Apple Scab Season Has Arrived

Based on our NEWA (Network for Environment and Weather Applications) Apple Scab Model, we have had multiple scab infection events beginning March 23 with spore maturity being very low (see chart below). But, with the first infection period, even though leaf tissues had not formed yet, the scab season has officially begun!  With no leaf tissue showing prior to green tip, any previous infection period would have no immediate effect on the leaf tissue, but we now know that there are spores out there.  Since we had our copper spray put on right at green tip the evening of April 7 and 8, we were protected from the infection once the spores began to mature.  With spore maturity and discharge being very low, the risk is also very low, but we still need to be protected because any high temperature day can cause the spores to mature very quickly. 

 

 

Ascospores mature as spring progresses with a few ascospores usually maturing by bud break (green tip). The proportion of ascospores maturing progresses slowly until about the tight cluster stage of blossom development. From tight cluster through bloom the percentage of mature ascospores rapidly increases with most ascospores matured by the end of bloom.  In the chart below, we cab see that the ascospore maturity level is still quite low.

 

Unusual weather conditions may contribute to significant ascospore discharges earlier than or later than the model predicts, and for that reason, we want to be sure we have a protective cover spray on the trees.. 

Mature ascospores begin to discharge into the air within 30 minutes during periods of rain. When rainfall begins at night, discharge may be delayed until daybreak. Ascospore discharge usually peaks from pink through bloom, and nearly all ascospores have been discharged within 1 or 2 weeks after petal fall.

Copper has been shown to be a protectant against scab on the tissue that has been covered, but not on any new tissue that would have grown since that copper spray was put on.   If no copper spray has been put on your trees as of today, and you have not put any other protectant on like Captan or Mancozeb, you still have time to get an eradicant fungicide put on your trees in the form of Immunox, which has a 72 to 96 hour reach back ability.  That means that you have up to 72 to 96 hours to get a spray on which will still be effective against any scab infection event 72 to 96 hours previous. Immunox is a xylum mobile fungicide which means when applied to leaves it will move throughout the leaves it was deposited on but will not move out of that leaf (McGrath, M.T. 2004. What are Fungicides. The Plant Health Instructor. DOI: 10.1094/PHI-I-2004-0825-01. Updated 2016.) 

For the home grower who may not have a weather station or scab model to help predict the apple scab infection periods, monitoring for apple scab can be quite complicated.  But there is an alternative.  Unless wetness periods are being monitored as outlined in the section above, you can simply apply protective or eradicant fungicides at regular intervals beginning with green tip. Spraying should be done every 7 to 10 days, depending on the number of rain events between sprays.  If there are no rain events between sprays, a single protectant spray will last at least 10 days but not more than 14 days, based on the product's label directions.  You will need to make sure that your trees and fruit are protected prior to any rain event if you are going to use only a protectant.  A good protectant is Captan or Mancozeb.  But, a protectant can lose its effectivness after 2" of rain, so you also want to keep an eradicant on hand like a myclobutanil, which is available as Spectracide Immunox, which I mention above.  

 

A protectant like Captan has to be applied prior to a rain event.  If no protection is available during the wetting event, then only an eradicant like Immunox can be applied that has a reach back of 72 to 96 hours as I have stated above.  That means that it can still have an effect on the scab pathogen for up to 96 hours after a wetting event, although it is a good practice to use the shorter 72 hours.. A good option is to actually use both a protectant and an erdicant at the same time, like Captan mixed with Immunox, which will give you both protection and eradicant action after a wetting event. Be sure to monitor wetness periods throughout the spring to insure that trees are always adequately protected. 

 But, regardless of the type of mobility that a fungicide possesses, no fungicide is effective after the development of visible disease symptoms. For that reason, timely fungicide application before establishment of the disease is important for optimal disease management.

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This publication contains pesticide recommendations that are subject to change at any time. These recommendations are provided only as a guide. It is always the pesticide applicator's responsibility, by law, to read and follow all current label directions for the specific pesticide being used. Due to constantly changing labels and product registration, some of the recommendations given in this writing may no longer be legal by the time you read them. If any information in these  recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned, nor is criticism meant for products not mentioned.  The author assumes no liability resulting from the use of these recommendations.

