Weeding.—Weeding should begin as soon as the flax is up, and weeds appear, and should continue at intervals till the crop has reached a height not exceeding 7 in. Seed-weeds should be pulled ; larger ones with strong roots may be cut. The weeders should work bare-footed, and must tread with the utmost gentleness, placing the feet flat upon the ground, and never twisting them. They should also work facing the wind, to assist the flattened plants in regaining an upright position. The crop soon recovers from careful weeding, but carelessness may ruin it utterly. Weeding must only be done when the ground is so moist that the weeds can be eradicated without disturbing the roots of the neighbouring plants ; in long continued dry weather, it must be foregone.
Rotation and Manuring.—Sufficient attention has not been paid to the subject of rotation when growing flax, and to this is due, in a great measure, the diminution of the yield per acre. The system recommended by Andrews, as being best calculated to maintain the fertility of the soil, is to include flax in the " four-course " rotation ; but, instead of putting wheat into all the land that carried a green crop in the preceding year, to haves in flax ands in wheat. By adopting the following rotation, flax is not repeated on the same land till the 9th year, while the space allowed to it does not exceed 10 per cent. of the whole, which is considered to be the most appropriate ratio. Thus :-1st year : turnips, potatoes ; 2nd year : wheat or oats, flax ; 3rd year : clover and grass ; 4th year : oats ; 5th year : potatoes, turnips ; 6th year : flax, wheat or oats ; 7th year : clover and grass ; 8th year : oats ; 9th year : turnips, potatoes ; 10th year : wheat or oats, flax. When growing turnips and potatoes, the flax crop succeeding them is shifted from side to side, so that it may never follow turnips, as this is very objectionable. After potatoes, or old pasture, off which one white crop has been taken, flax grows admirably. Lea-land, though often yielding a heavy crop of flax, is objectionable, on account of the troublesome tillage, and the probability of attacks from cut-worm, at least in S. Ireland. On no land should flax be repeated oftener than once in 7 years.
It is generally considered in Ireland that the use of artificial manure is objectionable in the case of flax, except to invigorate a crop whose growth has been retarded by bad weather. The
selection of land that will yield a fair crop without manuring, is deemed preferable. This is secured by good tillage, judicious rotation, and the thorough manuring of the previous crops. On the other hand, the finest specimens of flax shown at the Paris Exhibition, 1878, were grown by the aid of direct manuring. Analysis of the flax-plant dried at 100° (212° F.) shows per cent. of ash ; this ash contains per cent. of potash, 19.88 of lime, of phosphoric acid. It is estimated that the flax grown on 1 acre of land extracts from the soil about 50 lb. of alkalies (chiefly potash), and 24 lb. of phosphoric acid. Almost the whole of this might be returned immediately to the soil, if the refuse of the plants, and the retting water, were utilized. Where this is not done, manuring must be an expensive matter. Some eminent flax growers, in the French Department of Seine-Inferieure, prefer to employ a manure composed as follows cwt. nitrate of potash, 3 cwt. superphosphate of lime, and 3 cwt. gypsum per acre. In the first year's trial, the result was eminently satisfactory, and it is believed that by using such a compound, rotation might be dispensed with ; at least Loisel Wry, of Goderville, has obtained three successive flax crops off the same land by its use.
Diseases.—The worst evil that attacks the flax-plant is the appearance of dark-brown coloured blotches on the stems, known as " firing " or " burning," from their resemblance to the effect created by fire. The crop is most liable to it as it approaches maturity, and if the spots make rapid progress, the crop must be gathered at once, and steeped immediately, whether it be ready or not. The disease is usually considered incurable, but the recent researches of a French agriculturist go to show that the firing takes place only on poor soils, and especially those destitute of potash ; and that where this valuable and most necessary ingredient is supplied, the plant flourishes remarkably, while an adjoining plot, not so manured, may be completely destroyed. The flax crops in N.-E. Russia have been attacked by a caterpillar, especially those on high ground. Three or four caterpillars are usually found on a plant, feeding upon the upper branches and flowers. They are said to be proof against smoke and lime, but are driven away by deep ploughing. There is certainly abundant room for improvement in Russian agriculture.