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High Humidity = Bad Hair Days and Brown Rot.

Rain puddle from big summer rains 2015

Heavy morning dew and thick air make some summer days at our Ozark orchard–long. Sticky oppressiveness not only signals peach season but also Monilinia fruticola, a vicious fungus that destroys stone fruit. Wanting warm and wet conditions, brown rot thrives in rainy periods with degree days above 70 when precipitation and wind speed the spread of fungus spores. Peaches and nectarines are under particularly intense pressure from brown rot. The ideal moist and lush environment develops as fruit ripens and softens in too much condensation, and multiplying fungus spores quickly rot crops before, during, and after harvest. Split pits caused by high rainfall and infection dispersed by feeding Japanese and Green June Beetles further advance decay. Yuck.

Our first and best defense against brown rot is good cultural practices. Because we are an integrated pest management (IPM) orchard, we coordinate several tactics so that we can grow fruit without relying excessively on synthetic pesticides. Sitting high on a ridge, our orchard site is valuable. Young buds have favorable protection against spring frost and trees have improved air circulation in summer humidity. The more open the canopy, the better the air flow, allowing leaves and fruit to dry faster after rain or dew. Both dormant pruning and summer pruning also help create this openness and ensure removal of any diseased fruit and branches. Scheduled thinning is another critical step against brown rot and other pests. Late winter into early spring, we reduce peach and nectarine crops by hand prior to pit-hardening to prevent thinned fruit from maturing to the point that fungus spores can colonize. Eliminating such sources of brown rot stops the most avoidable escalation. Additionally, substituting cover crops for synthetic fertilizers balances nutrition, making trees fitter when insects and diseases assault.

Regular scouting–several times per day even–alerts us to pest damage so that we can promptly decide what if any action to take. Typically, maintaining sound IPM cultural measures lessens dependence on synthetic pesticides. In a summer growing season with low humidity and low rainfall, our orchard might use a fungicide on a 14- to 20-day cycle versus a 7- to 10-day cycle. This reduced spray program is possible only if assimilated with active scouting and solid overall pest management methodology, especially in an Ozark climate that puts fierce disease and insect stress on fruit. Weather determines the severity of this pressure. In a summer growing season with high humidity and high rainfall, fungicides protect fruit crops from rotting. Timing and targeting are key. To minimize potential harm to anything but the target pest, we time a control carefully. To ensure a control is specific to its target pest, we use the minimal amount of material required to effectively prevent disease. Applying an appropriate fungicide mixture early in the morning on a light breeze day, for instance, is more prudent than administering a too potent application in the afternoon on a windy day.*

Moments when the weather will not cooperate and the beetles are too successful can make us pause and wonder how many more seasons are reasonable. Safeguarding native habitat as well as orchard habitat urges us to brave the elements a bit longer, and raising there-are-no-words-to-describe-our-delicious-local-fruit begs us to share. Plus, we deserve some sunshine.

*Mitigating pesticide exposure is out of a concern for our neighbors, ourselves, our dogs, and our wild. A diluted fenbuconazole solution arrests brown rot in our orchard and poses a lesser threat to bees. We continually research and evaluate our controls, working toward as sustainable an orchard system as possible in our climate. Thanks to our entomology friends Dr. Donn Johnson and Research Assistant Barbara Lewis at the University of Arkansas for their many years of effort and to Tree Fruit Research Entomologist Dr. David Biddinger at Penn State for his extensive push to protect pollinators.

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So Much Fruit, So Little Time

Arrington nectarines on the grill

During fruit season at our orchard, there is not much I can or want to do to enhance a peach. I pick and eat a few while on the morning pack walk, seeking out the heavy overripes before the beetles descend. Many of you at Saturday market, however, insist I will “absolutely love” grilled peaches, so I compromised, asking John to try some of our Arrington nectarines on the last heat from coals used for dinner Monday evening. If Arringtons are unfamiliar, they may be a more floral than sweet variety, but they hold up well on the grill–firm and yellow.

