Components of the Balanced Organic Systems Approach

Orchard Site Selection and Design

The best corn field is not the best fruit orchard. The soil’s high fertility, lack of slope, and high water-holding-capacity would make for a difficult orchard site. Additionally, any site that has heavy clay, poor water drainage, and limited exposure to sunlight will also prove in time to grow fruit poorly if at all. Selection of the orchard site forever defines the orchard’s potential for growing excellent organic fruit.

Sun & Air

Sunlight exposure and air movement are the two most effective organic tools the orchardist can apply in the orchard. And the best way to set your orchard up for healthy sunlight exposure and air movement, is simply choosing the right site. Once the site is chosen, attention turns to tree row orientation and proper spacing.

Orienting the tree rows north to south provides each side of the tree with sunlight during the day. Sunlight kills tree and fruit disease organisms. Good air circulation allows foliage to dry more rapidly in between rains or after humid weather. Drier foliage means less fungal and bacteria disease development within the tree. Wider tree row spacing and greater distance between individual trees improves sunlight penetration into the tree and enhances air movement in the tree canopy. The resulting suppression of fruit and foliage rot also enhances the effectiveness of any organic pest management practices used by the orchardist over the life of the orchard.

Alternatively, when tree rows are planted east to west, the north side of the row will receive little direct sunlight, which will raise the risk for fungal and bacterial disease development in the tree and on the fruit. This fungal and bacterial disease development can be made even worse in orchards where the trees are planted too closely together; their shaded canopies create a nearly ideal environment for things like apple scab and powdery mildew to thrive.

Slope

The slope of the orchard plays an important role in the site’s suitability to grow fruit. Orchards planted on flat ground generally don’t thrive. They are often susceptible to soil drainage issues (like collar and root rot) as well as reduced air circulation in the tree canopy which can result in more fruit diseases. A gentle slope improves air and water movement and increases exposure to sunlight.

Soil

The suitability of soil type and soil drainage for fruit trees is of critical importance in growing strong root systems and fruitful wood on the tree. The orchardist is looking for a soil that is moderately fertile and has the capacity to drain off excess water during all seasons of the year in order to prevent root and trunk rots. Not all soils are naturally perfect for fruit production so improvements to nutrition and soil drainage can be made if deficiencies are not too great.

Although site selection and orchard design occur early in the life of the orchard, once decided upon, they have a daily effect on the quality of the fruit and the success of the orchard for the duration of the orchard’s existence.

Water

The experienced orchardist knows that water in its many forms both supports the orchard’s fruitfulness and can be the orchardist’s biggest headache. Water can make trees and fruit grow or destroy soil and wash away orchard roads. From initial orchard establishment to the daily management of tree and fruit growth, awareness of water is the foundation to success. The extremes of flood and drought must be expected and addressed throughout a single season and throughout the life of the orchard.

From my personal experience, water is a challenge that I have not always been prepared for during the growing season. I once planted young apple trees with no irrigation. Soon after planting the weather turned hot and dry. There was no significant rain and it was over 90 degrees F each day for weeks. All my wife and I could do was haul tanks of water from my pond up the steep orchard road to water each of thousands of trees by hand. At best my goal was to keep the trees alive. Most of the trees did live but I mis-spent valuable time and effort because I hadn’t prepared for drought from day one of orchard planting. I had to let other important tasks go undone. Weed control, early tree support and trellising were all delayed in order to keep the thirsty trees from dying. My lack of planning rippled across the orchard. Not a good way to start. My advice to you: expect drought, don't naively wish it away to a more convenient time.

