The use of pesticides and herbicide has significantly improved vegetable production in which farmers have now been able to produce bigger crops on less land. With pests such as plant diseases, insects, and weed, it can have a detrimental effect on horticultural operations by affecting the quantity, quality and ultimately, the marketability of the crops grown. Therefore, pest management has become an important component of crop production. Farmers often use manmade chemicals as a defence against destructive plant diseases, insects and weeds. When properly used, they can minimize agricultural losses and pest competition. Pest control can be costly by custom applicators, which is why most growers prefer to own their own spraying equipment. Among the many benefits, which include low cost and flexibility, owning and operating sprayers allow farmers to gain more control and independence over the management practices.

Why spraying business is so important in farming ?

When spray chemicals are used in inefficiently, they result in losses. This is since improper and inaccurate application is very expensive and eventually results in chemical being wasted, excessive carryover or crop damage. The success of a pesticide application depends on the pesticide and proper application. Improper application of pesticides can result in inefficient pest control, plant injury or excessive residues.

Pesticides application are a major part of the most crop budgets. There are three main reasons why spraying is an effective approach to ensure success of pest control.

• First, it allows farmers to control the pests even before they start. From proper sprayer maintenance between sprays to make sure the field is at its best conditions, it allows farmers to have a solid plan from start to finish.
• Second, farmers can manage in-season needs. While some pesticides and herbicides should be applied before the crop shows signs of disease or pests, other chemicals have been developed to be suppressive if your crops do begin to show signs.
• Lastly, pest management reduces competition, the alien plants can be highly destructive and difficult to control

Farm operators or applicators of chemicals should be aware of proper application methods, herbicide/insecticide/fungicide effects on spray equipment, calibration and correct cleaning methods. Pumps nozzles, and meters do wear out over time hence, re-calibration is important periodically.

Types of Chemicals

Many farmers run into trouble when trying to differentiate between generic chemicals vs. the ones that are branded. Another question that most farmers ask is whether or not it matters if they?re buying branded or generic chemicals? Although the generics are not identical to the brand, they are still similar in terms of its efficiency. The EPA states that a generic product have the same technical make-up as the branded version, meaning the active ingredient is the same.

Before you head out for a spray: Know these factors

Success of a chemical application can be determined by four factors: mode of action, canopy, water volume and target type/droplet behaviour. How much water required for a plant will vary based on the plant size. An early-season canopy doesn?t provide much of a barrier for target pests, so it may require a lower water volume than a denser, more mature canopy, where more water is required to reach the bottom layers. Thus, more layers require more water, resulting in coarser sprays. Larger more horizontal surfaces are better suited for coarser sprays, whereas smaller, more upright plants need finer sprays. Many broadleaf weeds are well suited for larger, coarser sprays. Grasses and young broadleaf weeds need finer sprays for effective control.

Different stages of plant development are another factor that should be acknowledged. It?s important to time weed and disease management with crop growth, because the crop?s growth and development impacts your timing for post-emergence herbicide applications, as well as when you can apply insecticides or fungicides per label instructions.

Spray Drift is a factor that should be considered with fine sprays. Paying special attention to environmental conditions is key to a successful spray. Temperature inversion, ground fog and lack of air movement are conditions that should be considered before you spray.

Weather conditions can impact how spray application will behave. In warm weather for example, translocated herbicides (i.e. glyphosate) may take longer to act in warm weather or be as effective. PPO-inhibitors, like sulfamethazine, should be used cautiously as temperature rise about a certain temperature.

Get to know your Spray Equipment

A spray nozzle is a simple device used to break apart a fluid flow into a spray pattern. Despite the apparent simplicity of nozzles, there are a very large number of different products reflecting the multitude of ways different industries need to spray various fluids. Spray coverage is dependent upon several factors including tractor speed, rate of diluent and droplet size. Farmers should spend a major portion of their time in preparing and calibrating the application equipment before spray. Therefore, finding the correct type of nozzle type for your needs is essential for a successful application.

Portable sprays that are handheld come in a variety of sizes. Most of the handheld sprayers are constructed of plastic or stainless steel. Backpack mist blower sprayers use a small motor to generate wind which acts as a carrier for the pesticide solution. The calibration is difficult due to variations in speed and flow rate. This type of sprayer is excellent for applying fungicides and insecticides to small acreage. Boom type sprayers use pumps to develop a constant pressure and a static boom equipped with atomizers that break up and direct the spray solution.

For vine crops such as watermelons, cucumbers, and cantaloupes, rates may range up to 100 gallons per acre on mature plants. Sprayers may be mounted on a tractor chassis or self-propelled. Tractor PTO, hydraulics, or independent power source operates the pump. Basic sprayer components consist of tank, pump, pressure gauge, regulator, agitator, hoses, valves, fittings and nozzles. Nozzles are mounted on the boom, which is suspended over the row. Row Crop Air Sprayers use a blower, which generates air that acts as part of the carrier for the pesticide. The spray solution is blown across several rows. Initially, sprayers used a two-way discharge. Cost of equipment and inability to spray during periods of moderate to high winds are two limiting aspects to the use of this sprayer type. Aerial Application involves the use of fixed-wing and helicopters for the application of pesticides. The size of fields and their location often restricts the efficient use of an aerial application.

Types of Sprayer Nozzles

Most agricultural spraying nozzles have a spray angle from 65 to 120 degrees. While narrow spray angles produce a more direct and penetrating spray, flat or wide-angle nozzles can be mounted closer to the target (crop or weed), spaced farther apart on the boom and provide overlapping coverage if needed.

Nozzles have three functions in spray operations: controlling the flow rate, droplet atomization, and droplet distribution. Choosing the right ones is important as each has a specific purpose in the pesticide/herbicide applications. Depending on the type of spray method, application rate and ground speed, there are a variety of spray patterns, angles, shapes and sizes to choose from.

There are three main types of nozzles: Hollow cone nozzles, flat fan spray nozzles, and flooding flat fans/nozzles. Hollow cone nozzles concentrate most of the spray solution at the outer edge of a conical pattern. This type produces small droplets at high pressure, which can easily penetrate plant canopies. Often, foliar nutrients, fungicides, and insecticide spray nozzles are designed this way. Flat fan spray nozzles generate narrow elliptical spray patterns. The spray pattern is uneven; the majority of the spray is deposited near the centre and a lesser amount is deposited at the out margin. Flat fan spray nozzles are often used with broadcast herbicides, soil fungicides and soil insecticides. Flooding flat fans/nozzles are used to apply pre-emergence and post-emergence herbicide. It has a fan pattern deposit and droplets are large.

Nozzle Sizes

If you need to find the right nozzle size for the application, there are two methods that can be used: a simple chart or a simple calculation. If you’re not using a chart, you?ll have to determine the nozzle flow rate at gallons per minute (GPM). The GPM can be determined by calculating the gallons per acre (GPA) times ground speed (mph) times spray width per nozzle (W) divided by 5,940 (constant to convert GPA, mph, and inches to GPM).

Final Steps for Successful Application

With farming, cropping, unexpected pests and shifting chemical needs it is important to develop plans and processes that work for you. After finishing the spraying in the field a crucial step is to make sure all leftover residue is cleaned. Residue buildup can damage the crop due to toxicity. Removing most of the mixture, diluting anything remaining in the tank, making sure that everything that had exposure to the spray gets cleaned. The best way to ensure there is a proper clean up each time is to keep a maintenance checklist and know how to inspect and maintain your equipment and keep it calibrated.