Figure 7.— A permanent shade. The cover is made of boards. 



temperature beneath them is re- 

 duced. Some of the materials tested 

 are listed below, in descending order 

 of effectiveness. 1 



Hay — 6-inch layer. 



Aluminum — top, white; bottom, black. 

 Plywood — V* to V2-inch. 

 Aluminum — new, unpainted. 

 HARDBOARD — Vs-inch, plain (Masonite). 2 

 SNOW FENCE — double layer, no opening. 

 Saran 2 SHADE CLOTH — type that produces 92- 

 percent shade. 

 SNOW FENCE — double layer, crisscrossed. 

 Snow fence — single layer. 



1 Source: Kelly, C. F., and Bond, T. E. EF- 

 FECTIVENESS OF ARTIFICIAL SHADE MATERIALS. 

 Agricultural Engineering 39 (12): 758-759. 

 1958. 



2 Trade names are used in this publication 

 solely for the purpose of providing specific 

 information. Mention of a trade name does 

 not constitute a guarantee or warranty of the 

 product named and does not signify that this 

 product is approved to the exclusion of other 

 comparable products. 



Portable Shades 



Portable shades can be built to 

 protect colonies placed in fields 

 for pollination, where permanent 

 shades cannot be used. 



A portable shade, designed by 

 USDA agricultural engineers at 

 Tucson, Ariz., is shown in figure 2. 

 This shade, which will cover 10 

 colonies, is 20 feet long, 6 feet wide, 

 and 6 feet high. It folds to a 6- by 

 20-foot rectangle, 4 inches thick, for 

 hauling. Two men can quickly set 

 it up or take it down. 



The following materials are needed 

 to build it: 



32 feet of steel tubing, lV2-inch (outside 



diameter), 16-gage wall. 

 36 feet of electrical metallic tubing, 3 /4-inch. 

 24 feet of electrical metallic tubing, V2-inch. 

 Four ells, lV4-inch. 

 Four ells, 3 /4-inch. 

 Eight conduit connectors, 3 /4-inch. 



