Take Heed With Temperature

Temperature is a key factor in controlling plant development and crop timing. Knowing the basics of temperature control, and the science behind temperature and its impact on other plant growth factors, is necessary to achieve desired crop results. Growers who master the ability to grow plants at the right temperatures are ultimately the masters of controlling their crops.

Temperature affects every aspect of the plant growth process,” says Ryan Warner, an associate professor of horticulture at Michigan State University.
“Plant growth increases as temperature increases, up to a point, and then declines if temperature continues to increase, while respiration continues,” Warner explains.

DIF

“With temperature, growers can control the rate at which plants grow. One of the main ways to do this is with DIF,” Warner says.

“Plant height is impacted by the relative day and night temperatures for most crops, the old DIF concept,” he says. “If the day is warmer than the night, plants will generally be taller than if they are grown under a constant temperature or in a temperature regime in which night temperatures are warmer than day temperatures.”

The key to using DIF is moving from a positive DIF (warm days, cool nights) to zero DIF (same average daily temperature, 24 hours a day) or negative DIF (cool days, warm nights), which significantly impacts plant height. Plants respond more to DIF under short days (late fall/winter) than under long days (spring, summer). However, crop time increases as growers lower temperatures, which can cause an economic impact if greenhouses are tied up longer.

Heat And Cold Stress

Every plant species has an optimum temperature range, and most can maintain growth between 50°F to 77°F. But when extreme temperatures set in and plant temperature drops below or goes above the ideal, plants become distressed.

“Heat stress can damage the photosynthetic machinery, which prevents the plant from being able to fix carbon and thus, grow,” Warner says. “Heat stress can reduce growth for several days after exposure. Some symptoms may be very subtle, for example just a lack of growth. Under more extreme heat stress, plants become chlorotic and floral initiation and development may be inhibited, as flowers are more heat-sensitive than vegetative growth.”

Under more severe heat and drought conditions, pores on the leaf (stomata) will close, which can ultimately cause plant death,” Warner says.“When stomata are closed, plants can’t take up carbon dioxide and leaf temperatures will increase. Water evaporated through the stomata (transpiration) helps to cool the plant and this process also closes down. Plants can die under prolonged heat/drought stress, as they can’t fix carbon but continue to metabolize the carbon that has already been used for growth.”

Cold temperatures affect plants differently than warm temperatures, as cold slows down the plant growth process. Plant roots grow poorly, respiration slows and plants become nutrient deficient.

“Mild cold stress results in slow or no growth, so plants look stunted,” Warner says. “If plants are wet, cold temperatures will keep plants and soil wet longer, which promotes disease. Extended cold stress can damage plant membranes, depending on the severity of the stress, which may result in water-soaked lesions appearing on the plant.”

Botrytis, Pythium and Thielaviopsis are common in some crops exposed to cold stress. While slowly dropping temperatures cause water to move out of cells before they freeze, and plants can sometimes recover if caught in time, sudden freezing temperatures cause plant cells to freeze and die.

Leave a Reply

One comment on “Take Heed With Temperature

More From ...

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

April 1, 2015

Philadelphia Flower Show Draws More Than 250,000 Attend…

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 H…

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
Basil_Persian-AAS2015_620x329

March 31, 2015

California Summer Vegetable Trials To Be Hosted By Nati…

Vegetable breeding companies will come together this August to host the Summer Vegetable Trials in California. Like the long-standing California Spring Trials that are held annually in California, attendees will have the opportunity to visit breeding companies' trial sites in seven locations throughout the state, from August 20-21, 2015. National Garden Bureau (NGB), the non-profit organization promoting gardening on behalf of the horticulture industry, is organizing and publicizing this event on behalf of its members.

Read More
DNA-logo

March 31, 2015

DNA Green Group Will Acquire Rijnplant

DNA Green Group and Riknplant have finalized DNA Green Group's acquisition of Rijnplant, meaning that the breeding and propagation activities in pot and cut anthurium, bougainvillea and heliconia will transfer to DNA Green Group.

Read More

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
Aquaponics At Brogue Hydroponics

March 30, 2015

10 Things You Need To Know About Aquaponics

Are you curious about expanding into aquaponics? From pest control to equipment, Bob and Jesse Kilgore of Brogue Hydroponics offer 10 factors you need to consider.

Read More
Aquaponics At Brogue Hydroponics

March 30, 2015

Aquaponics Is Making A Splash At Brogue Hydroponics

The owners of Brogue Hydroponics explain why they expanded into aquaponics, and how the shift has helped them uncover a new market opportunity.

Read More
Hendriks-Half-Open-Roof_GGS

March 26, 2015

10 Greenhouse Products For First-Rate Growing Environme…

From coverings to fork-lifts, greenhouse suppliers offer a variety of products to make growing easier. Check out the slideshow to learn more about these, plus several other products that can offer you value, versatility and durability.

Read More
Rose rosette on Knockout rose, April 2012. Photo credit: Alan Windham, University of Tennessee

March 25, 2015

$58 Million In APHIS Farm Bill Funding Will Support Hor…

Nearly $58 million as been allocated by the USDA's Animal and Plant Health Inspection Service (APHIS) to support the industry's Plant Pest and Disease Management and Disaster Prevention Program, under Farm Bill Section 10007. The program will support mitigation efforts for specialty crops, including providing research and other funding to address plant pest and disease priorities for the specialty crop industry, including floriculture and nursery crops.

Read More
AFE scholarship_Ryan Dickson

March 25, 2015

AFE Educational Grant And Scholarship Application Deadl…

Apply now for American Floral Endowment (AFE) scholarships or educational grants. Applications can be found online. For educational grants for 2015-2016, applications must be submitted no later than June 1. Scholarship applications are due May 1. AFE will award $40,000 in scholarships for 2015.

Read More

March 25, 2015

13 New Shrubs You’ll Find At The 2015 California …

Woody ornamentals serve as the foundation of many great landscapes, but beyond their traditional uses, shrubs also add color, structure, texture and interest to small gardens and even containers. Check out this slideshow to see some of the newest introductions you’ll get to see at this year’s California Spring Trials.

Read More

March 25, 2015

NASS Reports U.S. Honey Production Was Up By 19 Percent…

Honey production in 2014 from producers with five or more colonies totaled 178 million pounds, up 19 percent from 2013, according to a March 20 report from the USDA's National Agricultural Statistics Service (NASS).

Read More
Bloomtown_Screen Shot 2015-03-10

March 24, 2015

Bloomtown Exposes Consumers To The World Of Horticultur…

A new web series called Bloomtown is all about the mud, sweat and tears of horticulture. Filmed in St. Louis, Mo., it chronicles the world of horticulture using local flower growers, greenhouses, wholesalers, florists, consumers, retail shops and arborists, with the goal of opening consumers’ eyes to the world of horticulture around them.

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

March 23, 2015

UF/IFAS Appoints Joseph Albano As Director Of Mid-Flori…

The University of Florida's Institute of Food and Agricultural Sciences (UF/IFAS) has a new directors for its Mid-Florida Research and Education Center (REC) on Apopka, Fla. The role has been filled by Joseph Albano, a research horticulturist from the U.S. Department of Agriculture with more than 25 years of experience.

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

March 23, 2015

Update To Armitage’s Greatest Perennials & Annuals …

A new update to the Greatest Perennials & Annuals app narrows the gap between consumers and grower-retailers, while providing more of Armitage’s top picks and growing advice for success with plants.

Read More