— 46 — 



mold. This consists of the spore^bearing branches and spores of the fungus. 

 The disease may also attack clover, but no collections were made in this region. 



No effective measures of control are known, though early cutting of a badly 

 affected crop might be of some value in controlling the disease. 



Root and Stem Rot of Alfalfa and Clover {Sclerotinia trifolioriun). — 

 During the early summer of 1912 the alfalfa plots on the farm were seriously 

 attacked by this disease. In 1913 the alfalfa was almost free from attack, but 

 the clover grown in the exiperimental rows suffered severely, a large number of 

 the plants being killed during the fall and the succeeding spring, so that they had 

 in some cases the appearance of being winter-killed. 



The plants when attacked by this disease wilt and rapidly die. The top of 

 the root and the base of the stem of the diseased plants will be found to be de- 

 cayed, the rot extending for some distance up the stem and downwards into the 

 attacked. Later, small black, usually irregular, masses about the size of a pea 

 or smaller may be found attached to the diseased part. Frequenly in clover these 

 are found inside of the root or lower part of the stem, so that they can only be 

 seen by pulling the part to pieces. These black masses are called sclerotia and 

 are masses of the fungus which can live for years in the soil and under favourable 

 conditions start the disease again. 



To control the disease the affected plants should be dug out carefully and 

 burned to destroy the selerotia, and the ground sown to grain or grass crops for 

 several years. It is probable that this fungus is not distinct from Sclerotinia 

 libertiania which attacks vegetables, particularly in storage. This Sclerotinia rot 

 was common on vegetables in storage during the winter of 1912 and caused much 

 loss, especially of carrots and turnips. It will be found discussed further in the 

 paper on storage rots on another page. 



European Apple-tree Canker (Nectria galligena). — Specimens of this 

 disease were collected by Mr. P. I. Bryce in an orchard recently purchased by the 

 College. Examination of the orchard showed three trees severely attacked. Al- 

 though as far as the writer is aware this is the first report of this disease from 

 Quebec, yet it is probably widespread and has been overlooked as the fruiting parts 

 of the fungus are inconspicuous. The old cankers are very conspicuous, but they 

 may have been attributed to other causes. 



The disease forms unsightly, deep cankers on the branches and trunks and is 

 also common in the crotches. The disease spreads slowly, the canker growing 

 larger and deeper each year. Curvel, septate spores of the Fusarium type are pro- 

 duced in rainy weather during the summer, and in the spring another spore form 

 is produced encolsed in reddish cases or perithecia, which may be found in small 

 clusters in the diseased area. The spores find an entrance through wounds. The 

 disease is a serious one and in some of the apple-growing districts of the Mari- 

 time Provinces has done much injury. Measures should be taken to hold the 

 disease in check. The cankers should be carefully cut out well into the healthy 

 tissue, and the wounds disinfected and painted. 



Ascochyta Pea Blight (Ascochyta pisi). — A few specimens of this disease 

 were collected but it was not troublesome during 191 3. The disease causes spots 

 on the leaves and stems, which eventually bear small dark dots, the pycnidia in 

 which the spores are contained. It may also attack the pods and stems and some- 

 times does serious injury. The disease is doubtless carried over on the seed, so 

 that clean seed from fields free from the disease and rotation of -crops will aid in 



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