Control of grasshoppers (Phaulacridium vittatum) by ultra-low volume aerial application of technical maldison

Abstract

Field trials investigating ultra-low volume applications of undiluted technical maldison by aircraft against dense populations of Phaulacridium vittatum Sj÷stedt (wingless grasshopper) are described. In February 1965 an application rate of 8.2 fl oz an acre gave 90-95 per cent reduction of grasshopper populations on a property on the northern tablelands of New South Wales. A further trial in November 1965, using rates of 4.6 and 5.6 fl oz per acre, gave similar results for each rate-70 per cent reduction of the population one day after spraying, rising to 80-85 per cent within eleven days. Some aspects of a large aerial spraying campaign conducted from October to December 1965 are also described. More than 150,000 acres were treated with maldison at the rate of 6.3 fl oz an acre. Detailed observations of the campaign spraying were made on a single property as well as general surveys of the whole treated area. A minimum application rate of 8.0 fl oz maldison an acre is suggested for normal field usage against P. vitiatum.