Plant materials and pre treatment

Experiment begun January 19, 2019. Tomato species Lycopersicon lycopersicum, a dwarf variety to mature in 50 days, was used. Seeds used were “Tumbler Hybrid Tomato” (Lake Valley Seed, Boulder, CO). Seeds were sown into two 128-plug flats with a moist seed starter soil (Organic Starter Premium Potting Mix, Epsoma, Millville, NJ). Flats were placed on a greenhouse bench with natural light. Germination was induced by placing onto a heat mat. After 17 days in these conditions, 100 ppm N of 20-10-20 were added at every watering. The N was increased to 200 ppm after 7 days of growth.