Archive Article: 1997/07/19

19 July 1997




The show, trials and open day season peaks this month. The Crops team reports from the Royal Show, Arthur Rickwood EHF, and agchem distributor

open days across the country.

RAIN, rain and more rain; no wonder the talk at the Royal Show among arable growers was whether or not their cereals were still standing.

Lodging in NIABs wheat variety plots was in line with cereals specialist Richard Fenwicks expectations – confirming the standing power scores.

Although he wasnt surprised at the extent of lodging, Mr Fenwick thought many growers might have had a nasty shock – because theyd forgotten to take standing power scores into account. "Weve been lulled into complacency by the lack of lodging over the past few seasons," he said.

Reaper, with a rating equivalent to Hussar at 6, is a case in point. "Growers are aware Hussar can lodge because it was around in 1992, the last time there was a lodging year. But Reaper has the same score – so they shouldnt be surprised to see it going over now."

Riband, Consort, Buster, Hereward and Equinox were all standing well in NIABs plots – reflecting their scores of 8-9. Varieties looking the worse for wear were Rialto, Hussar, Crofter, Harrier, Maverick, Reaper, Mercia and Spark.

There were some surprises for Mr Fenwick: Charger was still upright in spite of a score of 6; and Soissons and Caxton were showing more lodging than their rating of 7 would suggest.

A tree adjoining the plots had encouraged some varieties to grow taller than normal, weakening the straw. For this reason he was reluctant to draw conclusions about Abbot and Chaucer.

However, Cantata was "going over a bit", and Savannah looked "fine, with a stiffness similar to Brigadier".

THEN AND NOW

JUST how far has wheat production come in the past twenty years? In yields, about 3-4t/ha (24-32cwt/acre).

Its down to better disease control and stiffer, shorter, high performance varieties, with larger ears and a more erect flag leaf, according to Keith Norman, of farming company Velcourt.

But disappointingly, todays varieties are not that much better on disease resistance, he suggested.

This point was illustrated at the Royal, where two wheats from the Seventies (old favourite Maris Huntsman and breadmaker Maris Widgeon) were grown side by side with current varieties Rialto and Consort. The untreated plots showed that Rialto and Consort fared somewhat worse than the old wheats against disease. Mildew and septoria were rife, and had reached the ears.

Grown under a 1970s-style programme – nitrogen, two fungicide applications of triadimefon (Bayleton) and tridemorph (Calixin), Cycocel, and IPU/CMPP autumn herbicide – all varieties showed some lodging, with the taller old varieties Maris Huntsman and Maris Widgeon going over at an earlier stage.

Disease control with these older products was "hopeless", said Mr Norman. "Although there was some good knock down, these fungicides just dont have the staying power we need today."

Controlling disease with the help of the latest fungicide products had also proved difficult. Despite early cyprodinil (Unix – not yet UK approved), then the new strobilurin kresoxim-methyl (Ensign) at T1 timing and finally epoxiconazole (Opus) at flag leaf/T2 timing, the treated plots werent completely clean. Septoria was still present.

"It appears that Ensign has a bit of a weakness against septoria," said Mr Norman. "It hasnt done as good a job as wed expected, particularly at the bottom of the canopy."

PESTICIDE CLEAN UP

BACTERIAL slimes could be used by growers in the future to clean up pesticide washings, according to scientists at the Scottish Agricultural College (SAC).

Dr Mike Hocart is aiming to identify bacteria which can digest pesticides, and then produce a concentrated form of these bugs.

The idea is that a bottle of such friendly bacterial slimes, thrown in to a holding tank for pesticide washings, could reduce potential pollutants to acceptable levels. Growers then could allow the digested pesticides to enter into a reed bed – to clear out the final residues.

Reed beds have been harnessed to clean up pollutants in a host of industries. Marsh plants such as reeds provide the perfect environment for encouraging pesticide-digesting bacteria. Its all the better if the reed bed is established on gravel, since there is a larger surface area for the bacteria to act on.

SAC research has focused on atrazine. Because it is not affected by this herbicide, yellow iris has been shown to be better suited to reed bed use than other marsh plants.

Although the work has concentrated on atrazine, Dr Hocart is confident that suitable bacteria could be identified, and encouraged by appropriate marsh plants, to break down most pesticides.

BREADMAKING QUALITY

MILLERS, plant breeders and ultimately growers could benefit from new research being conducted by the Food Research Institute.

Analytical tests, such as hagberg and NIR spectroscopy, show that a breadmaking sample conforms to a certain specification, but they will not guarantee good milling performance.

So, rather than relying on empirical tests to determine breadmaking quality, researchers are now using monoclonal antibodies as molecular probes for breadmaking quality.

