22 
AMERICAN POMOLOGICAL SOCIETY. 
Several members: Yes, sir. 
Prof. Alwood: Was it not the climatic conditions surrounding Mr. Mor- 
rill’s orchard that saved his buds? 
Prof. VanDeman: Mr. President, let me answer that question. One per- 
son may be attacked by a contagious disease while another, who has a vig- 
orous constitution that enables him to ward off the silent enemy, will not be 
affected by the disease; and the same thing is true of this orchard and the 
others. As a rule, the better the cultivation the better the orchard is able 
to withstand climatic conditions. What is the cause of the destruction of 
orchards? It is to be found in the evaporation, not in the degree of cold. 
The latter may intensify the evaporation but, whether the orchard is in my 
friend Atwood’s neighborhood or in North Dakota, it will be found that the 
fundamental trouble is in the evaporation. Winter killing is the effect of evap- 
oration. Where the soil is so moist and so well mulched with loose soil on 
top that the moisture cannot escape from below then it does not winter kill. 
Prof. Alwood: I take exception to the statement that culture alone will 
enable a plant to withstand a severe temperature. There is a critical point 
at which plants of various kinds will be absolutely killed. If, however, the 
physical conditions are somewhat different, through the use of cover crops 
or any other factor which tends to reduce the effect of the temperature, then 
it is very easy to see how the result mentioned might obtain. The compari- 
son with the forest trees will not hold, as they have been developed under the 
conditions there present and are in their native habitat, while fruit trees 
are purely artificial products, developed and transplanted by man, and not 
natural products of the neighborhood in which they stand. 
Mr. Kellogg: Mr. Morrill is surrounded by peach orchards without num- 
ber. Why is it that he has an enormous crop of peaches, year after year, 
while the other orchards are failures? In the fall of 1885, after traveling 
several hundred miles through Michigan and seeing the trees drying up, I 
visited Mr. Morrill’s orchard and took particular pains to note that not a 
single yellow leaf could be found. He has caused his orchard to fruit heavily 
year after year, by simply manipulating the soil in the manner described here, 
so as to bring his buds into perfect condition through the winter. He uses a 
cover crop every season, the soil being sown in oats. All around him, where 
these requirements have not been met, the orchards have proved frequently 
unproductive and practically failures. This is. not the result of climatic con- 
ditions but purely of cultural methods. 
Prof. Alwood: The fact of the orchard having a heavy cover of crimson 
clover or any other cover crop materially modifies the effect of temperature. 
It also modifies the statement that culture alone preserved the trees over 
those in adjacent orchards. 
Mr. G. G. Patten, Iowa: I believe the practical point in this question is a val- 
uable one. To my mind the question is one of latitude and climatic conditions. 
When you reach a northern latitude you must fix upon some time in the year 
at which you shall discontinue cultivation. I agree in what has been said in 
•reference to the cultivation up to a certain period, but that period is reached 
on parallel 43 N. L., in all the northwestern country, about July 20th. 
Thorough culture extended beyond that date, in that section, would be at the 
risk of serious loss. 
Mr. Hartshorne suggested that an arbitrary date would not be applicable 
to the whole country and that the better plan would be to continue cultivat- 
ing until the time came for sowing the cover crop, which is usually about the 
