Investigations on the phytotoxicity of Bordeaux mixture to tomatoes

Abstract

Bordeaux mixture (4-4-40) was shown in a series of experiments to have a higher toxicity for the tomato plant than Bordeaux 4-2-40 and various "inert" copper compounds. Experimental results indicated that the lime content of Bordeaux mixture is an important factor in phytotoxicity to tomatoes. The evidence obtained suggests that Bordeaux mixture adversely affects transpiration, photosynthesis and translocation, and through the general physiological upset impairs flower setting. A new method of estimating phytotoxicity was devised and is described in detail.