IowaProduce.org e-Newsletter
April 2015
Archive | ISU Extension and Outreach | ISU
Seasonal Notes
Joe Hannan, Commercial Horticulture Field Specialist
Online GAPs Course for Farmers Market Vendors
Four online modules have been designed to provide science-based information on safe food production
and handling specific to farmers' markets, with a focus on specialty foods and good agricultural practices
(GAP). Modules are free and can be viewed anytime. At the conclusion of all four courses, participants
receive a Certificate of Completion suitable to display at their vendor's booth or market stall.

Module 1: GAP implementation prior to harvest that will mitigate food safety risks that can
devastate a farm business.

Module 2: GAP from harvest to sales of your product.

Module 3: Promotion and communication of your food safety efforts, including sampling methods,
will increase profits and best practices at the market.

Module 4: Best food safety practices for value-added products will provide assurance regulations
are met.
For more information, visit the Farmer’s Market Food Safety Training webpage.
This project was funded by the USDA Specialty Crop Block Grant through the Iowa Department of
Agriculture and Land Stewardship.
2015 Production Guides Now Available
The 2015 Spray Guides are printed and are available at the Extension Publication Store. There have
been major updates to the Vegetable Production Guide the last couple of years with the integration of
Ohio State into the group. If it has been awhile since you purchased one of these books, it is time to do
so. The Small Fruit and Grape and the Tree Fruit Spray Guides have undergone smaller changes but
include updated information on Spotted Winged Drosophila and Brown Marmorated Stink Bug Control.
I
IowaProduce.org e-Newsletter
April 2015
Iowa State University Extension programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital
status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612.
Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.
National Fruit and Vegetable Retail Report
Below is an excerpt from the National Fruit and Vegetable Retail Report by the USDA Agricultural
Marketing Service. This weekly summary provides an average price for retail produce that is
ADVERTISED in weekly ads. These prices represent “wholesale plus” value, or prices that a grower
would receive from institutions, restaurants, etc. at a value added wholesale rate because the produce is
local. Farmer’s market prices might be 25% higher or more depending on the crop and season. This is a
small sample of the information in the report. Data shown is national data…Midwest regional data can
also be found within this report although it is not as complete as the national report. Prices may vary from
the national report to the Midwest report.
Friday April 10th.
Crop
Conventional
Apple (Golden Delicious)
Apple (Honeycrisp)
Greens (Kale)
Greens (Mustard)
Tomato (Vine Ripe)
Unit
Price per unit
Pound
Pound
Pound
Bunch
Pound
$1.18
$2.67
$1.17
$0.99
$1.95
Organic
Apple (Gala)
Apple (Golden Delicious)
Greens (Kale)
Greens (Swiss Chard)
Tomato (Vine Ripe)
Pound
Pound
Bunch
Bunch
Pound
$1.86
$1.77
$1.98
$2.49
$3.08
Water Sampling
It is time to sample irrigation and post-harvest wash water sources for E. coli and total coliform bacteria.
If you are on rural or city water, you can request a water report directly from your supplier. A word of
caution if you choose to use this report; the report will only reflect conditions at the sample site and does
not account for any contamination that may be present within lines between sample point and faucet. A
better approach would be to take a sample yourself as close to the field or post-harvest wash station as
possible. For well water systems, you will have to collect and submit a sample yourself. For wells, it is
better to do it sooner rather than later. In the event that a well water sample would fail, you will need time
fix the problem. Ponds and streams are the most variable irrigation sources because they are easily
contaminated by intake water. Ponds and streams should never be used for post-harvest handling.
When used for irrigation, they should be sampled more frequently especially during high risk periods such
as after heavy rainstorms when flood waters may overflow intake streams and surfaces.
You can order a water sample kit from the State Hygienic Laboratory at the University of Iowa. If you
qualify, water collections kits and funding for this testing may be available through your county health
department. To order a kit, visit the State Hygienic Laboratory website or call 800.421.4692.