 

Main Pests, Tree Growth Stages, and Spray Guide

If you have a Home Orchard or just a few apple trees in your back yard, and if you have not thought about how to handle those pest problems you had last season yet, now is the time to actively examine a spray protocol  for your fruit trees!  And start right away, before it is too late and the pests have a chance to establish themselves in your trees!  The question everyone needs to ask before spraying is “Do I want to spray or not?”   Well, unfortunately, in northern Illinois, we have four main pests that we will almost always have to spray for.  This is pretty much true for any area east of the Rocky Mountains.

The decision to spray or not depends on how much fruit loss you are willing to take. That is your threshold.  If you can accept some fruit loss, then the need to spray diminishes greatly.  But if you only have a few trees and some fruit damage may mean losing half your fruit, then spraying becomes more important.  Let’s meet our top four pests in northern Illinois,  southern Wisconsin, and in most of the states east of the Rocky Mountains. 

 The Four Main Pests

 

The four main pests that we face in apple orchards here in our climate zone of 5/5A are apple scab, plum curculio, codling moth and apple maggot, in that order. What isn't listed here is fire blight, whihc is a devastating disease that must be sprayed for because it can wipe out entire trees in a matter of days.  For more information on these and other potential apple tree pests, visit our web site Growing Guide page.  But how do we know when to spray for them if it is a last resort to protecting our fruit? 
 

All tree fruit have several distinct growth stages as the fruit matures.  Knowing and identifying those growth stages is  very important for the home grower because recommendations and spray timing for spray applications are linked to these specific growth stages.  The chart below shows the common growth stages for apple trees.  

Tree Growth Stages (Phenology)

 

Since the average home grower does not have access to their own weather stations or degree day calculators, the fruit tree development stages play an ever greater  role in pest management for the average grower.  Most spray schedules (protocol) follow the tree development stages to aid in the timing of sprays so they are most effective.  It is important to note that many diseases and some insects can only be controlled by spraying before they can be seen like apple scab.  Spraying less frequently or at the wrong time will typically result in poor results.  And, spraying more frequently will not necessarily give greater control.

The tree developmental stages or tree phenology gives us a guide as to when to spray, but what do we spray if we have to spray?  If we consult some of the various spray guides available to the home grower, we will find that most of the spray guides provide us with the tree’s development stages (phenology) and the insects or diseases that frequently  occur during each of theses stages.  So the tree phenology serves as timing guide when the application of a particular spray is recommended in order to control specific insects or diseases at the right time.   The following spray guide for apple trees will give us the time to spray based on tree phenology, the pest to spray for and the product recommendation for that pest(s).

Apple Spray Guide

This particular spray guide is included in “Managing Pests in Home Fruit Plantings” from the Purdue University Extensions Publication web site or our web site as a free download.  It goes into detail as to the various products available for spraying that include both conventional and organic alternatives.  The publication includes apples,  pears, peach, cherry, grape, strawberry and raspberry guides as well as the phenology charts for each fruit type.  For recommendations on spray products for the Home Orchard visit our spray product recommendations.

Reference in this publication to any specific commercial product, process, or service, or the use

of any trade, firm, or corporation name is for general informational purposes only and does not

constitute an endorsement or certification of any kind by Royal Oak Farm.

People using spray products assume responsibility for their use

in accordance with current label directions of the manufacturer.

Monitoring for Apple Maggot Begins

Fig. 1

In 2019 we trapped the first apple maggot fly on around the end of June at about 1150 Degree Days from January 1.  We are at 1016 DD as of today at 5:53 PM, so it is time to get out the  apple maggot traps  and get them set.  I set our orchard's traps a few days ago and , as of yet, have no flies trapped.  It only takes one non-baited trapped fly to  determine that they have arrived to the orchard!  The apple maggot (AM) is native to the Midwestern US and is considered a primary pest, along with plum curculio (PC), and codling moth (CM), which have been covered in previous posts. The adult apple maggot fly resembles a small housefly in size, with a black body, eyes of dark red, with the thorax and abdomen having distinctive white or cream colored bands. The AM is distinguished from other similar, and closely related flies, like cherry fruit fly and black cherry fruit fly, by the variation in dark banding on its wings (See Fig. 1).  

Fig. 2

The AM overwinters in the pupal stage in soil. As soil temperatures rise in early spring, development of pupae commences. The adult fly first emergence begins shortly thereafter (early summer, mid to late June in upper Illinois). It takes about 7 to 10 days for the female to mature enough to mate and lay eggs.  So there is a 7 - 10 day window for spraying prior to egg laying.  A feeding and mating period (pre-oviposition) during this 7-10 days is followed by egg laying directly under the skin of the apple. Females may deposit eggs over an approximate 30 day period laying as many as 300-500 eggs.

