2017 Fruit and Vegetable Field Day

Ajay Nair
Department of Horticulture
Iowa State University

Hello Iowa fruit and vegetable growers, Master Gardeners, and fruit and vegetable enthusiasts:

I am writing to invite you to the 2017 Fruit and Vegetable Field Day on 7^th August, 2017 (Monday) at the Iowa State University Horticulture Research Station, 55519 170th St., Ames, IA. The field day will run from 2 to 6:30 p.m. Similar to last year, registration is free but required for head counts for supper. Please click the link below to register. Registration deadline is 31 July, 2017

www.extension.iastate.edu/vegetablelab/2017-fruit-and-vegetable-field-day

The fruit and vegetable field day will provide an opportunity to evaluate several research projects focusing on high tunnel pepper and peach production, tomato grafting, integration of poultry and vegetable production, pest management in gourd crops, viticulture, growing hops and honey bee health and behavior studies. The functioning of equipment and tools (potato digger, vegetable wash station) will also be demonstrated. The overall objective is to highlight new and innovative production practices and techniques in fruit and vegetable production that could be utilized by commercial and local producers. Look forward seeing you at the Field Day.  

Magnesium deficiency symptoms

Dr. Ajay Nair and Kristine Neu
Department of Horticulture
Iowa State University

Iowa is finally getting some nice warm, in some cases hot, sunny days. This reigns in the importance of irrigation and supply of nutrients to plants for rapid growth and development. Nutrient deficiencies often show up with rapid plant growth. One we are observing now is magnesium deficiency.

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A typical indicator of magnesium deficiency in vegetables is interveinal chlorosis which develops between the leaf veins (first image). Due to magnesium’s mobility in plants, symptoms will typically affect older leaves first. Prolonged deficiency will eventually lead to death of the tissue (second image). Magnesium deficiency is widely observed in vegetable crops, particularly pepper and tomatoes due to their nutrient high requirements. To address deficiency soluble magnesium sources, for example Epsom salt, could be used both foliarly or through the drip. Foliar applications are effective but must be applied in low concentrations to avoid phytotoxicity. For smaller areas and backpack type operation, mix 1 lb of Epsom salt in 5 gallons of water and spray uniformly. For fertigation apply 15-25 lbs of actual magnesium per acre.

Iowa Cover Crop Survey

Ajay Nair
Department of Horticulture
Iowa State University

Cover crops can improve soil health, conserve resources and improve farm profitability. Now, your experience with what works and doesn't work can help shape the future of cover crop initiatives nationwide. Farmers who plant cover crops, used to plant cover crops, or have never tried cover crops are all encouraged to take this short survey, now in its fifth year.

Please take the survey at http://tinyurl.com/2017coverssurvey

Colorado potato beetle management

Dr. Ajay Nair
Department of Horticulture
Iowa State University

Ames, IA. Recently I was contacted by a fellow grower and good friend Ms. Laura Krouse from Abbe Hills Farm, Mt. Vernon, IA with a question regarding common enemy of ours: Colorado potato beetle (CPB). Given the mild winter we have had, CPB could pose a formidable challenge this year. If you follow strict crop rotation plans and have moved your potato plots around, hopefully 650 ft, you should be ok but it is always good to be prepared. Why is 650 ft? That is because research shows that CPB in their early development stages emerge from the soil and walk to find potato plantings and 650 ft is to much of a hike for them !

Anyways, let us briefly discuss few management aspects especially insecticides, both organic and conventional. Growers who use conventional insecticides are number of options, some commonly used insecticide classes include pyrethroids (Warrior, Mustang, Asana, Baythroid), carbamates (Sevin), and chloronicotinyl (Actara, Admire, Assail, Platinum), to name few. It is also important to rotate insecticides between different chemical classes. Repeated use of same insecticide can lead to resistance issues in CPB. 

Now, what about organic management. Bacillus thuringiensis products are effective but not all strains. Bacillus thringiensis var tenebrionis provides effective CPM control, however, it is only effective against small larvae (less than 1/4 inch) and should be applied at egg hatch or when larvae are first seen. When the larvae get larger than that, it is more difficult to control with Bt. A commercial OMRI approved product containing Bt tenebrionis is Trident® (Certis USA Inc.). One can also use neem-based products such as Azatin-O, which is OMRI approved. Botanical insecticides, such as neem, have limited persistence in the environment as the temperature, ultraviolet light, rainfall and other environmental factors can degrade neem. Repeated applications may be needed but apply based on label instructions to avoid any kind of phytotoxicity.

