ANNUAL REPORT, 1946-47 19 



The fungicide, in fertilizer, which gave the best results with one kind of vege- 

 table did not necessarily, however, give the best results with all others. Damping- 

 off of cabbage, onion, pepper, tomato, beet, and cucumber was well and safely 

 prevented by Tuads 0.5 gm. (Rates of application are expressed in grams per 

 square foot in all cases.) Dithane D14, 2.5 cc, gave good results with all of these 

 except cucumber. Dow Seed Protectant No. 9, 0.45 to 0.75 gm., gave good 

 results with beet, cabbage, and cucumber but not with onion, pepper, or tomato; 

 Phygon only with pepper and tomato. 



Fermate and Tuads applied to soil in fertilizer immediately before seeding 

 gave better control of onion smut than when applied in water to soil immediately 

 after seeding. Best control of onion smut was by Dithane D14, 3.0 cc; Phygon 

 0.6 gm.; or Tuads, 0.55 or 0.65 gm. With 53 percent smut in an untreated soil, 

 there was no smut in this soil when Phygon 0.65 gm. or Tuads 0.65 gm. had been 

 applied in the fertilizer. 



Tuads 0.55 gm. or 0.65 gm. thus applied gave good control of cabbage clubroot 

 in seedbeds and these treatments were followed by improved growth of plants.^ 



Fungicidal treatments of the seeds of Liliuni regale were continued, tetra- 

 methyl thiuram disulfide giving the best results, and a paper was written. 2 



It was found that, lacking all fungicides, fair control of damping-off is possible 

 by merely delating the first watering for a few days after seeding, and the abstract 

 of a paper read on the subject was published.^ 



Tomato Leaf Mold Caused by the Fungus Cladosporium fulvum Cke. (E. F. 

 Guba, Waltham.) Tomato types developed for resistance to Cladosporium 

 fulvum Cke. have been generally accepted by the greenhouse forcing industry. 

 The most satisfactory type has been designated Improved Bay State. The re- 

 sistance of Improved Bay State to tomato leaf mold was derived from a "pimpi- 

 nellifolium" wild type from Ecuador designated U.S.D.A. Plant Introduction 

 No. 112,215. The utility and resistance of Improved Bay State to Cladosporium 

 leaf mold has been substantiated by other station workers. Confirmation of 

 this fact by B. S. Crandall, Office of Foreign Agricultural Relations, U.S.D.A., 

 working at Estacion Experimental Agricola de Tingo Maria, Peru, South 

 America, is especially significant. 



Similar resistance was bred into Marglobe but the finished type lacks firm 

 fruits and a high yielding habit. The hybrid of L. esculentum var. Prince Borg- 

 hese X L. peruvianum outcrossed to Pan America, and submitted by W. S. Porte 

 of the U.S.D.A. as No. 44B292, is being pure-lined for resistance to leaf mold 

 and further study. 



Supervision of seed production of Improved Bay State is planned, to preserve 

 the desirable characters of the tomato for the industry. Seed samples have been 

 distributed to interested workers in many countries. 



This study, in progress since 1925, and since 1933 concerned with breeding for 

 resistance to the disease, is nearing completion. 



Causes and Control of Decay of Squash in Storage. (E. F. Guba, Waltham.) 

 Study was made of the effect of field applications of fungicides on disease control 

 and yield of Butternut squash. The plots were 16 x 210 feet in dimension. They 

 were sprayed five times from August 5 to September 10. 



The diseases involved were powdery and downy mildews (Erysiphe cichoracea- 

 rum DC and Pseudoperonospora cubensis (B «& C) Rost.) respectively, and black 

 rot {Mycosphaerella citridhna (Smith) Gross.). 



1 The writer read a paper on "Fungicides applied in fertilizer for the control of cabbage clubroot 

 and damping-off" at the Annual Meeting of the Northeastern Division of the American Phy to- 

 pathological Society on November 26, 1946. An abstract will appear in Phytopathology. 



2 Doran, W. L. The protection of lilies against damping-off. National Horticultural Magazine 

 25:4:385-386. 1946. 



' Doran, W. L. Control of damping-off by a delay in first watering after seeding. Phytopath- 

 ology 36:8:679. August 1946. 