Fig. 3

Egg-laying punctures cause dimples and distortion in the outer flesh of fruits. These punctures appear as pinpricks on the fruit surface. Larvae tunnel throughout the fruit leaving irregular trails.(Fig. 2) As eggs hatch, larvae funnel through fruit flesh leaving a winding brown trail.(Fig. 3)  Egg laying usually ceases in early to late August; however, it may continue longer if drought conditions exist throughout August.

Monitoring For Apple Maggot

Fig. 4

When monitoring for AM, the apple maggot fly tends to show a preference for golden delicious varieties, but no variety is immune from attack.  Sticky red spheres are effective monitoring devices for adult AM flies (Fig. 4). Females are attracted to the sphere for mating and egg laying activities and are trapped by the sticky coating. Hang traps shortly before expected adult emergence (mid to late June in upper Illinois). First emergence may be detected by checking traps daily until the first fly is spotted on the non-baited trap. 

Hang the sphere in the proximity to fruit at eye level on the perimeter of the south or southeast side of the tree. Attach the ball in a sturdy stem about 1 foot above a fruit cluster of approximately 6-10, cleaning out the foliage and other fruit for at least 18 inches to sides and top of the trap so it is easily visible. The spheres attract the insects that come within a few yards of them; therefore, the capture of ONE AM on any one non-baited trap at a time would indicate the need for an immediate control application. The capture of 5 flies on a baited trap would  indicate the need for an immediate control application. Once the pesticide is applied, AM captures are disregarded for the period during which the protective spray is effective (varies according to pesticide used).

Control for Apple Maggot

Fig 5.

Several insecticides can be used for apple maggot control including those used for codling moth control like   and/or spinosad.  Acetamiprid is a soft, conventional control and is available as  Ortho Flower, Fruit & Vegetable Insect Killer (Fig. 5).  This is a ready to use product that contains .006% acetamiprid, a synthetic organic compound of the family of chemicals that acts as neonicotinoid insecticides. Acetamiprid is a contact insecticide for sucking-type insects and can be applied as a foliar spray or a soil treatment. Acetamiprid acts on a broad spectrum of insects, including aphids, thrips, plum curculio, apple maggot and Lepidoptera, especially codling moth.  When sprayed in the evening at sunset, it will not harm bees or other beneficial insects.  Be sure to follow all label directions on the bottle for proper application.

Fig. 6

An all natural approach is available in the form of Bonide’s Captain Jack’s Dead Bug Brew (Fig. 6).  Captain Jack's Deadbug Brew® contains Spinosad (spin-OH-sid), a product first isolated from a naturally occurring soil dwelling bacterium that was collected on a Caribbean island from an abandoned rum distillery. Deadbug Brew® kills bagworms, borers, beetles, caterpillars, codling moth, gypsy moth, loopers, leaf miners, spider mites, tent caterpillars, thrips and more! Use on fruits, vegetables, berries, citrus, grapes, nuts and ornamentals and approved for organic gardening.

As always, be sure to follow all label directions on the bottle for proper application.

For additional information, see the following fact sheets and guides  which are available from local university extension services:

https://ecommons.cornell.edu/bitstream/handle/1813/43071/apple-maggot-FS-NYSIPM.pdf?sequence=1&isAllowed=y

http://extension.psu.edu/plants/tree-fruit/insects-mites/factsheets/apple-maggot

https://www.extension.purdue.edu/extmedia/ID/ID-146-W.pdf

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Reference in this blog to any specific commercial product, process, or service, or the use of any trade, firm, or corporation name is for general informational purposes only and does not constitute an endorsement, recommendation, or certification of any kind by Royal Oak Farm, Inc.   People using such products assume responsibility for their use in accordance with current label directions of the manufacturer.
 

It's July and Japanese Beetle is Beginning to Emerge

Figure 1.

Japanese Beetle emergence has begun here in Northern Illinois, but seems to be very spotty.  But once it has emerged in one location, it is only a matter of time before it emerges in another.  I noticed the first beetle last Monday and today they were still not in full on our Honeycrisp trees (Figure 1).  Due to the large amount of carbohydrates produced by the Honeycrisp trees, which is what makes the variety so sweet, the Japanese Beetle is seemingly attracted to it just like we are!  Honeycrisp seem to be the first leaves that attract them and then they move on to raspberries and several other berry varieties.   

