STUDIES ON THE BIONOMICS AND CONTROL OF THE BURSATE NEMATODES OF HORSES AND SHEEP: V. COMPARISONS OF THE LETHAL EFFECTS OF SOME NON-NITROGENOUS FERTILIZERS ON THE FREE-LIVING STAGES OF SCLEROSTOMES

Abstract

The effect on the free-living stages of sclerostomes of some non-nitrogenous artificial fertilizers, containing potash, phosphoric acid or calcium, is discussed. Of these fertilizers kainit has most practical advantages. Under the conditions of the experiments, which are otherwise ideal for the survival of the larvae, one part of kainit to 23 parts of fresh horse feces is necessary to sterilize them. The proportions in which the other fertilizers must be mixed are:—Muriate of potash 1:17, (potassium chloride, one of the main constituents of the previous fertilizer, is rather more lethal); carbonate of potash 1:13; sulphate of potash 1:5. Superphosphate (20%) sterilized when mixed at 1:5, and 16% superphosphate required 2:5. Basic slag and raw rock phosphate (Florida) had no sterilizing value. Lime, in spite of its reputation as a sterilizing agent for many pests has, when mixed with fresh feces, little effect on the free-living stages of sclerostomes.