Politics
No comments from the peanut gallery here. Just a few articles that may be of interest
 Questions and answers regarding nitrogen and water quality

Des Moines Board of Water Works Trustees Files Lawsuit and Do the Des Moines Water Works
Claims Hold Water: commentary from the Center for Ag Law and Taxation

Weed Killer, Long Cleared, is Doubted. A well rounded article about glyphosate and cancer from
the New York Times.
I
IowaProduce.org e-Newsletter
April 2015
Iowa State University Extension programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital
status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612.
Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.
Time To Reregister On The IDALS Sensitive Crop Website.
The Iowa Department of Agriculture and Land Stewardship maintains a
registry for producers to list the locations of their pesticide sensitive crops and
for beekeepers to list the locations of their apiaries. This registry will be used
to create an on-line directory for use by pesticide applicators to identify the
locations of sensitive crops and apiaries and minimize the potential for
pesticide drift damage.
Every year commercial fruit and vegetable growers and bee keepers need to
register if you wish to remain on the registry. You can register on the IDALS
website.
Even after registering, it is still a good idea to talk with your neighbors and
discuss the effects drift has on your crops and your business.
2014 ISU Research Farms Progress Reports
The 2014 ISU Research Farms Progress reports are now online and viewable in PDF format.
Resources from the Sustainable Agriculture Research and Education Program
Linda Naeve, State SARE Coordinator
This month’s SARE Resource Review covers a bulletin titled A Whole Farm Approach to Managing Pests.
Most farmers will agree that pest management is one of the most challenging aspects of crop production.
A lot of time and money is spent controlling weeds, insects, and diseases. Rather than discussing
management of specific pests on specific crops, this publication lays out basic ecological principles for
managing troublesome pests and suggests how to apply them to real farm situations. It provides
examples of cutting-edge research and anecdotes from farmers using such strategies in their fields. It
encourages farmers to rethink management practices and design improved systems that integrate
ecological pest management into other aspects of crop and soil management. The approach takes us
back to the early advocates of integrated pest management (IPM).
The 20-page bulletin begins with an article on how Steve Groff, a
Pennsylvania vegetable farmer, plants a winter cover crop of hairy tech
and rye and lets it grow 5 feet tall. After knocking it over in the spring
with a rolling chopper, he transplants his tomatoes into the remaining
thick mulch. Not only does it reduce weed pressure, he says it stalls
early blight. This system is just one of a fistful of tools that Groff uses
to stymie pests on his farm.
Written by a team of research scientists in 2003, this publication
presents several ecological principals that can be incorporated into
production systems. The antidotes give excellent examples of how
these principals have been put into practice by farmers around the
country on various crops to control different pests. The only content in
the publication that is out-of-date is the one-page resource list at the
end of the publication; it includes links to several publications and
websites that no longer exist or are wrong.
You can download the bulletin as a pdf document from the SARE website.
Sustainable Agriculture Research and Education (SARE) is a nationwide grants and education program
to advance sustainable innovation to American agriculture. The website, www.northcentralsare.org, is an
excellent resource for research-based agricultural information with an extensive library of publications
(books, fact sheets, bulletins) on several topics as well as summaries of completed research projects.
For more information on Iowa S.A.R.E. grant and education programs, contact Linda Naeve, State
S.A.R.E. Coordinator at [email protected].
I
IowaProduce.org e-Newsletter
April 2015
Iowa State University Extension programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital
status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612.
Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.
Don’t Let Invasive Fruit Fly Ruin Fruit Harvest
Joe Hannan, Commercial Horticulture Field Specialist
“Combating the Spotted Winged Drosophila Fruit Fly” workshops will be offered April 20
and 27, 2015, by Iowa State University Extension and Outreach to discuss trapping,
identification, prevention, and control of the spotted winged drosophila (SWD), an invasive
fruit fly that lays eggs in ripening fruit just prior to harvest.
