EXERCISE IX 



THE ACTION OF FUNGICIDES ON SEEDS 



Material. Seeds of the wheat, cabbage, and corn, 1 per cent 

 solution of copper sulphate, 25 per cent salt solution. 



Apparatus. 100-cc. wide-mouthed bottles, Geneva seed-tester. 



Seeds are often treated with fungicides to destroy the spores 

 of some diseases. This treatment, however, is dangerous and 

 must be applied with extreme care and precision, in order that 

 no damage may result to the seed. 



1. Count out two lots, of one hundred seeds each, of the wheat, 

 of the cabbage, and of the sweet corn. Place the samples of each 

 variety in separate bottles. Now cover one lot of seeds with a 

 1 per cent solution of copper sulphate. Place the second lot in 

 pure water to serve as a check. Allow both batches to soak for 

 two hours, and then germinate. Tabulate your results, and ex- 

 plain. What strength of solution would you recommend for the 

 treatment of seeds in order to insure the best results ? Compare 

 the treated seeds with the check. What is gained by the treat- 

 ment ? Did you note any fungus growing ? What seeds, if any, 

 were affected ? Discuss. 



2. Count out four lots of one hundred seeds each, as in 1. 

 Place each lot in a 100-cc. bottle, and keep one as a check. Pour 

 enough of the salt solution over the first batch to cover the 

 seeds, and allow them to remain immersed one minute. Soak 

 the second batch of seeds for five minutes and the third batch 

 for fifteen minutes. Germinate as in 1, and note the results. 

 Describe fully. Tabulate the results as in 1, and discuss fully. 



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