Wenjing Guan

Vegetable Crops Hotline Editor & Clinical Engagement Assistant Professor
Department of Horticulture and Landscape Architecture
Area(s) of Interest: Commercial Vegetable and Melon Production
Wenjing Guan's website

142 articles by this author

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Welcome to a new year of the Vegetable Crops Hotline (VCH), Purdue Extension’s newsletter for people in the business of growing vegetables. As usual, we will have fifteen issues throughout the 2018 growing season. The first issue of the year is sent to all who subscribed to VCH via US-mail in 2017 as well as new subscribers for 2018. To continue receiving future copies through US-mail, renew your Hotline subscription using the forms attached  to this issue. Note that we provide an up-to three years’ subscription of VCH with a reduced price. If you receive the issue through email, you will continue to receive the newsletters on the issue dates. In addition, you will receive emails if there are articles or announcements that need your immediate attention. These articles will be posted under Hot Topics and be included in the next issue. All the previous articles published in VCH are available on the website, and you will find additional articles under Veggie Extras. Frequently[Read More…]


A grafted tomato plant grown in a high tunnel

Awareness of tomato grafting has increased tremendously in the past years. Some growers fall in love with this technology and apply it to every tomato they grow. While others find this technology is not cost effective. The growers who have successfully adapted this technology are often small-scale, high tunnel or greenhouse growers who have mastered the grafting technique. They graft tomatoes by themselves and often can achieve a high survival rate. In this case, the added cost for grafted plants is mainly the cost of rootstock seeds, which is roughly 30-50 centers per plant. A small amount of yield increase could easily compensate for the added cost. This is particularly true for tomatoes grown in high tunnels that often sell at a higher price. In situations that farmers buy grafted plants, the cost rangs from $1 to $3 per plant. Farmers would expect a high percentage of yield increase to compensate for[Read More…]


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2018 Indiana Small Farm Conference Date: March 1-3 Location: Hendricks County Fairgrounds, Danville, Indiana The 2018 conference in Danville, Indiana begins with a series of daylong workshops on March 1. Topics include on-farm fresh produce food safety, regenerative farming with livestock and agroforestry, farm viability and financial management, and a four season farm tour. Breakout sessions on March 2-3 will cover topics ranging from vegetable and livestock production to farm management and marketing. Participants will have an opportunity to network with Extension educators, expert speakers, other farmers and vendors. The complete list of speakers will continue to be updated as presenters become finalized. The Small Farm Trade Show takes place on March 2-3 where more than 50 vendors will showcase their products and services. The Small Farm Poster Session on March 3 will feature research and programs on local foods, diversified agriculture, and small farm production and education. Detailed information about 2018 Indiana Small Farm Conference is available[Read More…]


Figure 1. Watermelon variety trial at Southwest Purdue Ag Center.

Seedless watermelon variety trials have been conducted at the Southwest Purdue Agricultural Center in Vincennes, IN for more than 20 years. In 2017, we evaluated the performance of 37 standard size seedless watermelon varieties and 4 mini watermelon varieties. This article introduces the top performing varieties in our trial in 2017. Standard size seedless watermelons Red Amber. This is a new variety. It had the highest yield among 37 varieties in 2017. Rind pattern of the variety is a medium green background with a medium dark crimson stripe. Average fruit weight in our trial was 16 lb. Red Amber had relatively firmer flesh compared with other varieties. 9651 and 9601. Both 9651 and 9601 are sugar baby type watermelons that have solid green rinds. Fruit shape is round to oval. Both varieties had a high yield in 2017, especially 9651. Average fruit size of 9651 was 16 lb and 9601[Read More…]


This is the final issue of the Vegetable Crops Hotline (VCH) for 2017. Now is the time for subscribers who receive a paper copy in the mail to renew. A renewal form is included with this issue. Note that we provide an up-to three years’ subscription of VCH with a reduced price. You can also sign-up for Veggie Texts with the same form. Email subscribers will remain on the subscription list for VCH as long as the email address works. Email subscribers will need to send us an email or call us to sign-up for Veggie Texts. An Indiana Vegetable Grower Association (IVGA) membership form is included here too. IVGA membership no longer automatically includes the VCH subscription. You need to indicate you would like to subscribe the VCH on the membership form. Thank you very much for your support of VCH. If you have any suggestions, ideas, comments, please do not hesitate to[Read More…]