Drainage lines are placed in the soil if some spots of the orchard drain too slowly. Poor water drainage encourages disease organisms that rot roots. The foundation for the irrigation system should be in place before the first tree is planted (a lesson I learned the hard way) so that the orchardist is ready for the day of drought when trees and fruit need more water than natural rainfall provides. Water within the tree canopy must also be managed. Extended periods of rain on leaves and fruit will result in leaf lesions and rots. The organic orchard solution is not more sprays but improving orchard climate conditions so that the leaves and fruit dry off more quickly, therefore inhibiting leaf disease lesions and rots. A well-chosen orchard site can provide well-drained soil and wise tree pruning can improve sunlight and air movement in the tree leaf canopy. Variety selection and timely harvests can help the orchardist to avoid cracked fruit during seasons of heavy rain. A balanced approach to water and its systematic management in the orchard turns water from a potential disaster into an orchard asset.

Fruit Variety Selection

When you pick an apple to eat, how do you choose? Do you like a sweet apple like a Gala or something more tart like a Granny Smith? Maybe red apples appeal to you more than yellow. Or is it that you like the first apple of the season, no matter the type? There are so many varieties of apples to choose from before the first bite or the first tree is planted in the ground. That first bite, that first crunch will tell you if you have made the right choice. However, when growing apples it may take 5 years before you know if you have chosen wisely. Because apple trees produce fruit for 20 to 25 years, it will be a long time before you can make that initial choice again.

Fruit variety selection is normally based on consumer demand and how it fits into the farm’s approach for fruit-growing and fruit-marketing. Organic fruit growers consider additional characteristics which will determine a variety’s suitability for organic production.

Every apple, peach, and pear variety is different. Some varieties have natural genetic resistance to common fruit diseases. Others may be less attractive to insects. Some fruit is less likely to rot or have insect injury simply because of the timing of the fruit’s ripening. Some varieties grow more vigorously resulting in thick growth and shaded tree canopies which increase the risk for leaf and fruit diseases. Some fruit varieties are best picked and sold quickly to maintain fruit quality and reduce the potential for rot while other varieties may hold well in cold storage providing the orchardist with quality marketable fruit many months after harvest.

The fruit varieties chosen and how they are each individually managed provides the foundation for balancing the organic orchard system and ensuring its ultimate fruitfulness. Focusing on the growth and pest requirements of each variety is the first step in a systematic organic approach. Balancing the farm business and market requirements with the growing and fruiting characteristics of each variety will direct the orchardist’s choice in fruit varieties and lead to successful organic fruit production.

Pollination

You know what I think of when I think of pollination—bears! Over the years I have managed many bee hives. I enjoy honey bees. I am amazed by their organization and single-minded determination to act as one unit. I found—over time—that the less I interfered the better. I planned all year to give my hives all the support I could in order for the colony to be ready for bloom and pollination in May of each year. My hives were well-placed for sunlight and air circulation. They had an abundant food source of native flowers which would supply the bees with nectar and pollen for rearing their young and building strong honeycomb. But local bears thought I was building up all my hives for them. Sure enough the hungry bears would emerge from their dens after a long winter and search out my hives for some tasty bee larvae and honey. The bears don’t just lick a little honey and move on, they eat it all! They smash the hive to bits searching out every drop of honey and every young bee to feast upon. Smashed hives also mean a steady release of 50,000 angry bees. After a visit by a bear the adult bees are still alive and well—ready to sting any warm blooded animal within 100 yards of the hive remnants. So not only did I have ruined hives right next to my orchard at bloom but I had angry bees to contend with as I cared for the orchard during the critical bloom period. So, when I think of pollination, I think of bears. Beyond bears, there are many other things an orchardist has to plan for and consider in order to be ready for a good pollination season.

Pollination is not simple. Achieving successful pollination is far more complex than placing a hive of honey bees in the orchard at bloom. Fruit varieties, the previous season’s growing conditions, pruning, fertilizing and weather conditions all contribute to orchard flowering and pollination.

Most pollinating insects perform best when it is warm and sunny during bloom. Honey bees are very active and provide very effective pollination of flowers when it is warm. However, honey bees do not perform well when it is cold and wet. But many native pollinating insects will actively pollinate flowers during cooler, less ideal conditions. Their numbers, however, may be too few to fully cover all the flowers in the orchard. The number of native pollinators available to visit flowers during bloom is dependent on how effectively the orchardist has managed the habitat that supports native pollinators in and around the orchard. Some orchards achieve very effective pollination with native pollinators alone, while other orchards must routinely bring in honey bee colonies to set a full fruit crop.

