A Consideration of Adverse Temperatures 319 



found where the trees were under the grass mulch method 

 of culture, . . . ; no injury was observed in any case where 

 the stems of the trees had been slightly banked or mounded 

 with a few shovels or forkfuls of soil, peat or manure. 



"Very few trees which, within the past few years, had 

 been affected with leaf-curl or infested with San Jose scale 

 or borers, remained alive or uninjured ; and very few trees 

 existing upon infertile or exhausted soil, depleted of humus, 

 escaped uninjured." 



It may be still further pointed out that any influence 

 which weakens the trees renders them more susceptible to 

 winter injury than trees in good vigor with strong vitality. 

 Overbearing is perhaps one of the more common and un- 

 suspected causes of winter injury because of its devitalizing 

 effects. The effects of any cause or condition that weakens 

 the tree also weakens the fruit-buds. It is a matter of 

 frequent observation that trees which are strong and on 

 which the fruit-buds are plump and well developed will 

 produce a good crop of fruit when other trees similarly 

 located but lacking in vigor w^ill produce little or no fruit, 

 following a hard winter or a frost, even though the weakened 

 trees may blossom. The embryo fruits or other essential 

 parts of the blossom of a weakened tree are themselves 

 weak, and are killed by adverse conditions which the 

 stronger blossoms are able to withstand. In general, trees 

 that are strong and vigorous blossom later than do those 

 which lack vitality. This is of importance, especially 

 where injury from late spring frost is likely to occur. 



The obvious course for the peach-grower is to maintain 

 his trees in a high state of culture with a view to making and 

 keeping them vigorous and possessed of a high degree of 

 vitality. 



