58 
THE CULTIVATOR. 
Feb. 
In the Canadian Ag. Journal for July, 1845, there is an 
article on mildew m wheat, in which it is said, “ Mil¬ 
dew in wheat has been shown by naturalists to be a mi¬ 
nute fungus, whose germs are floating in the atmosphere , 
and only require for their development, a particular 
condition the surface of whatever plant they attack, 
s, their growth is, doubtless, favored—perhaps 
•ed—by the exudation of sap from the ruptured 
ffs of the wheat plant, on which they may alight, 
rupture may be caused by a plethoric state of those 
ds—- erhaps, also, by a deficiency of silex in the 
ermis of the straw; and this condition is brought on 
whatever occasions a great flow of sap, or causes it 
mtinue too long; and the indications of it are a 
green color in the leaves and straw, and the con- 
mce of this dark green color a few inches below 
ear after the chaff has begun to turn off. When this 
ptom appears, a bad case of mildew is inevitable.” 
is an important question to farmers whether they 
e it in their power in any degree to guard against 
great losses that frequently occur by the mildew or 
upon their wheat crops. 
four correspondent from Tompkins county, “ be¬ 
es he has discovered a remedy for the rust, plant or 
plant. He is preparing to make the experiment 
t season, and if successful the result will be com- 
aicated.” I cannot but hope his experiment will be 
eessful—and that he will report the experiment 
ether it proves so or not. And in the meantime I 
d offer a few suggestions and facts that may possi- 
have some bearing upon the subject. 
J3y a chemical analysis of a plant we ascertain what 
the inorganic, or mineral parts are composed of. The 
principal part of the ash of wheat straw consists of 
silica; a ton of wheat straw will yield about 50 lbs. of 
it. Silica is the substance that gives the hard coating 
upon the surface, and strength to the straw of grain and 
the grasses. It is rendered soluble in the soil by the 
alkali, potash and soda. But there are many other 
substances, both mineral and organic, required for the 
perfect crop of wheat. All these substances should be 
in sufficient quantity, and none in very great excess. 
On very highly manured soils there is an excess of ni¬ 
trogenous matter, which is favorable to a luxuriant 
growth of straw, but it is deficient in strength and it 
lodges; and in the warm showery weather spoken of 
the flow of sap is excessive, and from the deficiency of 
coating upon the surface of the straw, the vessels are rup¬ 
tured, the sap exudes and presents a favorable place of de¬ 
posit for the vegetation of the seeds (spores) of fungi, 
(rust,) which, at certain seasons, are always floating in 
the atmosphere; the ascent of the sap to the ear is cut 
off by the ruptured state of the sap vessels; a light and 
shrivelled seed is the result. Instances orthis kind are 
frequently seen in fields of wheat growing on the sites 
of dung-heaps, when the other parts of the field are free 
from it. 
From some facts—or cases, that bear strong evidence 
of being facts, I think that a large amount of soluble 
silica in the soil, is the surest preventive againstaweak 
straw, and consequent rust or mildew. 
Payson Williams, Esq., of Fitchburg, Mass., has on 
very highly cultivated land, raised over 55 bushels of 
wheat per acre. Mr. Coleman, in his report says, « Mr. 
W.'s great crops of wheat were assisted by 50 bushels 
of wood ashes spread to the acre, and a good crop of 
wheat seldom fails to be obtained on newly cleared 
and burnt land. The potash is here in large quanti¬ 
ties.” 
One of the important offices of potash in the soil is to 
supply in a soluble state to the roots of grain plants, 
the silica which is so essential to the strength of their 
stems. Says Prof. Johnston—« This silica exists very 
frequently in the soil in a state in which it is insoluble 
in pure water, and yet is more or less readily taken up 
by water containing carbonate of potash, or soda, and 
as there is every reason to believe that nearly all the 
sfiica they contain is actually conveyed into circulation 
of plants by the agency of potash and soda. It is not 
unlikely that a portion of the beneficial action of these 
substances, especially on the grasses, and corn (grain) 
crops may be due to the quantity of silica they are the 
means of conveying into the interior of the growing 
plants. Silica enters the plant chiefly in the form of 
silicate of potash or soda.” 
