| The occurrence, host and damage of the vegetable root-knot nematodes from the different regions of Shandong province were first invested, then the four typical regions of different level of pesticides-used were selected as the study objects. The difference of nematicides resistance of the vegetable root-knot nematodes from the four different regions were outspreaded on the basis of establishing the diversified bioassays of nematicides, and the enzymes relative to nematicides resistance were also studied. In order to found out the effective nematicides to control vegetable root-knot nematodes, the potted plant experiments were employed in the first instance; the selected nematicides were evaluated in field test later. The results could be summarized as follows:(1) The vegetable root-knot nematodes diseases were having become the common ones in Shandong province. The south root-knot nematodes (Meloidogyne incognita) were the predominant species. The most hosts it damaged were the vegetables, which there were 51, accounting for 62% of the known crops in Shandong. There were about 20 vegetables which were damaged more than the others, especially cucumber, tomato, navy bean, cowpea, celery etc. being the most damaged. In some special vegetables such as ginger, burdock, the root-knot nematodes diseases were also widespread. It was also the common disease of fruit trees, flowers, Chinese herbs etc.(2) The nematicides studied were all able to restrain hatch of the eggs of the root-knot nematodes from the different regions in a way. The most effective nematicide was aldicarb; the second was ethoprophos; the effect of isofenphos-methyl and the phoxim were feeblish. Resistance different ratio of the eggs from the four different regions to the each nematicides was as follows:53etoprophos was between 1.00-1.23; isofenphos-methyl was between 1.00-1.21; phoxim was between 0.99-1.19; aldicarb was between 1.00-1.25. It was illuminated from the above that the resistant level of the eggs of the four regions is on the small side, that is, there was no obvious difference between the high-used nematicides regions and low-used namaticides regions.(3) The nematicides studied all could knock down the second juveniles (L) or restrain the movement of them of the root-knot nematodes from the different regions. The most effective nematicide was avermectin; the second was aldicarb; the effect of ethoprophos was the third; the effect of isofenphos-methyl and the phoxim were feeblish. Resistance different ratio of the Ji from the four different regions to the each nematicides was as follows: avermectin was between 1.00-1.23;etoprophos was between 0.87-1.30; isofenphos-methyl was between 0.91-1.00; phoxim was between 0.94-1.10; aldicarb was between 0.65-1.20. It was illuminated from the above that the resistant level of the J2 of the four regions was on the small side, that is, there was no obvious difference between the high-used nematicides regions and low-used namaticides regions.(4) Toxicity bioassayed with cucumber seedling method indicated that the toxicity difference of vegetable root-knot nematodes from the four regions was very low. The constraint effect of the same nematicides and the same concentrations to the root-knot nematodes of low-used nematicides regions and the ones of high-used nematicides regions had no difference. That was to say. there was no resistant difference of the four root-knot nematodes to the same nematicides. Toxicities of nematicides to M\ being the standard, resistance different ratio of the nematodes from the four different regions to the each nematicides was as follows: avermectin was between 0.97~1.07;etoprophos was between 1.00-1.39; isofenphos-methyl was between 1.00-1.29; phoxim was between 1.00-1.05; aldicarb was between 1.00-1.31.(5) Greenhouse & growth chamber soil treatment and field test were employed, and indicated that the effect of avermectin, ethoprophos, phoxim, ethopropho... |
PDF Full Text Request