Liz Maynard

Clinical Engagement Assistant Professor of Horticulture
Department of Horticulture and Landscape Architecture
Liz Maynard's website

107 articles by this author

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Bok choy with wooden stake.

A lot of things are different this year. With the changes come opportunities to try something new. Liz Brownlee with Hoosier Young Farmers Coalition mentioned to me that some markets, especially in rural areas, do not have a steady supply of Fall crops, and that farmers might be looking to extend the season with crops not grown before. Many Indiana vegetable farms thrive on the warm season crops planted in spring: tomatoes, peppers, cantaloupe, watermelon, squash, pumpkins, sweet corn. But cool season crops planted in late summer are also grown and marketed successfully at farmers’ markets and to other outlets like food hubs and online marketplaces. For those new to these crops and thinking about trying them, this is a reminder that it’s not too late to plant some crops for fall harvest. (Figures 1 and 2). Lettuce, spinach, kale and many other greens in the brassica family (mustards, mizuna,[Read More…]



When ground level ozone is high enough to trigger an Air Quality Action Day alert from the Indiana Dept. of Environmental Management (IDEM) it is a reminder that crops may be injured by ozone. A number of areas around the state have experienced alerts in recent days, e.g. July 14 in S. Indiana. If crops show the symptoms described below and ozone levels have been high, consider the possibility of ozone injury. Ozone is a gas with three oxygen atoms per molecule. It is formed in the air when nitrogen oxides and volatile organic compounds react in the presence of sunlight. Ground-level ozone is a primary component of smog. Ozone harms people by aggravating existing breathing problems like asthma and injuring lung tissue. It harms sensitive plants by damaging leaf tissue, reducing the capacity to photosynthesize. IDEM issues daily air quality forecasts for ground level ozone from May to September,[Read More…]


Hail injury on pumpkin

(This article is modified from one published in issue 537 of this newsletter written by Sarah E. Hulick and Steve Reiners, Department of Horticulture Science, Cornell University, NYSAES. Liz Maynard also contributed to this article.) Recent storms have brought hail to parts of Indiana. Loss of yield and quality in vegetable crops due to hail depends on the crop, stage of growth, amount of injury, and future growing conditions. Disease control is absolutely essential after hail damage. Surviving plants will also benefit from a sidedressing of nitrogen about a week after the damage occurred. The following is a summary of all the information we could find relating to hail and vegetable recovery. Bell Peppers. A study was conducted in North Carolina to determine the impact of hail on the incidence of bacterial spot. The hailstorm occurred 38 days after transplanting when the plants were still young and recovery was possible.[Read More…]


A few weeks ago, Great Lakes Vegetable Producer’s Network discussed hoophouse nutrient management. Judson Reid from Cornell University and David Van Eeckhout from The Good Acre, St. Paul, MN are the invited speakers. They shared their insights in hoophouse nutrient management. I find them very helpful, thus want to pass my notes to Indiana hoophouse growers. Judson pointed two things from greenhouse perspective that may greatly benefit hoophouse growers, one is ventilation, another is pollination. Ventilation is important for managing relative humidity and maintaining carbon dioxide level. But ventilation may be sacrificed in hoophouse for the reason of maintaining temperatures during periods of cool weather. For hoophouse growers, anything that can increase ventilation (end wall vents, peak vent) could greatly benefit vegetable production in the early season. Hoophouse tomato growers can also greatly benefit from bumblebees for pollination. If the structure is usually closed and there is little wind movement[Read More…]


Question: Why are the water droplets arranged so evenly around the edge of this cucurbit leaf? Answer: The water droplets came out of pores that are at the edge of the leaf where a vein ends. The pores are called hydathodes. The droplets form through the process of guttation. Guttation is when the water pressure in the plant is high enough to force water out of the hydathodes. This occurs when soil moisture and humidity are high, typically at night during rainy humid weather. The hydathodes may also serve as a means for bacterial pathogens to enter leaves. The water droplets can be drawn back into the plant as the sun comes out, relative humidity drops, and the leaf begins to lose water through transpiration. When bacterial diseases are present, these water droplets can be a major means of disease spread if people,  animals,  equipment, wind, or rain move water droplets[Read More…]


