Methods used in the determination of relative amounts of ear rot in dent corn

Hoppe, P.E.; Holbert, J.R.

Methods used in the determination of relative amounts of ear rot in dent corn

1936

Hoppe, P.E. | Holbert, J.R.

The data presented pertain to problems met in determining relative amounts of ear rot in strains of corn. The first study involved methods of measuring ear rot in field samples. The percentage of ears rotted was determined by count in each of 37 hybrids and varieties from 50-hill populations, or approximately 125 ears for each entry. The percentage-age of rotted kernels in the shelled grain from the same samples then was determined, using 200- to 300-gram samples for analysis. A comparison of the results from the two methods of determining ear rot in these identical samples showed the ear separation method to have given very inaccurate results, the coefficient of correlation between the two methods being only + 0.40. A modification of the ear separation method involving the determination of the percentage of rot by weight gave more efficient results as indicated by a coefficient of correlation of + 0.62. In the latter method the completely rotted ears and the rotted portions only of the partly rotted ears were included in the rotted separate. Bleached and otherwise doubtful looking ears were broken to determine whether they were internally rotted. The results from the experiments illustrate the difficulty of measuring accurately the amount of ear rot on a basis other than by the kernel separation method.

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