Spray Coverage Key To Uniform Pest And Disease Control In The Greenhouse

Greenhouse growers often are heard complaining that they aren’t getting uniform control of an insect or disease, or that a plant growth regulator has been erratic. Michigan State University Extension says in many of these cases, the problem isn’t the pesticide or plant growth regulator; it turns out that the material was not applied uniformly or didn’t get to where the problem was located.

Apply From Several Directions

Penetration into the leaf canopy of greenhouse crops can be a major headache. Unless there is very good air movement, when plants are widely spaced or the canopy hasn’t yet filled in, foggers, air blast sprayers, smokes or spray applications that don’t flip over leaves will deposit material mostly on the top surface of the upper leaves; relatively little penetrates deep into the canopy or to the underside of the lowest leaves. Changing the spray droplet does increase canopy penetration, but the leaves must still be flipped over by the force of the spray for optimal coverage of the lower surfaces. Applications must be made from several directions to hit leaves shielded by other leaves or other plants. This type of application method will greatly improve insect and disease control in crops with dense canopies.

Check Nozzles For Correct Pattern And Droplet Size

Droplet size is also key to coverage of the plant surface and penetration into unfolding leaves and other hiding places. The smaller the average droplet size, the greater the coverage and penetration. Droplet size is directly dependent upon the type of nozzle, the nozzle size and the pump pressure. Generally speaking, the higher the pump pressure, the greater the proportion of small droplets in the spray pattern. Growers need to check that the nozzles they’re using are of the correct pattern and size, aren’t worn and that the pump is providing the necessary pressure. Many growers change nozzles every year to ensure good coverage. For good coverage of plant leaves, hollow cone nozzles are much better than flat fan nozzles. Also, watch for dripping nozzles because that means they are plugged.

Drench With The Right Volume Of Solution Per Container

Uniform application is also dependent upon the amount of the spray or drench used. Drenching with too small a volume of solution per container means that part of the media might not be saturated and any roots in this area won’t take up the material. On the other hand, applying too much solution can cause overdosing and phytotoxicity. Applying ultra-concentrated materials is convenient because the application equipment is light and can be easily moved, but applying very small amounts of materials uniformly over large areas is tricky.

The bottom line is that no material will work as well as it could unless it is applied uniformly and to the proper area. Don’t let the pressure of everything else that must be done this season cause you to take shortcuts in pesticide and growth regulator applications; you are really wasting valuable time and may put the crop at risk.

Read the full article, “Spray coverage is key for effective treatment results in greenhouse.”

This article was published by Michigan State University Extension. Visit the Michigan State University Extension website for more information on related topics.

Leave a Reply

More From Crop Inputs...

April 1, 2015

Philadelphia Flower Show Draws More Than 250,000 Attendees With Disney Pixar Movie Theme

With more than 250,000 consumers attending the prestigious Philadelphia Flower Show in March each year, it's a great opportunity to get flowers and gardening products into the public eye. This year's show displays took on family favorites at the movies, with a focus on Disney and Pixar films. Check out some of the highlights in our slideshow.

Read More

April 1, 2015

Peace Tree Farms Grows Its Customer Base

Over the past five years, Peace Tree Farms in Kintnersville, Pa., has concentrated on growing its business by providing plant material for the displays at the illustrious Philadelphia Flower Show. We caught up with Peace Tree Farms’ Lloyd Traven to ask about how the Flower Show figures into his business plan.

Read More
protecting bees and pollinators video

March 31, 2015

New Video On Protecting Bees And Pollinators Educates Horticulture Industry Professionals

A new educational video that provides information on the horticultural industry’s essential role in bee and pollinator stewardship is one result of industry collaboration by the Horticultural Research Institute, AmericanHort, Society of American Florists and the American Floral Endowment. “Protecting Bees & Pollinators: What Horticulture Needs to Know,” narrates the current state of bee and pollinator health, provides information on factors that impact pollinators and the environment and underscores the beneficial role horticulture plays in providing healthy pollinator ecosystems.

Read More
Latest Stories

March 31, 2015

Manufacturers Are Taking Biologicals To The Next Level

Through acquisitions and new products, many crop protection companies are making firm commitments to the future of the biocontrols industry.

Read More
OxiPhos_BioSafe2

March 23, 2015

BioSafe Makes Label Changes To OxiPhos And ZeroTol 2.0

There have been some recent label changes made to the BioSafe Systems product OxiPhos, a systemic bactericide/fungicide that reduces downy mildew spores when tank mixed with ZeroTol 2.0.

Read More
Nufarm_logo

March 23, 2015

Nufarm Fungicides Now Registered For Use On Edible Crop…

Nufarm Americas announced label expansions for two of its fungicides that will provide more pest management options for the ornamental industry. The Cleary 3336 F and EG fungicides are now registered for use across a wider range of edible crops, including select greenhouse vegetables and transplants, herbs and backyard fruit.

