AGRICULTURAL INDUSTRIES 195 



in 1888, but the average for the ten-year term was 

 about 50 cents. 



To improve the quality of the crop, there exists 

 the Michigan Potato Producers Association, which, 

 starting as a series of county organizations chiefly 

 for educational purposes, was reorganized in 1920, 

 primarily for the purpose of inspection and certifica- 

 tion of seed potatoes, with attention to exhibits, 

 education and legislation in relation to the industry. 

 In 1920, the Association reported the inspection of 

 269 acres of seed potatoes, of which 192 acres passed 

 inspection and were certified. Approximately 25,000 

 bushels of certified seed potatoes were for sale in 

 Michigan in that year. In this work of inspection 

 and certification, the Association cooperates with the 

 Michigan Agricultural College, which provides the 

 inspectors. Two field and one bin inspections are 

 made. The standard for certification adopted by the 

 Association requires that a field must not show at 

 the first inspection moje than 10 per cent of black 

 scurf, wilt, blackleg, leaf-roll, curly dwarf, spindling 

 sprout, mosaic or hills weak from other causes, or 

 more than 15 per cent of all diseases combined. At 

 the second inspection a field is disqualified if it 

 shows more than -1 per cent of any one, or more than 

 8 per cent of all combined of the diseases named 

 above. Fields are disqualified if they show more 

 than 10 per cent of varietal mixture at the first 

 inspection, and more than 1 per cent at the second. 

 Fields infected with late blight or tip-burn, or in- 

 fested with leaf-hoppers, Colorado beetles or with 



