376 Annual Report for 1913 of the Botanist. 
Fruit . — Each year the same diseases are received for 
report, namely, peach curl, apple canker, leaf scorch, silver 
leaf, and strawberry spot. One interesting example of apple 
mildew ( Podosphaera Imcotricha ) was examined. The abun- 
dant growth of the mildew on the young shoots appeared to 
to be of an abnormal colour, and further observation showed 
that the parasite itself was attacked by a second parasite, a 
species of Cicinnobolus. The experiments made to determine 
the cause of leaf-scorch (Journal R.A.S.E., 1912, p. 289) hive 
not resulted in the isolation of any fungus or bacterium to 
which the disease can be attributed. Spraying with the usual 
fungicides has had no effect on checking the progress of the 
scorch — in fact the disease was more prevalent on sprayed 
trees during the past season than on those left untreated. 
Other Crops . — Two outbreaks of white rust ( Cystopus 
candidus) were reported on crops of white mustard, but the 
disease was too slight and the crop at too advanced a stage of 
ripeness to warrant the application of fungicides. One severe 
outbreak of celery spot ( Septoria petroselini apii) was 
enquired into, but again the request for help came too late for 
measures to be taken to control the outbreak. 
Amongst other diseases larch canker, mildew on vegetable 
marrows, garden peas and asters, and a spot disease on tobacco 
were dealt with. 
Weeds. 
No weed seems to have given more trouble in the past 
season than the common spurrey (Spergula arvensis). As the 
following quotations show, it has been particularly prevalent in 
newly broken land : — ( a ) “ When I break up any new land, 
either from heather or grass, for the first year or two I am free 
from spurrey. After this it increases each year and the better 
I do my crops the worse the spurrey becomes.” (b) “ The 
land was left to run wild forty years ago and broken up nine 
years since. It is now completely smothered. Acres of oats 
and barley are destroyed.” In this case 200 acres of arable 
land were infested with “ this horrible weed.” 
Spurrey is a weed characteristic of light soil and a vigorous 
growth of it generally denotes a deficiency of lime in the soil. 
Given these conditions it forms a dense mass of herbage from 
six inches to a foot in thickness, which can completely smother 
crops of clover, wheat or barley and render the cleaning of root 
crops a matter of great difficulty. 
The most important point to remember, when attempts are 
made to suppress it, is that the weed is a surface rooting, rapidly 
growing annual, which forms an abundance of seeds. Every 
effort should be made to prevent seeding and reinfestation of 
the land, even should this mean abandoning the crop, sheeping 