Monitoring for Japanese Beetle

Adult Japanese beetles emerge from the soil and live from 30 to 45 days feeding on plants over a four-to-six-week period.  The adults produce aggregation pheromones that attract individuals (both males and females) to the same feeding location. Adults can fly up to five miles to locate a feeding site; however, they tend to fly only short distances to feed and lay eggs.   The adult beetles normally emerge during the last week of June through July. The first beetles out of the ground seek out that suitable food , like Honeycrisp, and begin to feed. These early arrivals then begin to release that aggregation pheromone (odor) that attracts additional adults. Newly emerged females also release a sex pheromone that attracts males. After feeding and mating for a day or two, the females burrow into the soil to lay eggs at a depth of 2 to 4 inches. Females lay 1 to 5 eggs before returning to plants to feed and mate. This cycle of feeding, mating and egg laying continues until the female has laid 40 to 60 eggs. Most of the eggs are laid by mid-August though adults may be found until the first frost. The eggs hatch in 8 to 14 days and the first instar larvae dig to the soil surface to feed on roots and organic material. The first instars shed their skin (molt) in 17 to 25 days. The second instars take 18 to 45 days to mature and molt again. Most of the grubs are in the third instar by late September and by October they dig deeper into the soil to overwinter. The grubs return to thesurface in the spring as the soil temperature warms, usually in mid-April. The grubs continue their development and form a pupa in an earthen cell 1 to 3 inches in the soil. 

Figure 2.

When you see those first few beetles, that is the time to begin you plan of attack.  Those first few beetles are the food source scouts that will emit the aggregation pheromone letting other beetles know that a feast is on! The Japanese beetle adults feed through the upper leaf surface (epidermis) and leaf center (mesophyll), leaving the lower epidermis intact. Adults usually avoid feeding on tissue between leaf veins, resulting in leaves appearing lace-like or skeletonized (Figure 2). Controlling those first few beetles can give you a head start on stopping the feeding/mating cycle.

 Control for Japanese Beetle

There are some control options for the adult life stage One is physical removal and/or trapping of adults:  Removing beetles by hand, or trapping, may provide adequate protection  for  small plantings  when  beetle  numbers are low.  However, Japanese  beetle  adults  are capable  of  migrating  from  other  areas,  and  the presence  of  beetles  on  or  near  a  plant  will  attract more   beetles.  Consequently,   use   of   Japanese beetle traps often attracts more beetles, and results in subsequent damage to plants.  

Figure 3.

The other alternative is chemical control of adults:  Several insecticides are labeled  for  use  against  adult  Japanese  beetles.  Always  follow  label  directions.    Typically, this may entail 2 treatments during the peak beetle flight. Homeowners should make their first application before damage becomes intolerable and beetles are still abundant. The need for repeated applications can be curtailed by inspecting plants for additional beetle damage prior to applying a second treatment. Neem products containing Azadirachtin can be effective repellents that can reduce defoliation when applied regularly (but no more than weekly) during beetle flight.  Apply before defoliation becomes intolerable. In years when beetle populations are very high, noticeable defoliation may occur because adults will consume a small amount of insecticide tainted leaves before they are killed.  Treat  foliage  and flowers thoroughly.  For optimal control, apply in the late afternoon when beetles are most active. Several other insecticides can be used for Japanese beetle control including those used for codling moth and apple maggot control like acetamaprid.  There are others like Sevin, but I do not recommend the use of Sevin since it is toxic to bees and to beneficial insects.   Acetamiprid is a soft, conventional control and is available as  Ortho Flower, Fruit & Vegetable Insect Killer (Figure 3).  This is a ready to use product that contains .006% acetamiprid, a synthetic organic compound of the family of chemicals that acts as neonicotinoid insecticides. Acetamiprid is a contact insecticide for sucking-type insects and can be applied as a foliar spray or a soil treatment.  When sprayed in the evening at sunset, it will not harm bees or other beneficial insects. 

If you do choose to use chemical controls make sure that the plant you are applying to is listed on the label as well as Japanese Beetles. If controlling Japanese Beetles on food crops such brambles or apples – make sure to follow the harvest-restriction date on the label. Always READ and FOLLOW the label and do not apply at rates higher than listed.

