Daily and Seasonal Response of Huisache and Macartney Rose to Herbicides

Abstract

Triethylamine salts of 4-amino-3,5,6-trichloropicolinic acid (picloram) plus (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T) (1:1) sprays were more effective for the control of huisache(Acacia farnesiana(L.) Willd.) than for the control of Macartney rose(Rosa bracteataWendl.) at 13 dates of application in 1969 and 1970. Both species were more controlled effectively with the application rate of 1.12 than 0.56 kg/ha. Most effective control of huisache was obtained June 18, 1970, although other summer treatments in 1970 were effective. The herbicide was, on the average, more effective on huisache and Macartney rose when applied in the evening than morning or midday. Macartney rose was most effectively controlled by treatments applied in September and October of both years. Poorest control of the two species occurred when internal water stress was highest.