Cultivation of Arable Land. IFheat Mildew, Blighf, fyc. on. 29 



It has alfo been fuggefted, that where the grub is prevalent, rolling the- 

 iand in the early fpring months, foon in the morning, may have a tendency to 

 crufh and deftroy them : and that where the fly is found to abound, and come 

 out in the fummer evenings on the grafs lands or fallows, it is probable that, by 

 rolling at that time the return of it into the earth, as well as the depofit of the 

 ova, may be prevented, and the future propagation of the infect be guarded 

 againft.* 



As the ova of this deflructive animal is found to be chiefly deposited in the 

 long grafs on the fides of hedges and ditches, it has been propofed, as a fure 

 mode of preventing the propagation of the grub, to keep the tops of ditches 

 and hedge-fides perfectly clean and free from the coarfe long herbage with 

 which they are ufu ally covered.-^ And, on the fame principle, the keeping of 

 clover flubbles clofely eaten down by fheep or other animals after the hay has 

 been taken, till the wheat crop is nearly ready to be put in, has been found in 

 fomemeafure an effectual remedy againft the deftructive attacks of this infect.* 



Befides grubs, there are other infects which fometimes commit depredations 

 on grain crops. One of thefe, which is believed to be the Thrift Pbyjapus of 

 Linnaeus, is found to attack the late blofibming flems on their coming into 

 flower, on which account early fowing may be the moft effectual remedy. 



But, in addition to the attacks of thefe animals, wheat crops are often expofed to 

 injuries of other kinds, fuch as the mildew, blight, blaft, and fmut. 



The firft of thefe vegetable difeafes is frequently found to affect wheat and 

 other crops, in their more advanced flages of growth, in fuch feafons as are 

 wet and gloomy, for fome length of time together, without much fun. The 

 nature of this mucor mould, or mildew, feems not yet to have been fully invefti- 

 gated by writers on hufbandry ; but, from the obfervations contained in an in 

 genious paper in the feventeenth volume of the Annals of Agriculture, there 

 appear to be two varieties of it, the Hack and trie red. Various conjectures 

 have been entertained by writers concerning the caufe of the difeafe ; the mofb 

 probable of which feems to be, that it is a plant of the fungus kind, which, like 

 others of the fame fort, is capable of proceeding in its growth in clofe fhaded 

 fituations without much change of air, and which by its roots penetrates the 

 veffels of the plants to which it attaches itfelf, but which were probably, however, 

 previoufly in a morbid condition. 



* Darwin s Phytologia, p. 869. 



t Annals of Agriculture, vol. XXV. 



f Farmer s Magazine, vol. II. p. 365. 



Tranfaftions of Linuwan Society, yol, III. 



