Cooking and purifying the base. 3 Next, the gum base is cooked in kettles at 243 degrees Fahrenheit (116 degrees Celsius) until it has melted into a thick syrup. To purify it, workers pass it through screens and place it in a high speed centrifuge before refiltering it, this time through finer screens.
When unusually heavy rains saturate the soil, a tomato plant's leaves may curl. Plant roots need air, just like the above ground parts. When heavy rains saturate the soil, the roots can't get enough air. This can result in root damage, which causes the tomato to react in a similar way to sudden hot weather.
If you notice curling, shoestringing or cupping of leaves on your tomatoes, find out if someone in your household or a neighbor has recently applied herbicides in the vicinity of the tomato patch. Leaf curl is one of the indications of potential herbicide contamination.