High temperatures during bloom will cause the flowers to open quickly resulting in a short pollination window of time. In this case it’s an “all hands-on deck” situation. The more native pollinating insects and honey bee colonies in the orchard, the better the chances for successful pollination. If the orchardist has encouraged native pollinating insects and planned ahead with honey bee hives that are available during bloom, then the orchardist can anticipate an abundant harvest. Planning for extremes in weather reduces risk of crop loss not only at bloom but at every other stage of growing fruit.

Understanding and balancing the needs of the orchard, the pollinators, and the effects weather has on pollination will contribute to an abundant fruit crop at the end of the season.

Tree Growth and Fertility

Before we begin our discussion on fertility, let me take a minute and tell you a story about chicken manure, a topic only an organic farmer could love. I had an orchard that was in desperate need of nitrogen. I thought to myself, what better source of nitrogen for an orchard than chicken manure? It was readily available in my area from the many local chicken houses. Those farmers were always looking to get rid of manure and it was inexpensive unlike most of my other fertilizer choices. I did my homework. I got nutrient analysis for my soil to show I needed the nutrients the chicken manure would provide. I tested the chicken manure for nutrients and calculated the rate of manure per acre I should apply. I checked with my organic certifier to make sure I could use chicken manure and I double-checked my application window to be certain I stayed in compliance with USDA organic standards. I got my tractor ready with a front end loader. I borrowed a pull-behind custom manure spreader that I could calibrate and that would only deliver manure to the base of the trees. I was set. Application went well, my delivery and rate of application was near perfect. But, did you know chicken manure right out of the chicken house is very sticky and really smells? I didn’t know that. I had chicken manure all over the tractor, in the bucket, on me and my boots and clothes, inside the tractor cab-everywhere, I cleaned and scrubbed for days. I couldn’t even take my clothes into the house. The chicken manure worked perfectly. I got my hoped-for fertility improvement in my orchard. My trees responded exactly as I hoped they would but I never used chicken manure in my orchard again. From then on my focus was to use compost wisely with commercially available nutrient supplements. That approach worked well too and there was no smell or nasty clean-up. But smelly tractor tires are not the only thing to consider when it comes to using fertilizer.

If you look at your orchard and you notice the trees are not really green but yellow, what do you do? Or maybe you notice the trees are huge, growing three feet of new shoots by mid summer but without very many apples on the tree, the fruit you do have more green than red or yellow. Have the leaves on the inside of the tree turned yellow and fallen off? You may be thinking, now what’s the problem? The problem is that the nutrition in your orchard is out of balance. There is too much or too little fertilizer or maybe the wrong fertilizer has been used to meet the needs of the trees and fruit. Don’t despair, the situation can be changed or avoided in the first place with a little understanding of balanced fertilizer application.

If tree growth is poor the first solution considered is often to apply more fertilizer. But that isn’t always the best solution. Low fertility may be the problem, but yellow leaves and poor fruit quality can have other causes. Applying too much fertilizer or the wrong fertilizer is very detrimental to orchard health and fruitfulness. A successful organic fertility program has the goal of reaching a balance between tree, shoot, and leaf growth while at the same time supporting the current season’s abundant, healthy fruit crop. It is important to identify as many of the factors that may be limiting new growth as possible. This helps the orchardist to pinpoint the problem and apply the correct remedy, whether that’s fertilizer or something else. Some fruit varieties grow more slowly than others. Close observation in the orchard will instruct the orchardist as to which varieties naturally produce more or less shoot growth. Another factor that may limit growth is an imbalance of nutrient uptake by the tree due to low or high soil pH. The nutrients needed by the tree for growth may be in the soil but unavailable to the tree due to a chemical imbalance in the soil caused by a soil pH that is too high or too low.

