lo Jan., 1911-] Tlic Weeds of Victorta. 33 



grass to keep down its parasite. The reason for making tiie tests arose from 

 the observation that where thick patches of grass occurred over old drop- 

 pings, the Bartsia was usually scarce or absent. These experiments were 

 begun on 3rd November, 1909, and the results noted at the end of October, 

 1910. 



It is quite evident, from the above results, that the most effective way 

 of eradicating Bartsia from an affected pasture will be by bringing it 

 under temporary cultivation for a time. The manure used, if free from 

 weed seeds, and the working of the soil during cultivation, will leave the 

 ground in far better heart to produce a strong, luxuriant pasture than it was 

 before, and at the same time will reduce the parasitic Bartsia almost to 

 vanishing point. This is of considerable importance, because a pasture 

 badly infested with this weed must ultimately be ruined as the parasite 

 destroys the grass. 



In spite of the irregular distribution of the seed over the plots, it 

 is possible, by averaging, to get some idea as to whether the air-slaked 

 lime, quicklime or superphosphate affected in any way the numbers of 

 the Bartsia plants developing. For instance, the average number of plants 

 on the blank plots was 4,123, whereas during the previous season, the 

 average numljer over the whole area was 1,740 per plot. The average for 

 the plots treated with air-slaked lime was 1,351, and for the quicklime 

 plots 7,175, so that if these results can be relied upon, the air-slaked lime 

 reduces the number of seedlings establishing themselves, while the quicklime 

 increa.ses their numl:)er. The average for the whole of the superphosphate 

 plots was 3,125 plants per plot, which would appear to show a slight 

 decrease as compared with the blank plots. The same is suggested by the 

 fact that the superphosphate plot in the bottom row had considerably less 

 plants than the plots above and to the side of it, but this may have been 

 connected with the fact that the grass and clover on this plot, which received 

 the heaviest do.se of superphosphate, was thicker and more abundant than 

 on any other of the plots. Apparently, wherever the grass and clover are 

 very vigorous, the Bartsia is smothered, since although its roots are para- 

 sitic, the plant has green leaves and needs to be fairly well exposed to 

 light to attain its full flevelopment. Hence the abundant presence of this 

 weed in a pasture may be regarded as a sign that the pasture is deteriorat- 

 ing and that the soil needs to be loosened, opened and manured. 



It was also found that on another plot where the plants had been cut 

 before they were able to ripen any .seed, only 112 plants developed and 

 on another one which had been carefully hand-picked, only 24 plants 

 appeared in the following year, the seed of which had probablv been car- 

 ried by wind or water. 



.\p})arently, therefore, the seed of the plant is \tMy short-lived, and it 

 might be possible in cases where the pasture cannot Ix' cultivatfd, to keep 

 down the weed by dressing with sui)erphosi)hate in winter or spring and 

 mowing in October to No\cmlx>r, when the plant is in full flower and t)e- 

 fore it has seeded. Since tlie stem is short, however, and usually not more 

 than 3 to 6 inches high, this would only be of use when the ground is 

 fairly smooth .so that it can be mown. The only effective mode of sup- 

 pression appears to be l.v liringing tin* pasture under temporarv cultiva- 

 tion, talcing care to avoid the re-introduction of the weed when the pasture 

 is seeded down ag.iin. 



17-2'><i. " 



