-6- 



acre. Occasionally, grovrers exceed tiiis quantity, but they have learned that 

 heavy spring applications promote 7/eed grovrth and berries are too soft to stand 

 shipment. 



Practically every variety knovm has been tried out by the FalnOuth growers 

 and tested under their soil conditions, but the Hoi-^ard 17 has proven itself 

 superior to any other variety during the past 25 years. In general, grovers }iave 

 been rather free frora serious insect and disease problems during the past eight 

 or ten years, but indications are that strav;berry weevil is again on the increase,' 

 and growers must be alert throughout the year, in order to maintain plants capable 

 of high production, 



ERADIC./yilON OF JiPPLE SCAB WITH LIERCURI-AGET.4TE SP.^AYS AFTEH liTFECTION 



111 1945 the NexY York-New England Fruit Spray Specialists began to experiment 

 v/ith mercury sprays after Dr, Fran!-: lioivard, plant pathologist of the Rhode Island 

 State College, gave us the results of his pioneer v;ork v/ith Puratizod N5E, 



In 1945, at Waltham, Puratized H5E performed censationallj'- in clearing up 

 foliage scab. In ly46 caid 1947, apparently the s,'ime mercury fungicide, bearing 

 the name Puratized Agricultural Spray, usod experimentally end commercially to 

 eradic-ate scab gave variable, intriguing, tcid. often disappointing results. In 

 1948 the results in general v/crc hotter, VJlion used as a prot^jctant or preventive 

 spray, the control of scab in these years of epidemics has been excellent and most 

 satisfying. 



This year at 'lYaltham the scab oradicant action of other, mercury sprays was 

 studied, Mcintosh trees xioro sprayed for the first time on June 2 (five days 

 after calyx) when foliage scab was first evident. On June 14 the trees v;ere 

 sprayed a second time. These dates are 22 and 34 days after the first primary 

 scab infections. Almost all of tlae foliage; scab seemed to be eradicated after the 

 first application of mercuri-acetato and mercuri-f orm;'jriidc, and eradication v;as 

 definitely complete after the second application. 



ivlercuri-acetate gave the most satisfactory eradication and prevention of 



scab. Even the primary infections occurririu^ in the rains of ivlay 10- June 1, that 

 , J . ^ „ ■, o f'-lmosc/,cormas^aly „. -,^ , • a. a. 



had no-c yet appeared on June 2, ■'..-ore/ desrro;/&d,'' These results can have important 



implications. If all of the pri:.iar"y incubating scab am bo killed v/ith early but 

 poorly timed applioatioiis of morcuri-acotatc as the results suggest tmd in addi- 

 tion provide good. protectant or preventive action, the contr'"'l of apple scab 

 should be- greatly simplified, 



Mercuri-acetate is much superior to mercuri-lactate (Puratized Agricultural 

 Spray) as an oradicant for scab. Its action is Y-zry positive. Cooperating 

 growers this year obtained consistent and siiailur satisfying results i.'ith mercuri- 

 acetato. 



Interesting experiments are b«ing plrmnod for 1949, :a\d we sincerely hope 

 that the manufacturers can supply uri v.-ith stable products ef the stone composition 

 next year, 



— E. ?, Guba 



