Midwest Vegetable Guide - 2022 - 32

Organic Vegetable Production
associated with sublethal effects on development, foraging
behavior, immune system functionality, learning and memory
retention, longevity, orientation, overwintering survival, and
reproduction. In addition, indirect effects may be affiliated
with social interactions as a result of honey bees sharing a
contaminated food source.
In general, early morning or late evening applications of
pesticides pose less of a hazard because this is when most
bees are less active. However, this depends on temperature,
as bumble bees are active at lower temperatures (40°F)
whereas honey bees are active when temperatures are >50°F.
Do not apply pesticides to flowering plants or weeds.
Systemic insecticides, applied as either drenches or granules,
to the soil or growing medium, are less harmful to bees than
foliar applications. The pesticide formulation can influence
bee toxicity. For example, emulsifiable concentrates (EC) and
water-soluble (WS) formulations are typically less harmful to
bees than wettable powder (WP) formulations.
It is important to note that some fungicides can enhance the
toxicity of certain insecticides to honey bees when mixed
together. This enhanced toxicity is referred to as synergism,
which means that the combined toxicity is greater than the
sum of the toxicity of each pesticide applied separately. The
ergosterol or sterol biosynthesis inhibiting (EBI) class of
fungicides have been shown to increase the toxicity of certain
insecticides in various chemical classes, including:
organophosphates, pyrethroids, and neonicotinoids to honey
bees. For instance, the toxicity of pyrethroid insecticides to
honey bees is enhanced over a thousand fold when mixed
with ergosterol biosynthesis inhibitors. In addition, mixing
some neonicotinoid insecticides with certain fungicides can
enhance toxicity to honey bees as much as a thousandfold.
In addition to fungicides, insect growth regulators, which are
insecticides that disrupt insect growth and development, and
eventually lead to death, are known to be harmful to honey
bees. The three categories of insect growth regulators -
chitin synthesis inhibitors, juvenile hormone mimics, and
ecdysone receptor antagonists/ agonists -have been reported
to be directly and/or indirectly harmful to honey bees;
especially the larvae (brood).
The Fungicide Table and Insecticide Table contains Bee
Precaution information based on the toxicity of oral exposure
to honey bees, honey bee brood, and other bees. It is
important to read the pesticide label carefully to determine
the potential level of toxicity to all bee types (honey bees,
bumble bees, and native bees). Furthermore, you can
incorporate into pollination contracts a list of pesticides,
application methods, and timing of applications that are
mutually agreeable to both growers/producers and
beekeepers. These tables utilize the University of California
IPM Bee precaution pesticide ratings; a systematic review of
toxicity data for most crop management chemistries found at
www2.ipm.ucanr.edu/beeprecaution.
32
State laws may require that applicators notify beekeepers 24
hours before applying a pesticide that is directly or indirectly
harmful to honey bees when; 1) the treated crop is in flower
(blooming), and 2) the field is greater than a half-acre and
within a half-a-mile from a registered apiary. It is important
to contact your state department of agriculture to determine if
there are laws or regulations that protect other pollinators
(bumble bees and native bees).
For more information on bees and pesticides, refer to the
extension publication, Pesticides and Bees (Kansas State
University Agricultural Experiment Station and Cooperative
Extension Service. MF3428. Kansas State University;
Manhattan, KS. 8 pgs, bookstore.ksre.ksu.edu).
Organic Vegetable Production
Reviewed by Liz Maynard - Aug 2021
Organic vegetable farming is a production system that relies
on biological processes and natural materials to manage soil
fertility and pest populations, and to promote healthy crop
growth. The federal Organic Foods Production Act regulates
the use of the term " organic " to describe an agricultural
product in the marketplace. Vegetables sold as " organic "
must be grown and handled according to the National
Organic Rule and any applicable state regulations. The
National Organic Rule prohibits the use of most synthetic
chemicals (fertilizers, pesticides, etc.), and requires farmers
to write and follow organic production plans, as well as keep
farm and field records. Fields used to grow organic crops
may not have had any prohibited material applied to them in
the previous three years. In addition, USDA-accredited
organic certification agents must inspect and certify all
operations with more than $5,000 in gross annual sales of
products labeled " organic. "
Growers interested in transitioning to organic production
should educate themselves about practices used in their area
and plan carefully. Experience suggests that it can take a
number of years for pest populations and soil nutrient cycles
to adjust enough for successful organic production.
This guide includes recommendations for some inputs that
are permitted in organic production, but also for many that
are not. The note 'OMRI-listed' indicates pesticides that have
been listed by the Organic Materials Review Institute
(OMRI) as approved for use in organic production in the U.S.
Growers should always check with their organic certification
agents before using any product to make sure it meets their
certifier's criteria.
Other organic production resources include:
eOrganic, the Organic Agriculture Community of the
Extension Foundation eorganic.org
Organic Vegetable Gardening Techniques (University of
Missouri Extension Guide G6220) provides an introduction
Midwest Veg Guide 2022
http://bookstore.ksre.ksu.edu http://www.eorganic.org http://www2.ipm.ucanr.edu/beeprecaution https://extension.missouri.edu/publications/g6220
Midwest Vegetable Guide - 2022

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