What produce requires the most pesticides and chemicals? Answered!

Here is the second post in a series of discussions about Sustainability and Organics, helped out by my Dad, Dave. If you have a question you might like answered, or something in this area that you are unsure about, ask!

 
Lorraine from Not Quite Nigella asked
Which Fruit &Veg require the use of the most pesticides/chemicals?

This is a really broad questions and pretty difficult to answer as the amount of chemicals used depend on many factors including whether the produce is being grown in season. Out of season vegetables generally require more chemicals and pesticides. Although the question is very broad, it is still really important, so I am just going to focus on two items: Celery and Tomatoes.

Both of these foods are commonplace, items that we probably don’t think much about when we put them in the shopping basket, and they can’t be peeled. Dad describes celery and tomatoes as being ‘luxuriant foods’. Hold on, what? Celery, luxuriant? Surely not. I had to think about this for a moment, but now I see (after it was explained to me .

“We want our celery wet and crunchy. We want our tomatoes to be pumped up and ripe.”

True! I see now, but how do we get these crops luxuriant? The answer is lots of water (eep!) and lots of Nitrogen. Nitrogen is one of the three major plant nutrients and is essential to healthy plant  growth. To get Nitrogen into the plant it must be present in the soil, but how do you get Nitrogen into the soil? “Soil mirco-organisms capture Nitrogen  from the air and store it in Nitrogen fixing plants, like legumes. These plants use some of the Nitrogen for themselves, but they store a bit more then they need. By growing a whole cover crop of legumes and harvesting them at the right time, enough Nitrogen is deposited in the soil to grow a crop of vegetables. This solution gives the soil a break between vegetable crops, but it means that there is no sale-able crop grown on that plot for an entire season. The way to get around this problem, and not lose a crop  is to use Urea.

Asparagus Spear with cover crop behind it

Urea is a Nitrogen Release fertiliser. It is requires a lot of oil to make, and transport, and using it actually lessens the soil fertility and health. 

Growing the cover crop increases health a benefits soil structure but lessens profitability. Hmm.

Back to our tomatoes and celery. When Dad grew celery conventionally, his plot was completely covered in celery and chicken shit with no bare ground (sound delicious?). It was kept very damp, perfect conditions for fungi and bacteria to grow. As the crop matures the plot is completely covered in metre high celery, so you can’t get in to look for pests and diseases. So, lots of pesticides are used to produce a sale quality product.

“Tomatoes are attractive to nearly every pest and disease known to mankind. The parts of the tomato plant that are most attractive to pests and disease are the roots the stem the branches the shoots the leaves the flowers and the fruit.”  Again, lots of chemicals are required to produce blemish free fruit which we would buy in the shop.

Freshly picked Rhubarb, bunches. (Check out the farmers hands!)

The solution: grow your own. Growing your own tomatoes ensures that you get specimens with a full flavour, something that is of often missing with those that are store-bought. Also, many of the diseases that affect tomatoes are soil born, and therefore more likely that your backyard will be free from them. If you buy your food from a shop it has to be harvested up to a week before you get to eat it. Also, the vegetables are often bred for bench-life and ability to travel as opposed to taste. Dad makes a really good point here;  for store-bought produce “Availability comes before taste.”