6 August 1999

Fertiliser additive claims consistent rise in yields

A novel fertiliser additive

claimed to boost potato

yields is attracting growers

aiming at various markets.

Edward Long reports

AFTER FTC-1 brought yield increases of up to 15% in East Anglia last year, Dalgety Arable made it more widely available this season.

Developed in the US, its source is a commercial secret. But it is classified as a fertiliser and contains no hormones or "muck-and-mystery" ingredients. It is sold as a coating for blends and compounds, and as a formulation for liquids. Cost is £61.75/ha (£25/acre).

"When we were approached by the owner of FTC-1, who claimed it could boost potato yields by 15-16%, I was highly sceptical," says Dalgetys national fertiliser technical manager, Colin Barron. "So we treated a tonne of blended compound, applied it to Maris Piper and had a yield boost of 3t/acre."

Extended trials in 1996 on 17 sites in Scotland and East Anglia. "It was used on 11 varieties and gave an average yield increase of 10.5%. The following year, on 47 crops comprising 22 varieties, it lifted yields by over 15%," he says. Last year FTC-1 was launched commercially and the company monitored its effects on 155 crops. There was an 11.5%, or 6.2t/ha (2.5t/acre) lift, says Mr Barron.

"The additive encourages root development. It seems to trigger the plant into producing more roots sooner by persuading it to exploit its existing hormones better. Increased early rooting accelerates canopy development so the plant can intercept and exploit solar radiation better during the longest days of summer."

The additive needs to be applied close to the seed for early uptake. In a Cara trial this season there was a 58.7% rise in root weight seven weeks after planting compared with the untreated, he notes.

Increased rooting and shoot numbers were obvious in treated Maris Piper in Durham last year. Sap tests on a Scott Abbott Arable Crops Station crop near Peterborough showed plants took up 8.3% more phosphate, 15.3% more potassium, 48.2% more magnesium, and 10.6% more sulphur where the additive was used.

In Suffolk Levington Agriculture, found the leaf area index of Maris Bard in the treated area was 19.2% better than in the untreated, and there was an 18.9% yield gain.

"Although sap tests show FTC-1 boosts uptake of major nutrients, it is not always the same ones in the same proportion," says Mr Barron. "They seem to vary according to soil type and nutrient status. Treated crops are also better able to search for moisture in a dry time."

Root weight rise

In Marfona on light sandy loam on Elveden Estate this year a huge increase of root weight was recorded six weeks after planting where FTC-1 was used. Three plants each from treated and untreated areas, planted on Mar 10, were sampled. When they were cleaned up at Dalgetys laboratory there was a 53.3% difference between the treated and untreated. A follow-up visit in late May revealed 18.8% more green foliage in the treated crop.

More even-size tubers of right grade for range of markets

NORFOLK growers Ralph Harrison & Partners of Hall Farm, Wighton, near Wells, have used FTC-1 increasingly for the past four seasons.

The company grows 214ha (530 acres) of Lady Rosetta, Hermes, Saturna and Record for crisping.

"We tried it on 20 acres of Record in 1996, and there were noticeably more tubers a plant and a more even sample of larger tubers," says James Harrison. "The treated crop seemed full of growth all season. We harvested an extra 3t/acre compared with our normal 17t yield."

In 1997 half a 16ha (40-acre) field of Lady Rosetta was treated, and there was a similar result.

"Last year we used it on 100 acres, half Record the rest Lady Rosetta. The Record ended up with more even sized tubers and a bigger yield gain. It did 20t/acre compared with 17.5t from the untreated. But the real benefit was a higher proportion in the 60-70mm grade. There was slightly less advantage with the Rosetta." This year 72ha (180 acres), including all the Hermes, have been treated. Hermes is naturally shy to throw tubers. But after three years experience Mr Harrison is confident the root enhancer will help.

In east Norfolk R W Randall & Sons first tried FTC-1 three years ago on Pentland Dell for processing.

"We were attracted by the prospect of being able to raise tuber yield in the 50mm+ grade," says Paddy Randall, who, with brother Tom, grows 100ha (250 acres) for a range of markets.

"Half of our potatoes cannot be irrigated, so we need to boost reliability on unirrigated land. With bigger root systems, plants are better able to scavenge moisture."

In the first year the additive increased saleable yield by 5t/ha (2t/acre). So last year it was used on 80 acres of Dell with more variable results. There was a similar yield boost on 20ha (50 acres), but nothing extra from the rest of the treated crop on another field. &#42