Tomato grafting

Ajay Nair and Kristine Neu
Department of Horticulture

Iowa State University

High tunnels have emerged as a tool for Iowa vegetable growers to extend the growing season, increase crop production, and improve the quality of the produce, but production in this system does not come without challenges. Continuous cropping of tomatoes in the same high tunnel gives rise to recurring soilborne and foliar diseases, pest pressure, issues with soil fertility and salinity, and increased irrigation requirements. One tool to overcome these challenges may be the use of vegetable grafting. The process of grafting is accomplished by attaching the desired scion onto a rootstock that is typically bred for vigor and/or disease resistance.

Results from a two-year study of grafting a determinate (Mountain Fresh Plus) and an indeterminate (Cherokee Purple) tomato cultivar on RST-04-106T rootstock are available on sustainable vegetable production lab website. Click on the link below to download the report.

http://www.extension.iastate.edu/vegetablelab/

It is all about seeds !

Dr. Ajay Nair
Department of Horticulture
Iowa State University

This is the time everyone is busy planning for the upcoming season and for some time to order seeds. A successful cropping season rests largely on high-quality seeds. Seed quality is central when it comes to uniform germination, successful establishment, and high yields of vegetable crops. Key factors growers should be aware of:

1.       Seed storage: It is always good to buy new seeds every year but if you have leftover seeds from last year, you can still use them, provided they were stored properly (low moisture, cool, and dry storage conditions). It is better to avoid seeds that are more than 2 years old that were not properly stored.

2.       Cultivars: It is a good time to glean through university cultivar trial reports, extension publications, grower forums, and seed catalogs to identify the cultivar you want to grow. Use your own experience from previous growing seasons and customer feedback to make the right cultivar choice. Of course, there is nothing wrong in experimenting few new cultivars and vegetable types.

3.       Seed suppliers: Please make sure to order seeds from reputed and trusted vendors. Seeds should have high germination percentage, should be true to type, free of weeds and diseases. Sometimes it is better to call your area seed company representative. The Iowa Fruit and Vegetable Growers Association Conference (26-27 January 2017, Ankeny, IA) will host several seed companies that do business in Iowa. More information on www.ifvga.org

4.       Order the right amount: It is advisable to order a little more than what you need but it is not good to order large quantities of seeds that go unused.

To sum it all, seeds are the foundation of a successful production system. Seed quality plays an important role and its characteristics such as trueness to variety, germination percentage, purity, vigor, and appearance are important for optimum crop growth, performance, and yield. A good quality seed never costs, it pays!

Dr. Ajay Nair
Department of Horticulture
Iowa State University

A new publication providing information on micronutrient levels in soil and optimum range in plant tissue is now available at the Iowa State Extension and Outreach store. Although needed in very small amounts, micronutrients have an important role to play in plant growth and development. Most of them are involved in enzymatic reactions that are essential for plant survival such as photosynthesis and respiration. This publication highlights the major roles, deficiencies, and toxicity symptoms of micronutrients in plants and provides an understanding of the interactions between micronutrients in the soil. Click on the link below to download the guide

https://store.extension.iastate.edu/Product/Micronutrient-Publication-for-Vegetable-Growers

2016 Field Day Highlights

Dr. Ajay Nair, Kristine Neu, and John Krzton-Presson
Department of Horticulture
Iowa State University


We would like to offer up a HUGE thank you to everyone who attended and supported the 2016 Fruit and Vegetable Field Day! It was great to have a group of close to 100 people join us for research presentations and hands-on demonstrations.

We would like to especially thank the following individuals and organizations for their support:

• Eric Franzenburg and Iowa Fruit and Vegetable Growers Association
• Liz Kolbe and Practical Farmers of Iowa
• Brian Nordschow and Windridge Implements Inc.
• Donald Lewis, Lina Rodriguez-Salamanca and Laura Jesse with the Plant and Insect Diagnostic Clinic
• Joe Hannan and Patrick O'Malley with Iowa State Extension and Outreach

The day would not have been possible without the tireless efforts of Nick Howell, Brandon Carpenter, and the entire staff of the ISU Horticulture Research Station.

Please keep an eye on our website http://www.extension.iastate.edu/vegetablelab/ for winter workshops and presentations, and know that we already look forward to seeing you for the 2017 Field Day!

Brian Nordshow answering questions about planting and harvesting equipment available from Windridge Implements Inc.

Liz Kolbe sharing the message and work of Practical Farmers of Iowa. She is joined by Lina Rodriguez-Salamanca and Laura Jesse of the ISU Plant and Insect Diagnostic Clinic.

