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

114 articles by this author

Article List
Figure 1. Grafted Fascination plants were grown on the right bed, ungrafted plants were grown on the left bed. The field were naturally infested with Fusarium wilt.

Watermelon production is threatened by Fusarium wilt, a widely distributed soilborne disease that can cause yield losses up to 100%. Currently, there are no watermelon varieties that are completely resistant to all races of Fusarium wilt. One way to control the disease is through grafting. The grafted plant combines a watermelon cultivar with a squash rootstock that has resistance to Fusarium wilt. In a study conducted at Southwest Purdue Ag Center (SWPAC), we found grafted watermelons significantly reduced disease incidence, and more than doubled watermelon yield in a Fusarium wilt infected field (Figure 1). In addition to controlling Fusarium wilt, grafted watermelons often show substantial advantages in early watermelon production due to cold tolerance from rootstocks. In a study conducted in Arizona, grafted watermelons that were transplanted in the field two months before soil temperatures reached 70 °F had twice as much yield as ungrafted watermelons grown in the same[Read More…]

Southwest Purdue Ag Center Field Day  Southwest Purdue Ag Center Field Day will be held on June 29, 2017 at Southwest Purdue Agricultural Center, Vincennes, IN. The field day provides two choices of tours: Horticultural Crop Production and Agronomic Crop Production. The Horticultural Crop Production tour will feature Organic Tomato Production, High Tunnel Vegetable Production, Grape Research, Protecting Pollinators while Managing Insect Pests in Watermelon Production, and Produce Food Safety. A meal will accompany the tour with PARP classes available after lunch. Please contact Barb Joyner (joynerb@purdue.edu, 812-886-0198) for registration, or register online at https://purdue.qualtrics.com/jfe/form/SV_0rICQrMVJmiMnqZ. More information about the tour can be found here. Beginning Farmer Tours and Workshops  Join Purdue’s beginning farmer team for farm tours in 2017. June 15. Clay Bottom Farm near Goshen, IN uses intensive growing methods to support a CSA program on less than an acre of land. Learn about their ‘lean farm” approach to support a CSA, supply[Read More…]

Figure 1. A tomato plant showing nutrient deficiency symptoms.

Recent rain and cold conditions have brought detrimental effects to some of the early planted vegetables. In southwest Indiana, air temperatures have dropped into the 40s °F and soil temperatures have dropped into the 50s °F in early May. The low temperatures would have greatly inhibited absorption of water and mineral nutrients for many warm season vegetables. In one of our fields where watermelon and cantaloupe were transplanted on April 26, almost all the plants showed wilt symptoms on May 3. The wilt was caused by decreased water absorption from roots. The plants were dead due to the extended cold weather. Peppers and tomatoes that were planted about the same time maintained turgid and survived the cold period (Figure 1). But they showed symptoms similar to nutrient deficiency due to the reduced function of roots in the cold soil. The plants should start new growth when the temperature rises. Growers using low tunnels are more likely[Read More…]

thumbnail image

Southwest Purdue Ag Center Field Day Save the date June 29 for Southwest Purdue Ag Center Field Day Beginning Farmer Tours and Workshops  Join Purdue’s beginning farmer team for farm tours in 2017. June 15. Clay Bottom Farm near Goshen, IN uses intensive growing methods to support a CSA program on less than an acre of land. Learn about their ‘lean farm” approach to support a CSA, supply restaurants, and sell at farmers’ markets. June 24. Silverthorn Farm near Rossville, IN uses organic practices to produce a wide variety of fruits and vegetables. The tour will include a session on working with restaurants. September 11. Two tours for the price of one! Tour Little Prairie Farms, a small acreage vegetable farm near Brookston, IN, and the Purdue Student Farm near West Lafayette to learn about farming practices and tools for small acreage farms. September 27. Full Hand Farm is a[Read More…]

