May/June 2023 - 22

PLANT & SOIL HEALTH
Attack weeds and pathogens
Study shows combination of steam, chemicals offer control options
In a microplot study, NC State researchers
studied how growers can control weeds and
soilborne pathogens through steam and
alternative chemicals. Photos: NC State
BY DOUG OHLEMEIER
ASSISTANT EDITOR
R
esearchers are examining
how growers can control
weeds and soilborne
pathogens through steam and
alternative chemicals.
A session during the March
7-10 North American Strawberry
Symposium in San Luis Obispo,
California, examined research into
weed and pathogen control through
applying steam with quicklime, also
known as calcium oxide and burnt
lime, and sodium peroxide.
The study, by Emma Volk, a
research assistant in the North
Carolina State University Horticultural
Science Department, probed how
steam in combination with exothermic
chemicals - chemicals that release
heat in reaction with water - can
allow soils to reach higher maximum
soil temperatures and also possess
longer lasting thermal effects.
Steam and the chemicals will
22 | MAY/JUNE 2023
control pythium species populations
and weeds more than when the
components are used alone. Pythium
is a pathogen responsible for black
fruit rot and other fungi. Other
soilborne strawberry diseases
include verticillium wilt and charcoal
rot. Major weeds include nutsedge,
which can poke through plastic and
grow through the planting holes,
prickly sida and annual rye grass.
One of Volk's goals is to expand
grower pest control options and
lessen reliance on chemicals.
Previous research studied steam
as a soil disinfectant long used in
greenhouse production systems.
The method is effective as a
stationary application method, but
recent research is examining mobile
field steam applications, Volk said.
Steaming away
Steam, however, is material-,
time- and water-intensive and is
expensive. Volk wanted to see how
researchers could make steam
applications more efficient.
In North Carolina, growers typically
begin fumigation during the fall,
ahead of the state's April to June
strawberry season. For two seasons,
Volk conducted a microplot study at
NC State's Clayton, North Carolina,
research station. Researchers applied
six treatments in one by half-meter
randomized plots in Norfolk sandy
loam soil.
The treatments were 30-minute
applications of steam alone, steam
plus quicklime and steam plus sodium
peroxide, plus individual applications
of quicklime and sodium peroxide with
only room temperature water.
Researchers sampled soils and
inserted weed seed probes. To
discover how far treatments would be
effective from applicators, distance
points of 0.9, 4.7, 9.8 and 14.9 inches
were examined.
In pathogen control, Volk found
quicklime plus steam was the only
treatment able to lower pathogen

May/June 2023

Table of Contents for the Digital Edition of May/June 2023

Editor's Letter
Feature: Exiting the wholesale market
Weather Update: Extreme weather challenges
Cover Story: The survey shows…
Cover Story: Farm market pricing guide
CA Storage: Taking control
Plant & Soil Health: Steam controls weeds, pathogens
Food Safety: Ionized gas used for food safety
Technology: Precision agriculture
Farm Market & Agritourism: Seven takeaways from benchmark market survey
Ag Labor Review
Classifieds
Ad Index
May/June 2023 - 1
May/June 2023 - 2
May/June 2023 - 3
May/June 2023 - Editor's Letter
May/June 2023 - 5
May/June 2023 - Feature: Exiting the wholesale market
May/June 2023 - 7
May/June 2023 - Weather Update: Extreme weather challenges
May/June 2023 - 9
May/June 2023 - 10
May/June 2023 - 11
May/June 2023 - Cover Story: The survey shows…
May/June 2023 - 13
May/June 2023 - 14
May/June 2023 - 15
May/June 2023 - Cover Story: Farm market pricing guide
May/June 2023 - 17
May/June 2023 - CA Storage: Taking control
May/June 2023 - 19
May/June 2023 - 20
May/June 2023 - 21
May/June 2023 - Plant & Soil Health: Steam controls weeds, pathogens
May/June 2023 - 23
May/June 2023 - Food Safety: Ionized gas used for food safety
May/June 2023 - 25
May/June 2023 - 26
May/June 2023 - 27
May/June 2023 - Technology: Precision agriculture
May/June 2023 - 29
May/June 2023 - Farm Market & Agritourism: Seven takeaways from benchmark market survey
May/June 2023 - 31
May/June 2023 - Ag Labor Review
May/June 2023 - Classifieds
May/June 2023 - Ad Index
May/June 2023 - 35
May/June 2023 - 36
https://www.nxtbook.com/greatamericanmediaservices/VGN/april-2024
https://www.nxtbook.com/greatamericanmediaservices/VGN/march-2024
https://www.nxtbook.com/greatamericanmediaservices/VGN/february-2024
https://www.nxtbook.com/greatamericanmediaservices/VGN/vgn-digital-seed-guide-2024
https://www.nxtbook.com/greatamericanmediaservices/VGN/january-2024
https://www.nxtbook.com/greatamericanmediaservices/VGN/buyers-guide-2024
https://www.nxtbook.com/greatamericanmediaservices/VGN/december-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/november-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/september-october-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/july-august
https://www.nxtbook.com/greatamericanmediaservices/VGN/may-june-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/april-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/march-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/vgn-digital-seed-guide-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/february-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/january-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/december-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/buyers-guide-2023
https://www.nxtbook.com/greatamericanmediaservices/VGN/november-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/september-october-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/august-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/july-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/june-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/may-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/march-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/february-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/seedguide-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/buyersguide-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/january-2022
https://www.nxtbook.com/greatamericanmediaservices/VGN/december-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/november-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/october-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/september-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/august-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/july-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/june-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/may-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/april-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/march-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/february-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/seedguide-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/buyersguide-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/january-2021
https://www.nxtbook.com/greatamericanmediaservices/VGN/december-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/november-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/october-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/september-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/august-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/july-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/june-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/may-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/april-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/march-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/february-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/buyersguide-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/january-2020
https://www.nxtbook.com/greatamericanmediaservices/VGN/december-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/november-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/october-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/september-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/august-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/july-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/june-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/may-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/april-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/march-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/february-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/buyersguide-2019
https://www.nxtbook.com/greatamericanmediaservices/VGN/january-2019
https://www.nxtbookmedia.com