Understanding the cause of poor tree growth and correctly responding to the cause provides the best result for the balanced orchard. Adjusting fertilizer application, calibrating pruning severity, and maintaining an even crop load is necessary in order to achieve the desired tree growth and fruit production for current and future harvests.

Pruning

Pruning requires an understanding of balance within the tree. Pruning not only manages tree growth—it also opens the tree to sunlight and air circulation. Sunlight and airflow can suppress many diseases including fruit rots. Pruning also enhances fruit color and next season’s fruit bud development.

Although there are general ‘rules’ the orchardist adopts as a guide for pruning, each tree should be pruned to the individual needs of that tree. Dead or diseased branches are removed to prevent disease spread. Branches that are growing too close to one another or are crossing over each other are removed to improve sunlight interception in the tree. Large branches are removed to improve sunlight and air circulation. Branches growing straight up or down are removed. If the tree is growing on a trellis, branch position is changed to suppress too much growth in branches growing up or too little in those growing down. Removing branches also stimulates growth resulting in new fruiting wood and fruit buds for future crops. But even new growth must be balanced. Too much growth and the tree suffers from poor light and air circulation within the tree, poor fruit quality, and even greater disease susceptibility. Too little growth and the tree may lack healthy fruiting wood, fruit buds may have reduced fruit set and yield, and fruit may experience sunscald from too much exposure to the sun.

When I think of pruning I think of cold, crisp winter days. Pruning isn’t done only on dormant winter days but this is the pruning season I have enjoyed the most. Dormant season pruning to me means a thermos of hot tea and honey and having the off-season privilege of looking around, enjoying the landscape and the view. Sometimes during the pruning season the snow was so deep I wore snowshoes so that my feet weren’t buried in snow all day long. Pruning during the off-season also meant I had time to focus on my task single-mindedly, really getting to know the orchard and each individual tree.

Pruning is a special time for the orchardist to learn about the orchard and how it has been growing and fruiting over the last year. Each tree has a story to tell. Has growth been excessive (which the orchardist learns by observing new shoot growth throughout the tree)? If so, perhaps too much fertilizer has been applied. Or maybe the trees received too much water or excessive pruning the previous season. If growth was poor over the last growing season the orchardist may decide that soil fertility tests are needed to guide fertilizer application. Balance is truly the guide to understanding a tree’s health, its fruiting, and the wise application of pruning.

Orchard Insects

Understanding the insect groups and learning when and where they occur will help you to focus on the insect of the moment and not become overwhelmed. There are very effective synthetic insecticides that control these insects but they are not approved for organic fruit growing and they can have negative effects on the natural orchard balance.

Take heart. There are many natural pest insect controls available to the organic orchardist. It is true that they must be understood and used in a balanced approach, but they are available and they are effective in controlling pest insects. Bolstering orchard fertility also makes leaves and fruit less susceptible to insect damage. Orchardists can choose fruit varieties that are less impacted by some pest infestations. And beneficial insects can help suppress pest insect populations. When managed properly in the organic orchard, beneficial insects can be just as diverse in type and effect as their pest insect counterparts.

Many beneficial insects will not thrive and protect the tree and fruit from harmful pest insect infestations without an initial presence of pests. The orchardist knows which beneficial insects will respond to early pest populations, understands the biology and life cycle of the beneficial insects, and therefore knows what to expect from the beneficial insect on pest insect suppression once it is present in the orchard.

Rosy apple aphids are good examples of the pest and beneficial insect interaction. Aphids overwinter in the orchard as eggs on the branches while adult ladybugs overwinter beneath tree bark or leaf mulch. The ladybugs are hungry and ready to suppress rosy aphids as soon as the aphids hatch out in the spring. The orchardist's job is to make sure the ladybugs are not killed in the late season or early spring through harsh orchard practices. Overwintering sites of ladybugs must be protected. Understanding and promoting the delicate balance that exists between pests and beneficial insects provides the insight required to promote beneficial insects while suppressing the pest insects. Wise management of the balance between pests and beneficial insects provides the organic orchardist with an effective and dynamic living tool to combat pest insect damage in the orchard.

