Study: Rice Hull Effect On PGRs Comparable To Perlite

Greenhouse growers can substitute rice hulls for perlite in their media without the need for an increase in growth regulators, according to a Purdue University study.

Growing media for ornamental plants often consists of a soilless mix of peat and perlite, a processed mineral used to increase drainage. Growers also regularly use plant growth regulators to ensure consistent and desired plant characteristics such as height to meet market demands. Organic substitutes for perlite like tree bark have proven difficult because they absorb the plant-growth regulators and keep them from getting to the plants. Using bark requires a 25 percent increase in the volume of growth regulators applied.

"We were not sure whether rice hulls, as an organic component, would hold up the growth regulator," says Roberto Lopez, a Purdue assistant professor of horticulture and co-author of a “HortTechnology” paper that outlined the findings. "Testing showed that there were no differences in plants grown with rice hulls or perlite."

Pansies and calibrachoa were planted in an 80-20 mix of both peat and perlite and peat and rice hulls and then treated with several different growth regulators. The plants treated with and without growth regulators and grown in peat and perlite and peat and rice hulls had similar heights and stem lengths.

Finding a waste product to replace perlite could reduce the price of growing media because perlite must be mined and heat processed.

"It’s a really energy-intensive process and, because it’s a mineral, it’s non-renewable," says Chris Currey, a horticulture graduate student and co-author of the “HortTechnology” paper.

Rice hulls are an attractive option, Lopez says, because they can be easily transported on barges and rice growers in the South could increase profits by selling a traditional waste product.

"Often these rice hulls were being burned because there’s not a lot of other use for them," Lopez said.

Syngenta and Fine Americas funded the research. Lopez and Currey collaborated with Purdue research technician Diane Camberato and graduate student Ariana Torres.

Leave a Reply

16 comments on “Study: Rice Hull Effect On PGRs Comparable To Perlite

  1. I worked with a large greenhouse (over 10 acres)that converted to rice hulls from perlite to be organic. The company that the greenhouse bought the rice hulls from changed the way they processed the rice hulls. This process change caused the rice hulls to break down prematurely which in turn caused the soil to rob nutrients from the plugs/plant. The nurtient deficiency caused extensive stunting and plant loss and wreaked havoc on plant quality/availability.
    I understand another greenhouse lost their entire plug crop of Mother’s Day annuals. Be very careful–test on a small scale. The greenhouse I worked with has converted back to perlite….

  2. Fresh par boiled rice hulls do not break down prematurely. Excessive starch content robs soils of nutrients-and this issue has been addressed. Rice hulls are composed of lignin fiber, carbon and silica. Clean fresh par boiled hulls do not cause nitrogen problems. Rice hulls hold water differently that perlite-drying on the surface quicker-and often fool waterers to water prematurely. Growers have been successful when new products are embraced and adapted to. Rice Hulls are not perlite, and vice-versa. All changes in growing media require some adjustment in growing practices.

  3. The problem was that the rice hull processor was NOT using fresh water each time. They were recycling the same old water which lead to the faster break down and other problem. This processor had ALWAYS used fresh water in the past and for “cost savings” changed to reusing the same water—know one knew or was notified….growers lost hundreds of thousands of dollars from this one change… I understand new products take adjustment but when processors do not tell you about changes they make it makes you VERY hesitant to change…..This is a quality/trust issue.

  4. Growers may be able to squeak by using rice hulls in “grow it up and push it out the door” production. Rice hull compatibility with PGRs is fine for the producers of plants who are looking to reduce costs and attempt to be more “earth friendly”, but plants do NOT do well long term in this media. My observation is that hanging baskets and container gardens planted in this media WILL FAIL by mid-summer. Pretty much anything that is grown in rice hull media that is not planted into real soil or a non rice hull soilless mix by the customer will also FAIL. Customers DO get angry and tell all of their friends and family about their experience. They DO blame the garden center who sold it to them. They DO NOT know nor care about the difference in media types and if they need to do anything “special” to keep their investment alive. All they know is that they wasted their money and eventually will give up on plants and spend their money elsewhere.

  5. Maybe your hanging baskets failed because you had too much porosity(drainage). What about the peat? Peat is the main water holding source in a mix. What about the wetting agent?. Rice hulls have been used for many years by many growers who produce quality crops. I don’t agree that plants don’t do well long term. I’ve seen too many successful crops. The rice hull media plants I bought at Lowe’s this Spring lasted all Summer and Fall. Mr. Frost is going to have to get them. Rethink before you react.

