Archive for the ‘From the field’ Category

Harvest is Upon Us

This is the time of year when all the crops are going into harvest. I thought I would share what goes on in some of the crops I works with during this very busy part of the season. At this point most of my work is done. It is report card time and I get to see how well I did keeping the pests low when I see how the product comes off the plants.

Tomatoes: the tomatoes I work with are the processing varieties. These primarily go into paste which is shipped all over the world and used to make all the great tomato products you are familiar with. Some are also used for sliced, diced and whole peeled canned products. They are machined harvested. Workers are on the machine to help sort out the MOT (materials other than tomatoes) and any other thing not wanted to get into the truck. There are drivers for the tractors pulling the trailers through the fields and drivers for the trucks taking the trailers to the plant.

Cantaloupes: These are harvested and either packed in the field or taken to an indoor packing plant. They may be in the field for a number of weeks, picking as the melons become ripe. This video is a good one showing the entire process.

Cotton: This will be harvested in the early fall in my area. My job is to recommend products to apply to get all of the leaves dried and removed from the plant before the crop can be harvested. This video clip from the TV show America’s Heartland shows what comes next.

Almonds: As the nuts dry and open they are ready to be shaken off the tree. Then they continue to dry on the ground and when they are ready they are swept into rows, picked up by a small trailer and loaded into trucks off to the processing plant. Walnuts are also picked in much the same way.

Peaches and Nectarines: This harvest starts in late April and goes all summer. They are hand harvested and the crews move from field to field as the varieties become ripe.

Table grapes are picked and packed in the field.

Raisins can be harvested by hand and laid onto the paper trays on the ground or, as labor becomes more expensive, growers can use machines to shake the grapes off the vines and laid on the paper trays.

Wine grapes are picked much the same as mechanical raisin grapes harvest except they go into the trailers and out to the winery.

Thanks to all the wonderful videos being shared by farmers throughout the state for sharing with everyone what you do. Don’t forget to thank a farmer for your food and clothes.

 

 

Thankful for our food

As we prepare our Thanksgiving day feast it may be a good time to reflect on what it takes to get that food to your table. There are many people in many industries that work hard to bring us the abundance of food we have come to take for granted when we go to our local grocery store. As a plant doctor, I will use this post to summarize what my part of the “food chain” contributes to your Thanksgiving feast.

What is on your table?

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As you can see, without the benefits of crop protection products, organic or conventional, yields would suffer and the abundance of food we rely on would decrease making our Thanksgiving feast much more expensive.

Do you like pie?

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Plant bugs of all types are very hard to control. Even organic farmers have problems with these pests. Organic pesticides only deter these bugs for a short time making multiple applications necessary to protect the crop. Nasty little buggers!

Modern technology is doing more to increase yields and decrease the amount of pesticides needed to bring food to your table. Not so long ago many of our crop protection chemicals were broad spectrum and applied in pounds per acre. Now they are more targeted to the pest, safer for beneficial insects, safer for workers and applied in oz per acre. Better application techniques make spraying these low rates effective with less impact on the surrounding environment.

Agriculture has many challenges ahead of it to be able to bring more food to a growing population with less land and other resources.

There are still many challenges ahead. Environmental issues to solve. Promises of new technology such and Genetically Modified crops and other new technologies like CRISPer are just a few things science is looking into to make sure everyone on this planet has enough to eat. GMO technology has already  reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68% (from an articled penned by Klumper and Qaim in 2014; a meta study that summarizes his findings of 147 original studies on the impact of GMOs). 
With the help of modern agriculture techniques, hunger is disappearing but we still have a long way to go before the problems of food insecurity disappears as well.
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As our technology continues to improve, better solutions arise and agriculture continues to tackle the challenges of producing more food with less resources and keeping our environment, workers and families safe and healthy. The more we know the better we do. It is a challenge we take on with pride.

What does a Plant Doctor do after harvest?