Winter is the best time to recharge. In the last issue of this years’ Vegetable Crops Hotline newsletter, I would like to highlight a few free webinar resources that I found very useful in the past season. Hopefully, you can also benefit from them, and have a productive winter. eOrganic webinars http://articles.extension.org/pages/25242/webinars-by-eorganic A lot of great information related to organic production, including using biofungicides, biostimulants and biofertilizers to boost crop productivity and help manage vegetable diseases; Management options for striped cucumber beetle in organic cucurbits; Impacts of the food safety modernization act on diversified organic vegetable farms, and a lot more. Commercial Horticulture Webinars by Alabama Cooperative Extension http://www.aces.edu/anr/beginningfarms/webinararchive.php The webinar series cover topics including irrigation, greenhouse crop production, plant disease management, insect pest management, weed management and more. Vegetable webinars by Michigan State University Extension http://msue.anr.msu.edu/program/beginning_farmer_webinar_series/vegetable_webinars The webinar series target for beginning farmers, topics include cover crops, season extension, plasticulture,[Read More…]


Consumers love cucumbers that are sweet, seedless and have thin skins. They are willing to pay high prices for the long or mini cucumbers sold at grocery stores. These cucumbers are often grown in greenhouses and shipped long distances. It will attract consumers’ attention if greenhouse type cucumbers can be produced locally in high tunnels, and be available in the early-season’s market. There are at least three benefits for targeting early-season cucumber production. First, prices are higher; second, there are less pest problems; and third, things are going slower in early seasons compared to in the summer. However, we all know that cucumbers love high temperatures and do not grow well when soil temperature is low, even in high tunnels. This is especially true for the greenhouse type cucumbers. The situation may be changed with the use of grafting technology. Using squash as rootstocks, we were able to harvest cucumbers[Read More…]


Strawberry production in Indiana primarily utilizes matted row systems, in which bare root strawberry plants are set in the spring, fruit is first harvested in the second year and plants are maintained for a few seasons. Strawberry production using an annual plasticultural system is popular in the southern states, at where strawberry is planted in the fall and harvested in the next spring. In the annual plasticultural system, strawberries have a longer harvest period and produce fruit with better quality. Growing strawberries as an annual crop is a challenge in Indiana. This is because our short fall makes it difficult for plants to reach the desirable sizes that lead to a sufficient yield in the following spring. This impression can be changed with the use of high tunnels that provide additional heat units and moderate frost protection. In a trial conducted in a 30 ×96 high tunnel at the Southwest[Read More…]


In the past season, we tested performances of eight specialty melons grown under high tunnel, greenhouse, hydroponic, and conventional field systems. The melon varieties we have tested in our trials include Lilliput, Inspire, Sugar Cube, French Orange, Tasty Bites, Escorial, Savor, and Artemis. Many of these melon varieties are Charentais (Cucumis melo var. cantalupensis). A specialty melon type with an outstanding fragrant smell. If you are wondering how to grow these specialty melons, please follow us at the Indiana Hort Congress. We will present what we have learned about growing these specialty melons under different production systems.


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Southwest Indiana Melon and Vegetable Growers’ Technical Meeting  Date: November 21, 2017 5:00 p.m. to 8:00 p.m. (EST) Location: Southwest Purdue Ag Center (SWPAC), 4369 N. Purdue Road, Vincennes, IN The meeting will start at 5:00 p.m. for board members to discuss topics for the March meeting, which will be held in French Lick, IN. Any member who wants to participate in the discussion is welcome. At 6:00 p.m., dinner will be served. Following that, we will showcase variety trials conducted at SWPAC in 2017, which includes seedless watermelons, melons, and personal-sized watermelons. Any grower interested in becoming a member is invited to attend. Membership dues are $15 per year and can be paid at the meeting. To register please call (812) 886-0198. Registration is due by Nov. 10. Any questions, please contact Wenjing Guan at guan40@purdue.edu  Illiana Vegetable Growers Symposium Date: 8 a.m. to 4 p.m. (CST) Jan. 4 2018 Location: Teibel’s Restaurant, 1775 U.S. 41,[Read More…]