Impact of mechanisms of resistance on European corn borer resistance in selected maize hybrids
1997
Barry, B.D. | Darrah, L.L. (Missouri Univ. Coumbia (USA))
Four commercial maize hybrids plus a susceptible and a resistant check were compared in experiments to determine which mechanism(s) of resistance-i.e., (1) preference, (2) antibiosis and/or (3) tolerance to first and second generation European corn borer (ECB)-contributed to overall resistance. Preference evaluations were made under natural ECB infestations in an area where ECB is endemic using six replications and counting shot holes for the first generation and number of egg masses and tunnel length (stalk splitting)for the second generation. Antibiosis was determined by manual infestations and no infestation and using Guthrie's (1960) scale for first generation ECB. second generation ECB antibiosis was determined by splitting stalks of manually infested and non-infested hybrids and estimating the amount of tunneling. Tolerance was measured with leaf-feeding ratings and the amount of tunneling and all hybrids were infested with 0, 30, 120, and 240 larvae per plant. In all six experiments, yields were measured to relate the effects of resistance mechanisms and infestation levels.
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