Wednesday, November 7, 2007
296-14
Silicon Nutrition and European Corn Borer Resistance in Two Maize Hybrids.
Increasing the concentration of Si in plant tissue may provide a mechanical barrier against insect larval boring and feeding activity. Amending Si deficient soils may serve as a valuable component of integrated insect pest management as it leaves no insecticide residue. Field experiments were conducted on a Quakertown silt loam soil near Pittstown, NJ using Bt and non-Bt corn (Zea Mays L.) hybrids to study the effects of Si amendment of soil on managing European corn borer (ECB) (Ostrinia nubilalis Hubner). The plots were treated with two different liming materials as CaCO3 or CaSiO3 at the rate of 7840 kg/ha of calcium carbonate equivalent. Non-Bt hybrid stem tissue Si increased from 1.3 to 1.7 g/kg in 2002 and 1.8 to 3.3 in 2003 with Si amendment as compared with control plots. Grain yield did not respond to the calcium silicate amendment in either year, but hybrid type influenced yield in both years. The Bt-hybrid produced a greater yield than the non-Bt hybrid by 4% in 2002 and by 16% in 2003. European corn borer damage was greater in the non-Bt hybrid than in the Bt-hybrid both years which may have been responsible for some the grain yield suppression in the non-Bt hybrid relative to the Bt-hybrid. The calcium silicate amendment tended to decrease the amount of damage to the stem both years but this protection from European corn borer did not translate into a grain yield benefit. In 2002, the protective effect of calcium silicate from European corn borer damage was primarily exhibited as fewer tunnels per plant while in 2003 as a decrease in tunnel length.
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