A current exemption in UK law, commonly known as "grandfather rights", allows anyone born before December 31, 1964, to spray Plant Protection Products (PPPs) authorised for professional use on their own or their employer's land, without having a certificate of competence.

That all comes to an end on November 26, 2015 when everyone will have to be properly trained and possess a certificate.

In my ignorance as a young man, I never wore protective clothing, which was unheard of in those days. Driving a tractor with no cab, I sprayed with my shirt-sleeves rolled up on hot days!

Although I stopped spraying about ten years ago, I remember being alarmed by an EU report in 2005 that strengthened suspicion that pesticides can cause Parkinson's Disease.

The "Geoparkinson" study was published in the New Scientist and involved nearly 3000 people.

Headed by Anthony Seaton of Aberdeen University, the research found farmers were 43% more likely to develop Parkinson's because of their high exposure to pesticides.

There are other examples of the dangers of some pesticides with sheep dips an obvious one.

Dipping involves immersing sheep in a solution of pesticides that soak the fleece and get absorbed by the lanoline-rich grease next to the skin. They then protect the sheep from external parasites like lice, keds, ticks and sheep scab mites.

Dips also keep head-flies at bay and bluebottles, whose eggs hatch out into maggots that can literally eat a sheep alive.

Sadly, we never fully appreciated just how dangerous some of the pesticides were.

Aldrin, deildrin and DDT were all effective sheep dips that were so deadly they had to be withdrawn from use. DDT entered the food chain and caused infertility in birds of prey.

They were followed by organophosphate (OP) dips that had been developed from nerve gas used in the Second World War. Figures released in 1993 showed that between 1988 and 1992, 450 UK farmers and farm workers became ill after exposure to OP pesticides in sheep dip, and a number went on to suffer from serious, long-term, ill-health.

As a result of those alarming statistics, it became illegal from April 1995 to sell OP dips, except to holders of a Certificate of Competence. That certificate was granted to those who had passed an examination following an approved training course.

Recent amendments mean that the certificate is also needed to purchase synthetic pyrethroid sheep dips.

Dipping sheep nowadays involves wearing special protective clothing, gloves and face masks as opposed to the jeans and T-shirts I wore as a young man. No wonder some of us became seriously ill.

It's easy to be wise with the benefit of hindsight and today's better understanding of how deadly some of the pesticides we use in farming are.

An EU ban on the use of neonicotinoids will come into effect on December 1 after experts said they posed an "acute risk to bee health".

They have been widely used in seed dressings for maize, oilseed rape and sunflowers to control pests such as virus-carrying aphids and cabbage stem flea beetle. Farmers will now have to find alternatives.

This year has been a good year for leather jackets, the larvae of Daddy Long Legs that nibble crop seedlings and grass, and can lead to crop failure.

When larvae numbers reach one million per hectare they can nibble as much as 2.5 tonnes of dry matter per hectare, and that's when farmers spray pesticides.

Sometimes, large flocks of rooks or starlings get there first and feast on infested fields, devouring most of the pests. It's that type of natural pest control that we need to encourage.

Some arable farmers leave wide margins of uncultivated land round the edge of their fields, or strips through the centre. These are known as beetle banks and are a haven for useful bugs like ladybirds that eat aphids.

Then there is the work being undertaken by Rothamsted Research in Hertfordshire to develop genetically modified (GM), aphid-resistant wheat. The GM wheat produces a naturally occurring pheromone that not only repels aphids, but also attracts their natural enemies, such as ladybirds and wasps.

Currently a significant proportion of the UK wheat crop is sprayed with insecticides to control cereal aphids, which reduce yields by sucking sap from plants and transmitting barley yellow dwarf virus.

Unfortunately those sprays kill other beneficial species of insects as well, and consequently damage ecosystems – and then there is the question of whether they are really safe for humans to use?