were left untreated to serve as control five days after treatment both the treated and untreated plants were examined to determine the amount of disease control present the results of this examination are set forth below in table ii table ii______________________________________ percent control of phytophthora parasitica at the indicatedactive dosages of active compound incompound part per million by weight employed 2400 1200 600 150______________________________________6 chloro 100 100 50 252 methoxy 4 trichloro methyl pyri dinecontrol un treated plants 0 0 0 0______________________________________ dosage rate equivalent to 2 1 1 2 and 1 4 pounds of active compound pe acre assuming an application rate of 100 gallons per acre soil infected with the tobacco black shank pathogen phytophthora parasitica var nicotianae was uniformly mixed and placed in 2 inch pots to said pots were transplanted four week old tabacco seedlings of the 402 variety which had been grown in pathogen free soil test dispersions of each of the compounds 6 chloro 2 methoxy 4 trichloromethyl pyridine 6 chloro 2 methoxy 4 dichloromethyl pyridine and 6 chloro 2 methoxy 4 dichlorofluoromethyl pyridine were prepared by dispersing the chemicals in acetone and thereafter diluting the solution with water to prepare dispersions containing 100 and 25 parts by weight of each of the compounds per million parts of the ultimate dispersion thereafter the various test dispersions were employed to treat separate pots containing the seedlings by pouring 40 cubic centimeters of each of the dispersions onto the soil assuring root contact with sufficient chemical additional pots were treated with an aqueous acetone solution and water to serve as controls after.