19.4.11


Organic versus Synthetic Pesticides- The Debate Continues

For most of a modern lifetime, the debate has raged over the use of synthetic pesticides as opposed to natural pesticides. There is so much emotion and confusion over the debate that I hope I can bring some clarity to the issues so you can make your own decisions. In many analyses, especially in commercial agriculture and horticulture, economics of pest control is the ultimate ruler of how things get done. A grower might choose organic pest control methods, but might lose his profitability in the process.   

First, let's clarify the precepts of "pest control". There are myriad organisms, including insects, fungi, bacteria, mollusks, and higher organisms that bother both people and plants. Pesticides are products to control pests, and pesticides are not toxic by definition;  ( water or soap can kill mites quite effectively). The word "pesticide" itself carries emotional connotations. The issue of pest control really boils down to 3 issues:

 1. How much damage to your crops can you or are you willing to tolerate ( or nuisance to yourself) ?     
 2. How fast do you need or want the control ?  
 3. How much time and money are are you able or willing to devote to the control ?

Within these 3 criteria lie most of the issues. Many organic products work, but require extra time and machinery usage for repeated applications. There may also be a lack of the millions of pounds of organic products needed for commercial applications over very large areas. Many of the modern strains of diseases and pests have built up resistance to chemistry, making the problems even tougher to manage.



ground cinnamon
 
Given a very competitive produce market where buyers have a  zero tolerance for damage to their fresh produce and may even reject produce for a few blemishes on the inedible husks or skins of produce, organic methods may not be economically viable for massive operations. Given the costs of manpower and machinery to spray many thousands of acres of crops, most farmers will choose the methods that work the best, cost the least, require the lowest amount of manpower and then get his produce to market,  all within the legal strictures of governing agencies. If the farmer could use one synthetic product, perhaps twice per year, and get a bumper crop of clean produce  that would fetch a good price, then the ethics of organic farming and environmental stewardship might fall in the pathway of staying in business.  

It would take quite a groundswell from the buying public to change the ways of modern agriculture. There would have to be a majority of buyers who would have to say loud and clear " we are willing to pay premium prices for organic produce with a few blemishes on it." Some states are successful with organic gardening, but sometimes this change of tactics has come on the heels of tight legislation, poisoned soil or water, or lawsuits from farmworkers. Synthetic pesticide chemistry offers a lot of seemingly attractive points, including ease and infrequency of application, or modes of action not possible with organic methods. Many fungi ,insects and mites have to be managed systemically, from inside the plant. For instance, it would be impractical to attempt control of Emerald Ash Borer in 6 eastern states by spraying them one by one with an organic surface-acting pesticide unless the product was able to somehow penetrate the bark or be uptaken through the roots to attack the borers inside.   

With one case being made for synthetic pesticides, let's address the organic side. For homeowners and smaller commercial operations, there are myriad organic, low-toxicity products which can yield big benefits. Many organic pesticide products are quite effective, but need to sprayed very thoroughly on all parts of a plant, and need frequent applications. A great many of these products can accomplish great things, but don't last very long. The time and costs of application can be a major constraining factor. In the case of flying insect control, repellents can be used very effectively, provided they are used in non-public areas. Even the venerable sulfur powder works well as a pesticide, but would you like your home garden to smell like gunpowder ? And would you mind applying the product every few weeks ?




Cinnamon or Neem oil sprays, quite the fashion nowadays, work really well for many insect and fungus problems. They don't last very long, but are effective, non-toxic and inexpensive. They are also nasal irritants for many people. The same can be said for diatomaceous earth ( DE), the fine powder often used in pool filters. DE is extremely effective in controlling snails and slugs and many crawling insects, in addition to being organic and bio-safe. It is, essentially, finely ground glass, and behaves as such to pets and people if they contact it. It washes away after rain or irrigation, therefore it needs re-application every week or two. After repeated applications, many crawling / sliming pests have been eliminated, with no impact on the environment. In the absence of pest or children in the target areas, DE works very well.




In both organic and synthetic pest control, there are primary considerations for the environment, costs and frequency of application, effectiveness, and the time needed to enact control. Secondarily, growers and gardeners are concerned about groundwater contamination, whether they can produce a marketable crop, and for homeowners and public landscape stewards, whether there are direct impacts on the public. One salient point that is so often overlooked: we are buying more and more produce and plant crops from foreign countries. What assurances do we have that the plants have been treated with eco-friendly products ? Having visited several New World countries, I was unsettled to see huge billboards advertising the use of many pesticides the US had banned decades earlier due to toxicity reasons, but still sold overseas for food production.


Neem Soap

We rally behind the ideas of organic and holistic food production and pest control, but buy our produce from another country with fewer controls over pesticide usage. This defeats much of the good work that comes of trying to reduce pesticide usage in our domestic food chain. It is easy to see the harmful effects from massive farming operations on the Everglades watershed, and there are numerous areas in the country that have been damaged or rendered unusable by some types of agriculture. The question of pollution is more likely a matter of scale than it is of toxicity, since even manure can pollute groundwater, cause illnesses, and render areas unusable. A few pounds of manure in a  rose garden is a benefit, a few million pounds of manure in a watershed is a big problem. We need to look closely and objectively at what our needs, wants, and tolerances are, both personally and as a society before we widely condemn synthetic products as bad or laud organic products as good. There are plus and minus aspects on both sides. I propose that people make their own choices, but become educated before they do.                              

No comments:

Post a Comment