Weed-suppressing rice cultivars – does allelopathy play a role? |
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Authors: | Olofsdotter Navarez Rebulanan & Streibig |
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Institution: | International Rice Research Institute, APPA Division, PO Box 3127 MCPO, 1271 Makati City, Philippines,;Weed Science, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark |
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Abstract: | A range of 111 rice cultivars was studied for weed-suppressing ability in field experiments with a sown infestation of Echinochloa crus-galli. Cultivars differed significantly in their ability to suppress the growth of E. crus-galli , and the differences were reasonably reproducible over three seasons. The same rice cultivars were tested in a laboratory screening for allelopathic potential, which showed significant differences in the ability to reduce root growth of E. crus-galli . Correlation between the laboratory screening and the field experiments showed that field performance could be described to some extent by E. crus-galli root length reduction in the laboratory. Plant height in the field experiment was correlated with weed biomass 8 weeks after seeding. Even among the most weed-suppressing rice cultivars, however, all heights were represented. None of the measured growth parameters from greenhouse studies could explain the distribution of weed-suppressing rice cultivars. This indicates that allelopathy in combination with competitive ability determines the weed interference outcome of a given rice cultivar. |
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Keywords: | allelopathy Oryza sativa competition weed interference Echinochloa crus-galli |
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