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Pomological Paragraph 



CA Storage Capacity 



CA storage construction has been drastically reduced since 1961, 

 with only 3 new rooms constructed and operated for the first time dur- 

 ing the 1964-1965 storage season. Records kept by the Extension Pomol- 

 ogist indicate CA storage capacity for approximately 808,000 bushels in 

 Massachusetts . 



William J. Lord 

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



DECOMPOSITION OF HERBICIDES IN SOILS 



William J. Lord 

 Department of Plant and Soil Sciences 



Fruit growers, like all individuals that use herbicides, are inter- 

 ested in the fate of these materials in soils. Considerable research 

 has been conducted on the relation of decomposition to soil types, envi- 

 ronment and chemical structure of some herbicides. These research find- 

 ings have been reviewed by T. J. Sheets and his co-workers (T. J. Sheets 

 --"Persistence of Herbicides in Soils"--Proc . W.W.C.C. 19: 37-4-2, 1962, 

 and T. J. Sheets, C. I. Harris, D. D. Kaufman, and P. C. Kearney--"Fate 

 of Herbicides in Soils"--Proc. N.E.W.C.C. 18: 21-31, 1964). Most of the 

 information was taken from these articles. 



"The amount of soil water, the water solubility of herbicides, 

 and the degree and tenacity of soil adsorption may have con- 

 siderable influence on the persistence of herbicides. Most 

 organic herbicides are leached more readily in sands and sandy 

 loams than in clay loams, clays, and soils high in organic 

 matter. " 



Because of this, the recommended dosage of herbicides is usually 

 less for a sandy soil than for a clay soil. 



Degradation by soil micro-organisms is one of the major pathways 

 by which organic herbicides are detoxified. Most organic herbicides are 

 inactivated most rapidly in soil under the conditions optimum for growth 

 of micro-organisms. 



"Temperature, rainfall, wind, and sunlight affect the persist- 

 ence of herbicides directly and indirectly through their ef- 

 fects on soil processes. Temperature affects vaporization, 

 adsorption, chemical reactions, adsorption and metabolism by 

 micro-organisms and higher plants, solubility, and leaching. 

 In addition to directly causing movement and dilution in the 



