550 



How to Protect Wheat. 



[Sept., 



employed. The Ministry recommends one or other of two sub- 

 stances only, Viz., copper sulphate (blue-stone) and formaldehyde. 

 Other substances are commonly used, but these are for the most 

 part useless. It should also be noted particularly that no sub- 

 stance has been discovered which affords protection from both 

 birds and Bunt. 



The secret of success in Bunt control lies in : — (1) the use of 

 proper chemicals; (2) care in the method of pickling; and (3) 

 the prevention of subsequent contamination by the admixture of 

 untreated seed. It has been repeatedly proved that if these 

 points are attended to complete elimination of the disease, even 

 under farm conditions, can be obtained. 



Treatment. — Even if there is no evidence that Bunt is present 

 all doubtful seed should be pickled. For treatment with blue- 

 stone the pure copper sulphate should be obtained, and a solution 

 made at the rate of 1 lb. of copper sulphate to 10 gallons of water. 

 The seed may either be thoroughly wetted with the solution on 

 the barn floor, or steeped in a barrel for one to two hours, and 

 afterwards spread out to dry. The formaldehyde method is, if 

 anything, more satisfactory. With this substance 1 pint of 

 commercial formalin (=40 per cent, solution of formaldehyde) 

 is diluted with 20 gallons of water. (Smaller quantities may be 

 prepared at the rate of two teaspoonfuls of formalin to 1 gallon 

 of water.) The pickling solution should be thoroughly stirred 

 before using, and should be applied to the grain in the same 

 manner as the copper sulphate. If the steeping method is 

 employed 20 minutes is sufficient, and the grain should be 

 spread out afterwards to dry. (For full details see Leaflet 

 No. 92.) 



Yellow Rust. — The fungus causing Yellow Rust 

 (Puccinia glumarum) is bv far the most prevalent of all the 

 wheat-attacking fungi in Britain. It is present to a varying 

 extent every season even in the best wheat-growing areas, and 

 in the case of most varieties probably occurs in every field. 

 The disease is recognised by the innumerable, bright yellow spots 

 or " sori " on the leaves. These sori contain a golden powder, 

 the spores of the fungus which spread the disease. Sometimes 

 the lower leaves only are attacked, but the upper ones often 

 suffer also, the fungus spreading further to the ears and 

 even to the grains. Owing to Yellow Rust being a " leaf rust " 

 its effects are not so striking or disastrous as those of the 

 " Black Rust," which is a " stem rust," and hence the damage 

 inflicted is not always realised. The loss in the aggregate, how- 



