Investigation Of Nematode Parasites On Horticultural Crops In Export Plantations And Control Of Meloidogyne Incognita

In recent years, plant-parasitic nematodes have seriously damaged the production and exportation of horticultural plants such as vegetables and flowers in China.In this paper, the occurrence of nematode parasitized on horticultural plants from exported plantation in Jiangsu and Shandong provinces was investigated and the species were identified. A new control measure was developed in order to prevent the most dangerous root-knot nematode Meloidogyne incognita. This study provides the theoretical guidance to plant quarantine of agricultural products exportation and supported the field control of nematode disease on horticultural plants.In 2012, investigations were carried out on parasitic nematodes of vegetables and horticultural plant seedlings in export plantations in Lianyungang, Ganyu, Yancheng, Shuyang, Dafeng, Xinyi and Donghai of Jiangsu province and Cangshan of Shandong Province, China. Eighteen species of 9 genera were extracted from 65 samples collected from rhizosphere of 19 plant varieties. Fourteen species were confirmed by morphological characters or SCAR-PCR makers. Among these, four common species of genera Meloidogyne were discovered. M. incognita was the one frequently occurring nematode in different plantations and infected different hosts with relatively high population densities, thus played a threatening role for the agricultural exportation industry. M. hapla was found to infect Arctium lappa which planted in Cangshan County. Pratylenchus neglectus, Helicotylenchus crenacauda, Filenchus equisetus and Aphelenchus avenae were also frequently occurred in different plantations and infected several vegetables and horticultural plants. Scutellonema brachyurum was occurred in Lianyungang and infected seedlings of Dendranthema morifolium, Asparagus myrioeladus and A. cochinchinensis.Meloidogyne incognita causes serous damage to many horticultural plants and its control tests in greenhouse were carried out in Niangzhuang village, Dingji Town, Huaian District in Jiangsu Province. The effects of cucumber rotated with straw mushroom adding biocontrol agents (HDD) were evaluated on the reproduction of second stage juvenile (J2) and the yield of cucumber. The results showed that at 180 days after cucumber transplanted, the reproduction of M. incognita was significantly inhibited in the treatment of rotation with straw mushroom and the treatment of rotation combined with HDD, with the population density were 35.8 and 25.4 J2/100 mL soil, the disease index were 22.7 and 20.5, respectively. The population density of the control treatment was 200.5 J2/100 mL and the disease index was 85.7. The cucumber yield for the treatment of rotation combined with HDD increased 77.4%, for rotation with straw mushroom, increased 68.0% when compared with the control. The control efficiencies on M. incognita for both treatments were higher than 70%, which was significantly different from that of the treatment with 10% granule of Abamectin and fosthiazate mixture. The results indicated that the rotation of cucumber with straw mushroom can control M. incognita efficiently.