Read More
ColeusDMLeafSporulation_Daughtrey

March 11, 2015

Research Gives Clues For Preventing Coleus Downy Mildew

Maintaining awareness of coleus downy mildew is more important than ever to safeguard these attractive plants for reliable garden performance.

Read More
Rose Rosette on Knockout rose, May 2013. Photo credit: Alan Windham, University of Tennessee

March 2, 2015

Rose Rosette Disease Fight Gets A Boost From Government…

In 2014, $4.6 million was awarded through the Farm Bill to tackle rose rosette disease, a devastating pathogen that affects one of the industry’s most important crops.

Read More
Fig 1 Leafy Gall On Leucanthemum Becky

March 2, 2015

How To Prevent Leafy Gall Before You Lose Plants

Leafy gall is a nasty disease that can go undetected until plant damage is done. Take these steps to protect your crops from infection.

Read More

February 17, 2015

A New Look At Biological Control: Can Plants Affect The…

The success of a biological control program depends on a number of factors including quality of natural enemies, timing of release, release rates and environmental conditions. However, what is typically not taken into consideration is how plants can affect the performance of natural enemies, including attack rate and searching ability. Biological control agents work hard to protect plants, but plants have ways to help themselves, too.

Read More

February 1, 2015

New Pest Control Products For Your Toolbox

Add one of these new insecticides to your IPM program for successful pest control.

Read More
IR-4_profile_Feb2015

January 29, 2015

IR-4: A Pest Management Resource For Growers

Almost 40 years ago, IR-4 (Interregional Research Project Number 4) began serving the ornamental horticulture industry, helping to facilitate the registration of pest management tools. IR-4 does this primarily by surveying growers about their pest management issues and then hosting workshops to review survey results and set priorities for the coming years. Most recently, IR-4 coordinated a meeting of researchers and industry members on pollinator health and neonicotinoid chemistries to start a discussion on the needed research. The next step will be to get the outcomes from that workshop out to the public.

Read More

January 28, 2015

Biocontrols 2015 Conference & Tradeshow: Peace Tree…

Lloyd Traven, a speaker at the upcoming Biocontrols 2015 Conference & Tradeshow, was one of the industry’s early adopters of biocontrols in the greenhouse. Traven, owner of Peace Tree Farm, is evangelical about the technology as an effective tool for resistance management, as well as improved plant quality that contributes to a grower’s bottom line.

Read More

January 27, 2015

Southwest Perennials Improves Production, Shortens Crop…

A father-and-son team find LEDs deliver a higher rooting rate for cuttings propagated under the lights.

Read More
Wainwright-web-620x349

January 22, 2015

Quality Control With Biocontrols

Make sure the shipment of beneficials that just arrived is viable and ready to go to work in your greenhouse, nursery, or field. Here are five steps you can take to ensure success with your biocontrols.

Read More

January 9, 2015

6 New Fertilizer Products For Healthy Plants

These five products add even more options for delivering nutrients to the root zone.

Read More

January 7, 2015

Fertilizers And The Future

As growers look for new ways to cut costs and conserve resources, fertilizer and equipment companies are offering products that strive to save water, reduce toxic runoff and keep chemicals out of the equation.

Read More

December 31, 2014

Gain Greater Control Of Fertilizer With Automated Ferti…

University researchers look at integrating irrigation and fertilization with the help of water sensors to reduce fertilizer treatments and improve application timing.

Read More
As directed by EPA, the bee hazard icon appears in the Directions For Use for each application site for specific use restrictions and instructions to protect bee and other pollinators.

December 9, 2014

Fact Sheet: The Value Of Neonicotinoids To Turf And Orn…

An extensive study of the diverse turf and ornamental industry (“The Green Industry”) reveals that neonicotinoids are the top-rated products used by professionals to control their most important pests in greenhouses, landscapes, lawns, nurseries and trees.

Read More
As directed by EPA, the bee hazard icon appears in the Directions For Use for each application site for specific use restrictions and instructions to protect bee and other pollinators.

December 9, 2014

New Study Finds Neonicotinoids Are Top-Rated Products F…

According to results of a survey by AgInfomatics, professionals in the turf and ornamental industries fear the loss of neonicotinoid products would reduce the quality of their plants and services, increase costs and negatively impact their ability to manage pest resistance.

Read More

December 2, 2014

Grow-Tech Announces BioStrate, Its Newest Hydroponic Gr…

Grow-Tech LLC recently announced the release of BioStrate Felt, a biobased textile specifically engineered for the growing of hydroponic microgreens and baby salad greens.

Read More