I prepared the fruit with the rest of our meal, halving the nectarines stem down and then brushing the cut sides with oil. The coals were tame and the peach wood still smoky when we sat for dinner, so John placed the nectarines on the grill, skin side up, turning them after a minute or so. Covering the grill with a lid may make flipping the fruit unnecessary by the way, and if using gas, heat to medium.

Combined with thick yogurt, some honey, and chopped basil, the grilled fruit made a good end. Topping ice cream with grilled nectarines would also be worthwhile, especially if the ice cream is left to partially melt. Because we had plenty, I tossed the rest of the fruit into our leftover quinoa salad, and this weekend, before Arringtons finish for the season, I plan to grill Halloumi alongside the nectarines. Adding the cheese and fruit to arugula and an easy vinaigrette will be satisfying and uncomplicated.

Admittedly, the deeper into peach season we plunge, the simpler supper usually becomes. On a day with just the dogs, I am content to eat nothing for dinner but the peach saved on my windowsill. Of course, this peach will be the fat, perfumy pound of a white Nectar I’ve looked forward to since the middle of last July. No grilling required.

 

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Fooling with Pheromones–or Moths Keep Following Me Home

Pheromone Tie

Most orchards must deal with two serious insect offenders, the Oriental Fruit Moth and the Codling Moth. They can have multiple generations every summer, and each fertile female lays approximately 100 eggs per generation. That’s a lot of worm damage. Neither of these moths is native to the United States, nor do they have any “natural” enemies to reduce their numbers. As a preventive measure, we use pheromone disruption in early spring to confuse male moths so they do not mate. Suspended from fruit trees in a pattern particular to our orchard, pheromone laden wire ties saturate the atmosphere with the scent of female moths. In turn, the smell disrupts mating, averting egg and worm damage in our apples and peaches. Worth the extra expense, this organic strategy helps us eliminate several insecticide applications annually.

Because of its effectiveness, pheromone disruption has been part of our IPM program for many years, but it is not foolproof. To ensure Oriental Fruit and Codling Moths stay within a manageable range, we routinely scout (our daily dog walks), monitoring for pests and pest damage. This is also a good time to check our moth traps. Concurrent with mating disruption, we hang traps containing pheromone lures that attract male Oriental Fruit and Codling Moths. If we catch more than five per trap per generation, we exceed the minimum damage threshold, prompting us to determine our best control measure. Codling Moth Granulosis Virus is an organic material that we apply sparingly when necessary, and it specifically targets Oriental Fruit and Codling Moths, allowing beneficial insects to progress unharmed. To synchronize this control, we first must establish the number of days until egg hatch (a time period determined by a degree day temperature model).

Almost invariably, pheromone disruption arrests any need for further action against the moths. We choose instead to monitor traps and accept some damage rather than to depend on a calendar based spray schedule that may stamp out all insects–the good, the bad, and the ugly.

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Our Ozark Orchard–Gone Native

Foraging bumblebee in redbud blossoms

I live in the country, on an orchard, so I must be an authority on matters farm-related. Not so. Small town suburbia is my rightful domain, and rural life is unfamiliar. Twenty years in and I’m still learning about what not to take for granted–solitude, birdsong, night sky, bees.

If pressed to choose the insect I’d most like to resemble, I might pick one of the many thousands of bee species native to North America. Perhaps I’d imitate the fast flying Agapostemon, a bright, metallic green bee better known as the sweat bee; or maybe the dread cuckoo who can steal into other bees’ nests masked by pheromones; or possibly the Megachile Campanulae, a leafcutter who lines her home with petals, leaves, and recycled plastic?! John, of course, would choose the blue orchard mason, a bee as fruit obsessed as he.