Fruit Rots & Leaf Blights

Disease outbreaks in the orchard may seem overwhelming and completely unpredictable. Too often everything appears to be going well: trees are healthy, fruit is growing nicely and then from apparently nowhere, lesions appear on leaves and fruit begins to rot. What happened? How can the orchardist possibly grow healthy fruit with an unseen foe? Must the orchardist always be blindsided by disease outbreaks in the orchard or are they predictable and preventable? With a systematic, balanced approach to managing the diseases of fruit crops, fruit diseases are both predictable and manageable by the organic orchardist.

Right up front I’ll tell you the key to understanding and suppressing fruit diseases in the organic orchard. It’s a principle that every farmer and plant disease specialist knows and relies on to suppress diseases on any crop. A plant disease will only occur given these three conditions:

1. a plant that is susceptible to disease

2. a disease-causing organism, and

3. a favorable environment

in the orchard where infection and disease development can occur. That’s it.

If any one of these three disease components are missing, disease will not develop.

Disease control for every crop comes back to limiting one of these three components. The orchardist’s focus in fruit disease management is to prevent all three of these conditions from occurring at the same time in the orchard. Furthermore, the orchardist can predict when the conditions of susceptible fruit or leaves, the presence of fruit disease organisms, and the favorable environmental conditions will all exist in the orchard at the same time. With this prediction, the orchardist can plan and take steps ahead of time to reduce or suppress one of the disease components in order to prevent future disease infection in the orchard.

Day to day, disease control in the organic orchard is based on the application of cultural practices and timely spraying of organically approved materials. Orchard scouting and daily weather collection provides direction for the orchardist so that they may predict disease development and the potential for disease outbreak. In the long term, organic orchard success relies on many practices built upon from the first day the decision is made to grow organic fruit. The broad use of multiple tactics can prevent leaf blights, fruit rots, and sudden tree death in the organic orchard, transforming these problems from mysterious troubles to foreseeable, explainable, preventable situations.

Weeds

So, what are weeds? Weeds are plants that are growing “out of place.” Native flowering plants that contribute to supporting beneficial insects may often be referred to as a “weed,” but in an orchard setting they may be a valued asset, helping the orchard to build its native pollinator insect population. Or they may compete with the tree for water and nutrients. Or they might serve as a host to viruses that are detrimental to the fruit tree. The first step in managing weeds is to identify which plants in the orchard are weeds and which plants serve a beneficial purpose. Weeds are most successfully managed in the organic orchard by balancing the application of several weed suppression practices. Weed control begins before the first fruit tree is planted. The orchardist must attend to perennial weeds, especially ones that have deep roots and a long-lived potential for robbing the fruit tree of nutrients, water, and/or sunlight. Orchard site and soil preparation provide the opportunity for eradicating perennial weeds and inhibiting annual weeds and weed seeds from accumulating. Focused and balanced weed control continues throughout the life of the orchard by eradicating weeds before they go into seed through mowing, through cultivation, and through the prevention of new weed seed introduction. Weed seeds may be unknowingly introduced by the orchardist when applying organic materials such as manures, incompletely composted soil amendments, and even may be spread when the orchardist uses equipment that was previously used in a weed-laden area.

Scouting - Walking with the Trees

Scouting sounds like a chore. Standing around in the orchard, counting tiny little bugs you can barely see while there’s work to be done does not sound enjoyable. But for me scouting was one of the most enjoyable activities I had to do in the orchard. There are many ways to scout an orchard. My favorite was to ‘walk with the trees.’ Have you ever visited with a friend, found out how they have been doing, what has happened to them recently, what their plans are for the future? In the orchard setting that rendezvous is called scouting the orchard.

