Blueberry Thrips Control, 1975

On a new burn field at Sedgwick, Maine, test materials were applied to 2 x 3 ft plots on May 21 (newly emerging stems averaged 1/4 inch in height), May 24 (new growth averaged 1/2 inch), and May 28 (new growth at 3/4 inch). Dusts were placed into test tubes and applied onto the plots with a bicycle hand pump; a cage covered with clear plastic and located over the plot during the dusting was used to confine the dust to the plot. Cygon was mixed with water added at a rote of 50 gal per acre and sprayed onto the plots with a hand sprayer. No other pesticides were applied to the plots. There were 4 replications per treatment. A randomized complete block design was utilized with some blocks located in high thrips’ pressure areas and some in low. On July 30 all stems in each plot were counted, and stems were recorded as being curled (thrips’ injury) or noncurled. Percent effectiveness is based on Abbott’s formula. The number of stems ranged from 1402 to 1566 per treatment.