Energy from Waste Food

February 1, 2010 · Filed Under news · Comment 

In the past, ancient solar energy stored as fossil fuel has been so cheap that there has been little incentive to find ways to waste less. Similarly, with current solar energy collected by plants, not only do we waste the energy in millions of tonnes of waste food that goes in to landfill, but the methane gas given off – unless collected – is a very powerful greenhouse gas.

 

There are now encouraging signs that this is starting to change. A fantastic example is the potato packing and processing plant belonging to Fenmark in Cambridgeshire. Their new anaerobic digestion unit will divert thirty thousand tonnes of food waste each year from landfill to generate electricity and provide heat for water and space heating with the by-product sold as a soil conditioner.

 One small step towards food security.

Pesticides – the Pests fight back

May 17, 2009 · Filed Under news · Comment 

Over the past 60 years, food production has kept up with the population explosion partly due to the oil based pesticides that control diseases, insects and weeds. But now the whole world depends on the continuous development of new pesticides that are effective against pests that have become resistant to existing pesticides through selection. We kill most of the targeted pests but in time, the most resistant organisms survive the pesticide and pass on their genetic traits to their offspring.

These resistant offspring have less competition and become dominant. It’s man made survival of the fittest and can happen very quickly.

An example of the way we are losing the chemical war against pests is blight in potatoes.

In England in the late 1950’s, most potato varieties were fairly resistant to blight and were not usually sprayed with fungicide. Then farmers began to use a single application late in the growing season to keep the crop growing for a few weeks longer and thereby increase yields. We then began to apply odd sprays earlier in the season if there was a period of warm moist weather that favoured the spread of blight.

It seemed to many of us that blight was beaten, but instead we caused it to evolve quickly. The stronger strains that had survived now needed spraying every three weeks to keep the crop healthy and better fungicides needed to be constantly developed to keep on top.

We have now reached a situation that farmers of 50 years ago could not have imagined, this year we are being advised that we should start spraying as soon as the crop has emerged and then apply a spray every 7 days for the rest of the season, dropping to every 5-6 day intervals in high risk periods. This could mean up to an unbelievable 18 fungicide applications. How much worse can it get?

The new blight populations are more aggressive and more severe at lower temperatures and are more difficult to control. In just 3 years, the A2 Blue 13 strain, which is present right from the start of the season and completes it’s life cycle faster, has become the dominant strain across Britain.

Farmers are being told to use a combination of different fungicides in a robust programme to attack the blight pathogen at various points in it’s life cycle to reduce the risk of an evolving strain developing complete resistance to these fungicides.

Potato blight is just one example of the ongoing battle that pests seem to be winning. A few years ago, septoria tritici fungal populations in cereals became resistant to the highly effective strobulin fungicides. If alternative fungicides had not been available, we would have seen big reductions in yield.

The big danger is that our use of pesticides will cause the selection of a super strain of disease in a major crop such as wheat for which we do not have an effective pesticide. This could spread rapidly causing big yield losses or even crop failure and therefore food shortages.

Just another reason why our food supplies are on a knife edge and we are getting closer to Peak Food.

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