VARIETY. PLOT NO. 3. The vines receiving three applications of the Bordeaux Mixture. American Giant...... PLOT. A summary of the preceding four tables, arranged for the com parison of the averages of the results obtained in the experiment, is as follows: lbs. 201.7 15.9 lbs. The figures obtained from plot No. 2, show the results where no Bordeaux Mixture was used. By comparing the figures from plot No. 2 with those from plot No. 4, we have the benefits arising from the three applications of the mixture, and by comparing the figures from plot No. 2 with those from plot No. 1, and adding or subtracting, as the case may require, the difference between the results in plots Nos. 3 and 4, as a correction for any variation in the results that might be due to the constitutional differences of the varieties, the actual benefits arising from the five applications of the mixture are obtained. CONCLUSIONS DRAWN FROM THE COMPARISON OF THE RESULTS IN PLOTS NOS. 2 AND 4. First. The yield of merchantable potatoes was increased 9.9 per cent. by spraying the vines three times with the Bordeaux Mixture. Weight. Number. Second. The larger yield was due to an increase in the size of the tubers and not to an increase in number. Third. The per cent. (by number) affected by the rot, was one and one-half times, or 150 per cent. greater in plot No. 2, where no mixture was used, than in plot No. 4 where three applications were made. CONCLUSIONS DRAWN FROM A COMPARISON OF THE RESULTS IN PLOTS NOS. 1 AND 2. Fourth. The yield of merchantable tubers was increased 34.5 per cent. by spraying the vines five times with the Bordeaux Mix ture. Fifth. The application of the mixture did not increase the total number of tubers formed. Sixth. The average weight of the individual tubers was 35.5 per cent. more in plot No. 1 than in plot No. 2, or, if we add to this the 12.5 per cent. difference shown in the average weights of the individual tubers in plots Nos. 3 and 4, we have 48.0 per cent. as the actual increase in the weight of the individual potatoes arising from the five applications of the Bordeaux Mixture. Seventh. The per cent. of the potatoes affected by the rot in plots Nos. 1 and 2 varies but slightly; that is, it is but three and three-tenths of one per cent. less in plot No. 1 than in plot No. 2; but, again, if we add to this the correction for the constitutional differences of the varieties compared, shown in the difference of results in plots Nos. 3 and 4, we have as the actual benefit arising from the five applications of the Bordeaux Mixture an increase of 253.3 per cent. in the number of potatoes affected by the rot in plot No. 2 over plot No. 1. THE FORMULA USED IN PREPARING THE BORDEAUX MIXTURE. (1) Sulphate of Copper, 6 lbs., dissolved in 4 gallons of hot water. (2) Lime, 4 lbs., dissolved in 4 gallons of cold water. |