Youâ€™ve probably heard of the â€śDirty Dozen,â€ť a list of 12 fruits and vegetables named annually by the Environmental Working Group (EWG) to be the most laden with pesticides. The US advocacy groupâ€™s message is that people can limit their exposure to pesticides by buying these 12 products from the organic aisle. Toddler favourites are routinely among the top offenders, and this yearâ€™s list, released in March, is no different: strawberries and grapes are named as pesticide peddlers. If youâ€™re pregnant or parenting little ones, the list could drive you to buy these foods organic, or, at the very least, feel guilty for eating the non-organic variety or serving them to your kids.
But is it really necessary to buy strawberries and grapes in the organic section? Is it actually safer?
Combating pests is an ongoing part of the job when it comes to crop production. Itâ€™s important that producers can make use of different tools, including pesticides, to protect our food supply from destructive weeds, insects, and diseases.
Spring planting got off to a really rough start in much of Ontario, but most farmers in the province are (slowly) working towards finishing #plant17.
How late did it really go? Many farmers had to balance spraying the fields they planted on time while still planting others.
First on the agenda for spraying this spring would be spraying the winter wheat planted last fall. Wheat will need to be sprayed if it has strong symptoms of a disease outbreak. Cool and wet conditions are a breeding ground for fungal and bacteria spores. Many farmers are now working hard to spray fungicides onto their wheat crops before fusarium and rust spores damage the crop.
Once the barley, corn, oats, and soybeans have been planted across the province, farmers will diligently monitor the fields as the crops grow. They are checking to see if there are pests that arrive in the fields to cause harm to the growing plants. Baby plants are very susceptible to even the smallest threat of a pest, whether thatâ€™s an insect a disease or even competition from neighbouring weeds. Farmers must be diligent during this growing period to monitor the smallest threat and determine if a spray is necessary. They will only spray if there is a large threat that will cause significant damage to the growing crop, as pesticides are expensive and could harm the crop if not applied correctly.
There are two kinds of farmers who have never seen an aphid on a soybean plant: extraordinarily lucky ones, and ones who need to get their eyes checked. Most Ontario soybean farmers are all too familiar with this tiny crop pest. Aphids are a very small, greenish-brown insect that blows in on winds from the south and can cause huge issues in farmerâ€™s soybean fields.
Current weather patterns that Ontario has been experiencing are perfect for aphid development: warm and dry. Aphids have a piercing/sucking mouth part that they use to suck the juice out of the soybean plant, causing yellowing, curled leaves, wilting leaves, and in severe cases, plant death. A dead plant at this stage of the growing season does not contribute anything to the final yield.
Farmers scout their fields this time of the year in order to monitor aphid populations. This means they walk through the field, inspecting random plants, as well as looking out across the field for any areas that might not look the same as the rest of the field. Farmers are especially concerned with lower elevation areas and areas protected by trees. When looking at individual plants, the farmer counts the number of aphids on each leaf and the stem–usually, they will make the decision to spray pesticides if the threshold of 250 aphids per plant is reached throughout a reasonable portion of the field. Aphids do have some natural predators, which are taken into account prior to a spray decision. If many lady bugs or lace wings are present in the field, the decision to spray may be held off; however, with ideal weather, aphid populations can double in approximately 3 days. If a soybean field has not reached the economic threshold for aphids the farmer will re scout the field every 3-7 days. Farmers do not want to spray any field unless they absolutely must, because it is extremely expensive.