Scouting is the key to success in organic fruit growing. If scouting is done poorly (or not at all), the orchard and fruit production will fail. Organic fruit growing requires that the orchard is maintained in its natural balance. To observe whether the orchard is in balance, it must be monitored. The only way to monitor the orchard is through scouting. In the organic orchard the orchardist is not only looking for what’s wrong but also for what’s right. If pests are present, are there adequate numbers of beneficial insects to suppress the outbreak? Are pollinator plants in and around the orchard growing well and flowering enough to build up pollinating insect populations so that they are present at bloom? Are the slow release compost applications made in the early spring supplying adequate nutrition for tree and fruit growth mid-summer? All these questions and many more are only answered through scouting. Managing the organic orchard without scouting is operating the orchard blind.

To first think about scouting and how the orchardist accomplishes this task can be overwhelming to consider. It may seem that the orchard is too complex and that there is too much to see. How can all the potential problems be recognized? Balance and a systematic approach will be your guide to scouting. Rather than relying on a complex process of steps and rules, your practiced understanding of BOSA will be what guides you, what notifies you when something is imbalanced. Your eye will naturally be drawn to what’s wrong. My co-author Tim once worked as a bank teller. He tells me that the way tellers are trained to spot counterfeit money is by seeing many, many real bills. He says when the eye is accustomed to what is real, what is fake really stands out. In the same way, a grower has to have the knowledge of what “healthy” looks like in the orchard in order to be able to spot the “unhealthy” or problem areas. Scouting relies heavily on a systematic approach as well. Your focus in scouting is to look for the specific problems that occur at that specific time of the growing season in their specific location. The orchardist must not be overwhelmed by all the potential orchard problems for the season, the focus is only on what may occur now, where to look for it, and what signs to look for as the orchard is scouted.

The more you scout and ‘walk’ with the trees the more you will learn and the better of an orchardist you will be. Trees are amazing: imagine the capability to be exposed to sunlight, take in air, water, and nutrients and produce delicious fruit. Trees are incredible. They do need some help sometimes and that’s the job of the orchardist.

You will notice I didn’t say ‘riding the tractor seat’ with the trees. By the time the orchardist notices a problem from a tractor seat it’s often too late to avoid a problem. Getting down off the tractor, and walking the orchard rows amongst the trees is what is required; that is ‘how’ you walk with the trees. In walking the orchard, the number one rule is to be observant and to focus. Don’t think about all the things you aren’t getting done. What are you looking for? You are looking for “normal and healthy.” Anything that is not “normal and healthy” should stick out like a counterfeit bill. What do you notice that is out of balance? In time you will notice trees that are off color, or growing poorly, or producing too many flowers, or producing too few flowers. You’ll notice leaf spots, leaves falling off, leaves curling up. All these symptoms indicate imbalance in the orchard.

There are other ways to scout an orchard which fit into everyday tasks. You will learn to practice scouting as other work in the orchard is being accomplished. Pruning in the dormant season provides the orchardist with abundant information on the status of the trees. The orchardist will learn by observing the tree health across the orchard prior to the new season, last year’s growth and fruit bud development, fertility requirements and variety comparisons. Thinning in early or late summer enables you to look closely at the fruit which provides you with information about yield potential, stage of ripeness, and the presence or extent of fruit injury. Effective scouting is both a deliberate activity and an opportunity taken.

When you can see and understand the balance that naturally exists in an organic orchard, scouting will itself be a natural outcome. A systematic understanding of the orchard’s complexity will provide clarity and direction to scouting. It’s worth repeating: the more you ‘walk’ with the trees the more you will learn and the better of an orchardist you will become.

Weather

My wife Donna had a friend who was going on a date with a farmer. Donna’s friend was not a farmer. She asked for suggestions of things they could talk about on their date. I suggested they talk about the weather. Every farmer loves to talk about the weather. The weather is so important to farming and it drives both abundant harvests and crop loss. Most farmers have plenty to say about the weather and certainly understand the impacts major weather events have on their crops. In fruit growing it’s the day-to-day weather and microclimate around leaves and fruit that regulate fruit development, pest and disease outbreaks and the orchardist’s daily work schedule.

