Annual Report for 1911 of the Botanist. .377 



The most striking feature of the inquiries concerned with 

 seeds was the effect of the abnormally dry season on the 

 germination of swede and mangold seed. In many parts of 

 the country these were sown on unusually dry seed beds. A 

 small percentage germinated at the usual time, but the bulk 

 only started to grow when rain fell. Some Members con- 

 sidered that these two distinct periods of germination indicated 

 a mixture of old and new seed, but where some of the original 

 seed was still available for analysis it was found to germinate 

 uniformly under suitable conditions. 



Few of the inquiries with regard to weeds were of any 

 general interest. Lepidiuni draba, stated to be spreading in 

 the south of England in the last Report, was received from 

 Essex, where it also appears to have obtained a hold in hedge- 

 rows and arable land. Elodea canadensis., the American water 

 weed, was sent from two localities. In one it had spoiled the 

 fishing in a series of trout ponds ; in the other its growth was 

 so abundant that the watercourses on the farm were partially 

 blocked, and could only be kept sufficiently open by repeatedly 

 cutting the weed. No really satisfactory methods for dealing 

 with it are known, but fortunately it generally disappears more 

 or less completely after a few seasons' growth. The Dyer's 

 genista {Genista tinctoria) was received from three widely 

 separated districts, and in each case reported to be ruining 

 valuable pastures. Stock rarely graze this weed, and conse- 

 quently it sets seed freely, and under suitable conditions may 

 almost monopolise the ground. If mown whilst flowering it 

 can generally be extei'minated without much difficulty. The 

 common spurrey {^pergula arvensis) was sent in on several 

 occasions, with the report that it was one of the worst weeds 

 of light arable lands. It seeds, as a rule, before the corn crop 

 can be harvested, and much of the seed does not germinate 

 till late in the following spring. If sprayed with a 2 — 4 per 

 cent, solution of copper sulphate whilst still young the weed 

 can be eradicated. The application of lime to the soil fre- 

 quently gives satisfactory results also. Bracken {Pteris 

 aquilina) was twice reported as spreading seriously. Attempts 

 should be made to suppress this weed as soon as its presence 

 is noticed in pastures. If allowed to spread it soon covers a 

 large area and spoils the land for feeding purposes. The only 

 satisfactory method of dealing with it is to mow the shoots off 

 repeatedly, never allowing any to expand. Two seasons' 

 treatment will generally cripple the weed, and little trouble 

 will be incurred in keeping it under the following year. A 

 dressing of basic slag is then often of value. 



The fungoid diseases of plants were of more interest than 

 usual. One of the results of the abnormally dry season was 



