Posts Tagged ‘integrated pest management’

The lovely month of May

May it’s a very busy month for a Plant Doctor in California. All pests seem to really get going in May. This year with the dry winter the herbicides used to keep weeds from coming up early didn’t work as long as hoped. That, along with rain in April brought up a flush of weeds that grew faster than most growers could keep up with. Rain delayed many sprays and weeds grew while it was too wet to spray or while applicants tried to catch up from delays.

May is also the time when many insect pests in the tree and grape crops hatch. Most tree fruit and nut crops get what we call a “May spray” because worms are hatching out ready to start feeding on the developing fruit or nuts.

Peach Twig Borer on a peach

Worm damage on grape flower

At the same time the grapes are blooming (yes, grapes have flowers) and sprays to combat mildew and worms also need to be applied on those crops as well.

We use traps to catch the moths that lay the eggs for the worms to tell us when they are present and use weather data and calculations to determine when the eggs will hatch. That way we are only spraying when a hatch is going to happen. We can tell based on the numbers of moths we catch and what kind of damage we had last season to let us know if we should spray or not. Sometimes we can skip the May spray and wait to see if the next generation hatch will be more and target that spray.

At the same time this is going on, workers are in the fields thinning the fruit, clearing away extra shoots and leave from around the grape bunches, driving tractors to clean the weeds from between the vine or tree rows, irrigating, etc. We have to make sure whatever we do it is safe for the workers.

There is a lot of juggling of people, equipment and figuring out what to do and when. Sometimes I wonder how we manage it all but it gets done and beautiful safe, nutritious fruit is provided to a hungry society.

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Beautiful Fruit

This ;time of year the stone fruit trees, peaches, plums, nectarines and cherries, are in bloom and it is a very beautiful sight. Miles and miles of blooming orchards in various shades of pink and white. Fresno County has a driving tour called the Blossom Trail that is wonderful. Check it out if you are in the area.

This time of year a major project for the Plant Doctor is to make sure that a little insect called a Thrip Image

doesn’t get into the nectarine flowers and start feeding on the developing fruit. If they feed on the fruit the damage they do will cause a small scar that will expand into a very big ugly scar as the fruit grows. That scar makes the fruit ugly and people won’t buy it. This scar doesn’t do anything to damage the fruit in any way but to make it look ugly. It think it is unfortunate that we have to spray for insects just to make the fruit look pretty but people don’t want ugly fruit. They say they dislike pesticides but then they don’t like ugly fruit either. But if they won’t but scarred fruit, we have to keep it clean.

Check out my video to see how I check for thrip during the bloom period.

 

Many things to juggle

As the growing season goes into a time were lots of things are happening, it is always interesting to me how it all gets done. Each grower has their own way of keeping track of it all and they always amaze me. Annual crops have been planted and are out of the ground. Weeds need to be hoed or sprayed, fertlizer needs to be applied, ground needs to be culitvated and prepared for irrigation. Harvest is starting on some of the early fruit trees and the later trees are still being thinned so that ther fruit that is left has plenty of room to size. In the grapes there are crews removing leaves and shoots around the developing fruit clusters so they get plenty of air and light. Activity everywhere.

All this activity can cause interesting dilemmas for us Plant Doctors. Many researchers have spent a lot of time looking a certain crops and their pests and telling us exactly what to look for and how we should decide when pest thresholds are high enough to treat. Counting bugs and looking and crop damange and stages, checking on weather and caluclating when pests will hatch. The list of techniques goes on and on. But what can throw a wrench in this system, that is generally not considered by research, is what is going on that is not pest related.

Are there people scheduled to go into the field to thin or pick? Do we need to treat early enough, before pest reach our target to treat so that it will be safe for the workers to go in? Are crops going to be harvested next to a block to be treated? Should we treat earlier so as not to risk a problem with an adjacent field? Are the ditches going up to irrigate and making the field inaccessible to spraying for a while? Should we treat before the water starts? There is a tractor going through to spray for on thing, can we save a trip through the field and piggyback a spray for something else, thus saving gas and reducing applicator exposure?

Not all pest control decisions can be based solely on the pest counts in the field. Those issue do not exisit in a vaccum. Pest population numbers and trends, potential crop damage, numbers of beneficial insects working on the pest are the best indicators of what needs to be done. But sometimes other operations going on can disrupt your best laid IPM plans and you just have to make a decision that works best for all.

Busy outstanding in my field(s)

It has been months since my last blog. Work keeps me busy and I find it hard to think that my seemingly mundane daily activites would be of interst to anyone. Maybe they aren’t. But I feel the need to talk about what I do so people can understand more about what goes on surrounding the production of their food. People say that people care. Do you?

This year started off very wet. It rained alot during the time the fruit and almond trees were blooming. Flowers produce the fruit and wet weather can cause fungus to grow on the flower and then they die. So, farmers spray crop protection products to keep that from happening. It is my job to know when to spray. Just because there has been rain forecasted doesn’t necessarily mean you need to spray. Fungus needs the proper temperatures as well. For the beginning of bloom the rains that came were associated with cold storms so we were able to avoid spraying. We did spray most everything two times. We still had some disease issues but those were acceptible and can be dealt with.

Now we are moving into May and the big “May spray” is upon us. Most of the fruit trees and grapes have worms that hatch out in May. So just about everything is getting some spray if the traps in the fields and past history suggested continued worm issues. For me, it is important to choose crop protection products that are reduced risk for workers and environmental reasons. There is a lot of labor going on right now. That needs to be a big factor in choosing what to use. We also have a long way to go and it is important that products are not what we call “disruptive” to the natural balence in the fields. We just want to keep the worms under control. We don’t need to kill every bug out there.

