130 MASS. EXPERIMENT STATION BULLETIN 254 



of precipitation did not permit the growth of crystals, the product was powdery 

 and the particles amorphous or too slightly crystalline to be detected. All the 

 samples of high basic sulfate were amorphous. Nearly all the samples except the 

 flourlike showed a fair flow in the bottle but poor on a pane of glass, and the 

 fibrous were inferior to the powdery. The adhesive power of the fibrous samples 

 to glass was also inferior to the powdery, and sample "g" with particles of 1.8 

 microns in size the most promising. 



Field Work in 1925 with Commercial Basic Copper Sulfate 



Attention has been called (6, p. 748) to the relative effectiveness of laboratory 

 prepared basic copper sulfate and of Bordeaux with various spores as determined 

 by W. L. Doran of the department of botany of this Station, using the method of 

 Reddick and Wallace (13). Slightly greater concentration (copper content) of 

 basic sulfate than of Bordeaux was required to inhibit the germination of the more 

 resistant fungi. In addition (6, p. 749-750) field experiments were conducted in 

 1925 by E. F. Guba of the Market Garden Field Station at Waltham, Mass., to 

 determine the relative effectiveness of basic copper sulfate (lot 1) and of Bordeaux 

 4-4-50 in controlhng anthracnose and downy mildew on cucumbers and early 

 and late blights on celery. Observations and yields indicate that basic sulfate 

 was substantially as effective, per unit of copper, as Bordeaux in both instances. 



Field Work in 1926 



The field work of 1926 with basic sulfate includes experiments with cucumbers 

 and celery at the Market Garden Field Station at Waltham, with potatoes on the 

 farm of E. S. Fulton at North Amherst, and with apples, plums and grapes in the 

 College orchard and vineyard. The experiments with cucumbers and celery were 

 conducted by E. F. Guba as in the previous year. 



Cucumbers 



The cucumber experiment consisted of 3 plots, 132 by 12 feet, of 2 rows each, 

 planted in hills 6 feet apart each w-ay. The seed was sown three times and that of 

 June 16 finally gave a successful stand. The plants were sprayed before vining by 

 a knapsack sprayer and later by a Bean Truck or Arlington X. L. sprayer with 

 Friend nozzles under 200 to 250 pounds pressure. Frequent applications were 

 necessary on account of rains. Lead arsenate and lime 2-2-50 were applied on 

 July 7, 15, 20 and 26 for the striped beetle. \'ining began about August 2. 

 Basic sulfate (lot 2) 3.84-50 and Bordeaux 4-4-50 with lead arsenate 2-50 were 

 applied on August 2, 5 and 11; the fungicides alone on August 17 and 25, and the 

 fungicides with one-half pint of nicotine sulfate for green aphis on September 1. 

 The basic sulfate was mixed with approximately 6.17 ounces of Wilkinite and 0.88 

 ounces of crude saponin to increase wetting, spreading and adhesiveness. The 

 cucumbers were inoculated with anthracnose fungus, CoUetotrichum lagenarium 

 (Pass.) Ells, and Hals., on August 17 and 27. The fungicides were prominent on 

 the foliage at the time. Powdery mildew, Erysiphe cidioracearum D. C, appeared 

 naturally and developed on the check plot. 



The season was unfavorable for cucurbits, due to poor growing conditions and a 

 fairly general infestation of mosaic, bacterial wilt, striped beetles and green 

 aphis which affected both the stand and the yield. Leaf counts made on Septem- 

 ber 8 and 10 may serve, however, to indicate the relative effectiveness of the two 

 fungicides. 



