Growth and Development of Silverleaf Nightshade (Solanum elaeagnifolium)1

Controlled - environment studies were conducted to determine the influence of temperature, light, seed weight, depth of planting, substrate pH, and salinity on the germina- tion and emergence of silverleaf nightshade (Solanum elaeagni- folium Cav.). The effects of planting date, top removal, and root-cutting length on establishment were studied in the field. Fluctuating temperatures of 20 to 30C produced 57% germination. Maximum germination, 59%, occurred between pH 6 and 7. NaCl concentrations greater than 2500 ppmw caused germination to decrease 85% or more compared to the control. Light was not important for germination. Mean seedling emergence was 46% from depths of 1.0 to 2.5 cm. Silverleaf nightshade seedling emergence from a 2-cm depth was 31% greater in a sandy soil than a loam. Delayed seeding caused a decline in dry-weight accumulation of above-ground parts. Fifteen percent of seedlings clipped 15 days after emergence were capable of regrowth, and after 30 days or more, 90% of the clipped plants regrew. Additional index words. Planting date, top removal, root length, planting depth, salinity.