25 



Mar3hall/M.26. Marshall on M.26 was favored. The model suggested 

 planting 36 of the total 50 acres with Mar3hall/M.26. The early coloring strain 

 and the more open tree in this combination gives the earliest and longest 

 harvest season of the trees compared. Also, because of its precocity, 

 Marsha 11/M. 26 reaches full production earlier than other strain-rootstock 

 combinations. Therefore, this combination has less conpetition for labor ind 

 cooling capacity, and are the primary factors leading to its selection for the 

 most planting. 



Marsha 1 l/OAR 1. The combliation of Marshall on 0AR1 composed 

 practically all the remainder of the 50 acres. This strain-rootstock combination 

 should yield later in the season, extending the harvest at least 3 days beyond 

 other combinations. A disadvantage is that full production is not reached until 

 approximately 3 years after Marshall/M.26. Also, it is less precocious and 

 begins bearing later than other combinations. Hence, its contribution to returns 

 to management was delayed. The model decided to plant 5 acres in year 10 

 because maximum yield would not be reached by year 20, so less burden was 

 placed on storage capacity. OARl is, at this time, purely experimentnl, and we 

 do not know how it will perform with a Mcintosh scion and under 

 Massachusetts conditions. However, it is obvious that a strain-rootstock 

 combiiation which ripens later than norrnal i:an be advantageous because of its 

 ability to expand the harvest season and reduce comijctition for labor ind 

 cooling. 



Rogors/M.7A. The model suggested planting only 0.1 acre of Rogers/?4.7A. 

 Rogers and seedling Mcintosh are harvested over a similar time period. 

 Replacing seedling trees with Rogers on M.7A did not expand the harvest 

 season; thus, that action does not alleviate any pressures caused by the nonuse 

 of Alar''". However, some benefits may be gained with a smaller tree, such as 

 less picking time per bushel. 



Marshall/M. 7A. No acreage was suggested for planting Marshall/M. 7A 

 given the conditions of the original model. This strain-rootstock combination 

 competes with MarshaU/M.26 for resources during the sane periods. Marshall/ 

 M.7A's have a somewhat shorter harvest season than Marshall/M. 2fi, and a 

 higher percentage of tne crop is picked during the first week. Also, 

 Marshall/M. 7A reaches full production 1 year later than Marshall/M.26, so it 

 offered no financial advantage. 



Some alterations were made in constraints to allow the model to operate. 

 First, to not violate the assumj^tion that all fruit must be stored, storage 

 capacity was increased frorn 20,000 busliels to 48,500 by year 20. Also, in year 

 20, cooling capacity was increased from 9,000 bushels to 0,800 to harvest 

 periods 4 through 8, which were the most prolific harvest periods. This change 

 resulted in cooling capacity becoming most constraining in period 3. Harvest 

 labor was set initially at 189 ho.irs jjcr 3-Jay harvest period. Thu .vas in<;rensed 

 to 550 hours by year 20 as trees reached full maturity. The 189 hours became 

 constraining in year 11 during the 4^^^ and 5t'i harvest periods. If labor was 

 reduced in the S^fi period, then Rogers/M.7A would not be planted. If the 

 amount of labor increased then the <]uantity of Marshall/OARl selected for 

 planting declined. 