  6. I worked with a large greenhouse (over 10 acres)that converted to rice hulls from perlite to be organic. The company that the greenhouse bought the rice hulls from changed the way they processed the rice hulls. This process change caused the rice hulls to break down prematurely which in turn caused the soil to rob nutrients from the plugs/plant. The nurtient deficiency caused extensive stunting and plant loss and wreaked havoc on plant quality/availability.
    I understand another greenhouse lost their entire plug crop of Mother’s Day annuals. Be very careful–test on a small scale. The greenhouse I worked with has converted back to perlite….

  7. Fresh par boiled rice hulls do not break down prematurely. Excessive starch content robs soils of nutrients-and this issue has been addressed. Rice hulls are composed of lignin fiber, carbon and silica. Clean fresh par boiled hulls do not cause nitrogen problems. Rice hulls hold water differently that perlite-drying on the surface quicker-and often fool waterers to water prematurely. Growers have been successful when new products are embraced and adapted to. Rice Hulls are not perlite, and vice-versa. All changes in growing media require some adjustment in growing practices.

  8. The problem was that the rice hull processor was NOT using fresh water each time. They were recycling the same old water which lead to the faster break down and other problem. This processor had ALWAYS used fresh water in the past and for “cost savings” changed to reusing the same water—know one knew or was notified….growers lost hundreds of thousands of dollars from this one change… I understand new products take adjustment but when processors do not tell you about changes they make it makes you VERY hesitant to change…..This is a quality/trust issue.

  9. Growers may be able to squeak by using rice hulls in “grow it up and push it out the door” production. Rice hull compatibility with PGRs is fine for the producers of plants who are looking to reduce costs and attempt to be more “earth friendly”, but plants do NOT do well long term in this media. My observation is that hanging baskets and container gardens planted in this media WILL FAIL by mid-summer. Pretty much anything that is grown in rice hull media that is not planted into real soil or a non rice hull soilless mix by the customer will also FAIL. Customers DO get angry and tell all of their friends and family about their experience. They DO blame the garden center who sold it to them. They DO NOT know nor care about the difference in media types and if they need to do anything “special” to keep their investment alive. All they know is that they wasted their money and eventually will give up on plants and spend their money elsewhere.

  10. Maybe your hanging baskets failed because you had too much porosity(drainage). What about the peat? Peat is the main water holding source in a mix. What about the wetting agent?. Rice hulls have been used for many years by many growers who produce quality crops. I don’t agree that plants don’t do well long term. I’ve seen too many successful crops. The rice hull media plants I bought at Lowe’s this Spring lasted all Summer and Fall. Mr. Frost is going to have to get them. Rethink before you react.

  11. Wow I just purchased several bales of PBH. I hope this "recycled water" issue has been taken care of and the batch I purchased is from fresh stock. I plan on using it as a perlite replacement. Switching from peat to coir also. I Think the changeover will go smoothly as long as the PBH performs as advertised. Can either of you who actually know the details of the problem let me know which manufacturer and time frame we are talking about here please.

  12. Were working with a vertical gardening system that provides mechanical root anchorage and do not need the caking properties of Peat Moss. We would like to see information about accelerating nitrogen lock up / decomposition. And what is the max % of rice hulls we might be able to go with. A picture should help. http://www.facebook.com /the vertical eco garden or http://www.verticalecogarden.com

Latest Stories
Greenhouse Grower’s 2015 Head Grower Of The Year Tom Wheeler - Feature image

August 31, 2016

SAF Elects New Retail, Wholesale, And Grower Council Me…

The segment council members play an important role by helping the Society of American Florists keep its finger on the pulse of what is happening at the grower, wholesale, and retail level across the country.

Read More
Bee on Sunflowers

August 30, 2016

Bee Vectoring Technologies Names New President And CEO

Ashish Malik, a former Vice President of Global Marketing at Bayer CropScience, will focus on marketing Bee Vectoring Technologies’ patented proprietary tray dispenser system that uses bees to delivery organic compounds directly to crops.

Read More
Griffin Onliant Logo

August 30, 2016

Griffin Launches New Digital Greenhouse Ordering System

Onliant, which replaces Griffin’s previous e-commerce sites, provides growers and retailers with a new platform to source plants, hard goods, equipment, and retail inputs.

Read More
Phlox 'Pink Profusion' (Green Leaf Plants)

August 30, 2016

13 Cool Season Plants To Kick Off The Spring Season

These new cultivar introductions for 2016 are spring bloomers that can take the cold for early-season sales.

Read More
America In Bloom Project

August 29, 2016

Your Chance To Help America In Bloom As It Celebrates I…

America In Bloom is launching a fundraising campaign to help the group continue its mission of creating beautiful and vibrant communities across the country.

