Geostatistical analysis of field spatial distribution patterns of soybean cyst nematode
Geostatistical analysis of field spatial distribution patterns of soybean cyst nematode
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DOI：
10.2134/agronj2003.0936
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发表时间：
2003-07-01
期刊：
影响因子：
2.1
通讯作者：
Melakeberhan, H
中科院分区：
文献类型：
--
作者：
Avendaño, F;Schabenberger, O;Melakeberhan, H
如果对大豆包囊线虫（Heterodera glycine Ichinohe）的时空动态有充分的了解和结构，对其进行定点管理是可行的。对SCN空间分布的变化具有足够的幅度和结构，并且具有足够的时间不变性的假设进行了测试，以支持在SCN侵染的田地中使用特定地点的管理。采用几何级数缩短距离的嵌套调查抽样设计对密歇根州的两个农田进行了研究。从1999年和2000年种植前采集的单芯土壤样品中提取包囊，估计每个包囊的卵数，每个包囊的卵数乘以包囊数得到每个样品的卵数。利用地质统计学工具，如半方差图、克里格和原始数据对数变换值的交叉相关图，对这三个变量的分布进行了表征。2个大田100 cm（-3）土壤平均包囊密度为6 ~ 33个。虽然SCN种群的空间结构因田而异，种群密度因年而异，但高、低囊密度区域的位置可以重复识别。线虫呈现聚集分布的原因尚不清楚。对与确定SCN空间分布有关的因素进行评估是一个正在进行的项目的一部分，该项目旨在发展SCN特定地点的管理。
Site-specific management of soybean cyst nematode [Heterodera glycines Ichinohe] (SCN) is plausible if its spatial and temporal dynamics are adequately known and structured. The hypothesis that variation in the spatial distribution of SCN is sufficient in magnitude and structure and sufficiently time invariant to support the use of site-specific management in SCN-infested fields was tested. A nested survey sampling design with distances reduced by geometric progression was applied on two fields in Michigan. Cysts were extracted from single-core soil samples collected before planting in 1999 and 2000, the number of eggs per cyst was estimated, and the number of eggs per sample was obtained by multiplying eggs per cyst by the number of cysts. The distribution of the three variables was characterized using geostatistical tools such as semivariograms, kriging, and cross-correlograms on log-transformed values of the original data. Mean cyst population density ranged from 6 to 33 cysts 100 cm(-3) soil in the two fields. Although the spatial structure of SCN population varied between fields and SCN population density varied between years, the location of areas of high or low cyst density could be identified repeatedly. The reasons why nematodes exhibited an aggregated distribution are not yet understood. The evaluation of factors associated with the determination of SCN spatial distribution is part of an ongoing project toward the development of SCN site-specific management.