Caswell Tobacco Tips – Starting Out on the Right Foot

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Caswell Tobacco Tips

Your source of NC State tobacco research and reminders throughout the season 

Issue: 2020.1  Starting Out on the Right Foot

Each year with seeding time is another opportunity to reassess how we do things and make changes to try and help with problems we have had in the past. Starting tobacco seeds in a greenhouse is a great way to produce uniform and healthy seedlings that take off once they get planted in your field. However, it also has great potential for something to go wrong that will hinder your yield potential all season. There is nothing worse than going into transplanting with weak or diseased seedlings. Below are a few tips backed up by NC State University research to help with this year’s seeding:

Sanitation: Starting out with clean trays, clean & weed-free greenhouse, and fresh transplanting media is essential to prevent disease from entering your greenhouse. Consider setting up a way to steam your trays using your tobacco barn (Learn how). Research shows 140°F for 2 hours provides great control of Pythium and other pathogens. You can also do this post-transplanting and be ready to go the following year. Although it is not recommended by Cooperative Extension, if you are using bleach for any sanitation, make sure you rinse trays THOROUGHLY after exposure. Bleach is Sodium Hypochlorite. Excess Sodium is harmful to transplants and Chloride is especially bad for tobacco seedlings.  

Water Source: In the float system, water plays a vital role as a means to evenly soak the seed pellet prior to germination and to provide water, nutrition, and pest management materials once the seed has germinated. It is vital that this water be free of pathogens and not be too high or low in any chemical compounds or minerals. It is also important that the pH is correct; much like the pH of your soil, if the pH of your water is incorrect, it is extremely difficult for your seedlings to take up nutrients and grow properly. The N.C. Department of Agriculture & Consumer Services Agronomic Division does water sample analyses for float water and I would highly encourage you to get a sample done before seeding. These water samples are $5 and could make or break your whole season. It is also important to take a sample after fertilization to monitor your fertilizer rates. During this time it is especially important to watch your salts in this water as fertilizer is a salt and can harm your plants at the wrong concentration. It is also recommended to flush your well system and pipes before filling your beds to avoid any stagnant water or water with high concentrations of undesirable elements. (NCDA&CS Water Sample website)  

Temperature: Research has shown that temperature fluctuation is important for tobacco seed germination. Tiny tobacco seeds do not have enough energy to push up from deep within the soil, so if they are held at a constant temperature they “know” they are deep in the soil and will wait to germinate. A seed that experiences temperature fluctuation “assumes” it is near the soil surface and will have enough energy to reach the sunlight. 68°F during the night and 86°F during the day has been shown to have the highest level of germination across varieties. Additionally, the temperature during the daytime has been shown to have a huge effect on germination. For example, increasing the daytime temperature from 86०F to 95°F led to an additional 1-2 days added for germination. This is important during days with variable weather when the greenhouse can rapidly heat up if cloud cover disappears.

As always, If you start to see something developing, or the plants are not growing as you would expect, please call the office and I will come out as soon as I am able. I may not be able to solve your problem right then and there, but I can work with NC State Extension specialists, NC State University Plant Diagnostic Lab, NCDA&CS resources, and anyone else I can think of to work towards a solution.

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