Dr Mike Morgan explained: "We are harnessing technology that is widely used in clinical medicine. It is just a matter of identifying the antibodies and antigens responsible for breadmaking quality."

A collection of such antibodies which recognise quality-associated wheat proteins can then be used to produce a rapid and sensitive test for millers to help identify flours suitable for breadmaking. Or indeed help plant breeders isolate varieties suitable for this market.

FRI researcher, Dr Sally Francis pointed to yet another use, that of testing the crop in the field to identify a shortage of sulphur or nitrogen.

Both are vital for breadmaking protein quality before harvest. "It would make it possible for growers to know when to boost the protein quality of their crops by applying a final N application," she said.

MANGANESE THREAT

MANGANESE deficiency is a widespread threat to wheat on fertile organic soil. "The black fen is manganese deficiency country," says ADASs Mark Dewes.

"Organic matter in soil locks it up. Symptoms in wheat include pale and limp foliage, and failure to tiller properly. Weakened plants are vulnerable to wheat bulb fly attack and frost damage."

Fen farmers usually spray manganese sulphate but this year researchers at ADAS Arthur Rickwood in Cambridgeshire, wanted to see the effects of manganese in sulphate, nitrate, and chelated forms, and as manganese oxide granules applied pre-drilling and as a seeddressing.

Symptoms in November-drilled Riband appeared shortly after emergence. The first sprays were applied in late January and kept the crop trouble-free until late March when four follow-up sprays were needed in five weeks. In untreated plots the plant population was halved.

"Evidence from this trial shows there is little benefit from granules or seed dressings in the fens and, due to cost, the cheap sulphate treatment cannot be beaten," Mr Dewes said.

Tillering ability needs to be considered when selecting varieties for rich peat. Wheat produces between nine and 14 leaves and for each one after leaf 3 a tiller is produced.

So there is huge potential for compensation in a thin crop. ADAS and NIAB are looking at tillering ability of varieties to see what effect it has on the lodging risk.

Growers struggle for yield but have little difficulty producing milling samples. But fen wheat is prone to mildew and poor finishing with low grain bushel weight so ADAS recommends copper to boost finishing.

"The mildew risk is high, particularly where trace element deficiencies occur," says consultant Jon Bellamy. "In an HGCA-funded trial we have found nothing good enough to provide proper protection as a single spray.

Ensign is as good as anything for a single treatment, but due to disease pressure a programmed approach is needed, with the first spray no later than GS32."

Last year high numbers of migrating Silver Y moths blown in on strong southerly winds from the Continent damaged beet. They laid eggs and after hatching larvae stripped leaves.

"Eggs were found earlier this season which shows the pest has successfully overwintered here," said Rickwoods Mr Saunders.

"Beet growers need to check crops carefully and apply a pyrethroid insecticide when caterpillars are seen feeding on upper surfaces of leaves."

To give early warning of attack a sex pheromone-trap baited to attract males is being tested. Lots are being caught so crops are vulnerable.

VARIETY VERDICT

SHOULD I try Equinox or Charger, or play safe and stick with Brigadier? With a NIAB regional trials site in its patch, Bartholomews of Chichester is fortunate enough to have first hand variety information at its fingertips to answer such questions.

Crop protection sales manager, David Andrews, was one of the first to recognise the qualities of Brigadier and plumped for it when most went for Hunter and Hussar. This autumn he is expecting to promote Charger, which yields similarly but has some breadmaking quality so may fetch a premium of about £5/t. "Charger has yielded excellently even after sowing late, it stands well and has good disease resistance. But best of all, the hard milling variety has more than one use, and is popular with European millers," he explained.

Of the breadmakers for the UK market, the companys money is on Abbot with its 5% yield advantage over Hereward and better disease resistance. Of the other contenders for full recommendation, it is interested in feed wheat Equinox with its good yield and high soluble carbohydrate content.

"Equinox looks promising for our light land growers because it produces thicker stems which can withstand drought more effectively. That should be of benefit in dry seasons," says Mr Andrews.

With only one crop of sugar beet in Bartholomews territory, theres not much demand for imidacloprid (Gaucho) to control virus yellows. But that active ingredient may be in demand once it has approval for use in cereals to control barley yellow dwarf virus, believes Mr Andrews.

"The aphids which spread BYDV first appeared in this area, and our local climate encourages high activity. We often have to recommend spraying three times in the autumn. On the basis of what Ive seen in our trials, I would advise growers to use an imidacloprid seed treatment instead, particularly for barleys sown before the start of October," he says.

Bayers technical support manager, David Clark, hopes imidacloprid will be approved for cereals by autumn 1998. French growers have found they can drill much earlier without risk of BYDV using a seed treatment with imidacloprid.


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