February 2023 - 24

PLANT & SOIL HEALTH
Soil solutions
Tips for strawberry growers take
center stage
BY GARY PULLANO
VGN SENIOR CORRESPONDENT
A
fter conducting more than
20 years of perennial
strawberry soil health
research, Marvin Pritts has
identified strategies for growers
who produce the finicky plants.
Pritts is director of
undergraduate studies for the SIPS
Horticulture Section at Cornell
University. He spoke at the Great
Lakes Fruit, Vegetable & Farm
Market EXPO held in December in
Grand Rapids, Michigan.
Characteristics of healthy soils,
which can be determined with a soil
test, include good tilth, sufficient
(but not excess) nutrients, good
water storage and drainage.
" Chemical components of soil are
just one-third of what makes plants
grow well, " Pitts said. " The other
parts are the physical and biological
properties of the soil.
" In general, strawberry fields'
soil are not doing that great, " he
said when comparing strawberries
to other tested crops at Cornell.
" Soil from strawberry fields was
less healthy than soils from other
fields we get in, including field crops
and other vegetables. Strawberry
field soils showed low organic
24 | FEBRUARY 2023
matter, active carbon and potentially
mineralizable nitrogen in the tests. "
Symptoms of poor soil health
show patchy patterns with
complete blackening of the main/
perennial roots and deterioration
of perennial and feeder roots, all
leading to a smaller root system.
Field symptoms include the aboveground
structure being stunted,
reddened or collapsing, leading to
a lack of runnering and a decline in
vigor and productivity.
Researchers identified 27
strawberry fields in New York that
have problems with poor soil health.
They compared good and bad soil
areas on those farms. Variables
included cultural, historical,
physical and chemical features in
each of the soil samples.
Grower practices, the history of
the site, and the physical properties,
including the compaction and
chemical soil tests, were evaluated.
The factors that most highly
correlated with poor root health
included the age of the plantings,
cumulative years of strawberry
production, soil compaction, fine
soil texture (clay), absence of raised
beds, high application rates of
terbacil, non-use of metalaxl and
the frequency of fumigation.
" These factors, especially
when co-occurring, create an
environment favorable for the
proliferation of disease-causing
organisms, " he said.
Fumigation may not be beneficial
in perennial strawberries.
" We found that the more growers
fumigated, the poorer the soil health
was. You do have better soil the year
after fumigation, but in subsequent
years on perennial strawberries, it's
actually worse.
" When you fumigate, you're killing
all beneficials. You're killing the bad
guys, too. But then, there's nothing
to compete with the bad guys in the
odd years. They come on raging
in that second and third year than
they did if you wouldn't have done
anything. "
The common pathogens causing
poor soil health in strawberries
include Pratylenchus penetrans
(nematode), Rhizotonia spp and
Pythium spp. Other associated
organismas are Verticillium
albo-atrum, Fusarium spp.,
Cylindrocarpon spp., Phytopthora
spp., Idriella lunata and others.
Various varieties of strawberries
have different levels of resistance to
these pathogens.
" That makes it really hard to
generalize that this or that variety is
resistant, or this pathogen is causing
February 2023

Table of Contents for the Digital Edition of February 2023
