ANNUAL REPORT, 1938 31 



Miscellaneous Tests and Experiments. (E. F. Guba and C. J. Gilgut, VValtham.) 



1. Apple Scab Control. Five brands of wettable sulfur, ranging from 30 to 

 "PS.S percent sulfur and varying from 6-7 microns to 45-50 microns in maximum 

 particle size, were compared on an equivalent sulfur basis determined from Kolo- 

 fog, a product containing 30 percent sulfur. Delicious and Mcintosh varieties 

 were used in the experiment^ and the sulfur sprays were applied six times from 

 April 25 to June 2, using about 300 pounds pressure. 



All the materials gave good control of scab. In each row of Delicious yielding 

 apples, there was no russeting of the fruit so prevalent throughout the State this 

 season. In marked contrast to the results of the previous season, which showed 

 a significantly superior fungicidal influence of sulfur of small maximum particle 

 size, the different brands of sulfur offered no striking contrasts in the control of 

 scab. All of the foliage of an unsprayed seedling in this orchard, representing 

 the check on the test, was badly scabbed. 



2. Copper Sprays for Cucumber, Muskmelon, and Tomato. All the commer- 

 cial brands of copper fungicides were used on an approximately equal copper 

 basis comparable to Bordeaux 4-4-50. Between July 6 and September 4, eight 

 treatments were applied with a power sprayer (pressure 250-300 pounds) and a 

 two-nozzle spray rod. The unsprayed plots of cucumber and melon were badly 

 infested with downy mildew and the yield was significantly reduced. There was 

 no disease in the tomato planting; hence the value of the various fungicides could 

 not be determined for tomatoes. The check plots of tomatoes yielded as well 

 as the best treatment. The merit of these fungicides on the basis of this season's 

 tests is shown in the accompanying table by a numerical rank determined from 

 yield. 



Fungicide Rating of Fungicide on — 



Cucumber Muskmelon 



Dow Bordow 1 1 



Copper Oxychloride A 1 2 



Bordeaux 3-3-50 1 4 



Bordeaux 4-4-50 1 4 



Cupro-K 2 3 



Coprote Dust 2 6 



Copper Zeolite 3 2 



Basi-Cop 4 1 



Burgundy 1-11/^-50 4 3 



Copper Hydro 40 4 4 



Bordeaux 2-2-50* 4 5 



Cuprocide 54 5 2 



Bordeaux 1-1-50* 5 5 



Coposil 6 4 



Check** 6 6 



Border* 7 7 



♦Average of 2 rows. 

 **Average of 3 rows. 



Control of Greenhouse Vegetable Diseases. (E. F. Guba, VValtham.) Since 

 the previous report, leaf mold resistant lines of tomato from hybrids of a previous 

 cross were hybridized a third time with the Waltham Field Station Forcing tomato. 

 The Fg generation of this last cross, now growing, shows satisfactory qualities 

 for commercial culture. Arrangements have been made with many greenhouse 

 tomato growers for growing this new leaf mold resistant tomato during the 1939 



