矿质元素与“恭城水柿”顶腐病发生研究

Relationships between Mineral Elements and Top Rot Occurrence in 'Gongchengshuishi' Persimmon

【目的】分析矿质元素与"恭城水柿"(Diospyros kaki Thunb.)顶腐病发生关系,为顶腐病防治提供理论依据。【方法】测定21个恭城水柿顶腐病发病柿园中果实、叶片及土壤N、K、Ca、Mg、Mn、B含量,运用多重比较、多元回归、通径分析等方法,系统分析矿质元素及其比值与顶腐病发生关系。【结果】随顶腐病发病程度加深,叶片钙浓度显著降低。发病率与叶片硼浓度呈显著负相关,相关系数为-0.480 1,与土壤p H极显著负相关,相关系数为-0.667 7,与土壤速效钾/交换性钙值存在极显著正相关,相关系数为0.564 1,与土壤水解性氮/交换性钙显著正相关,相关系数为0.506 8。土壤p H和叶片钙含量对顶腐病发生存在较大直接负作用,通径系数分别为-1.222、-0.824。【结论】恭城水柿顶腐病与生理性缺钙关系密切。同时,恭城当地酸化、高镁、高氮的土壤环境均不利于柿对钙吸收与转运,从而导致矿质营养失衡、进而易发生顶腐病。

【Objective】The aim of the study was to reveal relationships between mineral elements and top rot（TP） occurrence in persimmon（Diospyros kaki Thunb.）. Our study was expected to provide some scientific references for the prevention and cure of top rot disease.【Method】Nitrogen（N）,potassium（K）,calcium（Ca）,Magnesium（Mg）,manganese（Mn） and boron（B） contents in fruits,leaves and soil from 21 ‘Gongchengshuishi＇orchards with top rot disease were measured. Diverse statistical method,including path analysis,multiple multiple regression and post hoc were used to comprehensively analyze relationships between mineral elements and top rot occurrence.【Result】Leaf Ca content decreased with magnitude of TP occurrence. There were significantly negative correlations between TP occurrence and leaf B content（r=-0.480 1） and p H value（r=-0.667 7）. However,there were significantly positive correlations between TP occurrence and soil N/Ca ratio（r=0.564 1）. and K/Ca ratio（r=0.506 8）. Both multiple regression analysis and path analysis showed that soil p H value（r=-1.222） and leaf Ca content（r=-0.824） had relatively strong negative effect on top rot occurrence.【Conclusion】There was a close relationship between Ca deficiency and TP occurrence within‘Gongchengshuishi＇persimmon. In addition,acidification,higher Mg and N content in soils could be not favorable to Ca absorption and transport.