The relation of stored food to cambial activity in the apple

does not appear. First page follows. Introduction This paper reports an attempt to determine, by defoliation methods, to what extent cambial activity and storage of food are correlated. There have been observations along this line for many years, which have been ably summarized by Knudson,(7) Harper,(9) Grossenbacher,(3) André,(1) and Robbins.(11) The present state of knowledge, as judged from these and other less intimately related papers, seems to be a well-defined idea that cambial activity is dependent on leaf activity. Wieler(14) found that covering three or four-year-old trees of Quercus sessiliflora before leaf development in spring, by means of boxes lined with black paper, caused a reduction in diameter growth as compared with checks. Jost (cited by Grossenbacher(3), removed the terminal buds and thereby caused failure of radial growth in pine. Harper(4) observed the effects of successive defoliations of the larch by insects which caused first, a reduction in thickness of the cell walls and then, a decrease in the width of the annual rings until, in a few years, growth ceased entirely. A report by Harvey(5) which is closely allied, and in some respects very similar, to the paper here presented, has recently appeared. Defoliation was found to accelerate or retard growth as measured by terminal elongation, according to the stage of development of the shoot.