Dr. Ajay Nair and Kristine Neu giving an overview of their colored bell pepper cultivar trial and shading study.

Field day attendees explore the grafted tomato research in a high tunnel. Project supported by IDALS.

Dr. Diana Cochran sharing updates on the apple rootstock trial.

Bryn Takle explains the layout of his hops research focusing on nitrogen fertility.

Kenny McCabe demonstrating the use of the HopsHarvester.

Dr. Ajay Nair and John Krzton-Presson talk about conservation tillage and food safety in muskmelon production.

Hayley Nelson and Dr. Mark Gleason explaining row covers, ProtekNet, and their role in the potential prevention of bacterial wilt.

Students and staff who played a vital role in the success of the 2016 Fruit and Vegetable Field Day.

Dr. Ajay Nair
Department of Horticulture
Iowa State University

A new publication providing information on commercial asparagus production is now available at the Iowa State Extension and Outreach store. The production guide discusses all aspects of production including cultivar selection, fertility management, insect-disease-and weed management, harvesting and storage. Click on the link below to download the guide

https://store.extension.iastate.edu/Product/Commercial-Asparagus-Production

Commercial melon production

Ajay Nair and John Krzton-Presson

Department of Horticulture

Iowa State University

A new publication providing information on commercial melon production is now available at the Iowa State Extension and Outreach store. The production guide discusses all aspects of production including cultivar selection, transplant production, fertility requirement, insect-disease-and weed management, harvesting and storage. Click on the link below to download the guide

https://store.extension.iastate.edu/Product/Commercial-Melon-Production

Wind Damage on High Tunnels

Kristine Neu and Ajay Nair,
Department of Horticulture,
Iowa State University

We've recently received some much needed rain in Central Iowa; however, this has brought along some necessary evils. Wind and the other damaging culprits that accompany summer thunderstorms have been especially unwelcome for producers growing in high tunnels. 

On the evening of July 11 the ISU Horticulture Farm fell victim to the 30+ mph hour winds with gusts upwards of 50 mph. The results were the complete loss of one high tunnel skin and the displacement of a shade cloth on another. Thankfully the research was not compromised. We hope that our local growers did not face the same misfortune!

Ajay Nair

Department of Horticulture

Iowa State University

A new publication providing information on all aspects of Pak Choi production is now available at the Iowa State Extension and Outreach Online Store. The commercial production guide discusses all aspects of pak choi production, starting with with choosing appropriate cultivar, planting method, fertility, etc. Click on the link below to download the guide

http://store.extension.iastate.edu/Product/Commercial-Production-of-Pak-Choi

Managing Stress in High Tunnels: Shade Cloth

Kristine Neu and Ajay Nair,
Department of Horticulture,
Iowa State University

The early onset of high temperatures in June has kept us on our toes as we manage our high tunnel production systems at the ISU Horticulture Research Station. While high tunnels bring many benefits to high value crop production, including season extension and increased produce quality, we find that one major downfall is the increase of heat stress. 

Last year, after blossom abortion due to heat stress and severe sun scald damage on tomatoes within our high tunnel, a 30% light reducing shade cloth was purchased to alleviate some of these issues.When the predicted highs reached over 90 degrees early this month, we knew it was once again time to place the shade cloth on our high tunnel, and there was an audible sigh of relief from the tomatoes.

On June 24 we applied shade cloth to small high tunnels that are being used to trial seven colored bell pepper cultivars. In addition to trialing the cultivars, we are examining the response of the plants and fruit to three different shade treatments- no shade, 30% shade, and 50% shade. Our hope is to hone in on the best production methods for colored bell peppers in high tunnels.

A shade cloth may be a valuable tool to utilize in your high tunnel production system, but we understand that cost is a huge decision factor. Here is a short breakdown of approximate costs taken from a large grower supply company:

• 30% polyethylene knitted shade cloth = $0.20 / square foot
• 1000' spool of polyester curtain cord = $30
• Shade Clip (suggested placement is 2' spacing) = $0.47 / clip

Cost to cover a 30' x 96' structure with a 30% shade cloth = $500 + shipping

Please watch for updates throughout the season regarding our high tunnel production of tomatoes and colored bell peppers.

Unique Insect Feeding Damage on Peppers

Kristine Neu and Ajay Nair,
Department of Horticulture,
Iowa State University

The growing season is never without challenges, and this summer is no exception- especially for our high tunnel bell pepper research! On June 13 we noticed some unique feeding damage on the stems of our pepper plants. This damage was isolated to the stem area beneath the mulch layer.