The two, half-day workshops are offered at two locations across the state, Iowa City and
Clarion. Commercial fruit farmers, should attend one of the SWD pest management
workshops before fruit ripen and become susceptible to attack.
Since 2012, infestations of the spotted wing drosophila have been detected in Story, Linn, Johnson, Polk,
Dallas, Pottawattamie and Dubuque counties. However, it is believed to be widely spread across the
state. SWD causes damage when the female flies cut a slit and lay eggs in healthy, undamaged fruit,
particularly thin-skinned fruits such as raspberries, blackberries, blueberries, cherries, strawberries and
grapes. Larvae emerge inside the fruit and begin to feed causing collapse and eventual decay and
complete destruction of the fruit.
Joe Hannan, horticulture specialist with ISU Extension and Outreach said, “This emerging pest threat
forces growers to increase insecticide applications near harvest time or they will experience increased
loss of product.” Currently, fruit damaged by spotted winged drosophila is removed from fields during
harvest and destroyed, even though consumption poses no health risks.
Workshop attendance will also include an opportunity to participate in an ISU Extension and Outreach
grant project during summer 2015, to monitor the presence of the spotted winged drosophila in Iowa and
find alternative uses for damaged fruit. Hannan explains, “We propose using berries damaged by the
spotted winged drosophila in processed, value-added products rather than discarding them. This strategy
would reduce food waste and create new markets for produce that is normally discarded, while increasing
grower profitability.”
Upcoming workshops:
 Monday, April 20, 9:00 a.m. to noon –ISU Extension Johnson County Office
3109 Old Highway 218 South, Iowa City, Iowa

Monday, April 27, 9:00 a.m. to noon –ISU Extension Wright County Office
210 1st St. SW, Clarion, Iowa
The workshops are free, but require advanced registration by contacting Dallas County Extension Office,
515-993-4281 or ([email protected] or [email protected])
Scaling Up You Production? Consider sharing Machinery
Linda Naeve and Georgeanne Artz
As the demand for local food increases, you may be considering expanding
your production for retail and wholesale markets. However, to remain
profitable you need to balance production with increased labor costs and
the need for specialized machinery. You have likely seen the diversity of
specialized machinery for fruit and vegetable production at trade shows and
how they can reduce labor inputs and help expand operations, however,
after seeing the price tag, you quickly decided it might not be an economical
investment for your farm.
Sharing equipment may be one option by which many small-scale growers
can acquire use of equipment that is used infrequently and is relatively
expensive. A 2012 survey of Iowa fruit and vegetable growers shows there
is a strong interest among growers in sharing machinery in order to reduce
costs; seventy percent of the respondents answered they would consider
sharing equipment with other growers.
I
IowaProduce.org e-Newsletter
April 2015
Iowa State University Extension programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital
status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612.
Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.
Although equipment-sharing is a good idea and works for many farmers, there are some considerations
that need to be addressed before you enter a sharing agreement. These include: What can be shared?
Who to share with? How to share – what type of agreement is needed?
These issues were addressed in a project we conducted in 2013 with small-scale fruit and vegetable
producers from around the state. The project, funded by the Leopold Center for Sustainable Agriculture,
worked with five groups of 2 to 8 producers that used different types of equipment and sharing strategies.
From their experiences and comments, we developed case studies and best practices associated with
machinery sharing. The objective of this project was to create awareness of alternative strategies for
equipment ownership that growers can implement in their operations to enhance profitability and reduce
risk when scaling up production.
Our case study research revealed a number of common themes, or lessons learned when it comes to
forming and sustaining a successful equipment sharing group:
Lesson 1. Trust and communication are important
Trust and good communication are important factors for making shared equipment use successful. This is
extremely important when the partnerships are forming. Transparency about what type of equipment is
being purchased to share, who will store it and what are the costs to operate and maintain the equipment
is critical to build trust and a good business relationship. Also, plant and row spacing needs of the
equipment may need to be communicated early in the planning so the machine and crop spacing are
compatible.