This publication contains pesticide recommendations that are subject to change at any time. These recommendations are provided only as a guide. It is always the pesticide applicator's responsibility, by law, to read and follow all current label directions for the specific pesticide being used. Due to constantly changing labels and product registration, some of the recommendations given in this writing may no longer be legal by the time you read them. If any information in these  recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned, nor is criticism meant for products not mentioned.  The author assumes no liability resulting from the use of these recommendations.

Codling Moth Flight Begins......Very Slowly!

Everyone likes to eat apples, including over 70 insects, and a long list of fungi and bacteria.  To produce good tasting, good looking fruit, we have to control those pests.  We have discussed plum curculio in the May 29 post, but of all the flying pests we encounter in the upper Midwest, codling moth (CM) is one of  the insect pests needing to be controlled the most.  Codling moth is responsible for the proverbial worm in the apple, so to speak! Yet, so far this spring, we have only trapped 2 CM (codling moth) in traps thus far.  With the cooler nights, flight has been remarkably low.  So, before CM flights becomes consistent, let's review the development and movement of CM.

Codling moth (CM) is a small moth whose caterpillars bore into the fruits of apple and pear trees during mid- to late-spring and summer.  Codling moth is the cause of what is often referred to as "the proverbial worm in the apple". The caterpillars of this insect can damage a high proportion of the fruits on apple trees in gardens in a small amount of time. 

Codling Moth Larvae

Newly-hatched larvae (caterpillars) chew through the fruit skin and bore their way to the core. The presence in fruit of one or more holes plugged with frass (excrement) is characteristic of attack by codling moth. The larvae enter the fruit through the sides, stem end, or calyx end, and a syrupy substance may exude from the holes as the fruit matures. Shallow entries called "stings" result when larvae penetrate a short distance and then die from insecticide poisoning or natural causes.

The eggs, larvae and pupae of codling moth each have specific physiological time requirements to complete development before they transform to the next stage. Temperature also affects the flight, mating, and egg laying activities of the adults. Although the minimum threshold for emergence of moths is 50 degrees Fahrenheit, male moths do not fly until temperatures exceed 55.4 degrees F and codling moths do not mate until temperatures exceed 60.8 degrees F in the evening beginning at or right after sunset.

   

Pheromone lure with trapped moths.

To determine when flight begins for codling moth, commercial growers make use of pheromone traps.  Once moths have been trapped for  two consecutive days in a row, a biofix is set  that initiates the beginning of growing-degree-day calculations.  We know that at 100 degree days after the biofix date codling moths begin to lay eggs and those eggs begin to hatch at 250 degree days after biofix.  It is this information that aids in the timing of necessary sprays for codling moth so they do not damage fruit.  Growers wishing to time sprays based on egg development and hatch should make an application of an insecticide at 250 DD (base 50 degrees F) after the first sustained capture of males in the sex pheromone traps.  Here is a Detailed Growing Degree Day Model for Codling Moth.   

 

We have not yet established a biofix for CM this spring and may establish one within the next few days  But for the home orchardist who does not have the benefit of a weather station or other means to calculate degree days, a simple tree growth stage time table can be followed.  Codling moths usually start flying at bloom time or just after bloom time at petal fall and approximately at the same time as plum curculio.  Eggs laid by these moths begin to hatch about two weeks after petal fall, depending on the weather. You can apply the first codling moth spray at this time, about two weeks after petal fall, to prevent larvae from entering the fruit. Because most insecticide residues last 7 to 10 days and moths are continuously present throughout the summer, apply a spray every 7 to 10 days to prevent later broods of codling moth larvae from entering apple and pear fruits. If using a natural product like Spinosad, then spray after every rain due to washoff.  Always follow the label directions of any spray you may use.

Several insecticides can be used for codling moth control including acetmaprid and/or spinosad.  Acetamiprid is a soft, conventional control and is available as  Ortho Flower, Fruit & Vegetable Insect Killer.  This is a ready to use product that contains .006% acetamiprid, and is also available in a concentrate containing .5% acetamiprid, a synthetic organic compound of the family of chemicals that acts as neonicotinoid insecticides. Acetamiprid is a contact, translaminar insecticide for sucking-type insects and can be applied as a foliar spray. Translaminar insecticides are absorbed by leaves and can move through the leaf to the opposite surface they contact. They are not truly systemic and do not move throughout the entire plant. Acetamiprid acts on a broad spectrum of insects, including aphids, thrips, plum curculio, apple maggot and Lepidoptera, especially codling moth.  When sprayed in the evening at sunset, it will not harm bees or other beneficial insects. Be sure to follow all label directions on the bottle for proper application.

