Abstract:

This study is aimed at controlling the occurrence number of wheat aphid with species diversity by intercropping and mixed cropping of different wheat varieties. The intercropping and mixed cropping was conducted with five wheat varieties. The wheat variety with monoculture was used as the control. The number of wheat aphids was investigated at the critical stage and the aphid-peak stage. The insect resistance among different wheat varieties was compared with aphid ratio method. The occurrence of wheat aphids was used to compare the differences among different combinations, and to contrast the control effects. The results showed that the susceptibility of monocropping varieties was highly susceptible: Shi 7816 > 95-108 > Lantian13, susceptible: Lantian 6 > Lantian 1. The occurrence of wheat aphid in the intercropping and mixed cropping combinations was significantly lower than that of one monoculture variety (P<0.05), at the flowering and grouting period. Except Lantian 1/Shi 7816, Lantian 13/95-108, Lantian 6/95-108 and Lantian 1/95-108 having negative-increasing control effect, all the intercropping and mixed cropping combinations showed control effect on the wheat aphid. The average control effect of intercropping was 12.94% with a range of -24.67%-44.33%. The average control effect of mixed cropping was 28.92%, with a range of 1.67%-61.33%. Relatively, the best combinations of control effect were Lantian 1/Lantian 6/Lantian 13/95-108/shi7816, with the control effect of 44.33% and 61.33%, respectively. In conclusion, most of the intercropping and mixed cropping combinations have effective control effect on the occurrence of wheat aphid.

Key words: wheat, wheat aphid, biodiversity, intercropping, mixed cropping