Lesson 2. Compatibility matters
When choosing partners for a sharing arrangement, growers should consider both similarities and
complementarities of the farms and people involved. One group we interviewed works because they are
all beginning farmers who have skills, strengths and interests that complement each other. This good
embodied the idea that “the sum may be greater than the parts.”
Having farms with similar production methods, such as certified organic, makes the use and maintenance
of the machinery less complicated, but differences are not insurmountable.
Lesson 3. Consider the complexity of the equipment and the learning curve
Unlike a lawn mower that works the same in most backyard situations, farm equipment does not perform
the same from field to field, under a variety of soil types and terrain and when pulled by different sizes
and types of tractors. Also, various tractor tire spacings and hitches can require time-consuming
adjustments for some equipment.
Lesson 4. Distance matters
We typically assume that close proximity will
make sharing equipment easier by reducing
transportation costs and allowing the equipment
to be used more frequently. However, in certain
situations, long-distance sharing can make
sense. One advantage of long-distance sharing
is conflicts over scheduling can be avoided if
there is enough variation in the growing
seasons of participating farms and the
equipment is used only once per season.
Lesson 5. Not everything is worth sharing
In addition to considering the cost of mileage
and time spent in transport, it is important to
think about the labor required, the need for
timeliness, and the difficulty of the task the
machine would perform.
Lesson 6. Equipment sharing can evolve into greater partnerships
There is a lot of potential for small-scale fruit and vegetable producers to expand their partnerships
beyond machinery sharing. A natural extension would be to cooperatively purchase transplants and
I
IowaProduce.org e-Newsletter
April 2015
Iowa State University Extension programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital
status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612.
Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.
supplies, such as crates, boxes, and bags, to reduce the unit costs. These partnerships can also evolve
into shared marketing of the product.
An ISU Extension and Outreach publication, Machinery Sharing for Fruit and Vegetable Producers, was
written to help small scale fruit and vegetable producers with information to help them determine if
machinery sharing right for them and how to make it work. It also includes sharing agreement templates
and five case studies of groups who shared various pieces of machinery in our project. You can download
a free copy of this publication from the Extension Publication Store.
Managing Soil pH in Horticulture Crops – Part 3: Increasing Soil pH
Joe Hannan, Commercial Horticulture Field Specialist
After writing this article, I found it was simply too long to include in this newsletter all at once. See Part 1:
Introduction and Part 2 Decreasing Soil pH. The following is a discussion on liming the soil. The series
will conclude in May with a discussion on special cases.
Increasing soil pH
The pH of acidic soil can be raised by incorporating limestone into the soil. Most limestone found in Iowa
is a mix of calcium and magnesium carbonate although the ratios will vary. Limestone is slow acting but it
is relatively inexpensive and safe to use. It is not water soluble and must be incorporated to a depth of 68 inches to be effective. Hydrated lime is more reactive and will increase the soil pH faster than lime,
however it is caustic and can be dangerous to work with.
Two pieces of information are required to determine how much lime is necessary to increase the soil pH:
current buffer pH and desired pH. Buffer pH is a measure of a soil’s resistance to change in pH. Actual
rates of limestone to apply are calculated from the recommended CaCO3 rate (table below) and the
Effective Calcium Carbonate Equivalent (ECCE), of the limestone product to be applied (ECCE is
determined for all agricultural limestone sources in Iowa and available from supplier prior to purchase).
The ECCE of limestone is determined by its particle size and purity. Smaller particles react faster than
larger particles. To calculate the quantity of limestone to apply, divide the rate from the chart below by
the percent ECCE.
