How many Signifact figures does 0.000300

3 significant digits

Explanation:

The first 0 don't count (that's the rule in significant digits). So 3,0,0 are left over. Count them and total will be 3 significant digits. (remember the last zero count if there is a decimal but the first zeros doesn't count even with the decimals)

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary