- 9 



tances and machines having catwalks that extend both left and 

 right. Apples could then be harvested from both sides of the har- 

 vesting aid as it proceeds up the rows. 



It appears that harvesting platforms with catwalks may be suc- 

 cessful in some si tuati ons---when women are employed as pickers or 

 when a high percentage of pickers are inexperienced v/orkers. For 

 increasing the harvest efficiency of the majority of orchardists, 

 however, this author suggest only the growth of smaller trees and 

 The use of Alar at this time. 



*************** 



COST OF OXYGEN AND CARBON DIOXIDE CONTROL SYSTEMS 

 FOR CONTROLLED ATMOSPHERE STORAGES 



Wi 1 1 iam J . Braml age 

 Department of Plant and Soil Sciences 



The above is the title of a recent publication by David Gure- 

 vitz and I.J. Pflug of Michigan State University. The authors re- 

 port in this publication the results of cost-analysis studies for 

 a number of different methods of regulating 0^ and CO^ in CA stor- 

 ages. Cost-analyses were made for 15,000, 207000, ana 60,000 bush- 

 el storages and comparisons were made for high vs. low utility rates 

 and high vs. low labor rates. 



Some of the findings were the following. The most economical 

 CO2 scrubbing systems where utility costs are high and local labor 

 is available are the dry-lime and water systems. Where utilities 

 are low and labor is expensive, water scrubbing is the most econom- 

 ical, followed closely by dry-lime. 



Oxygen reduction costs were based on 1 pulldown vs. 4 pulldowns 

 With either high or low utility costs, and 1 pulldown, liquid nitro- 

 gen flushing seemed most economical; for 4 pulldowns, oxygen burners 

 were most economical. 



Calculations were made for various combinations of CO2 and 0^ 

 removal systems, and the best combinations depended on management 

 practices. Where a single pulldown is need, i.e., where the room 

 is only opened once, a combination of drylime or water scrubbing 

 with liquid nitrogen (for Op flushing and cooling) appeared to be 

 most economical. If the room is to be opened more than once, a 

 combination of any of several COp scrubbers with a burner seemed 

 most satisfactory. If a room is to be operated only partially 

 filled, dry lime in combination with an oxygen burner offers the 

 most economy. The calculations pointed out the necessity for a 

 gas-tight room for economical operation of any of these systems. 



