Annual Report for 1912 of the Botanist. 287 



particularly on those lying on gravel, chalk and limestone, 

 large patches of the herbage were " burnt out." In most cases 

 the clovers, especially white clover, were completely killed. 

 The better grasses failed to spread over these areas, with the 

 result that the bare ground was occupied by seedlings of 

 various kinds. The correspondence on the subject indicates 

 that the commonest of these colonisers was soft brome grass — a 

 species few care to see in any quantity amongst herbage — and 

 the less harmful annual meadow grass. The soft brome grass 

 sheds its seeds at about the time the more useful grasses 

 are sufficiently mature for cutting, and if this is allowed to 

 occur a good meadow may easily be much depreciated. As it 

 generally dies after being cut whilst in flower members were 

 recommended to mow the fields as early as possible. In two 

 of the worst cases it was considered advisable to sow the bare 

 patches with a suitable grass mixture, as the area was so great 

 that gradual colonisation by the better grasses might have taken 

 several years. 



As in former years a number of enquiries have been dealt 

 with on the formation of permanent and temporary pastures 

 and also of lawns. 



Suitable seed mixtures have been recommended for these 

 various purposes. 



Fungoid Diseases of Crops. 



Potatoes. — The first specimen of the potato disease 

 (Phytophfhora infestans) was sent in at an unusually early 

 date, namely, mid-June. Later on, at more normal times, 

 numbers of specimens were received with enquiries as to 

 whether it was too late to spray the crops in the hopes of 

 checking the spread of the disease. Unfortunately the weather 

 conditions in most parts of the country were very unsuitable 

 for this purpose, and practically nothing could be done to 

 check the spread of the epidemic. One disastrous spraying 

 operation was reported on by a member who in his anxiety to 

 check potato disease had sprayed the crop with a mixture 

 made up of eight pounds of copper sulphate and ten of washing 

 soda in forty gallons of water. The result was a yellowing and 

 partial defoliation of all the plants so treated. On hearing this 

 a trial of the mixture was made in order to watch its effects. 

 Similar results were obtained, but a fresh crop of leaves was 

 produced after the fall of the injured ones. These were at 

 once attacked by the fungus. 



" Curl " was reported by several members, and a change of 

 seed, preferably from Scotland, recommended for the following 

 season. No cases of "black scab" or "wart disease" have 

 been received. 



