Aldrin from rice

Aldrin from Rice. An important off-take for aldrin is in the treatment of rice seed to protect the seedling against grape colaspis larvae and rice water weevils. The seed is usually sprayed with sufficient volume of an aldrin-hydrocarbon solution to give 2-4 oz. of aldrin per bushel of seed. The seed is either flown onto flooded fields or drilled into dry fields and then flooded. The planting rate, which determines the amount of aldrin applied per acre, will vary with the variety and local cultural practices. The fields are drained and reflooded a few times before harvest, the frequency depending upon the amount of rainfall and degree... 

Aldrin from Rice. The maximum amount of insecticide that can be emptied from a paddy planted with aldrin-treated rice is below 1 gram per acre. At the end of a growing season, the paddy water and the top 3 inches of soil are the same as before the planting with respect to insecticide residue. The concentration of the drainage entering a waterway rapidly diminishes to a few p.p.t. by dilution and by physicochemical and biodegradation factors. 

Table I. Analysis of Water from Paddy Planted with Aldrin-Treated Rice...

Fish taken from streams and rivers receiving the drainage of aldrin-treated rice fields contain residues well below acceptable tolerances on agricultural food commodities. 

In general, it appears that normal sowing of aldrin-treated rice seed, spraying of cotton fields with endrin, or incorporation of aldrin into the soil of cornfields do not lead to a high degree of contamination of watercourses receiving drainage from the land masses on which these activities take place. 

Tests were conducted to determine the concentrations of insecticides found in waterways, fish, and mud from a cotton field treated three times with endrin at 0.3 lb./acre, corn fields (soil) treated with 5 lb. aldrin/acre/year, and rice paddies (seed) treated at a rate equivalent to 4 oz. aldrin/ acre. Endrin in the soil did not exceed 0.04 p.p.m., even after subsequent sprayings. Runoff water from the cotton field showed only low concentrations of endrin and only 50 p.p.t. after the last spraying. Traces of endrin were found in fish but none in mud. Similarly, aldrin and dieldrin residues were also low. Residues in water from com fields or waterways draining rice fields did not exceed a few p.p.t. Residues in fish taken from waterways draining rice fields rarely exceeded 10 p.p.b. aldrin plus dieldrin. 

Table III. Estimated Quantities of Insecticide Admitted to Waterways from Aldrin Treatment of Rice Seed...

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