In other parts of the field landscapes, cotton, corn, tomatoes are all up and growing. Alfalfa has been cut once and is growing again, waiting for the second cutting. Pretty soon we will be dealing with pests in those crops as well. For the cotton and tomatoes, right now, it is keeping the weeds under control. Soon there will be other creepy crawlies. Stay tuned!

After a winter break

Most of the activity out in the fields between November and January do not involved the services of a plant doctor. Farmers are preparing their fields for planting and pruning the trees and vines. My biggest job is going out in December and checking on the weed growth. Keeping the weeds from growing and using the soil mositure and nutrients we are trying to store up for out crops is very important. For your yard at home it is more of keeping your flower beds and lawn looking good. But most people know that if you let the weeds take over, the plants you want won’t last very long. We try to use weed control products that will last a long time on the soil so we do not have to spray and cultivate a lot in the winter. With all the rainfall, if is almost impossible to do any work out in the field. Making sure we know what weeds are in the fields and what are the right products to use is my job. There are many choices of things to use and it is important to use the right tools for the job.

Another winter project comes in the tree crops. Diseases and insects will hide on the trees in the nooks and crannies and it is important to mointor what is hiding out there in the winter and make a decision if treating the trees while they are dormant is something that is necessary or not. This involves going out and sampling the small branches and looking a the places these pest hide in and determining if there is enough of a problem to deal with.

Mites lay eggs on wood

For peach and nectarine trees there are certain spring diseases that are best treated while the tree is dormant. So for tree crops, many farmers are now applying what we call a “dormant” spray. Not all orchards get this spray, just thost that need it. So I have to go out and look at the orchards and find out, based on what pests we had at the end of the last season and what I see now, which orchards need a spray. The worst part of this chore is having to go out when it is cold and foggy. I hate cold and foggy.

How pest control decisions are made with sustainable farming practices.

Responsible farmers use pest control products responsibility. When walking through a farm field or orchard there is a lot going on that isn’t always obvious to the untrained eye. It is a living system and in order to keep a sustainable system in balance there is a lot to evaluate. Just because there are pests out there doesn’t necessarily mean that you call out the machines and blast them away. Many people think that farmers are always spraying for pests but more often than not, my weekly inspections of farmers’ fields do not call for any spraying at all. When I am checking a field I am actually counting the pests, looking at any damage they may be doing and deciding if the pest populations and the amount of damage they are doing are something the farmer can live with. Using the tools of Integrated Pest Management there are bug traps , sweep nets (like kids use to catch butterflies) , counting pests on a certain number of leaves or fruit, all to take a sample of what is there, how much damage if going on, what kinds of natural control may be going on and how much the situation has changed since the last check. Sounds complicated? Well it is. That is why there are trained, licensed people out there checking and evaluating what is going on. Decisions are made based on what is going on in the field, is the damage beginning to get to the point the crop yield is going to be economically damaged? Are the natural controls going to be able to keep the pests in check or is there something that can be done to augment that system? Many times sprays can be used to knock down the pest levels to a point where natural control can take over and balance is restored. Pest sprays are not meant to completely clean out the entire natural system. When used responsibility they can help farmers grow our food safely and with very low environmental impacts.

New decision brings more angst.

Early this month the California Department of Pesticide Regulation approved restricted use for a new pesticide, Methyl Iodide. This product is supposed to be the best replacement for certain uses of the now discontinued Methyl Bromide pesticide, which can’t be used because of ozone issues. As usual, there were a lot of letters, data, discussion, etc. on both sides of the issue. Not surprisingly, there was scientific data showing the product could be used safely and data showing it could not. Letters from well-respected organization on both side flooded in. Those on the side that wanted the product thought that the decision as a good one and those on the side that did not want the product cried foul and vowed to fight for a repel of the decision. Does this sound familiar? Seems like a news flash from any number of decision and any topic these days.
So, how do we know that these decisions are made in everyone’s best interest? How do we swim through the flood of commentary to understand if we should be concerned or relieved? Well, if you think I have that answer I don’t. It is all just as confusing for me. I do know that I understand the process. I can look at all the studies that they do and see that they are looking at a wide variety of issues, human health, environmental health, worker issues, and etc. It seems like they are trying to cover all the bases, even if I don’t understand all the technical stuff. I try to look at the sources of the data, who is doing what and where the experts working on the issues are from. I take data that comes from the company that is making the product with a grain-of-salt and do not pay much attention to any scientific data that comes from sources that are based in organizations that have a track record of being anti-pesticide. And I trust. I trust that people who are working on these things are like you and me, wanting to do a good job and are able to use the skill and knowledge they worked so hard to get to come up with the best decisions. If, at some point down the road there is a problem with the use of this product, I will expect that the problem will be looked at in a professional manner and mitigation measure will be developed where possible or the product will be pulled if not. It is unrealistic to think that all possible future risks and issue can be foreseen.
Isn’t that all we can hope for with anything? We seem to have this idea that if a product causes injury that the makers should have foreseen it and since they did not they are held criminally negligent. Maybe I am just naive or too good natured but I just believe that most people are not out to destroy when they develop a product. That is not to say there are no problems with cutting corners or making faulty products or safety concerns and government standards, regulations and inspections are indeed needed.
Back to the Methly Iodide issue, the State of California has the most restrictive regulations for its use than any other state, as with many other pesticide products as well. They had done their best to look at the major concerns and figure out way to mitigate them. It is not going to be an easy pesticide to use but those that need it will be able to have access to it. Safety concerns were looked at and addressed and not ignored. It hard work of all the people who tirelessly worked on this decision should not be maligned just because people who do not want any pesticide use are upset.

If you are interested in seeing the information regarding this issue on the DPR website, here is the link: http://www.cdpr.ca.gov/docs/registration/methyl_iodide.htm