土壤条件引起柑桔和樟树缺铁黄化症的研究

Investigation on Fe-Deficient Chlorosis of Citrus and Camphor-tree in Relation to Soil Condition

柑桔和樟树叶片的失绿黄化症,主要起因于土壤条件,即土壤pH高,HCO_3^-离子多,从而影响了土壤中铁的活化;另一方面植株大量吸收磷素,使植株体内铁磷比失调,影响铁的运转,导致叶片失绿,并降低过氧化氢酶和过氧化物酶的活性。施用铁肥有良好的复绿效果,其中以尿素铁防治效果最佳。尿素铁施用浓度:埋瓶为8％;樟树喷施为0.5～1％;柑桔喷施为1％。直接把铁肥施入介质的效果不好。

The chlorosis of citrus and camphor—tree grown on definit soils resulted largely from the soil conditions, the most impotant of which were higher soil pH and more HCO_3^-, as well as sail.s obvious effervesce response to HCl. Under such conditios, available soil iron was inactivated, subsequently to prevent the plant roots from uptaking Fe. On the other hand, a larger amount of P were absorbed by these plants than the non-chlorosis plants from the soils, resulting in an imbalance of Fe to P and inhibiting Fe transportation whthin the plant. It was also found that the activities of perhydrogenase and peroxidase in the chlorosis leaves were obviously lower than those in the normal leaves. A promissing technology to cure the chlorosis was developed by the authers of this paper. The apphcatioh of iron fertilizers was found to be able to make the leaves recover green, among these the iron urate was the best. The concentration of the iron urate when applied was 8.0% for the embedded bottle method, while 0.5—1.0%and 1.0% for spraying on camphor—tree and Citrus respectively. Little effect was observed when Fe—fertilizers were applied directly to the soils.