Many types of these bees call the Ozarks home, and they go largely unnoticed while assisting the local ecosystem. Our orchard, in fact, relies exclusively on wild bees. Their strength and diversity is vital to us considering without these bees, we would have a lot less fruit. Nevertheless, I have underappreciated them. Every spring I stand in the dizzy bee frenzy of full-bloom nectarines, but only now have I contemplated our native bee population, realizing suddenly our good fortune and our responsibility.

Native bees’ requirements are basic: food (pollen and nectar) and shelter (nesting sites). Better habitat, indigenous plants in a number of settings, encourages heterogeneity. This is a big win because a mix of bees ensures an assortment of flowers. Here at the farm, some of our pollinator plantings result by chance and others by careful design, and it’s this array of fields, forest, fencerows, pond banks, ditches, edges, and orchard blocks that protects and feeds our wild bee community. Standing dead trees remain in the wooded areas of our farm, and small, untidy meadows break up the neat, straight rows of apples and peaches. These features lend important nesting prospects by supplying dry, sunny, open spots for ground-nesting digger and bumble bees and hollow rock and tree cavities for feral honey bees. And once cut, the ill-planned stands of bamboo growing thick beside our home will make fine tunnels for leafcutter and mason bees.

Nonetheless, we are delinquents rather than do-gooders indulging our expanse of lawn. However sensuous and fresh and green, it fails to provide the varied terrain necessary for native bee homebodies who spend most of their time inside their nests or, when searching for food, close to their nests. As pollinators then, they are especially appealing because native bees forage in a tighter radius, transferring the “right” pollen from flower-to-flower. This behavior is a boon to orchardists but puts pressure on habitat; bee resources need to be nearby and need to coincide. Blossoms and fallen fruit yield adequate farm forage much of the year, and despite our lawnscape, even our yard proper attracts wild bees. A haphazard collection of trees and shrubs and plants mostly characteristic of an Ozark broadleaf forest, beautyberries, irises, goldenrods, black-eyed susans, and asters grow with abandon–lucky rather than calculated wild bee preferences.

My inattention to bee specific blooms spills over to the beds nearest our front door. Although filled with fragrance and color, they were planted with other pollinators in mind, so to the butterfly bushes, I’ll add more salvias, sunflowers, and penstemons, accommodating wild bees’ penchant for yellow, white, and blue. These casual, carefree plantings defy my minimalist partiality, but a variety of flower shapes will suit the tastes and tongue-lengths of many different bees. More native plants also should draw wild bees nearer to the spots I frequent, giving me opportunity for closer scrutiny. I’m curious to know what bees reside here, where they build their nests, and how they carry pollen. By late fall, my bee count notebook will detail entries that can help me assess and improve their environment.

I trust the bees will accept my invitation to forage and nest in our gardens and at our farm long-term. More intentional care to enhance their diminishing habitat is an easy exchange for the value they supply. Our farm is an ongoing experiment that asks how we can maintain a productive orchard within a recovering ecosystem, and our wild bees have been helping with this effort however invisible to us.

 

Resources

The Xerces Society – A nonprofit dedicated to invertebrate conservation. Look for the pdf read Farming for Bees: Guidelines for Providing Native Bee Habitat on Farms.

The Pollinator Partnership – An organization devoted to pollinators–protection of their habitat and their future. The ecoregional planting guide is helpful (Arkansas and Missouri fall into the Eastern/Ozark Broadleaf area).

The Great Sunflower Project – Dedicated to habitat improvement, the site provides a good start for anyone interested in keeping a pollinator count.

Speaking of habitat, Debbie Hadley’s 12 Things You Can Do to Help Native Bees and Michael D. Warriner’s The Buzz on Native Bees are two articles that address ways to better our pollinators’ environment.

A recent find is my soft copy of Heather Holm’s Pollinators of Native Plants: Attract, Observe and Identify Pollinators and Beneficial Insects with Native Plants that details insect interaction with prairie land, woodland, and wetland plants.