𝐿𝑖𝑚𝑒𝑠𝑡𝑜𝑛𝑒 𝐴𝑝𝑝𝑙𝑖𝑒𝑑 =
(𝑃𝑜𝑢𝑛𝑑𝑠 𝑜𝑓 𝑃𝑢𝑟𝑒 𝑓𝑖𝑛e 𝐶𝑎𝑙𝑐𝑖𝑢𝑚 𝐶𝑎𝑟𝑏𝑜𝑛𝑎𝑡𝑒)
% 𝐸𝐶𝐶𝐸
The table below lists lime recommendations, based on SMP Buffer Test, given in pounds of pure fine
calcium carbonate (CaCO3) to increase soil pH from its present level to pH 6.0, 6.5, or 6.9 to a depth of 6
inches. From Table 16 of extension publication
Buffer
Desired pH
Buffer
Desired pH
pH
6.0
6.5
6.9
pH
6.0
6.5
6.9
7
0
0
1100
6.3
1400
4200
680
6.9
0
0
1900
6.2
2000
5000
7700
6.8
0
600
2700
6.1
2500
5700
8500
6.7
0
1300
3500
6
3100
6400
9300
6.6
0
2100
4400
5.9
3700
7100
10100
6.5
200
2800
5200
5.8
4300
7900
11000
6.4
800
3500
6000
5.7
4900
8600
11800
For example, your soil test indicates you have a pH of 5.6 with a buffer pH of 6.6 and you are
experiencing a downward movement of your pH over several years. You decide to lime the soil to pH 6.5
with a limestone that is 90% pure (90% ECCE). To calculate your total limestone need from the chart and
table above:
I
IowaProduce.org e-Newsletter
April 2015
Iowa State University Extension programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital
status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612.
Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.
𝐿𝑖𝑚𝑒𝑠𝑡𝑜𝑛𝑒 𝐴𝑝𝑝𝑙𝑖𝑒𝑑 =
2100 𝑃𝑜𝑢𝑛𝑑𝑠 𝑜𝑓 𝑃𝑢𝑟𝑒 𝑓𝑖𝑛𝑒 𝐶𝑎𝑙𝑐𝑖𝑢𝑚 𝐶𝑎𝑟𝑏𝑜𝑛𝑎𝑡𝑒
90%
𝐿𝑖𝑚𝑒𝑠𝑡𝑜𝑛𝑒 𝐴𝑝𝑝𝑙𝑖𝑒𝑑 = 2333 𝑝𝑜𝑢𝑛𝑑𝑠
To raise the pH to 6.5 from 5.6 with a buffer pH of 6.6, you require 2333 pounds of limestone per acre
and incorporated to a depth of six inches.
Upcoming Events
April 20
Spotted Winged Drosophila trapping and management. Monday April 20th from 9 to noon at the Johnson
County Extension Office (3109 Old Highway 218 S) in Iowa City. Please preregister by emailing Joe at
[email protected].
April 27
Spotted Winged Drosophila trapping and management. Monday April 27th from 9 to noon at the Wright
County Extension Office (210 1st St. SW) in Clarion. Please preregister by emailing Joe at
[email protected].
August 10
2015 Fruit and Vegetable Field Day. Horticulture Research Station. 1:30 to 7:30. More info to follow.
For more information about Commercial Fruit and Vegetable Production
contact:
Joseph Hannan, Commercial Fruit and Vegetable Specialist serving Central and Western IA, (515) 993-4281,
[email protected], or visit my website at www.iowaproduce.org
This work sponsored in part by Iowa State University Extension and Outreach, the Leopold Center for Sustainable
Agriculture, Value Added Ag, The Research and Demonstration Farms, and the Dept. of Horticulture.
I
IowaProduce.org e-Newsletter
April 2015
Iowa State University Extension programs are available to all without regard to race, color, age, religion, national origin, sexual orientation, gender identity, genetic information, sex, marital
status, disability, or status as a U.S. veteran. Inquiries can be directed to the Director of Equal Opportunity and Compliance, 3280 Beardshear Hall, (515) 294-7612.
Cooperative Extension Service, Iowa State University of Science and Technology, and the United States Department of Agriculture cooperating.