As harvest winds down to a close the hard part of my job as a Plant Doctor is slowing down as well. But just because the crops have been harvested doesn’t mean that there aren’t pests to deal with. Now is the time to evaluate how things went during the season. After harvest and during the winter when trees and vines are dormant is a good time to see what may be in store for next year as well.

Almond harvest, seen below, is generally finished in September. Walnuts go into late October.

  In the nut crops, almonds and walnuts, I have samples of the nuts from each block take before the nuts were removed from the field. I crack the nuts open and look for any worm or other pest damage. I’ll crack about 200 nuts on every block (my friends who bake get the good ones). On almonds, ants can eat the nuts when the hulls have split and when the nuts have been shaken off the trees and drying on the ground. If your ant control wasn’t good, you’ll see damage in the crack outs. Other damage that can be seen on almonds is damage from stink bugs.

Stink bug on almond

Stink bug can damage nuts late. Kernels of damaged nuts either become wrinkled and misshapen, or if already hardened before bug damage, will contain a black spot at the puncture site.

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Navel Orange worm in almond

Another pest you can find in either nut is the Navel Orange worm. Not really sure where it got it’s name but it is a pest primarily of nuts. Can be a pest in pomegranates too. They usually attack the nuts late, after the hull and husks have split. The key to controlling this pest it to make sure the populations do not get out of control early in the season. Since they go into the nuts, they are almost impossible to control once they get in.

Another worm that can be found in walnuts is the Codling moth. If you see damage from Navel Orange worm in walnuts it generally means your Codling moth control probably wasn’t very good. Navel Orange worm usually gets into walnuts through the holes left by early Codling moth damage.

After the leaves are off of the trees it is important to take a look and make sure there are no nuts still hanging in the trees. These “mummy” nuts will be places where Navel Orange worm will survive over the winter. Mummy nuts are removed from the almond trees with workers using poles to knock them down. If there is enough rain, most of the nuts will fall as they get heavy with moisture. You don’t want to have more than an average of 1-2 mummy nuts in a tree throughout the orchard. My job is to go around and count these mummies and determine if they need to come off.

Another important task in the winter, on all the tree crops, is to examine scaffolds, limbs, branches, and prunings for scale insects and mites. Walnut scale, San Jose scale, frosted scale nymphs, and European red mite eggs can all be found by examining the wood during the dormant period.  I’ll gather about 100 samples of smaller twigs for every block. I usually bring them home and look at them in the warmth of my kitchen.

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Pile of frass at entrance of peach twig borer hibernaculum.

In the late winter, usually after the first of the year, I’ll decide, based on what I’ve found during the checks I’ve mentioned above and on observations made during the year, what stone fruit and almond trees will need a “dormant spray”. This is a spray that we put on the trees just before they start to wake up for spring. Disease such as shot hole and leaf curl will over winter as spores on the wood and those can be controlled in the dormant spray. Scale, mites and any worms that over winter in the trees, can also be controlled at this time. Peach twig borer overwinters on the tree as a first- or second-instar larva within a tiny cell, called a hibernaculum, that is located in crotches of 1- to 3-year-old wood, in pruning wounds, or in deep cracks in bark. The overwintering site is marked by a chimney of frass and is especially noticeable when first constructed or before winter rains set in. Larvae emerge in early spring, usually just before and during bloom, and migrate up twigs and branches where they attack newly emerged leaves, blossoms, and shoots. Dormant spray will help control this pest.

Grapes generally don’t need much attention after harvest. This year however, the vine mealybugs were so bad I am considering doing some post harvest sprays. These pests will go down below ground and spend the winter on the roots, only to come back up again next season. The fewer going down will mean less coming back up, or at least I hope so. These warm winters are not helping. We are not getting the winter knock down of pest populations we usually see. Monitoring for these pests during the winter entails digging around at the base of the vine to see what kinds of population levels are hiding out.

