Fresh-Market Cabbage:
Increasing Economic Returns While Reducing Risk
W.D. Hutchison, E.C. Burkness, and M.A. Carrillo Dept. of Entomology, University of Minnesota; T.M. Hurley
Dept. of Applied Economics, University of Minnesota; and G. Pahl, Pahl’s Farms, Inc., Apple Valley, Minnesota
Overview
Crucifer crops
(cabbage, broccoli
and cauliflower)
continue to be
important vegetable
crops for Midwestern
U.S. growers,
for both processing
and fresh market.
Annually, ≈750 acres
of cabbage and related crucifer crops are produced in
Minnesota for fresh-market (grocers, farmer’s markets,
and roadside stands). Despite the relatively low acreage,
the high value of the crop (≈$4000/acre), and traditionally
high insecticide use of as many as seven applications per
season, continue to create a demand for alternative insect
management programs.
In Minnesota, and throughout much of the U.S.,
cabbage is attacked by three Lepidopteran (larval) pests,
including the cabbage looper, imported cabbageworm,
and diamondback moth. However, since 1990 the cabbage
looper has become the most dominant and difficult pest
to manage. Because of high insecticide use, we developed
a research-based Integrated Pest Management (IPM)
program that is based upon timely pest monitoring, the
use of action thresholds to determine when pest control is
needed, and reduced-risk insecticides to conserve natural
enemies (e.g., insect predators) of multiple insect pests.
IPM Approach
The purpose of
this study was to
conduct an “IPM Pilot
Test” of a Cabbage
IPM Program with
a large fresh-market
grower in Minnesota
to assess the economic
value and risk of
IPM. The pilot test
was based on previous research conducted at the University
of Minnesota Outreach and Research center (UMORE
Park) that confirmed the efficacy of new reduced-risk
insecticides (e.g., SpinTor®, Avaunt®), and the use of an action threshold based on the percentage of plants
infested with cabbage looper larvae (i.e., rapid presence/
absence sampling). A key aspect of this approach was
that reduced-risk insecticides were used early in the season
to conserve beneficial natural enemies (predators and
parasites), to provide additional biological control, and
to prevent “aphid flare-ups.” The use of pyrethroids (e.g.,
Warrior®) was limited to late-season sprays when pest
population pressure increased and protection of cabbage
heads became critical.
When cabbage looper was present, an action threshold
of 10% of the plants infested with larvae was used.
However, when only diamondback moth and/or imported
cabbageworm were present, an action threshold
of 50% of the plants infested with larvae, until heading,
was used; a 10% larval infestation from heading to
harvest was used for late-season crop protection. The
IPM program was compared with the grower’s standard
pest control practice which may or may not include pest
monitoring. Since few growers were willing to quickly
adopt the new IPM approach on a large scale, the IPM
Pilot Test was conducted from 1998-2001 using six commercial
fields provided by Pahl’s Farms, and as part of an
On-farm, 100-ac, Private-Public Sector Partnership developed
at UMORE Park.
RESULTS
Economic Value and Risk of IPM vs Conventional Programs
For all four years, the IPM-based program resulted in
increased net returns compared to the Conventional and
No pest control (do nothing) programs (Table 1, Fig.
1). Benefits provided by IPM were due to several factors.
On average, the IPM program increased marketable
yield >10% and decreased the number of insecticide applications
by 23%. Net returns for IPM were also higher
despite the increased cost of pest monitoring ($12/ac;
no monitoring costs were included for conventional).
The IPM program increased net returns by $401/acre,
compared with the conventional program (Table 1); i.e.,
net returns from IPM were 6.3X higher than that of the
conventional program. In addition, the standard deviation
(risk) of net returns was only about ½ of that for the
conventional program. The standard deviation (SD) is a
common measure of economic risk, reflecting the volatility or variability in net returns. As with all agricultural crops,
there are many factors that influence the variability in
pest pressure, final yields and produce quality. One of
the goals of IPM is to reduce the SD of net returns. As
a statistical term, the SD refers to 68% of the possible
distribution of net returns. For example, for IPM, the SD of $393 indicates that 68% of the time the expected net
return of $476/ac should fall between $83 and $870/ac.
The higher SD for the Conventional program ($692/ac),
indicates greater volatility, with expected net return ($75/
ac) ranging from $-617 to $767/ac.
In addition to the expected average return and risk,
probability analysis of the 4-year data set indicated the
IPM program always had the highest probability of
achieving any particular net return goal (Fig. 1). These
results clearly illustrate the value of the IPM program
compared to the conventional grower program. From an
economic perspective, the results also indicate that an IPM program for Lepidopteran pests in Midwestern U.S.
cabbage should be an attractive incentive to many growers,
regardless of whether they view themselves as riskaverse
or risk-takers. In addition to economic goals, the
environmental benefits and costs for this IPM program
could also be evaluated.
Fig. 1. Probability (chance) of a Midwest U.S. grower
achieving various net returns using different pest
management programs. The dashed line indicates
that the probability of achieving a profit of $500/acre
is 70% for IPM, 38% for conventional, and 14% if no
pest control is used (4 year study: 1998-2001).
Further reading:
Hutchison, W.D. et al. (2004). Integrating novel technologies
for cabbage IPM in the USA: Value of on-farm research, pp.
371-379. In Proc. 4th International Workshop on the Management
of Diamondback Moth, Nov. 2001, Melbourne, Australia.
Hines, R. C. and W. D. Hutchison. (2001). Evaluation of action
thresholds and spinosad for Lepidopteran pest management in
Minnesota cabbage. J. Econ. Entomol. 94: 190-196.
DISCLAIMER
Reference to products in this publication is not intended to be an endorsement to the exclusion of others. Any person using products
listed in this publication assumes full responsibility for their use in accordance with current manufacturer directions.
ACKNOWLEDGEMENTS
Funding for this series of IPM publications was provided by the USDA Risk Management Agency (USDA-RMA)
in cooperation with the Minnesota Fruit and Vegetable Growers Assoc., and the MN IPM Program (USDA-CSREES).
Initial research was funded by the MN Agric. Utilization Research Institute (AURI), and the Minn. Dept. of Agric.
IPM Program. For more information regarding this project or Vegetable IPM in the Midwestern U.S., see the VegEdge Web site.
Citation: Hutchison, W.D., E.C. Burkness, M.A. Carrillo, T.M. Hurley, and G. Pahl. 2006. Fresh-market cabbage:
Increasing economic returns while reducing risk. Public. 08230. Univ. of Minnesota Extension Service, St. Paul, MN.
