10 ALFRED E. CAMERON. 



Two years previously the same field had been planted in potatoes. Then followed 

 a rotation of grass, clover and timothy, which was mowed in the summer following 

 for hay. Late in the autumn it underwent ploughing, the soil being turned up to 

 a depth of eight inches, and then in the spring it was worked with a Clark cut-away 

 harrow. Fertiliser of the formula 4-8-10 was administered at the time of seed- 

 planting at the rate of about a ton and a quarter to the acre. 



At Freehold. From 21st June until the end of July, representing the most important 

 period of growi:h of the foliage, there was only 4*8 inches of rain, and although the 

 weather was excessively dry and warm at times, the plants made such headway 

 that the profuse foliage of the " Giant " variety was meeting in the rows almost at 

 the time of the fourth application of the treatments on 16th June. Here there was 

 a fair amount of " tip-burn," and also some Fusarium oxysporum, the fungus 

 of dry rot. There was no late blight and only an infinitesimal amount of early 

 blight which appeared first late in the season, about 20th July. Practically none 

 was to be found on the plots sprayed with Bordeaux mixture or with the Ansbacher 

 preparation, but the lead arsenate and sulphur dust plots had a fair amount. 

 However, not a great deal of damage was done as the foliage was already dying. 



There were eight series of six plots at Freehold with one smaller series of but two 

 plots. The area of the field was 24' 57 acres and each plot had but eight rows. At 

 no time throughout the season could the eye observe any difference in the foliage 

 of the various plots that could be supposed to be due to difference of treatment, 

 and as the probable reasons for this remarkable fact have already been detailed 

 (page 2), it will not be necessary to take up the discussion again at this point. 



The same notable fluctuation in the presence of the flea-beetle was likewise observed 

 here as at Elmer and also at Kobbinsville, lending further support to my belief that 

 there are three broods of this pest in New Jersey. Johannsen* is quite emphatic 

 in his assertion that there is but a single brood in the State of Maine, or at most a 

 partial second, and quotes Sirrine's experience in New York State as supporting 

 his statement. This however does not prove that single-broodedness is a universal 

 characteristic of the species. 



The yields as obtained at Freehold are set forth in the table, and a glance at the 

 last column will readily show how little advantage accrued from the spraying or 

 dusting. Still, something was achieved, in that the home-made Bordeaux mixture 

 vindicated itself, if ever so little, here as at Elmer ; but on this occasion the lead 

 arsenate control plots came out somewhat ahead of those treated with the pro- 

 prietary Ansbacher preparation. Perhaps the results would have worked out 

 somewhat differently had it been possible to apply the sulphur-gypsum-lead arsenate 

 in a more satisfactory fashion. Again, the non-application of this material during 

 the first and second treatments also militated against a true comparison of the 

 results. 



At Freehold the variety most grown is the " Giant," and the tubers are sold mixed, 

 there being no separation into firsts and seconds, or marketables and culls. 



♦Johannsen (0. A.). — Potato Flea-Beetle. Bull. 211, Maine Agr. Exper. Sta., 1913, 

 pp. 39-40. 



