Show KILL OFF APPLE APHIS PEST carbon sulphide may be applied to roots by injection or in water poured around I 1 I 1 experiments in the use of poisonous gases against the woolly apple aphis indicate that carbon mai may with good results be applied to the roots by injection or in water poured around the roots experiments in the control of the woolly aphis on the roots of nursery apple stock by the use of poisonous gases indicate that while the use of carbon Is impracticable under nursery conditions para parn offers promise against this pest |