Chen J, Bird G W, Mather R L
J Nematol. 1995 Dec;27(4S):654-60.
Five cropping regimes involving combinations of 2 legumes, alfalfa (Medicago sativa) and yellow sweet dover (Melilotus officinalis), 2 monocots, corn (Zea mays) and sudax (Sorghum halupeuse x Sorghum sudanese), and potato (Solanum tuberosum cv. Superior) were tested for their impact on potato yields in a field infested with Pratylenchus penetrans and Verticillium dahliae. No differences in 1990 tuber yields were observed among the five cropping regimes (P < 0.05). In 1991, yields following 1 year of corn, sudax, sweet clover, or alfalfa and 2 years of potato were not different from that of 3 years of continuous potato (P < 0.05). Two years of sweet clover or alfalfa followed by potato resulted in significantly increased potato tuber yields compared with 3 years of potato (P < 0.05). The 2-year legume and 2-year grain rotations resulted in lower P. penetrans population densities at the end of the 3-year rotation compared with 3 years of continuous potato (P < 0.01). The highest preplant V. dahliae population density (34 cfu/g soil), together with a P. penetrans density of 12/100 cm(3) of soil was in the sudax-sudax-potato cropping regime and resulted in the lowest potato tuber yield. The highest preplant P. penetrans population density (54/100 cm(3) soil), together with a V. dahliae population density of 19.5 cfu/g soil was observed in the corn-corn-potato cropping regime and resulted in the second lowest potato tuber yield in 1991. After 3 years, potato tuber yields were negatively related to preplant densities of V. dahliae (r(2) = 0.237), P. penetrans (r(2) = 0.175), and both pathogens (r(2) = 0.380). A comprehensive regression model was developed to isolate pathogen effects on potato yields from cropping regime effects encompassing all 10 cropping regimes (r(2) = 0.915).
在一块受到穿刺短体线虫和大丽轮枝菌侵染的田地里，对五种种植制度进行了测试，这五种种植制度包括两种豆科植物（紫花苜蓿和草木犀）、两种单子叶植物（玉米和苏丹草）以及马铃薯（“超级”品种）的不同组合。1990年，五种种植制度下的块茎产量没有差异（P < 0.05）。1991年，种植1年玉米、苏丹草、草木犀或紫花苜蓿后再种植2年马铃薯的产量与连续种植3年马铃薯的产量没有差异（P < 0.05）。与连续种植3年马铃薯相比，先种植2年草木犀或紫花苜蓿再种植马铃薯，马铃薯块茎产量显著增加（P < 0.05）。与连续种植3年马铃薯相比，2年轮作豆科植物和2年轮作谷物在3年轮作结束时，穿刺短体线虫的种群密度较低（P < 0.01）。在苏丹草 - 苏丹草 - 马铃薯种植制度中，种植前大丽轮枝菌的种群密度最高（34 cfu/g土壤），穿刺短体线虫密度为12/100 cm³土壤，该种植制度下马铃薯块茎产量最低。在玉米 - 玉米 - 马铃薯种植制度中，种植前穿刺短体线虫的种群密度最高（54/100 cm³土壤），大丽轮枝菌种群密度为19.5 cfu/g土壤，该种植制度在1991年的马铃薯块茎产量排第二低。3年后，马铃薯块茎产量与种植前大丽轮枝菌密度（r² = 0.237）、穿刺短体线虫密度（r² = 0.175）以及两种病原菌密度（r² = 0.380）均呈负相关。建立了一个综合回归模型，以从涵盖所有10种种植制度的种植制度效应中分离出病原菌对马铃薯产量的影响（r² = 0.915）。
