20 MASS. EXPERIMENT STATION BULLETIN 441 



Comparisons were made of Fermate l}4, Phygon 1, Zerlate 2, pounds in water, 

 100 gallons, Bordeaux 4-4-100, tribasic copper sulfate 4, and no treatment. The 

 percentage of infected fruits in the unsprayed plots at harvest was 18.5 percent 

 and 22.7 percent of the total. The percentage of infected fruits in the sprayed 

 plots varied from 3.5 to 9.1 percent. The best control was obtained with Phygon. 



The plots sprayed with Phygon and with copper showed the least foliage dis- 

 ease. The total yield and the average weight of the squash fruits were the least 

 in the Phygon-sprayed plots. 



Like numbers of squash from the sprayed plots were dipped in fungicide and 

 combined fungicide and wax emulsions at harvest and then stored until mid- 

 January. The least loss from black rot occurred in lots of squash from the Phygon- 

 sprayed plots immersed in Phygon or in combined Phygon and wax emulsion, 

 and from the Zerlate-sprayed plots immersed in Zerlate or Formalin solution. 

 Control of rot in storage was not significant when the squash fruits from the 

 sprayed plots were not immersed before storage. The least shrinkage from 

 evaporation of moisture occurred among the lots of squash immersed at harvest 

 in combined fungicide and wax emulsion. 



Interrelation of Wettable Sulfur, Lead Arsenate and Lime in Apple Spraying. 



(E. F. Cuba, Waltham.) Except for drought conditions from June 25 to July 24, 

 the growing season was marked by continuous rains which contributed to the 

 worst scab epidemic on record. Severe frosts caused a great reduction in the 

 set of fruit of some varieties. Premature defoliation and discoloration of Mcintosh 

 trees from scab was prevalent. 



Scab was controlled best on Delicious with Phygon and Puratized in a through- 

 out schedule of six applications, and with a schedule of three sprays of Flotation 

 Sulfur Paste alternating with three sprays of Puratized. Fermate gave significant 

 control, and lime added to Flotation Sulfur Paste and lead arsenate controlled 

 scab as well as the same mixture without lime. On Mcintosh the best scab 

 control was obtained with Phygon, Puratized, and Fermate, and significant con- 

 trol with Flotation Sulfur Paste and Puratized alternating. Eradication of 

 foliage scab was best accomplished with Puratized. The action of liquid lime 

 sulfur on the fungus was less satisfactory. Phygon and Fermate exert a marked 

 fungistatic or inactivating action on the scab spores in foliage infections. Wet- 

 table sulfurs are not fungistatic in this respect. Fermate and wettable sulfur 

 combined offer advantages over either fungicide alone in the control of scab. 



The least amount of russeted Delicious fruit was associated with Phygon and 

 Fermate, each combined with lead arsenate, and with wettable sulfur alone and 

 with lead arsenate alone. Frost russeting was prevalent on Baldwin fruit among 

 all treatments; russet ranged from 25 percent with Phygon to 70 percent with 

 Puratized, indicating a significant influence of the spray chemical on the incidence 

 of injury. The Phygon-sprayed trees showed abnormally colored foliage and 

 depreciated weight of the harvested fruit. 



Analysis of the sulfur residue before and after applications of sulfur indicates 

 that the addition of lime increases the loss of sulfur from weathering. Paste 

 sulfurs or the finest particle sulfurs weather off less than coarse sulfur. 



Tobacco Frenching Induced by High Soil Temperature. (L. H. Jones and 

 M. A. Tic.) Two varieties of tobacco — Havana Seed, a cigar tobacco, and Yellow 

 Mammoth, a cigarette tobacco — were grown in a compost soil at two soil tem- 

 peratures, a high of 95° F. and a low of 70° F. Frenching symptoms in the most 

 extreme forms appeared on both varieties at the high soil temperature in 8 days. 

 In 21 days terminal growth stopped, and rosetting or polj'phylly was the main 

 characteristic symptom. No frenching symptoms developed at the low soil 

 temperature. 