The stems appear to be completely girdled, but the vascular system of the pepper seems to still be functioning at some level. A week and a half later and many of the damaged plants are beginning to fall over. Some have snapped off completely at the weakened point, but many are still trying to press on and flower. Unfortunately, these plants will likely not be viable much longer either. 

We are working with ISU Professor and Extension Entomologist, Dr. Donald Lewis, to narrow down the source of the damage. Dr. Lewis agrees that this doesn't look like the normal feeding damage for the typical cutworm that plagues vegetable production in Iowa. 

Have you ever seen damage like this in your production system? We would love to hear from you!

Sweet Pea Harvest in Central Iowa

Kristine Neu and Ajay Nair,
Department of Horticulture,
Iowa State University

Yesterday we were invited to check out the harvest of 100 acres of sweet peas on a farm in Central Iowa. The harvest began at 5:00 a.m. and would be completed by early afternoon. The crew included 7 harvesters, 2 transport carts, 2 teams of mechanical support, and a crew of 10 semi trucks on a continuous rotation. The drivers were transporting the peas 180 miles to a processing plant in southern Minnesota; each semi truck load contained approximately 28,000 lbs of shelled peas.

Rye Cultivar Trial - Anthesis and Roller Crimping

Kristine Neu and Ajay Nair,
Department of Horticulture,
Iowa State University


Cereal rye plots at anthesis on May 21, 2016.

Early summer has kept us busy with our cereal rye cultivar trial located at the ISU Horticulture Research Station near Gilbert, IA. This study is comparing five cultivars of cereal rye (Aroostook, Elbon, Prima, Wheeler, and Wrens Abruzzi) for their performance as a cover crop in a roller crimping system. Each cultivar was planted on two dates last fall - September 16 and October 13. 

Pollen being shed at anthesis.

One of our primary questions of interest is, "When does each cultivar reach anthesis?" This question is important because cereal rye cannot be successfully killed with a roller crimper until it has reach flowering stage, also known as anthesis. We saw Aroostook reaching anthesis on May 17 with Elbon and Wrens Abruzzi following two days later. Prima and Wheeler both reached anthesis on May 21.

Cereal rye being terminated with the roller crimper.

   










Due to recent rain our roller crimping was slightly delayed, and all plots were terminated with the roller crimper on Friday, June 3. The plots were evaluated on Tuesday, June 7 to assess the success of the kill with the roller crimper. Aroostook and Wrens Abruzzi appear to have the best rate of kill and would be ready for strip tilling and planting of a vegetable crop. Wheeler and Prima appear to be standing back up, and would require another round of roller crimping to be a viable mulch bed.

Prima (left) and Aroostook (right) on June 7.

For more information on cereal rye and roller crimping, please visit reference our extension publication Strip Tillage in Vegetable Production.
  

Carrot harvest from soil benches

Ajay Nair
Department of Horticulture
Iowa State University

Today (4/21/16) we harvested carrots (cultivar Nelson) and parsnips (cultivar Javelin) from the soil benches. These were planted by students in HORT 471 class (Vegetable Production and Management). Carrots were seeded on 12 January, 2016.

From a 4ft by 4 ft section we harvested between 25-30 lbs of carrots. Parsnips did not do that well and produced smaller roots and yielded around 5-8 lbs from a similar area.

Commercial Potato Production Guide

Ajay Nair

Department of Horticulture
Iowa State University

A new publication providing information on all aspects of potato production is now available at the Iowa State Extension and Outreach Online Store. The Commercial Potato Production Guide, The publication discusses all aspects of potato production, beginning with choosing the correct type of potato to grow, size of seed potatoes, spacing, fertility, and pest management. Click on the link below to download the guide

http://www.extension.iastate.edu/article/commercial-potato-production-discussed-new-publication

Salad greens- Vegetable Production class

Dr. Ajay Nair
Department of Horticulture
Iowa State University

Students in HORT 471 (Vegetable Production and Management) course are growing variety of vegetables in HORT greenhouse. Crops were seeded/transplanted on soil benches with medium consisting of soil, compost, and peat. The course provides students with theoretical knowledge and hands-on experience required for successfully producing vegetable crops. Some of the crops being grown include leafy greens (arugula, tatsoi, lettuce, mizuna, bok choy), summer squash, carrot, pepper, tomato, pole bean, bush bean, sweet corn, cabbage, cauliflower, collards, brussels sprout, and radish. Students had a great time collecting data, harvesting greens, and enjoyed a full-service salad bar yesterday (24 February, 2016). Check out the pictures: