The results of spraying fully grown charlock varied accord- 

 ing to the strength of the solution, but in all cases when the 

 weather was suitable the leaves were killed, but the flowers 

 and stems were only partially destroyed. 



It was abundantly proved that success can only be obtained 

 when the plants are taken in the youngest stage. The opera- 

 tion is calculated to destroy charlock leaves only. 



If the charlock is sprayed after the stems and flowers are 

 formed, though the leaves are destroyed, the stems and flowers 

 retain sufficient vitality to form seeds, the number of which is, 

 however, much less than in the case of a plant in its normal 

 condition. Spraying strong, well-grown charlock produces a 

 stunted growth, and enables the corn, if good, to gain the 

 mastery of it. It was noticed that although the leaves were 

 killed and the stems damaged the formation of seed was 

 hastened. 



IV. STRENGTH OF SOLUTION 



On account of the probable danger of destroying the corn 

 and the young seeds, rather weak solutions were at first applied. 

 Later, however, these were strengthened in the case of Sul- 

 phate of Iron to 12, 14 and 16 per cent, and other conditions 

 being suitable 40 gallons per acre of such solutions will give 

 satisfactory results. 



But for the difficulty of making stronger solutions and 

 also the difficulty of getting the machine to apply the desired 

 quantity, still heavier doses of Sulphate of Iron would have 

 been applied. 



It was quite apparent on the one hand that solutions of 

 greater strength would not injure the corn, and on the other 

 hand that weaker solutions would not effect the desired de- 

 struction of charlock and runch. 



The general experience with regard to the strength and 

 quantity of solution was that the largest doses produced the 

 best results, and that 2 per cent solutions of Sulpate of Copper 

 or anything under a 10 per cent solution of Sulphate of Iron 

 was much too weak to be really beneficial. It must be borne 

 in mind, however, that these strong solutions were applied to 

 strong grown charlock. Owing to the weather we were not 

 permitted to test them on very young plants. 