Citrus leaves with citrus leafminer larvae,

Citrus is a year round crop. The new crop is developing as the old crop is maturing and getting ready to pick. Trees are always green and pests can be found all year. Most of the time pest are not much of an issue in the winter. But when the winter is warm, like it has been the last few years, some pests can keep active. Red scale usually is dormant in the winter but last winter you could pick up males flying around in the traps even in the winter. So going out a couple time a month to keep an eye on what is going on is a must. Bean thrip is sometimes active in these warm winters and some of the export markets don’t what to see them so if fruit is going to these markets, bean thrip need to be dealt with. If not, I just ignore them. Citrus leaf and peel miners can also remain active in the fall if temperatures remain warm.  Citrus tree will put on their last flush of growth in the fall so you want to keep these miners off the leaves.

About this time of year we are expecting (and hoping) for rain so sprays on the citrus for brown rot and Septoria spot are being applied. Certain export markets don’t want certain disease so you need to keep the fruit clean. As the weather gets cooler and hopefully wetter, the snail will come out from under the trees and make baiting for them easier. They are a real pain. Did you know snail eat oranges?

Brown garden snail.

 

 

 

 

Alfalfa will go dormant when it gets cold enough. The only thing to watch out for there are aphids. Certain ones, like cowpea and blue alfalfa aphid can damage the plants if they build up to significant levels.

Last but not least, WEEDS. In all the crops and on the bare row crop beds, weeds will be something to contend with all winter. If it gets cold enough weeds will stop growing or grow slow enough not to worry about too much. There are spray that will go out that will keep them from coming up but most need to be rain activated so if we don’t get enough rain, they do not work very well. We need all the moisture we get in the soil, not being sucked up by weeds. Weeds are my constant bane of existence all year long.

What else does a plant doctor do in the winter? Education!! Plenty of meetings to learn and keep up with all the new technology, pest trends, research, etc. In California I need 40 hours of continuing education to keep my state license but I generally get more than that. So much to keep up on. Always learning.

Note: Thanks for the UCIPM website for all the great photos. These are much better than I could take.

Foreign Invasion threat to farming

Creeping MenaceForeign terrorists have been invading our farms and environment for a long time. These terrorists are called Invasive species. An invasive species is a plant or animal that is not native to a specific location (an introduced species); and has a tendency to spread, which is believed to cause damage to the environment, human economy and/or human health. Species that are moved or migrate to an area where they have not been to before can disrupt the ecology of an area because the native species have not evolved to interact with the newcomer. There may be no natural predators to keep the new species in check or the new species may find a food source that has no defense against the newcomer. There are invasive pests that have invaded our forests, waterways, homes and fields.

The following are just a few I’ve chosen to highlight from the USDA APHIS Hungry Pest website:

gypsy moth“The Asian gypsy moth (AGM) is a destructive, non-native pest that feeds on over 600 types of plants. Large infestations of AGM can completely defoliate trees, leaving them weak and more susceptible to disease or attack by other insects. If defoliation is repeated for two or more years, it can lead to the death of large sections of forests, orchards, and landscaping.” Not only damaging our forests but our landscaping in our cities.

Imported Fire Ants are nasty pests. If you have run into these and have been attacked, you’ll know why. They also damage crops and attack livestock.

giant-snailGiant African Snail is one of the most damaging snails in the world because it consumes at least 500 types of plants and can cause structural damage to plaster and stucco structures. This snail can also carry a parasitic nematode that can lead to meningitis in humans.

Some of these pest have been here a long time and have become “established”. The Asian Tiger Mosquito arrived a long time ago, hitching a ride in some imported tires from China. This mosquito carries West Nile Virus (Link for more on West Nile Virus for WebMD). West Nile virus infects humans and horses. Invasive mosquitoes are also carrying yellow fever, Dengue fever and chikungunya fever.

HydrillaInvasive plants can cause problems as well. Hydrilla is an aquatic plant that invaded Florida and has spread across the country. It is an aggressive plant that out competes native aquatic species and destroys native aquatic ecosystems.

