4 MASS. EXPERIMENT STATION BULLETIN 328 



outyielded the cultivated. Nevertheless the latter maintained superiority in 

 growth as measured by trunk girth in all trials. 



In 1916, the same investigator ( 11 ) reported results of these and four other 

 experiments in bearing orchards in different parts of the state, the orchards 

 ranging in age from 6 to 36 years at the start of the experiments. His conclusion 

 follows: "In general the mulch treatment, reinforced by outside materials, has 

 been most efficient in improving the yield, growth, and average size of fruit in 

 orchards up to about twenty years of age. In older orchards, it has been sur- 

 passed slightly by tillage and cover crops, unless accompanied by adequate 

 fertilization. It has also been most efficient in conserving moisture, in all cases 

 that have been determined." 



The experiments of Green and Ballou ( 7) , Ellenwood ( 5) , and Wiggans (12 ) 

 showed favorable results from mulching, but these experiments dealt with young 

 trees while we are concerned here with trees of bearing age. Somewhat approach- 

 ing this specifically designated field are the orchard soil management studies of 

 Cullinan and Baker (4) in Indiana. Even here, however, treatment of young 

 trees is of major importance. The study concerned the effects of tillage with 

 cover crop, straw mulch, and sod on the growth and production of Grimes, 

 Jonathan, and Stayman apple trees. The study covered a fifteen-year period 

 and was begun after the trees had grown one year in the orchard. It was found 

 that the trees receiving a heavy mulch were "nearly equal" to the trees under 

 cultivation. However, a statement closely following this observation should 

 be borne in mind. "We are not certain that the amount of straw used on Plot 

 C constituted an adequate mulch." This is a very important consideration, 

 especially when this plot was just as productive, over a ten-year period as the 

 trees under cultivation and further maintained a more uniform yearly produc- 

 tion. "With a substantial increase in the amount of mulch material used, the 

 growth and production of the mulched trees might well have exceeded the 

 "nearly equal" comparison with cultivation. 



At the Missouri State Fruit Experiment Station at Mountain Grove (6 ) com- 

 parative tests of straw mulching and other common methods of soil manage- 

 ment by Faurot revealed that in yield, trunk circumference, and growth of head 

 the straw mulch plots were outstanding. One orchard was set in 1902 and the 

 other in 1921. The findings thus support the theory that mulching as an 

 orchard soil management practice is equally suitable for young or mature 

 orchards; i.e., if mulching material is already available or is procurable at low 

 cost. However, Faurot deemed it unwise to advocate mulching for commercial 

 orchards ' ' because of scarcity of straw and more because of possible fire hazard." 



Experimental Work 



In 1921 the Experiment Station took over two orchard blocks of approxi- 

 mately two-thirds acre each. One block was planted to 18 Mcintosh trees, 40 

 feet apart, and the other to 18 Wealthy on seedling roots 40 feet apart and inter- 

 planted with Wealthy on Doucin stock. These stocks proved to be Mailing V, 

 the Improved Doucin. These dwarf trees were removed in the fall of 1932. 



The trees had been planted in 1911 and were originally interplanted with 

 dwarf Wealthy on Paradise roots, pears, and currants. For a few years the 

 orchards were intensively cultivated and probably well fertilized. Later, 



