216 EXPERIMENTAL FARMS 



1-2 EDWARD VII., A. 1902 



in good condition as to moisture and very carefully prepared. The seed was thorough- 

 ly cleaned and the wheat came up promptly. Writing on November 1G, Mr. Waliis 

 reported that there was hardly any Hessian Fly to be found in this field, while other 

 fields in the same locality sown on August 30 and September 1, were badly affected. 



It may be pointed out that September 10 for the county of Middlesex, where Mr. 

 Wallis's land is situated, is the date given in Prof. Loehhead's bulletin as the average 

 date when wheat may be sown there with safety. As has been frequently stated, the 

 emergence of the adult Hessian Flies is dependent to a very large measure on the 

 weather, considerable moisture seeming to be necessary before the flies will leave the 

 puparia. This accounts for a somewhat wide range in the dates when the majority of 

 the flies appear in any season. Prof. Webster, of Ohio, who is one of the highest 

 authorities concerning the Hessian Fly, says : — ' The dates after which sowing can be 

 safely undertaken in the State of Ohio vary over a period of at least a month from the 

 northern to the southern latitudes of the State, or approximately from September 10 in 

 the north to October 10 in the south. Wheat sown after the dates mentioned or after 

 intervening dates in intervening latitudes will germinate in normal seasons after the 

 Hessian Fly has appeared, and be free from attack.' 



If a farmer who intends sowing fall wheat will watch the weather during August, 

 he may calculate pretty well for himself when it will be safe for him to sow. As 

 Prof. Lochhead has pointed out, ' the farmer, if he wishes to grow wheat free from the 

 fly, must follow the season rather than the almanac ; for the best date for one season 

 may not be the best date for another. For instance, a rainless August, such as we had 

 in 1S99 and 1900, will retard the emergence of the fly for two weeks, but an August 

 with a considerable rainfall during the last two weeks will bring forth the flies about 

 September 1, to deposit their eggs ; in which case it will be quite safe to sow accord- 

 ing to the dates given.' 



From the above facts it is manifest that no definite dates can be fixed upon for 

 every year, but at the same time average dates of safety may be mentioned as the pro- 

 per time for sowing fall wheat, as far as injury from the Hessian Fly is concerned. 

 Prof. Lochhead says : — ' It seems not safe to sow, in ordinary seasons, before Sep- 

 tember 15, in the counties bordering on Lake Erie, and the tract of land occupying the 

 valley of the Thames. In the next row of counties, including Lambton, North Middle- 

 sex, Oxford, Brant, Wentworth, and those bordering on Lake Ontario, the probable 

 safe date would be September 10, while in the counties farther north, the safe date 

 may be placed at September 5.' 



The only objection to sowing late — at the end of September instead of at the end 

 of August — is that the plants, it is claimed, have not time to make vigorous roots 

 and tops so as to withstand the cold of severe winters. I have, however, frequently 

 eeen excellent crops which were sown late in September, and, as long as the Hessian 

 Fly is abundant, I have no hesitation in recommending farmers sowing fall wheat to 

 delay this operation until the end of September. There certainly is an advantage in 

 sowing early, but this is not sufficient to offset the risk of losing the whole or a large 

 percentage of the crop from the attacks of the fly. Prof. Zavitz, Experimentalist, of 

 the Ontario Agricultural College, has kindly favoured me with the following data : — 



' Guelph, May 3. — In the average of four years' experiments in sowing wheat at 

 different dates, we find that by sowing from August 25 to 26 we get an average yield 

 of 44 bushels per acre ; from sowing September 2 to 3, an average of 39 -4, and from 

 cowing September 17 to 20, an average of 37-3. There is, therefore, a difference of 

 less than 7 bushels per acre between the yield of the first and last seedings.' 



Parasites. — Parasites, but in small numbers, have been reared from almost every 

 district from which we have received specimens of the Hessian Fly this season. In 

 no cases, however, were these parasites in such numbers as to warrant the hope that 

 the Hessian Fly would be very much lessened in numbers next season. Nevertheless. 

 past experience has shown that parasites may sometimes be present in sufficient num- 



