Weed seed contamination of substrates often leads to weeds competing with the desired plant species for essential resources. The objective of this research was to evaluate if a solar oven provides a simple sustainable, solarization method for reducing weed competition in small batches of contaminated pine-bark based substrate. In the laboratory, petri dishes containing 100 weed seeds per plate that were subjected to 15 or 30-min heat treatments at 45, 60, and 75°C using a electric oven. Non-heat-treated seeds served as controls. Heat treated seeds and controls were then germinated in a growth chamber over twenty-one days. Weed seeds that were heat treated at higher temperatures for 30-min resulted in declining germination rates, while weed seeds exposed to corresponding temperatures for 15-min exhibited less efficacy in reducing germination. Based on the laboratory results, a field experiment was setup to evaluate solarization of a weed seed contaminated substrate using a solar oven. Substrates were mixed with 100 weed seeds per replication and subjected to >65°C for 30-min. Substrates were placed under greenhouse conditions to measure seed emergence. Weed seed emergence declined after solarization, however, performance of the solar oven was dependent on environmental fluctuations.