Weather’s impact on organic fruit growing is often the misunderstood component to a successful season. The impact of different weather events can appear random, unexplainable, and unpredictable. But that isn’t completely true. The weather in the orchard can be measured and its potential impact can be understood and predicted. If the orchardist can record, analyze, and understand weather events that occur in the orchard, weather events will not result in confusion and unexpected surprise, instead providing critical information to orchard decision making for insect pests, diseases, and fruit development.

In a discussion of balance within an orchard and a systematic approach to orcharding, the collection of weather information and its utilization in decision-making is central. Weather collection and analysis can provide something that is very amazing: it can predict the future. What insects, diseases, fruit quality, and yield will occur tomorrow depends entirely on what the weather has been and is today. Knowing what the future may bring based on understanding the weather completely changes the grower’s odds for success and confidence in growing quality organic fruit.

Weather collection may seem a daunting task. You may think that expensive weather machines that require constant maintenance, reams of daily weather records and complex mathematical models are required to make informed orchard decisions. Who’s got time to spend a day a week on weather collection and analysis? This is where some balance and a systematic approach can make sense of weather information collection. Although some orchardists may require the machine-based system previously described, a much simpler approach will serve most fruit growers well. Weather collection and utilization can be tailored to the orchardist’s time and resources and orchard decision making requirements. Consistency is the key to collection of useful weather information. Basically, a thermometer, rain gauge and some daily observations of weather events will serve most growers very well in orchard decision making. The thermometer is read each day at the same time of the day. The rain gauge must be read and emptied after each rain event. A few short notes on the day’s weather is all that’s needed to provide an abundance of support in orchard decision making. A weather machine offers automation in weather information collection but you can just as well do it yourself with very little hardware expense.

Most often when farmers talk about the growing season it’s a discussion about the weather and its impact on crop growth and, ultimately, yield. For example, insect growth is dependent on temperature. Knowing the last weeks’ temperatures can guide decision making. During hot dry weather mite populations can explode. Knowing this the grower can begin scouting for mites and mite predators on leaves as the temperature increases in the summer. Dry humid conditions early in the spring encourages the disease powdery mildew while other fungal disease organisms require wetness for infection. Dry or wet spring weather will key the grower in on which diseases are most likely to develop in the orchard. With this weather information in hand the orchardist is guided on the best management approach for the diseases of highest risk. Open flowers are susceptible to fire blight infection if it’s wet and temperatures in the orchard are over 65 degrees F. But if there is extended wetting and it’s only 58 degrees F when the flowers are in bloom, there is no risk for infection. The grower need not be concerned. If the orchardist knows it’s warm but hasn’t measured the actual temperature, then they may be tempted to spray an organic material just to be safe. This wastes time, money and resources when a simple thermometer may have prevented the waste.

Similarly, a rain gauge keeps the orchardist informed on how much water the orchard is getting, providing guidance in drought risk assessment. A few notes on the type of rain received during a weather event may also allude to the potential for disease spread and risk. Some fungi and bacteria like black rot and fire blight survive in wood cankers and must be rain slashed by hard driving rain in order to spread and cause infection. A gentle mist or fog may reduce the risk for such diseases but will aggravate other orchard diseases causing leaf and fruit lesions. When it comes to growing fruit, a little knowledge, measurement, and observation takes the guesswork out of dealing with weather.

If you’re inclined to weather machines or hour-by-hour agricultural predictive models, you’ll find that they can in fact save money and time over the long run. Weather machines are an investment and a time and money saver if used wisely.

Weather’s influence will be a common theme woven throughout this site from horticultural practices to pest management and fruit harvest. A wet spring triggers later season fruit rots. A dry spring promotes mites which can quickly turn a green orchard brown by sucking chlorophyll out of leaves. A systematic and balanced approach to weather collection and interpretation is highly valuable for day-to-day decision-making and for foreseeing future orchard events.

Now that we’ve begun to discuss orchard sites, water, variety selection, fertility, pruning, insects, rots, blights, weeds, scouting, and weather — let’s take a step back for a big picture example of all the BOSA elements interlacing during a very common, real life orcharding event: apple bloom and fire blight.