Acidified Sprays, Pollinator Safety, and Integrated Pest Control on Alfalfa Grown for Seed1

Effect of acidification of insecticide sprays in pest control of sugar beet seedlings

“…Injury caused by L. rugulipennis and C. concinna and number of piesmid eggs in sugar beet seedlings treated with acidified (a) and non acidified (n) spray liquids. Acidification did thus not improve the efficiency of insecticides known to be rather quickly inactivated in alkaline spray waters as was the case in studies made by Johansen and Eves (1972). The insecticides were, however, different in these studies as also were the acidifiers.…”

“…formetanate and methidathion, as well as dirnethoate, which is mostly used by the farmers for this purpose, are more quickly inactivated in alkaline than in acid spray waters (manufacturers' bulletins) the question whether the effect of some insecticides can be improved by acidification of sprays was studied in Tikkurila. In the studies of Johansen and Eves (1972) acidification of trichlorfon and carbofuran sprays increased their effectiveness against lygus bugs.…”

Use of ammonium or potassium dihydrogen phosphate to protect pesticides in spray mixtures prepared with alkaline waters

“…Any delay in the use of spray mixtures after preparation-whether because of sickness, equipment breakdown, or unexpected weather conditions-could result in poorer pest control than expected. Consequently, extra pesticide applications are needed, resulting in increased crop production costs (Valk, 1975) and perhaps further environmental pollution.To prevent pesticide decomposition in alkaline water and to maintain biological activity, Johansen and Eves (1972) attempted to stabilize these chemicals with acids and nutrient spray acidifiers. They were, however, unable to maintain a constant pH and found that some pesticides were hazardous to honey bees if the pH spray mixtures was too low.…”

“…To prevent pesticide decomposition in alkaline water and to maintain biological activity, Johansen and Eves (1972) attempted to stabilize these chemicals with acids and nutrient spray acidifiers. They were, however, unable to maintain a constant pH and found that some pesticides were hazardous to honey bees if the pH spray mixtures was too low.…”