Relation Between Factors Nalysis And Leaf Diagnosis Of Iron Deficiency Induced Chlorosis Of Kuerle Xiangli (Pyrus Bretschneideri)

Kuerle Xiangli is an excellent local pear species of Xinjiang. Recent years, the leaf iron deficient chlorosis caused by the calcrete soil has seriously affected the development of this characteristic industry. Based on the researches people had done on this problem in the past 30 years, this article investigate the major soil factors causing the disease, the leafs character of physiology and anatomical structure, discuss the mechanism.Thediagnos is and the target are brought forward.The results are as follows:1. The orchard survey shows that, chlorosis disease occur is very universally in the xiangli producing areas, Shayidong Garden and Ying Xia village are especially affected in these areas.2. After the occurrence of yellowing plants,the mesophyll palisad tissue and spongy tissue present obvious thin, the amount of chloroplast reduced obviously, the peak value of the chlorophyll contents was only about 30.1% of those normal trees. The symptom appears all through the whole growth season, and especially in June and July.3. Injectting"Guangtai" nutrient on xiangli chlorosis trees is good for Pear trees recover green. Fertilizing FeSO4 can improve fruit quality.4. The active iron content can be considered as the preferred indicators to diagnose the iron deficient chlorosis. Unit leaf area as the end of period is more suitable to measure the total iron and active iron contents. Leaf iron deficient chlorosis diagnos indxs as follows:total iron diagnos index is 400mg-kg-1 or 300ug-dm-1,the active iron diagnos index is 150 mg-kg-1 or 100 ug-dm-1. For the measurement of total iron content, we take that dry ash distill, C12H8N2·H2O show color, then spectrophotometer colorimetry.5. In Kuerle areas, high pH (above 8.5) is the direct or indirect factors for Xiangli iron deficient chlorosis. Light salt pickled is the potential factor. The soil active iron deficient is universality,the active iron deficiency in the top soil may be the most fundamental and most important factors. All above the results of these studies to further improve the mechanism of chlorosis laid a theoretical foundation, and it supply the technology support for the further people research optimize xiangli iron deficient chloritic disease.