II. INFLUENCE OF WEATHER 



At a very early stage in the tests it was quite apparent 

 that the influence of the weather was a most important factor 

 in determining the success or failure of the operation. 



The first trial was at Emley, and was made on a bright, 

 dry and calm day. At this centre the operation was a decided 

 success. The second test was at Stainton on a showery day. 

 Of all the centres this was one of the least successful. At 

 Wressle, where the third trial was made, the weather was not 

 only wet but very windy, and it was found that the spray was 

 blown by the wind against the rows of corn, which acted as a 

 shelter to the charlock growing between them, and this, com- 

 bined with the wet weather, brought about a result scarcely 

 more successful than that at Stainton. 



As it was very evident that the operation, if performed 

 during wet, windy weather, would be only attended by very 

 slight success, no further demonstrations were made until the 

 weather had improved. Thereafter the experience was uni- 

 form, viz.: that charlock or runch sprayed with a proper 

 amount of material, before, during, or immediately after wet 

 weather, to a large extent, escaped destruction, the same being 

 the case when the weather was windy; when, however, the 

 spraying was done in dry weather and on a bright calm day, 

 with a sufficient quantity of solution of the requisite strength, 

 the results were equally uniform, viz.: the leaves of charlock 

 were blackened and eventually completely destroyed. 



III. THE INFLUENCE OF AGE OF 

 THE CHARLOCK 



Unfortunately the weather broke at a time when a large 

 number of demonstrations had been arranged. One was made 

 at the proper time, viz., at Emley. In this case the charlock 

 plants were just getting into rough leaf, and the rows of barley 

 were about three inches high. The result was that where the 

 solutions were put on in proper quantity the effect on the 

 charlock was to reduce the leaves to a black cinder, from 

 which few recovered. As the season advanced the plants at 

 other centres became larger and larger, and in some cases 

 attempts were made to kill plants that had formed a strong 

 stem and were in full flower. 