An all natural approach is available in the form of Bonide’s Captain Jack’s Dead Bug Brew.  Captain Jack's Deadbug Brew® contains Spinosad (spin-OH-sid), a product first isolated from a naturally occurring soil dwelling bacterium that was collected on a Caribbean island from an abandoned rum distillery. Deadbug Brew® kills bagworms, borers, beetles, caterpillars, codling moth, gypsy moth, loopers, leaf miners, spider mites, tent caterpillars, thrips and more! Use on fruits, vegetables, berries, citrus, grapes, nuts and ornamentals and approved for organic gardening.

For additional information, see the following fact sheets which are available from local university extension services:

https://ecommons.cornell.edu/bitstream/handle/1813/43086/codling-moth-FS-NYSIPM.pdf

http://extension.psu.edu/plants/tree-fruit/insects-mites/factsheets/codling-moth

 Reference in this publication to any specific commercial product, process, or service, or the use

of any trade, firm, or corporation name is for general informational purposes only and does not

constitute an endorsement or certification of any kind by Royal Oak Farm.

People using spray products assume responsibility for their use

in accordance with current label directions of the manufacturer.

Time for the Spring Dormant Spray

It's time to begin thinking about a dormant oil and copper spray for your fruit trees! The apple trees are at silver tip in the orchard here at Royal Oak Farm Orchard in northern Illinois and will green tip this week with the nice temperatures.  That is a sure sign that spring has arrived!! It also indicates that just as soon as the nights stay above freezing, it will be time to do a dormant oil and copper spray. The oil (mineral oil) is sprayed for mites, scale and aphids because spring is the time to cover those eggs at the base of the buds before they begin to hatch.  The oil smothers the eggs and they suffocate before hatching.  Below you can see aphid eggs that were laid last fall.
 

 

Copper is also sprayed at this time for control of fire blight and to aid in the suppression of apple scab pathogens, both being severe diseases that can destroy a crop as well as the trees. We also have to be aware of the spring critical temperatures as the buds progress in development. Each spring I post the spring critical temperatures chart from Utah State to help you determine at what stage your fruit trees may be at as spring progresses.

 

Ever wonder how the fruit trees know when it's time to come out of dormancy? Well, the trees won't come out of dormancy until they have endured a certain amount of time with temperatures between 32 and 45 degrees Fahrenheit. Once the number of chill hours they need is achieved and temperatures warm in the spring, the trees come out of dormancy and resume their normal growth. The number of hours required at cooler temperatures is known as the chill requirement or chill hours.  Most apple varieties require 400-1000 chill hours, so most of the trees in our area have met their requirement and will come out of dormancy just as soon as temperatures warm. Growth resumption can be predicted by tracking what we call growth units. Growth units are the number of degree hours above 41 F. For example, if the temperature averages 51 F for and hour, then 10 degree units are accumulated. Bud break initiates after approx 3710 F growth units accumulate, and progresses depending on the temperature. We do our dormant oil and copper spray generally around April 10. The best time to spray is at silver tip....when the buds have that silvery/gray tinted fuzz on them. You can use the chart below to determine the growth stage your trees may be at.

 

As I mentioned earlier, now is the time to do our fire blight copper spray and our horticultural oil spray.  We want to get the copper on the trees before they reach full 1/4” green and the horticultural oil can be sprayed at the same time in a tank mix or done as a dormant,silver tip,green tip, or 1/4” green spray.  In other words, your oil can be sprayed at any time from silver tip through 1/4” green providing you are using a mineral oil based product such as Superior Oil 70sec or an off the shelf Horticultural Oil such as Bonide’s All Seasons Horticultural Spray Oil.  Your copper spray should be done before the trees reach 1/4” green to avoid any phytotoxicity issues.  For your copper spray you can also use an off the shelf brand such as Bonide Copper Fungicide RTU (Ready to Use).  Both of these products should be available at your local hardware store or garden center of from Amazon.com.

A dormant oil and copper spray should not be done until we get at least a 24 hour period that is above freezing at night. The oil cannot freeze on the trees, but it pretty much dries within about 24 hours. Once dry, there is no chance of it freezing.  We usually get at least one 24 hour period above freezing at night before the trees get to 1/4" green. 

