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
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The Small Farm Education Field Day and Webinar Series will take place 12:00 -1:10 pm EST, July 30 to Aug. 14, 2020. Register at https://tinyurl.com/y5ahtrow. After you register, a Zoom link will be emailed to you. If you have any questions, please contact Petrus Langenhoven at (765) 496-7955 or plangenh@purdue.edu     


U.S. Secretary of Agriculture Sonny Perdue announced an initial list of additional commodities that have been added to the Coronavirus Food Assistance Program (CFAP), and that the U.S. Department of Agriculture (USDA) made other adjustments to the program based on comments received from agricultural producers and organizations and review of market data. Producers will be able to submit applications that include these commodities on Monday, July 13, 2020. USDA’s Farm Service Agency (FSA) is accepting through Aug. 28, 2020, applications for CFAP, which helps offset price declines and additional marketing costs because of the coronavirus pandemic. USDA expects additional eligible commodities to be announced in the coming weeks. USDA collected comments and supporting data for consideration of additional commodities through June 22, 2020. Changes to CFAP include: Adding the following commodities: alfalfa sprouts, anise, arugula, basil, bean sprouts, beets, blackberries, Brussels sprouts, celeriac (celery root), chives, cilantro, coconuts, collard greens,[Read More…]


The NOAA Climate Prediction Center is showing consistent patterns the last several days for a high risk of excessive heat July 17-19. Please be prepared. Here is a factsheet about Protecting Yourself from Sun Exposure provided by Purdue Safety Specialist Brian McDonald that can be very helpful this time of the year.


Figure 1. Manganese toxicity on cantaloupe.

Manganese (Mn) toxicity was observed in a cantaloupe field at the Southwest Purdue Agricultural Center this year. This is a plant nutritional disorder related to acid soils and it usually occurs in clusters in a field. A plant tissue test confirmed that the Mn level in the leaves of the affected plants was 3766 ppm, which was 23 times higher than the Mn level in healthy leaves. The symptom occurs first on older leaves. The diagnostic feature of manganese toxicity is the tiny pin-hole type lesions with yellow halos clustered between the veins. Leaves are best viewed when held up to the light. In severe cases, it may cause heavy defoliation and exposed fruit to sunburn (Figure 1). More photos and information about the symptom can be found in the article Manganese Toxicity in Cantaloupe published in Issue 631 of 2017.  The remedy for these disorders is to raise soil pH,[Read More…]



About half of the watermelon fields in our area are not equipped with supplemental irrigation. Watermelon production in these fields is therefore dependent exclusively on rainfall. In fields where supplemental irrigation is available, drip irrigation under black plastic mulch is the most commonly used system. Overhead irrigation through central pivot is also used in some fields. Irrigation management is complex in our area because of significant but unpredictable rainfalls during the watermelon production season. Supplemental irrigation is profitable because it avoids water stress during periods of drought, thereby increasing and stabilizing yields. However, there is always a question whether supplemental irrigation is required for watermelon production in our region; if so, how much water should be applied; if not, what would be the consequence if there was an extended drought period. I do not have a straightforward answer to all the questions. But here are a few facts that I[Read More…]



During an OFRR, produce safety experts from ISDH, ISDA, and Purdue Extension will visit produce farms in the state to assess readiness for a FSMA inspection. These reviews are free, voluntary, and confidential. An OFRR takes approximately 2 hours, and it is scheduled at a time that is convenient for the grower. The reviewers will not take any notes or photos, as these reviews are simply designed to assist produce growers in implementing practices to meet food safety regulations. At the conclusion of the visit, the reviewers will provide feedback on areas for opportunity and suggestions for improving compliance. This is a great tool for growers to prepare for their first inspection! Growers can schedule a review by calling Tari Gary at (317) 407-9802, or email TGary@isda.in.gov. If anyone has questions, they may reach out to Tari or contact Dr. Amanda Deering at Purdue by calling (765) 494-0512, or email[Read More…]


Hoosier Food Market, an online sales platform where farmers can sell directly to consumers with no overhead costs. COVID-19 has changed the way we do a lot of things. Purdue Agriculture recognized that many farmers markets may not be operating at the same capacity, and restaurants may not be purchasing the same amount of product as they were before the pandemic. Faculty and staff from the Purdue College of Agriculture teamed up with Microsoft in a collaboration to provide a free online virtual marketplace that was adapted from the Open Food Network where growers can make their own individual shops to sell their products, and market masters can work with their growers to offer the same goods they offered before, but just online. They call this platform Hoosier Food Market (www.hoosierfoodmarket.com). You can read more about this platform in the press release from Purdue Agricultural Communications: https://ag.purdue.edu/stories/how-microsoft-and-purdue-ag-are-working-together-to-help-hoosier-farmers/


Figure 1. Place shadecloth on high tunnels for colored bell pepper production. Photo credit: Ajay Nair

On hot days in the summer, high tunnel growers may wonder whether to place shadecloth on high tunnels. Considering excessive heat inside the structures that may lead to plant stress, blossom drop and unmarketable fruit, there is a rational for doing it. However, it is important to realize the limitations of placing shadecloth on high tunnels in the Midwest. A few years ago, we compared the effect of 30% black shadecloth on temperature and light levels inside a high tunnel. We found shadecloth significantly decreased maximal temperatures for about 10 degrees Fahrenheit while it had no effect on nighttime temperatures.  In terms of light reduction, it ranged from 60% in a sunny day to 30% in a cloudy day. More information about this comparison can be found in the article Temperature and Light Intensity in a High Tunnel Covered with 30% Black Shadecloth in Issue 619. In our experience of[Read More…]