What are some of the more important invasive species that agriculture has to deal with? There are quite a few. First I’ll cover a few that directly impact the crops and then I’ll explain some other ways invasive pest cause problems for agriculture.

Let’s start with one that is something I’m dealing with directly, the Asian citrus psyllid. This pest feeds on the new leaf growth of citrus trees cause the leaves to twist and die back. They are not a particularly difficult insect to control. The biggest problem with this pest is that it can, if infected, transmit a bacteria that causes Huanglongbing (HLB or citrus greening) disease.

Citrus GreeningHuanglongbing causes shoots to yellow, asymmetrically (blotchy mottle), and results in asymmetrically shaped fruit with aborted seeds and bitter juice. The disease can kill a citrus tree within 5 to 8 years, and there is no known cure for the disease.This has already devastated the citrus industry in Florida. It has spread to California, first detected in the Los Angeles area. Even with strict regulations in place about moving citrus trees (the pest does not get on the fruit) it still managed to move from Florida to LA and now up into California’s central valley, the largest citrus growing area in the state.Until just a few months ago none of the psylids found were infected with HLB. Quarantines are in place around areas where the psylids have been caught and this means a lot of extra work if you have to move your fruit to a packing house outside of the area. This includes, but not limited to, spraying pesticides before each pick. A farmer may go through and pick many times before all the fruit is harvested.

BMSBAnother invasive pest headed my way but not yet here is the Brown Marmorated Stink Bug (BMSB). It “has been detected in California. Wherever BMSB takes up residence, it causes severe crop and garden losses and becomes a nuisance to people. The ability of BMSB to hitchhike in vehicles and planes has allowed it to spread rapidly to new areas. Since it was introduced to the United States from Asia in the 1990s, BMSB has become established in the mid-Atlantic states as well as in Portland, Ore., and Los Angeles”. (from UCIPM website). This pest has recently been found in large numbers in the Sacramento area and has been found Stockton. A number of other native stink bugs are pests in agriculture  They are not easy to control and usually require harsher pesticides to get rid of them. The BMSB has been found to be very hard to control and will definitely be a big impact to our IPM programs as they infest a large number of crops.

These are just two but there are many. Many that have come into California and many that are being tracked for possible entry. You can see a pretty comprehensive list for California here

But other countries are watching us as well and they have their own lists and things they do not want us introducing into their environments. This creates issues for farmers because the packers and shippers must ensure what they are exporting comply with the importing countries regulations concerning these pests. Following is a summary of a few of our pests that we have to take extra measures to control and monitor, and why, in some cases, this causes a problem in our IPM programs.

The Oriental Fruit Moth is a common pest that mainly infests stone fruit (Peaches, Nectarines, Plums, etc). Mexico does not have this pest (or so they claim) so they do not want any fruit coming across the border that may have any of this pest in it. Growers and Packers who want to ship fruit to Mexico must pay into a program for extra monitoring for this pest. This includes paying for inspectors for Mexico to be on site during the growing and harvest season, increased trap density and the costs to have people check these traps more frequently than on a non export field, Since you are not allowed to have ANY of this pest in your fruit you need to make sure you spray every hatch (one a month) even if your trap catches do not indicate a serious infestation. Any trap catches and you are required to spray and you can’t use any of the newer more environmentally friendly products because Mexico doesn’t think they work as well. You really can’t have a good IPM program with someone else dictating what you have to do.

fuller rose beetleFuller Rose beetle is a pest that will lay it’s eggs on citrus fruit, under the stem and can be hard to find. South Korea doesn’t want it. Even if you don’t have it in your fields you are required by the packers to spray at least once before harvest. The citrus industry exports a lot of product and there are other spray programs that are dictated more for appeasing the export markets than for what is going on in the field.

