i>i?i-:ases xot due to parasites or of uxkxowx ORir.ix 119; 



92^ - Some Practical Means of Control of Wheat ' Stretta", in the South of Italy. — 



Maxcixi Camillo in // Coltivatorc, 6^n(] Year, Xo. 17, pp. 52:5-328. Ca^al Monfcrmt, 

 June 20, 1916. 



Wheat growing, extensively practised in the South of Italy, is very much 

 checked by the disease called " stretta " of the wheat. This is a sort of 

 sudden stoppage of growth accompanied by an almost certain dr>'ing when 

 the wheat is in ear, and followed by unusual acceleration towards maturity, 

 although the grain is not yet entirely full. The culm yellows early, and this 

 yellowing afterwards spreads to the entire ear or a part only. The affected 

 ear remains half empty and gives a smaller yield, because at the same time 

 the grains are atrophied, small and light. " Stretta " usually occurs be- 

 tween the end of May and the beginning of June. The principal cause which 

 gives rise to it is drought, and insufficient fertility' of the soil is another cause. 

 " Stretta " is more frequent in years with a hot and dr}- .spring, and is more 

 serious in too compact or too light soils, which, for opposite reasons, suffer 

 more from the drought. On the other hand, " stretta " does not occur in 

 wheat sown on beans or lupin ploughed in as green manures, or on broken-up 

 meadow, lucerne, clover or sainfoin land. 



From personal observations and experiments carried out during 40 years 

 as an agriculturist, the writer advises the following means as being very 

 effective against " stretta " and within the reach of all : i) Deep tillage of 

 the soil at the right time : very dry soils when deeply tilled during the summer 

 did not suffer with " .stretta ", while neighbouring soils tilled very super- 

 ficially with the plough did not even yield an equivalent of the seed ; 

 2) thin sowing, both in rows and broadcast, accompanied by rational and 

 svifficient manuring, so as to allow and induce tillering ; 3) cultivation work 

 in autumn, winter and spring ; it is ver}- useful to cultivate two or three 

 times between the autumn and the beginning of spring. 



<)2J, - Studies on the Amylase in Healthy Potatoes and in Those Suffering from "Leaf 



Curl". — See X''o. 851 of this Bulletin. 



925 - Diseases of Undetermined Origin in the Tomato, in Ontario. — howitt j. e. and 



Stoxk R. E., in Phytnpatholo'^y, \o\. 6, Xo. },, pp. 162-166. Baltimore, Md., 1916. 



In 1914 and 1915, tomatoes grown under glass were attacked by a dis- 

 ease the origin of which is still unknown, in several parts of Ontario. 

 On the leaves, between the principal ribs, clearly outlined angular spots of 

 a dark colour made their appearance, often combining and forming larger 

 blotches. The infection involves not only the mesophyll but also the second- 

 ary ribs (more rarely the main ones) so that the bundles of vessels are colour- 

 ed brown. The leaves attacked do not grow normally, and in time wither 

 and fall. 



The .soft young leaves of the terminal branches are the first to be at- 

 tacked, then the disease descends towards the base, where it also attacks 

 the already grown leaves. 



Here and there along the stems, without any specific localisation, 

 oblong spots I to 3 cm. in length appear, only involving the most superficial 

 tissue and rarely (in fact only in very severe cases) extending to the \'as- 

 cular bundles. 



