The price is right for blight control

UK - June 07, 2005

The average cost of a total potato blight programme from rosette stage to desiccation last year was £148/ha, equivalent to only 7% of the total growing costs, according to new independent research of farmers and advisors conducted on behalf of Dow AgroSciences.

"A robust and effective potato blight programme is a necessary investment, bearing in mind that this disease can cause up to 40% yield loss and severe problems of tuber quality.  If you are unfortunate enough to get tuber blight in your crop, the cost of grading out is around £15 per tonne, which far outweighs the cost of any good preventative spray programme.  Survey results showed that growers and advisors were much more concerned with performance than with price.  When asked what they considered to be the most important feature of a blight fungicide, 65% of respondents said that efficacy was the most important.  A further 39% said that persistence was the most important feature.  Price was mentioned by 35% of respondents and rainfastness by 28%," reports John Sellars, Marketing Specialist from Dow AgroSciences.

The cost of a blight programme is relatively small when compared to the detrimental effects of the disease and the overall costs of growing the crop.  The survey gave a wide range of costs for a complete blight programme from as low as £60/ha to over £250/ha, but the majority was between £130-£160 per hectare.  The Farm Management Pocketbook 2005, by John Nix, reports the cost of potato seed being £525 per hectare, fertiliser £225 per hectare, total sprays £425/ha, casual labour for grading and harvesting £675/ha and sundries such as the levy and sacks £400 per hectare, which comes to a total variable cost of £2,250 per hectare.  The least expensive blight programme would be a mere 3% of this cost, whilst the most expensive 11%, with the average being only 7% of the variable costs, " says John.  

Potato blight is a major threat to the potato crop and growers are prepared to use a robust and effective blight programme to keep their crops clean.  In British Potato Council trials, the Belchim/Dow AgroSciences manufacturers' programme, consisting of two treatments of Epok (mefenoxam (metalaxyl-M) plus fluazinam), followed by Electis (zoxium + mancozeb) alternating with Ranman TP (cyazofamid plus adjuvant) up until desiccation, gave the best control of foliar and tuber blight.  It makes sound economic sense to use the best programme you can, as the true costs of reduced yields, lower quality sample and grading out are far more critical to the bottom line," reports John Sellars.