A few years back we had an outbreak of European Grapevine Moth that had hitched a ride on some smuggled grapevines from France over to Napa. They hung out in the Napa area, slowly building populations before someone noticed these were not our common type of worm generally found. Napa doesn’t normally have a big problem with worm pests and this one was causing a lot of problems especially for organic growers. Then it moved. Someone brought infested wood down to Fresno and then the export of table grapes came to a halt. For me, it was just another worm pest that was easily dealt with in my current program but in order to satisfy export markets areas with the pest were quarantined and when and what to spray was dictated by the USDA. No one in those areas could ship out of the US and the industry lost a lot of money.

Spotted Wing Drosophila is a fruit fly that, unlike many of our native fruit flies, will attack undamaged fruit and has many generations in a short period of time. They infest cherries and berries mainly. Also a pest we have to spray for even if we don’t see it because one fly can cause the whole field to be kicked out of an export program.

How do these pest move around? Well, mostly by human activity but also changing climate patterns are opening up new habitats in locations where these pests can move to as well. I mentioned that the European Grapevine moth came in by way of some grapevine cuttings that were transported from France to Napa. They did not go through legal import procedures, otherwise the pests would have been detected. Plants and fruit travel to and from places all the time but if they go through airports or border stations, they can generally be intercepted. But it they do not, hitchhiking pests are never far. This local story is about smuggled fruit being sold by roadside vendors and some had invasive pests on them.

We can all help in the fight against these pests. The USDA’s Hungry Pest website has good information on “What Can You Do“.

Thrown out – food waste and the war on farming

There has been plenty of talk lately about who is wasting water. Farmers are the newest target for the wrath of the newly water conscience public. People complain about many things that farmers do. Too much water, too many pesticides, the list seems to just keep growing. It is always easier to point a finger at someone else and not look at your own contributions to a problem. I thought I would use this post to talk about one aspect that many probably don’t consider, the problem of food waste.

In an archived episode of Science Friday, one of the authors of “Wasted: How America is Losing Up to 40 Percent of Its Food from Farm to Fork to Landfill” stated that “over half the land area in the U.S. is dedicated to food production, and over 80 percent of the water that we consume goes into growing and producing our food. So when we throw out, say, half a hamburger, according to an estimate by the Water Footprint Network, that’s equivalent to taking over an hour shower, in the water use that was required for that half hamburger you just tossed.” I wonder how much water the cities are wasting in this way, while they complain about how much water it takes to grow an almond.

Another aspect of food waste is the “ugly food” issue. On recent news story from my local NPR station KVPR, there was a story about “ugly food” which stated that “because of food beauty standards over 6 billion pounds of produce is wasted on farms every year.” No scar, blemishes, bumps, lumps, malformed produce allowed. Damage from hail, mechanical damage, fruit that just has the wrong shape, size or color can all be kick out of the box and into the cull bin.  Also, some insect damage can also cause cosmetic damage that would send an otherwise perfectly edible piece of fruit straight to the dumpster. A small bite on a small piece of fruit can turn into a large ugly scar as the fruit sizes. A small bite on a piece of fruit just before harvest can send it straight to the dumpster.

People complain about pesticide use but I have to do many sprays that are only done so that produce can make the grade as far as looks go. Insects called Thrip can scar nectarines when they are small, just after bloom and even just before harvest when their feeding on the surface of the fruit can cause the fruit not to color properly. Thrip will also scar developing citrus just after bloom as well. For this reason, these crops are sprayed just after bloom to keep these scars from forming. Katydids, a type of grasshopper, can also cause scars and small bite damage on fruit. These are larger insects and can take harsher insecticides to kill them, all in the name of the perfect piece of fruit. Worms in apples and pears will also cause a small bite mark on the surface of fruit. Less toxic materials can’t be used because these insecticides need to be ingested by the worm to work and it is that first bite that causes the damage. The worm doesn’t even have to get into the fruit to cause damage enough to send the fruit to the trash.

Damage on outside of orange only.

Damage on outside of orange only.

Early thrip feeding at bloom causes a scar that expands as fruit grows.

Early thrip feeding at bloom causes a scar that expands as fruit grows.

Worm will take a bite on the outside of the fruit. Cut it away and you have a nice apple.

