"Hot water treatment for vegetable seeds just got a little cheaper"

Bacterial diseases of tomato, pepper and brassica vegetable crops are difficult to manage. One practice that growers are increasingly adopting to produce healthy transplants is the use of hot water seed treatments. Hot water seed treatment is an effective way to minimize bacterial inoculum on the surface of seeds, and can even kill bacterial pathogens embedded in the seed coat.

Seed heat treatment follows a strict time and temperature protocol and is best done with thermostatically controlled water baths. Two baths are required: one for pre-heating, and the second for the effective (pathogen killing) temperature. For pepper seed, the initial pre-heating is at 100 degrees F (38 degrees C) for 10 minutes, followed by the effective temperature of 125 degrees F (52 degrees C) for 30 minutes. For tomato seed, the initial pre-heating is at 100 degrees F (38 degrees C) for 10 minutes, followed by the effective temperature of 122 degrees F (52 degrees C) for 25 minutes.

Dr. Beth Gugino, vegetable pathologist at Penn State University, has been experimenting with substituting a sous vide device for the initial pre-heating water bath, with good results. A sous vide device is an immersion circulator that heats water and circulates it around the pot to maintain precise temperatures evenly. Sous vide cooking has been popular among professional chefs for many years. Recently, consumer models of sous vide devices have made their way into home kitchens. Dr. Gugino has found that a sous vide device works well for the pre-heating step, but is not recommending it for the pathogen-killing step. The sous vide cost, around $70, is less than a quarter of the cost of a water bath.

For more information on hot water treating seeds, including using a sous vide device for the pre-heating step, see Hot Water Treatment for Tomato and Pepper Seeds.

Source: eGroBlog (Lee Stivers)