-17^ 



the soil level a week or two should be allowed after harvest for 

 the vegetation to recover and for the mice to re-establish their 

 travel systems. 



After the bait is applied mowing can then work to the growers 

 advantage by providing protective cover for the bait and giving the 

 mice the secluded feeding cover they require. 



Reminder : A permit is required from Massachusetts Division of 

 Fisheries and Wildlife to applying orchard mouse bait. Apply 

 early and beat the last minute rush. 



AAA******* 



PREVENTING EXPLOSIONS IN CA STORAGES WHEN 

 ATMOSPHERE GENERATORS ARE EMPLOYED 



F. W. Southwick 

 Department of Plant and Soil Sciences 



Many Controlled Atmosphere (CA) storage operators have atmos- 

 phere generators available to hasten the rate of oxygen (0^) 

 decline to around 5%. These generators often use propane as the 

 fuel source but some may use natural gas. Incomplete combustion 

 or leakage past the generator burner may result in the accumu- 

 lation of propane (where propane is the fuel source) or methane 

 (where natural gas is the fuel source) above their lower explos- 

 ive limit (L.E.L.) in the CA room. Propane and methane detectors 

 are available to warn CA operators before these gases reach 

 explosive levels so that the generator can be shut down before any 

 hazard exists. The safety of personnel and property is so important 

 that we believe all CA operators utilizing atmosphere generators 

 should have a suitable gas detector available whenever a generator 

 is being used. 



In addition, CA operators can greatly reduce the explosive haz- 

 ard associated with the use of an atmosphere generator by not using 

 a generator until the 0^ level in CA rooms is below 10%. Theoret- 

 ically, neither propane nor methane is explosive at O2 levels below 

 10%. Also, annual tightening of CA rooms against atmosphere leaks 

 can greatly reduce or completely eliminate the need for an atmos- 

 phere generator. Apples in CA rooms which are very gas tight are 

 capable of reducing the 0^ level to the desired point (by their 

 normal respiration) within the time span allowed by our CA laws 

 without any assistance from an atmosphere generator. 



