28 AMERICAN VINES. 



be at least i Ib dissolved in 2 gallons of water or liquid 

 manure. 



Poured about the foot of the vine in April, this solution 

 has a very durable action, and in the majority of cases assures 

 healthy vegetation during the whole summer. 



Sprayed on the leaves the effect is more immediate ; eight 

 or ten days after being treated the leaves become green again. 

 But the action is purely local, and does not extend to the 

 tissues, which have not been placed in direct contact with the 

 liquid. The new shoots gain very little by it. The spraying, 

 therefore, must be repeated very frequently when the 

 chlorosis is in an advanced form. The solution should be 

 weak, even at i per cent, strength it sometimes burns the 

 tissues; 11-3 ounces of sulphate of iron per gallon of water 

 is the best strength to use. 



Dr. Rassiguier proposed painting the trunk, before pruning, 

 with a solution of sulphate of iron containing 30 to 45 per 

 cent. The results are very satisfactory, and this method 

 has been applied on a large scale in French vineyards. It is 

 when the vine is in a state of active life that the effects of 

 the painting are best: in autumn, before the leaves fall; the 

 results are almost nil in spring, when the too abundant 

 bleeding prevents the absorption of the ferrous solution, or 

 rejects it outside. One proceeds with the pruning, and 

 directly after, all the cuts, the spurs, the long rods and the 

 trunk are painted in the same manner as is done in the 

 treatment for anthracnosis. The Rassiguier method assures 

 a good growth of the American vines in the majority of cal- 

 careous soils. 



All these treatments may be applied simultaneously, thair 

 effects are added, and we may doubtless in this way attenuate 

 chlorosis; but these operations become relatively expensive, 

 and it is only in special cases that they may be applied, 

 notably for vines which only become chlorotic at intervals; 

 or, again, in order to assure the normal development of young 

 vines which became yellow at the second or third year after 

 planting. 



Chlorosis, Light, and Heat. Absence, as well as excess, of 

 light may cause a disappearance of chlorophyll. Boussin- 

 gault and Gris were the first to point out this phenomena. 

 It suffices to recall the light colour of plants grown in a dark 

 place, or of organs exposed to too much light, but in vines 

 nothing of the sort takes place. 



