32 Cultivation of Arable Land. Wheat Wights in. 



every cafe done to fuch crops as have not been perfectly covered after fowing, or 

 when the feed is very near the furface, while fuch as are depofited to a greater 

 depth almoft wholly efcape, it is fuggeftcd, that, by depofiting the grain more 

 deeply in the foil, and covering it in a more perfect manner, as by drilling or dib 

 bling, much may be effected in the prevention of this malady. 



Others, however, confider the difeafe as a fungus of the linear, oblong, tawny, 

 black kind, that attaches itfelf to the ftems of the wheat plants at the period 

 when the grain is nearly ripe, in fuch feafons as are very moift, affording a footy 

 appearance to the crop. It is aiTerted that the ftems are apparently Iplit, and 

 the growth of the plants greatly impaired and reftricted.* The author of Phy- 

 tologia fuppofes it to be a malady in fome meafure fimilar to the rubigo or ruft,, 

 a difeafe that attacks particular plants that are previoufly in an unhealthy con 

 dition, and which may probably be prevented, or remedied, by the expofure of 

 them to more light, and a greater degree of ventilation, as in the mildew or white 

 mucor. 



Some alfo affert the caufe of this affection to be a vitiated ftate of the juices 

 of the vegetables proceeding from obftruction, induced by fudden alternations 

 of heat, cold, and moifture, without fufficient fun to caufe the abforption of the 

 latter, in confequence of which infects are generated in the plants, and their 

 growth thus injured, and, on thefe grounds, advife fimilar modes of removing it 

 to thofc that have been mentioned above.f It is well obferved that the blights 

 occafioned by froft generally happen in the fpring, when cold nights fucceed 

 to warm funny days, as the living power of the plant has then been previoufly 

 exhaufted by the ftimulus of heat; and is therefore I efs capable of being excited 

 into the actions which arc neceffary to vegetable life, by the greatly diminifhed 

 flimulus of a freezing atmofphere. But whether the malady originate from 



riods of their growth : when put upon plants in the flower,and while the ftalks and blades were green 

 -and tender, they adhered firmly, and completely effected the deftru&ion of the ear; but when put 

 upon, fuch as had made fome progrefs towards rilling the blades, and the ftalks of which were begin 

 ning to harden and become tough, they not only entered upon them with more difficulty, but if the 

 growth and filling had advanced beyond a certain period, and the blades, &c. had loft their faccha- 

 rine tafte, they would not remain upon them ; or if they did, they died, feemingly of hunger. He 

 tried them upon feveral hundreds of healthy ears in this way, and with the fame refult ; from which he 

 thinks it is at leaft prefumable, that a certain degree of hardnefs in the ftalks and hulks of the wheat is 

 a fufficient protection againft this infecl ; and that after the grain has pail the milky ftate, it is be 

 yond the reach of being injured by them. 



* Lambert, in Tranfaftions of Linnxan Society, vol. IV. -f New Farmer s Calendar, p. 408. 



