CtJLTURE dF WHEAT. 71 



tJie productive power of the plant will thereby be lessened, yet 

 if circumstances are aftoiV/ards favorable, the quality of the 

 grain produced may not be much impaired ; or it may appear 

 after the grain is fully formed, and then very little damage will 

 be sustained, except by the straw. 



"Mildew, again, strictly speaking, may be ranked as a dis- 

 ease which affects the ear, and is brought on by causes similar 

 to those which occasion blight, though at a more advanced 

 period of the season. If this disorder comes on immediately 

 after the first appearance of the ear, the straw will also be af- 

 fected ; but if the grain is nearly or fully formed, then injury 

 on the straw is not much discernible. We have seen a crop 

 which carried wheat that was mildewed when the straw was 

 perfectly fresh, though this rarely happens. A severe mil- 

 dew, however, effectually prevents both corn and straw from 

 making any further progress ; the whole plant apparently go- 

 ing backward every day, till existence in a manner ceases al- 

 together. Something akin to mildew is the gum or red ochre, 

 which in warm moist seasons, attaches itself to the ear, and 

 often occasions considerable damage. All these different dis- 

 orders are generally accompanied by insects ; which animal- 

 culae, by many people who take the effect for the cause, are 

 considered though without the least foundation, as the authors 

 of the mischief that follows. Their appearance, however, may 

 justly be attributed to the diseased state of the plant ; for, 

 wherever putrefaction takes place, either in animal or vegeta- 

 ble substances, the presence of these insects w^ill never be 

 wanting. Another aisorder which affects wheat, aid by sev- 

 eral people denominated the red rust, is brought on by exces- 

 sive heats, which occasion the plants to suffer from a privation 

 of nourishment, and become sickly and feeble. In this state, 

 a kind of dust gathers on the stalk and leaves which increases 

 with the disease, till the plant is in a great measure worn out 

 and exhausted. The only remedy in this case is one that can- 

 not be administered by the hand, a plentiful supply of moisture, 

 by which if it is received, before consumption is too far advan- 

 ed, the crop is benefited in a degree proportioual to the ex- 

 tent of nourishment received, and the stage at which the dis- 

 ease has arrived. 



"There is not the slightest reason to believe that parasitical 

 animalculse are the agents of these diseases, because the whole 

 of them may be imputed to atmospherical influence, yet it is 

 not easily ascertained whether excessive drought or excessive 

 rains are most pernicious. Perhaps both may have an influ- 

 ea©€, as tlie plant being stinted and debilitated by drought ii^ 



