早熟柑橘黄龙病流行与产量损失关系研究

2002-2009年测定了早熟柑橘品种‘宫川’（以下简称早熟柑橘）黄龙病病情扩散速率与产量的关系。结果表明：早熟柑橘黄龙病病情随时序推进呈Logistic曲线上升，总体上病情扩散速率为先快后慢，并呈现从强到弱的趋势特征，前4年因病原基数低而病情增长幅度大，扩散速率快；后4年因病原基数处于较高状态，而相对传染扩散速率减慢，表现扩散速率较平缓，形成随病级上升单株结果数减少、健果率下降、产量下降的危害规律；由此建立早熟‘宫川’黄龙病病情扩散速率（P）与发病时序（N）的关系模型为：P=65.082 7/［1+EXP(4.017 8-0.752 838N)］（R=0.999 1*），株发病率（P）与病情指数（M）关系模型为：M=0.571 2P-2.398 6（R=0.993 7*），不同病级(m)病树与其果数(G)、健果率(J)的关系模型：G=1 344.833 9/［1+EXP(-3.693 7+0.549 3m)］(R=-0.988 6*〖KG-*2〗*）；J=91.560 5/［1+EXP(-6.677 0+1.090 4m)］（R=-0.974 2*〖KG-*2〗*）；不同病级(m)病树与其单果重(W)、单株产量(Y)、产量损失率（Rp）的关系模型：W=95.427 8/［1+EXP(-29.770 1+3.993 2m)］ （R=-0.990 6*〖KG-*2〗*）；Y=44.138 2/［1+EXP(-4.019 2+0.689 1m)］（R=-0.984 2*〖KG-*2〗*）、Rp=131.536 4/［1+EXP(4.239 9-0.592 4m)］（R=-0.984 7*〖KG-*2〗*）。

Studies on epidemics of the citrus Huanglongbing and yield loss in early maturing citrus orchards

The epidemic diffusion velocity of Huanglongbing(HLB) and the yield loss due to it were measured in early-maturing citrus orchards from 2002 to 2009.The results showed that HLB rised by Logistic curve with temporal evolution.General tendency of the epidemic diffusion velocity was quick and strong first,followed by slow and weak.A linear model between the epidemic diffusion velocity of HLB(P) and morbidity time series(N) was established: P=65.082 7/1+EXP(4.017 8-0.752 838N)];the relationship between morbidi...