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We received calls recently reporting observations of leaf curling on tomatoes. This article discusses factors that may cause tomato leaf curling. In a similar way as other vegetables, hot and dry conditions may cause leaf curling on tomatoes. In late spring and early summer, plants that are actively growing and developing fruit have a high demand for water. Under hot and dry conditions, plants respond by rolling the leaves to reduce the surface area exposed to high radiation. Lower leaves on a tomato plant are often affected first, they may recover if environmental stresses are reduced. Leaf curling itself due to the environmental stresses is not a significant concern, but if the stress condition continues, it may eventually lead to blossom end rot fruit and decreased yield. There is a great variation among tomato varieties in terms of whether the observation of leaf curling suggests the plant is suffering water[Read More…]


Veg Crops Hotline - COVID-19 Image

New 6-3-2020: Application for Coronavirus Food Assistance Program (CFAP) open; Jim Mintert and Indiana FSA Director Steve Brown discuss CFAP application;Indiana State Dept. of Health – Food Safety Guidance (English and Spanish); Guidance for Migrant Farm Workers, Labor Camps Operators and their Employers (Spanish); FDA and USDA release recommendations for those short of PPE. What is new? (6-3-2020) Coronavirus Food Assistance Program Application Details with Purdue’s Jim Mintert and Indiana FSA Director Steve Brown – video and podcast  (5/27) https://ag.purdue.edu/commercialag/home/resource/2020/05/coronavirus-food-assistance-program/ Application for Coronavirus Food Assistance Program open on May 26 (5/27) https://www.farmers.gov/cfap Indiana State Dept. of Health – Food Safety Guidance – 5/29 update (6/3) English https://www.coronavirus.in.gov/files/IN_COVID-19_FoodGuidance_5.29.20.pdf Spanish https://www.coronavirus.in.gov/files/IN_COVID-19_FoodGuidance_03.31.20_version%20nueva.pdf Indiana State Dept. of Health – Interim Coronavirus Disease 2019 (COVID-19) Guidance for Migrant Farm Workers, Labor Camps Operators and their Employers – Spanish version (5/19) https://www.coronavirus.in.gov/files/COVID-19%20migrant%20worker%20Spanish%205.19.20.pdf FDA and USDA release recommendations for those short of PPE (5/22) https://www.fda.gov/food/cfsan-constituent-updates/fda-and-usda-release-recommendations-those-food-and-agriculture-sector-experiencing-shortages-ppe  Here are[Read More…]



Veg Crops Hotline - COVID-19 Image

New 5-21-2020: Application for Coronavirus Food Assistance Program will begin on May 26; Indiana Registered Disinfectants for Use Against COVID-19 (updated) What is new? (5-21-2020) Application for Coronavirus Food Assistance Program will begin on May 26 (5/20) https://www.farmers.gov/cfap  Indiana Registered Disinfectants for Use Against COVID-19 (updated) https://www.oisc.purdue.edu/pesticide/pdf/covid-19_disinfectants_051520.pdf Here are the categorized information resources Financial Application for Coronavirus Food Assistance Program will begin on May 26 (5/20) https://www.farmers.gov/cfap SBA COVID-19 DISASTER LOANS FOR INDIANA SMALL BUSINESSES (link update 5/7) https://isbdc.org/indianacovid19smallbusiness/ https://www.sba.gov/funding-programs/loans/coronavirus-relief-options SBA Help for Small (and Family) Businesses, Purdue Institute for Family Farms (update) (4/28) https://ag.purdue.edu/agecon/fambiz/Documents/SBA_Help_for_Small_Businesses.pdf COVID-19 Affected Business and Employee Resource Guide from Sen. Braun (3/27) https://www.braun.senate.gov/sites/default/files/2020-03/Senator%20Mike%20Braun%20COVID-19%20Affected%20Business%20and%20Employee%20Resource%20Guide_0.pdf Information about the Coronavirus Aid, Relief, and Economic Security (CARES Act); the Families First Coronavirus Response Act; and Small Business Economic Injury Disaster Loans (EIDL). Production COVID-19 response plan template and FAQ for fruit and vegetable farms from UMN. (5/7) https://blog-fruit-vegetable-ipm.extension.umn.edu/2020/04/covid-19-response-plan-template-and-faq.html This template can[Read More…]