It is said that grain never lodges or rusts upon the 
sites of coal hearths, or in the soil that has covered th© 
coal-pit while burning. If that is a fact it is not urn- 
reasonable to suppose there is an abundant supply of 
soluble silica in such soils. 
Mr. Pell has succeeded in raising very large crops ef 
wheat on highly manured soils, by applying a large 
quantity of ground charcoal to the soil at the time of 
sowing the wheat. Perhaps too, that may have had 
the effect of giving strength to the straw. 
In the Farmer’s Monthly Visitor, for Nov., 1845, 
there is an account copied from the Genesee Farmer, 
detailing some experiments by Mr Haywood, of the 
city of Buffalo, upon the application of charcoal to the 
wheat crop. When there was applied 50 bushels of 
ground charcoal, the yield was 25 to 35 bushels of 
wheat per acre; same kind of soil without the charcoal 
produced from three to five bushels, only, per acre, and 
badly rusted. The experiments were upon a large 
scale, extending to over 90 acres. It is also stated in 
the same article that where twenty bushels of unleached 
ashes had been scattered over an acre at the time of seed¬ 
ing, it has evidently increased the crop some ten or 
twelve bushels per acre. 
Some writers of note in the agricultural world , doubt the 
utility of the use of lime in agriculture, but notwithstand¬ 
ing, some farmers , in the middle and southern states, as 
well as in many parts of Europe, persevere in the use of it. 
By the use of lime and clover much of the exhausted 
land in the southern states have been reclaimed, and 
now produce good crops of wheat. When a crop of 
clover is turned under upon land that has had a dressing 
of lime, one of the consequences would be to produce 
an increased amount of soluble silica in the soil. The 
decomposition of the clover would produce carbonic 
acid, that in turn would when aided by the moisture in 
the soil decompose the carbonate of lime, and its alkali 
would act upon the insoluble silica in the soil and ren¬ 
der it available to the succeeding crop of wheat; and 
Prof. Johnston states, that it is said wheat is never laid 
(lodged) that follows a clover lay. If that is a fact, 
we must suppose it has a stiff straw, and that that stiff¬ 
ness is due to the soluble silex in the soil. 
I presume, Mr. Editor, you have the London Gardiner’s 
Chronicle. If so, if you will turn to that of Aug. 9th, 
1845, you will find a very interesting article by Prof. 
Johnston on the use of silicate of soda as a manure for 
the wheat crop—or rather its application to the soil 
for the purpose of giving more strength to the straw of 
wheat. Some English agricultural writers have ad¬ 
vanced the idea of the necessity of the application of 
the silicate of soda in connection with guano, or dis¬ 
solved bones, for the purpose of giving to the crop solu¬ 
ble silica. 
Prof. J. analyzed four different soils in his laboratory 
for the purpose of ascertaining the amount of soluble 
silica in them. The quantity he found in the soil that 
contained the least, amounted to 6,700 lbs. upon the 
acre, taking the soil twelve inches deep. Allowing 
3,000 lbs. of straw to the acre, the amount of silica car¬ 
ried off by a crop of straw, amounts to 75 lbs. per acre$ 
ergo, the soluble silica alone in the soil, will supply 
silica to the crops for 900 years in succession. And the 
soil that contained the most—four times as much— 
would supply it for 3,600 crops. From the above analy¬ 
sis he comes to the conclusion that it is not necessary 
to apply a soluble silicate to the soil. I do not doubt 
the accuracy of his analysis, but he is a strong advo¬ 
cate for the application of ashes and lime to the soil, 
and one of the effects of their application is to increase 
the quantity of soluble silex. 
As observed by Mr. Colman, a good crop of wheat 
seldom fails to be obtained on newly cleared and burnt 
land. Where the forest growth has been burned, and 
all the ashes left upon the ground, the amount of soluble 
silica must, I think, be many times greater in the burnt 
soil, than in the soils he analyzed. 
