OCR Text |
Show Natural Acid May Be Used to Protect Plants London. Arsenic, lead, copper and other mineral poisons now used to protect plants against fungus, bacterial bac-terial and insect enemies may find practicable and harmless replacement in an acid naturally formed by living liv-ing plants, suggests Maurice Copisarow, Manchester biologist. biol-ogist. The substance'is known as maleic acid. Experiments have shown that it exercises an inhibitory effect on the growth of micro-organisms ol decay, and Mr. Copisarow suggests that its effect may extend also to viruses hidden in dormant seeds and to insects in early stages of development. de-velopment. This same natural inhibitor, in-hibitor, he adds, is probably transformed trans-formed into the natural accelerator of fruit ripening, ethylene, by a chemical change involving the liberation lib-eration of carbon dioxide. Mr. Copisarow suggests that maleic acid may be applied as a spray in some suitable neutral oily medium. Unlike the mineral poisons poi-sons commonly used for plant protection, pro-tection, maleic acid can be eaten by human beings without harm. |