This “window of opportunity” for dormant sprays for fruit trees depends on the bud stage of your target fruit tree. You can follow these guidelines:

Apples: swollen bud to 1/4” green
Pears: swollen bud to cluster bud
Peaches/Nectarines: swollen bud to pre-bloom
Apricot: before bloom

When applying, spray trees just until they are dripping to get good application on all the stems and crevices at the buds. If you are using horticultural oil alone, use a rate of 2% (mixed in water) for best results or follow your chosen product’s label rate.  For situations where aphids have been real problems in the past, consider adding an insecticide (such as acetamiprid, etc.) to 1.5 - 2% oil or use one of the Bonide RTU (ready to use) pre-mixes for insect pests.

 

For get our Growing Guide on maintaining your trees and Resources for the Home Orchard Grower of the above charts, visit our Nursery Growing Guide web page!

Planning for Pest Management for the 2019 Growing Season

Many homeowners enjoy raising their own fruit, but anyone who has attempted to grow fruit in their backyard knows that fruit crops are attacked by a wide variety of insect and disease pests and prone to environmental damage, especially in the Midwest.  For your Home Orchard, we recommend the use of an entirely new approach to managing pests called Biointensive Integrated Pest management (Bio-IPM) to minimize the insect and disease damage to your fruit. Biointensive IPM utilizes a systems approach to pest management based on an understanding of pest ecology and tree physiology.  It begins with steps to accurately diagnose the nature and source of pest problems, and then relies on a range of preventive tactics and biological controls to keep pest populations within acceptable limits.  The preventative tactics include a combination of ecological, biological, natural, and cultural controls to keep applications of chemical and organic controls to a minimum. The goal is only to spray as a last resort for the control of pest and disease and to only use the most environmentally friendly materials.

In the northern regions of Illinois and in most apple growing regions east of the Mississippi, there are four main pests of apple trees.  Those four main pests are plum curculio, codling moth, apple maggot, fire blight and apple scab. To learn more about these pests and how to control them, you may want to download the available pest fact sheets  and the "Managing Pests in Home Fruit Plantings" guide from Purdue University available here or on our web site. This publication provides homeowners with the information they need to produce an acceptable amount of quality fruit (apples, pears, peaches, plums, cherries, grapes, strawberries, raspberries, blackberries, currants, gooseberries).

  

Often there are enough beneficials (insects that prey upon other insects) to control the pest(s) in your orchard without spraying.  On other occasions you might use traps to catch pest species as they enter your orchard, or determine from the traps that there are too few of the pest to cause serious damage to your trees or fruit. But if you do have to control insect pests, there are many new all natural products on the market today that can be a 100% ecological solution.  One of those products is spinosad. Spinosad is a natural substance made by a soil bacterium that can be toxic to insects. It is a mixture of two abcterium called spinosyn A and spinosyn D. It is can be used to control a wide variety of insect pests. But  always, as a last resort, reduced- risk pesticides may need to be used if other tactics have not been adequately effective, and with care to minimize risks. 



 As the growing season approaches, now is the  time to determine what pest problems you had last season, or may have this season, and what the best approach is to handle those problems.  As the various stages of tree growth develop, so does the growth of pests.   The "Managing Pests in Home Fruit Plantings" guide will provide for you a chart of the growth cycles of the tree and a spray guide chart to let you know what pests are prevalent during those growth stages.  The "Spray Guide" will give you a list of environmentally friendly products you might need to use against those pests as a last resort.  Remember, spray chemicals is a last resort, but is also necessary if bio-controls are not working on your pests.


 
The benefits of implementing biointensive IPM include reduced chemical input costs, reduced environmental impacts, and more effective and sustainable pest management.  An ecology-based IPM has the potential of decreasing inputs of natural chemicals and synthetic chemicals - all of which are energy intensive and increasingly costly in terms of financial and environmental impact.  All these efforts make it possible for you to apply chemical controls only a few times each season when they are truly required. And we can recommend the use the most environmentally friendly materials available in our Nursery Center.      

I hope you find this post useful!  As always, if you have any questions contact me anytime via comments or through our web site!

Japanese Beetle Emergence

Figure 1.

