In the UK the most problematic pests of the potato crop are the potato cyst nematodes Globodera rostochiensis and G. paUida. A structured survey of potato growing land in England and Wales was undertaken to reassess their occurrence and distribution. peN were present in 64% of sites sampled and of the populations found, 67% were G. pallida, 8% were G. rostochiensis and 25% contained both species. Just over 50% of the sites sampled had a rotation length of 1 in 5 or less and cultivars with partial resistance to G. paUida represented only 6% of the total number of plantings while those with resistance to G. rostochiensis represented 43%. The results show an increase in the incidence of peN compared with previous surveys and confirm the perceived shift towards G. paUida as the predominant species. Two field experiments were done to look at the integration of methods for the control of peN and subsequent reduction in yield loss in situations of very high peN levels. The first experiment assessed the use of 1,3-dichloropropene (1,3-D) with the granular nematicides aldicarb, oxamyl and fosthiazate when growing the susceptible cultivar Estima. The second experiment assessed the use of the resistant cultivar Sante with 1,3-D and oxamyl at full and half-rates. 1,3-D significantly advanced emergence, increased percentage ground cover, root invasion, yield, tuber numbers, and improved tuber size distribution. Nematode multiplication was significantly reduced by fumigation in the first experiment. The use of 1,3-D for the control of weed seeds was assessed and the results show a reduction in germination of weed seeds in soil after fumigation. The use of 1,3-D for the control of Rhizoctonia solani was also assessed and a trend in reduction in R. solani was observed after fumigation although the differences were not statistically significant.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:367220 |
| Date | January 2000 |
| Creators | Minnis, Stephen T. |
| Publisher | Open University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://oro.open.ac.uk/58068/ |
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