CHARLOCK.

Lyttelton Times, Volume CXIV, Issue 16192, 19 March 1913, Page 12

CHARLOCK.

Tho charlock plant—or: to give ft ths full botanical name which its unpleasant notoriety merits, Sinapis Arvensia —has a prolific seeding capacity. One plant subjected to examination was found to carry 14,000 seeds, although tho average plant fortunately v;beara considerably less; perhaps 1500 seeds represents the usual number. The germinating capacity of the seeds is 95 per cent, and in consequence of tho oily character of the seed tho duration of its germinating power is practically unlimited- Seeds have been known to spring into life after lying buried in the ground for a period of fifty years. From these characteristics, fecundity and persistency, the weed is one of tha most pestilent pests that a farmer has to encounter. . ~!;..

It is estimated that in localities where the weed is prevalent, cereaj crops pay toll to, it to the extent ol 30 per cent of the crop, and cases are reported when the crop has been so much infested that it has been deemed better to. cut the growing crop rather than to let the weeds ripen. '

What is the best method of combating such an evilP Prevention and cure: First, prevent as far as possible tho access of tho weed seeds to the soil; secondly, destroy tho weeds as they grow. For prevention, we must take car a that we ourselves aro not the sinner? who sow tho seeds. Intentionally, o{ course, no one would be guilty of such a tiling, but still it does occur. When we throw screenings from threshing machines or sweepings from barns on the manure or compost heap, we may be indirectly sowing charlock seeds. Similarly, if the screenings or sweepings aro given as feed to stock, we may be committing tho 6ame imprudence, because from their nature they pass undigested through the animals on to the manure heap, and thence to the field. All such refuse material, especially when charlock seed may bo among it, should l>e burnt. That is the only safe course.

Tho crop oeeds which we 60W should, of couise, be free from all impurities. The sellers of the seeds should guarantee their purity, and tho buyers should carefully examine them with a magnifying glass. Any charlock plants growing on road, sides or waste places adjoining fields should bo cut down. Whon land is known to be infested with the weed, a fallow, during-which a thorough cleaning can be undertaken, is the best course. ; ',•>;« el

But assuming the cereal -crop is coming up, and it is observed that, nnfor> tunately, there is also a prevalent crop of charlock _ mingled with it, 'the resources of civilisation are not exhausted, and effective measures can be adopted. The remedy is, then, the application of a solution of either sulphate of copper or sulphate of iron. This method has been extensively tried, and has been found to answer the pur peso. .. \ The point to be noted is that th* spraying operation to be effected must be carried out at the »*ialit time, and that is when tho weed has developed its fourth leaf. If deferred, the charlock plant is no longer sensitive to the chemical, and if applied too early the operation may probably have to bo repeated. Also, it may bo remarket' that tho operation should be performed when the plant is dry and when no rain is expected for the space .of-some hours.

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