Japanese Beetle emergence has begun here in Northern Illinois.  I noticed the first beetles on Monday and today they were in full view on our Honeycrisp trees (Figure 1).  Due to the large amount of carbohydrates produced by the Honeycrisp trees, which is what makes the variety so sweet, the Japanese Beetle is seemingly attracted to it just like we are!  Honeycrisp seem to be the first leaves that attract them and then they move on to raspberries and several other berry varieties.  

 Monitoring for Japanese Beetle

Adult Japanese beetles emerge from the soil and live from 30 to 45 days feeding on plants over a four-to-six-week period.  The adults produce aggregation pheromones that attract individuals (both males and females) to the same feeding location. Adults can fly up to five miles to locate a feeding site; however, they tend to fly only short distances to feed and lay eggs.   The adult beetles normally emerge during the last week of June through July. The first beetles out of the ground seek out that suitable food , like Honeycrisp, and begin to feed. These early arrivals then begin to release that aggregation pheromone (odor) that attracts additional adults. Newly emerged females also release a sex pheromone that attracts males. After feeding and mating for a day or two, the females burrow into the soil to lay eggs at a depth of 2 to 4 inches. Females lay 1 to 5 eggs before returning to plants to feed and mate. This cycle of feeding, mating and egg laying continues until the female has laid 40 to 60 eggs. Most of the eggs are laid by mid-August though adults may be found until the first frost. The eggs hatch in 8 to 14 days and the first instar larvae dig to the soil surface to feed on roots and organic material. The first instars shed their skin (molt) in 17 to 25 days. The second instars take 18 to 45 days to mature and molt again. Most of the grubs are in the third instar by late September and by October they dig deeper into the soil to overwinter. The grubs return to thesurface in the spring as the soil temperature warms, usually in mid-April. The grubs continue their development and form a pupa in an earthen cell 1 to 3 inches in the soil. 

Figure 2.

When you see those first few beetles, that is the time to begin you plan of attack.  Those first few beetles are the food source scouts that will emit the aggregation pheromone letting other beetles know that a feast is on! The Japanese beetle adults feed through the upper leaf surface (epidermis) and leaf center (mesophyll), leaving the lower epidermis intact. Adults usually avoid feeding on tissue between leaf veins, resulting in leaves appearing lace-like or skeletonized (Figure 2). Controlling those first few beetles can give you a head start on stopping the feeding/mating cycle.

 Control for Japanese Beetle

There are some control options for the adult life stage One is physical removal and/or trapping of adults:  Removing beetles by hand, or trapping, may provide adequate protection  for  small plantings  when  beetle  numbers are low.  However, Japanese  beetle  adults  are capable  of  migrating  from  other  areas,  and  the presence  of  beetles  on  or  near  a  plant  will  attract more   beetles.  Consequently,   use   of   Japanese beetle traps often attracts more beetles, and results in subsequent damage to plants. 

Figure 3.

The other alternative is chemical control of adults:  Several insecticides are labeled  for  use  against  adult  Japanese  beetles.  Always  follow  label  directions.    Treat  foliage  and flowers thoroughly.  For optimal control, apply in the late afternoon when beetles are most active. Several insecticides can be used for apple maggot control including those used for codling moth and apple maggot control like acetmaprid.  There are others like Sevin, but I do not recommend the use of Sevin since it is toxic to bees and to beneficial insects.   Acetamiprid is a soft, conventional control and is available as  Ortho Flower, Fruit & Vegetable Insect Killer (Figure 3).  This is a ready to use product that contains .006% acetamiprid, a synthetic organic compound of the family of chemicals that acts as neonicotinoid insecticides. Acetamiprid is a contact insecticide for sucking-type insects and can be applied as a foliar spray or a soil treatment.  When sprayed in the evening at sunset, it will not harm bees or other beneficial insects. 

 
If you do choose to use chemical controls make sure that the plant you are applying to is listed on the label as well as Japanese Beetles. If controlling Japanese Beetles on food crops such brambles or apples – make sure to follow the harvest-restriction date on the label. Always READ and FOLLOW the label and do not apply at rates higher than listed.

This publication contains pesticide recommendations that are subject to change at any time. These recommendations are provided only as a guide. It is always the pesticide applicator's responsibility, by law, to read and follow all current label directions for the specific pesticide being used. Due to constantly changing labels and product registration, some of the recommendations given in this writing may no longer be legal by the time you read them. If any information in these  recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned, nor is criticism meant for products not mentioned.  The author assumes no liability resulting from the use of these recommendations.