Worm will take a bite on the outside of the fruit. Cut it away and you have a nice apple.

Katydids will take a bite out of a nectarine.

Katydids will take a bite out of a nectarine.

Katydids can damage small fruit causing a scar that will get larger as fruit grows.

Katydids can damage small fruit causing a scar that will get larger as fruit grows.

When thinking about agricultural practices, it is best to remember that this is a business. A business that wastes expensive resources doesn’t stay in business long. All businesses that want to remain profitable are constantly refining their practices and farmers are doing this all the time. If farmers could sell ALL the produce they send to the packing house and save money on sprays that really don’t protect anything, it would certainly be a better use of resources, and would save me some time as well.

Note: I have not fact checked the stories mentioned above as I consider them credible sources. There are links to other sources of information in those stories if you are interested in reading further on this topic.

What dangers are threatening our food supply?

There are many things one can say about farming but “easy” sure isn’t one of them. Many things can threaten a farmer’s crop, insects, weeds, poor soil, lack of water, diseases, lack of labor, well this list could go on and on but most people are aware that there are lots of things a farmer has to deal with, just like all of us in whatever work we do.

For this post I am going to focus on a singular happening in our corner of the world that most of us have not seen in quite some time. This year we had a very dry winter and spring. This caused the plants in the foothills surrounding our valley to dry up quickly, much sooner than usual. Up in those foothills lives an insect called the Beet leafhopper.beet leafhopper

This particular little beastie is vector of a disease that is deadly to certain crops and because it can be so devasting, there was a program that the government used to carry out to spray the foothills when the beet leafhopper populations were high so that they did not desend into the valley and raise havoc to the crops below. Well, for a varity of reason, enviornmental and monetary, that program was cut way back and now they only spray ditches, roadsides and abandonned fields. So this year as the hills dried up and the large number of leafhoppers desended into the valley looking for food what did they find? Tomatoes!

Processing tomatoes has become a big part of the valley crops cycle. Many farmers have spent a lot of money putting field into drip irrigation to help conserve water and they are planting tomatoes because they yield very well with drip irrigation. But not long after planting they starting seeing plants stop growing and turn a sickly color and die. curly top All over the valley, thousands of acres of tomatoes are affected, some just a few plants here and there and some as many as 50-80% of the plants were infected.

Ok, so what is the point, other than many farmers are going to take it in the shorts because a pest damaged their crop. Isn’t that part of farming? What does this have to do with a threatend food supply. Well in all seriousness, no one will starve if we grow a few thousand tons less of tomatoes this year. But think about it. Remember the potato famine in Ireland? There is a disease that is devasting bananas right now too. We are on our 4th pesticide spray to try to keep our tomatoes from being infected and we all know that more pesticide sprays is really not a sustainable way to go. I thank the stars we are not trying to grow organic tomatoes this year. The best option would be of breed a variety of tomatoes that is resistant to this disease, but so far, through normal breeding techiques, that hasn’t happended.

What if they fould a way to genetically modify a tomato to be resistant to this? No more need to spray the hills or ditch banks or roadsides. No more multi pesticide sprays to try to ward of the leafhopper. Less pesticide sprays are what people want, right? Oh yea, I forgot, GMO food is that evil “Monsanto” thing. So what is it that people want anyway? How are we to protect our food supply and cut down on pesticide use if we can’t even use the best technology out there to fight off diesease, make plant more drought tolerant, yeild more, need less pesticides,etc. Maybe some are thinking that farmers shouldn’t have planted so many tomatoes and that our monculture type of farming is to blame. Well, seriously, a guy had to make a living and there are only so many things one can choose to grow. The choices of what to plant has a lot of componets to it. It isn’t like deciding what to put in your backyard garden.

Well, this post is long enough. Just one little scenario to think on the next time you eat something made from tomatoes and “like” another rant on the evils of “Monsanto”. There is a world to feed and a lot less land to do it on. Just think about that next time you are at the grocery store.

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.