MULCHING IN BEARING APPLE ORCHARDS 7 



to Mcintosh in Massachusetts during the winter of 1933-34, none was observed 

 in this orchard. Neither have there been any signs of winter injury of the 

 Wealthy trees. Terminal bud formation has taken place a little later on the 

 mulched trees in some years. 



Shoot growth measurements of the Mcintosh trees on the mulched and cul- 

 tivated plots were taken at 10-day intervals during the 1927 growing season. 

 Growth started on the mulched and cultivated plots at about the same time, 

 and the first measurements were taken ten days after the shoot growth started. 

 When the last measurements were taken, 95 percent of the measured shoots on 

 the mulched plots and only 40 percent of the shoots on the cultivated plots 

 had formed terminal buds. 



Table 2. — Progress op Shoot Growth on McIntosh Trees, 1927. 



(Centimeters) 



Mulch Cultivation 



May 26 8.7 7.6 



June 6 6.2 5.6 



June 17 5.0 4.9 



June 28 1.4 1.5 



July 9 0.1 0.3 



Total 21.4 19.9 



While the shoots on the mulched trees grew more this year, they formed 

 terminal buds earlier. This was not true every year. Measures of annual 

 shoot growth have been made, generally every three years, measuring four 

 seasons' growth each time. These give the picture shown in Figure 1. Shoot 

 growth was generally greater on the mulched plot until nitrogen was applied to 

 the cultivated plot in 1931, but there has been little difference since. The 

 shoot growth of the trees on the mulched plot exceeded that of the trees on the 

 cultivated plot more in 1921, 1922, and 1923 than it did in most later years. 

 In these earlier years it is very doubtful if any nitrogen from the mulch had 

 become available to the trees. Possibly the mulched trees had a better moisture 

 supply. In no year has shoot growth on the mulched trees been excessive. 

 There is a slight negative correlation between size of crop and shoot growth 

 the succeeding year, but there is little or none between size of crop and shoot 

 growth the same year. No measures of shoot growth of the Wealthy have been 

 made because of the terminal bearing habit of this variety. 



