. “In the spring I was assessing areas of black-grass infestation to see if they were viable and, although many looked bad from a distance, the wheat stands beneath were often surprisingly good. On closer inspection there didn’t seem to be quite such high black-grass plant populations, but large numbers of tillers, and so I don’t think the yield penalty in wheat was as bad this year as it has been in other seasons,” he reasoned.

“We managed some good black-grass control last autumn with both residual and contact material but what was left was able to tiller throughout the warm, open winter and had more of a visual impact than a yield limiting one.”

Oilseed rape looked phenomenal all last season, he continued, with excellent crop growth, little pigeon damage and low visual disease levels in the spring, and yet final yields didn’t quite live up to expectations.

“Verticillium wilt was probably the reason the crop suffered a bit. I saw a lot of it in senescing crops and post-harvest stubbles last year and while there isn’t a lot of information on varietal resistance to the disease, we have to consider growing more varieties which show some tolerance to it.

“The AICC has recently published some excellent trials data on varietal susceptibility to verticillium which is the key way forward in terms of dealing with the disease,” he added.

In terms of new season crops, slugs are currently quite problematic in oilseed rape, particularly on the heavier land where there is high pressure. Metaldehyde-based pellets have been applied for the majority of treatments although ferric phosphate is the choice where there is a potential risk of contamination to a watercourse. “I’ve been quite impressed with the levels of control from ferric phosphate-based pellets – it might be more expensive but it is doing a good job,” he stated.

With OSR crops at variable growth stages, Damian is keeping a look out for flea beetle damage on the more vulnerable and less well established, post-August planted crops, and pyrethroids have already been applied where spray thresholds have been met.

For black-grass control in OSR, he pointed out that clethodim (as in Centurion Max) provided some effective control last season, while reminding growers ahead of treatments this autumn that best practice advice is that no other chemical applications should be made to the crop 14 days before or after its application, and it should be applied with no other mixing partners – not even water conditioners.

He estimated that winter wheat drilling would be under way by 25th September in less black-grass prone fields, but he warned that, in terms of pre-em herbicide treatments, there were concerns over sufficient availability of both flufenacet (as in Liberator and Crystal) and Avadex (tri-allate) supplies.

*Damian can be contacted on email: [email protected].

 

Western England Further west, harvest was “average to above average”, said Herefordshire-based adviser Antony Wade. As in other parts of the country oilseed rape was a little disappointing but only because crops looked so well all season but yielded 3.5-4t/ha rather than the expected 4.5-5t/ha, he stated.

“Wheats were the reverse whereby we thought they would suffer because of the high disease pressure earlier in the season but, in the end, they yielded well,” he pointed out.

“Winter barley was probably the highlight of the crops being the most the consistent in terms of yield,” he added.

Antony said that hybrid winter barley variety Volume yielded a little higher than conventional varieties – probably 0.5-0.9t/ha more – but pointed out that 1.5t-2.0t/ha additional yield was needed to justify the extra cost of the seed. “Volume’s specific weight was a little low this season and, in one case I know, a grower had to blend it with Cassia to meet the required specification.”

The last of the oilseed rape was drilled by the end of the first week in September and he was keeping an eye out for expected news of insecticide Biscaya’s (thiacloprid) registration for autumn use on aphids with incidental control of flea beetle. This could provide growers with an alternative (or additional) product to Plenum, which can only be applied once in the autumn, he said.

Antony reminded growers that on-farm stocks of flusilazole, for phoma control in OSR, must be used up by 12th October. “Light leaf spot is very much on the radar now in this part of the country and it’s perhaps one of the reasons why yields were not quite as good as expected last season,” he continued.

“Proline (prothioconazole) is probably the best treatment for light leaf spot but I think availability again is tight for this autumn.

“Refinzar is a new product from DuPont for phoma and LLS, and we’ll certainly have a look at that later in October,” he added.

*Antony can be contacted on 07973243590 or on Twitter: @HTSagronomy


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