- Sciences TEMPERATURE ("C) ESTION 3 HIW table below shows the results of a sturly that investigated the effect of temperature light on the yield of tomatoes in two greenhouses on a farm 31 NSC -10 5 10 15 20 25 30 AVERAGE YIELD OF TOMATOES PER PLANT (kg) HIGH LIGHT LEVELS LOW LIGHT LEVELS 0.5 1.5 Test: Ecosystems 3,0 3,6 3,5 2,5 2,5 5,0 8.5 7.8 6.2 State TWO steps the investigator may have taken into consideration during the planning stage of the investigation.​