Figure 2. A seedless cucumber

A plant is considered to be seedless if it is able to produce a fruit without or contain a much-reduced number of seeds, or in some cases, only present traces of aborted seeds. Seedlessness is a desirable fruit character because seeds are often hard, have a bad taste and produce hormones that lead to fruit deterioration. As a result, seedless fruit often has better quality and longer shelf lives. Seedless watermelons that were introduced in the 1990s have become the main type of watermelons grown in the U.S.  Besides seedless watermelons, breeders have developed seedless varieties for other fruiting vegetables. This article briefly introduces the different types of seedless fruit and discusses potential opportunities for growing theses varieties. Seedlessness exists in two forms. In the case of seedless watermelons, the fruit contains partially formed seeds that are aborted after fertilization (Figure 1.). Seedless watermelon plants are self-infertile. They must be[Read More…]

Farmer Rancher Grant Program of NCR-SARE is for farmers and ranchers who want to explore sustainable solutions to problems through on-farm research, demonstration, and education projects. The Farmer Rancher Grant offers grants of up to $7,500 for an individual applicant, $15,000 for 2 applicant farmers cooperating, and $22,500 for three or more farmers cooperating. More information about the grant is available at http://www.northcentralsare.org/Grants/Our-Grant-Programs/Farmer-Rancher-Grant-Program In Indiana, we had five farmer-initiated projects selected to receive funding in 2017. They were: James Catron of Hallelujah Acres Farm in Lebanon, IN was awarded $7,500 for the project, “Measure the Effectiveness of Interseeded Cover Crops for Proactive Weed Prevention in a Chemical-free, Low-till Vegetable Market Garden Operation.” Jane Loomis of Old Loon Farm in Columbia City, IN was awarded $22,477 for the project, “Investigating the Possibilities of Cooperative Sorghum Syrup Production and Marketing for Strengthening Small Farm Sustainability in Northern Indiana.” Thomas McEvilly of McEvilly Gardens[Read More…]

Indiana Farm Market Association (IFMA) Spring Tour Day The spring tour day will be held on May 2, 2017 in the Fort Wayne area. This is open to anyone with a farm retail store, farm market, or agritourism farm.  It’s a great time for sharing ideas and gather new ones. This is a driving tour, map and directions will be provided. The tour begins at… 10:00 Cook’s Bison Ranch cooksbisonranch.com.  It is located in Wolcottville, Indiana. Lunch at Sandra D’s Italian Garden in Auburn, Indiana. 12:00-2:00   The owner/chief, Bentley Dillinger will also give a brief talk on his business and his relationship to local farmers.  The menu will be specially selected, and it will include their famous dessert, tiramasu.  Note: they are listed as Sandra Ds Garden Cafe for Google Maps. The afternoon will conclude with a tour of Sechler’s Pickles. Tour at 3:00 p.m. There is a requirement of no open-toed shoes,[Read More…]

It is with the deepest sorrow that we inform our readers of the deaths of Tom Roney of Tuttle Orchards in Greenfield, John Hilger of Hilger Family Farm in Fort Wayne and Abner Horrall of Melon Acres in Oaktown. They were all great leaders of the vegetable industry in Indiana. They will be greatly missed.

Hydroponic Lettuce Production Workshop The department of Horticulture and Landscape Architecture is hosting a Hydroponic Lettuce Production Workshop on Wednesday, March 29, 2017, 8:30 am to 11:30 am (EST) in room 222, Horticulture Building at Purdue University. Topics include: Most common mistakes made during hydroponic lettuce production (Petrus Langenhoven); Nutrition, temperature and supplemental lighting for hydroponic lettuce production (Krishna Nemali); Market access (Jodee Ellett), and Tour of hydroponic lettuce research at HLA (Krishna Nemali and Petrus Langenhoven). The workshop is free, please RSVP no later than March 20, 2017 by contacting Lori Jolly-Brown (ljollybr@purdue.edu). For More information, please contact Petrus Langenhoven (plangenh@purdue.edu) or Krishna Nemali (knemali@purdue.edu). Michiana Vegetable & Fruit Growers Meeting  Purdue Extension and Michigan State University Extension services are hosting a daylong event that runs from 8:00 am to 4:00 pm on March 21, 2017, at the Elkhart County 4-H Fairgrounds, 17746 County Road 34, Goshen, Indiana. Topics[Read More…]