Read More

August 29, 2016

Does Point-Of-Sale (POS) Make A Difference for Plant Re…

When Greenhouse Grower RETAILING asked plant retailers about their plant pricing techniques, we also asked if they use POS or not. We decided to take a close look at where these two groups differ:

Read More
Griffin Logo

August 29, 2016

What You Should Do At The Griffin Expos, Massachusetts …

The first of the fall Griffin Expos takes place this week in West Springfield, MA, August 31 and September 1, 2016. A Lancaster, PA, Expo will take place next month. If you’re heading to this distributor show, make sure you check out these highlights: White Elephant Sale Each year, Griffin clears out its branch warehouses by holding a sale of its closeout and overstock items. The discounts are deep, and the competition for the items are fierce. “Once items are gone, they’re gone. So, that first hour or so is kind of like ‘the running of the brides’ at Filene’s,” says Tracey Gorrell, Marketing Communications Lead at Griffin. On-Site Experts Griffin offers opportunities to connect face-to-face with industry experts and get answers, tips, and advice catered to your unique needs and interests: The GGSPro team is available to field your questions; and 150 manufacturers, breeders, and young-plant producers can discuss […]

Read More

August 29, 2016

Fire Damages Swanson Nursery

Fire crews were called to Seattle-based Swanson’s Nursery in the middle of the night on August 22, the Ballard News Tribune reported. The fire, likely started by an “electrical issue,” destroyed bathrooms and a seminar room, Retail Manager Eric Nordstrom told the news outlet. Smoke damage was more extensive, however. Swanson’s President, Brian Damron says the fire also reached a storage area and utility room. A fire department spokesman says the fire broke through the greenhouse walls, and that part of a wooden wall had to be removed so the crew could reach the flames. The store’s café resides next to the damaged area, and is temporarily closed. It’s an important part of Swanson’s off season revenue strategy. The store is working with a timeline of repairs with its insurance company so it can determine when the cafe can reopen, the news outlet reports. The fire was out relatively quickly once […]

Read More
North Creek Nurseries Feature Image

August 29, 2016

North Creek Nurseries Unites Horticulture With Sustaina…

The team at North Creek Nurseries, Greenhouse Grower’s 2016 Operation Of The Year, leads the way in implementing ecologically responsible practices that will sustain the future of growing.

Read More

August 28, 2016

BioWorks IPM/Sustainable Practices Scholarship Goes To …

Schaller, a senior at the University of Arizona in the Plant Sciences Department, is interested in ornamental and floriculture crop breeding and crop physiology.

Read More
Next Generation

August 27, 2016

Australia Launches Initiative To Ignite A New Generatio…

Hort Innovation Chief Executive John Lloyd says the goal is to identify and build future industry leaders at all stages of their career through investment in a host of new initiatives.

Read More
Penn State University Trial Day

August 26, 2016

How Greenhouse Growers Can Broaden Their Horizons

Allan Armitage says you can learn new ideas to help your business when you get out to visit plant trials and other growers.

Read More
Albert Grimm, Jefferys Greenhouses

August 25, 2016

7 Ways Albert Grimm Strives To Be An Effective Leader

Grimm, Greenhouse Grower's 2016 Head Grower Of The Year, tries to live by the "Seven Habits Of Highly Effective People” from author Stephen R. Covey.

Read More
Tidal Creek Growers

August 25, 2016

Maryland-Based SunMed Growers Nabs Cannabis License

The company was one of 15 licensees selected by the commission out of a pool of 145 grower applicants to receive one of the license pre-approvals.

Read More
GrowSpan Light Deprivation Greenhouse

August 25, 2016

New Light Deprivation Greenhouses Help With Light Manag…

The GrowSpan light deprivation greenhouse from Growers Supply is outfitted with a blackout system that provides growers with control over the light cycle.

Read More
Albert Grimm GOY feature

August 25, 2016

Up Close And Personal With Head Grower Of The Year Albe…

According to Grimm, Greenhouse Grower’s 2016 Head Grower Of The Year, the key to being a successful grower is educating and inspiring yourself, your staff, your customers, and the next generation of growers.

Read More
To offer consumers an attractive crop, Local Appetite uses high tunnels to grow cherry tomatoes

August 24, 2016

New Food Safety Compliance Resource Available For Green…

The FSMA Wizard from Registrar Corp makes it easy for food producers, including greenhouse vegetable growers, to determine their possible requirements under the Food Safety Modernization Act.

Read More
Cannabis Structure

August 23, 2016

5 Factors To Consider In Your Cannabis Structure

Along with the size and specs of your greenhouse, it's also important to focus on ventilation, light deprivation, benching, irrigation, and odor control.

Read More
[gravityform id="35" title="false" description="false"]