Weed Biology and Management (2009) 9, 20-26

Takuhito Nozoe, Masaaki Tachibana, Akira Uchino and Narifumi Yokogami (2009)
Effects of ferrous iron (Fe) on the germination and root elongation of paddy rice and weeds
Weed Biology and Management 9 (1), 20-26
Abstract: Laboratory experiments were conducted to analyze the iron (Fe) tolerance of paddy weeds and rice varieties (Oryza sativa) for germination and root elongation. Under a waterlogged soil condition, the Fe(II) content in a soil solution increased with an increase in the ratio of rice straw to the soil. In the presence of 0.9% (w/w) straw to soil, which corresponds approximately to 8 t of straw applied to an area of 1 ha × 10 cm depth in the field, ~80 mg L⁻¹ of Fe(II) was produced in the soil solution. Based on this result, the seeds of rice and the weeds were incubated in a solution with <100 mg L⁻¹ of Fe(II). The presence of 100 mg L⁻¹ of Fe(II) suppressed the germination of Echinochloa crus-galli var. crus-galli, Cyperus serotinus, Cyperus difformis, and Monochoria korsakowii. However, it had no effect on the germination of Echinochloa oryzicola, Schoenoplectus juncoides (= Scirpus juncoides var. ohwianus), and Monochoria vaginalis. This level of Fe tolerance was the same as that of rice. These findings suggest that E. oryzicola, S. juncoides, and M. vaginalis can grow under more severe conditions than E. crus-galli, C. serotinus, C. difformis, and M. korsakowii. In relation to seminal root elongation, the order of tolerance of Fe toxicity was O. sativa cv. Dunghan Shali > O. sativa cv. Hoshinoyume > E. oryzicola > M. vaginalis > S. juncoides. Thus, the results show that the tolerance of rice is greater than that of E. oryzicola, which had a comparatively strong tolerance among the weeds examined, and also that there are differences in tolerance among the rice varieties. These findings suggest that the difference in Fe tolerance is involved in weed control systems when organic materials are applied. If this difference is an important factor in the weed control system, Fe-tolerant rice varieties, like cv. D. Shali, could facilitate weed control systems due to their higher Fe tolerance ability.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: English)
Link to article at publishers website
Database assignments for author(s): Akira Uchino

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Echinochloa crus-galli (weed)	Rice (Oryza)	Japan
	Monochoria vaginalis (weed)	Rice (Oryza)	Japan
	Cyperus difformis (weed)	Rice (Oryza)	Japan
	Echinochloa oryzoides (weed)	Rice (Oryza)	Japan
	Schoenoplectiella juncoides (weed)	Rice (Oryza)	Japan
	Cyperus serotinus (weed)	Rice (Oryza)	Japan
	Monochoria korsakowii (weed)	Rice (Oryza)	Japan