Premium
Assessment of the losses caused to potatoes by the potato cyst nematodes, Globodera rostochiensis and G. pallida
Author(s) -
BROWN E. B.,
SYKES G. B.
Publication year - 1983
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1983.tb02764.x
Subject(s) - globodera rostochiensis , biology , loam , globodera pallida , potato cyst nematode , pest analysis , agronomy , population , population density , nematology , soil water , horticulture , botany , ecology , solanaceae , nematode , biochemistry , demography , sociology , gene
SUMMARY Nine field trials were carried out from 1967 to 1973 on sandy loam soils in Staffordshire and Worcestershire to study the relationship between potato yield and numbers of potato cyst nematodes ( Globodera spp.). Three (probably five) of these trial sites appeared to be infested with G. rostochiensis only, whereas both species occurred on the remaining four sites which grew the resistant variety, Maris Piper. Although mixtures of the two species occurred on some plots they tended to have different distributions within each trial site. The results from this work have been analysed, together with those from earlier work in the Eastern Counties on peat and silt soils, over two population density ranges, 0–40 eggs/g (5 sites) and 0–160 eggs/g (16 sites). There is no evidence of any difference in the regression of yield on eggs/g amongst the five sites in the lower range (b =–0.90 + 0.11) nor amongst 15 of the 16 sites in the higher range (b = ‐0–40 ± 0–02). Analysis of 10 sites with sufficient data in the 40–160 eggs/g range gave b = ‐0.24 ± 0.06. Thus the regression lines are essentially parallel for each of the two ranges, covering several potato varieties, soil textures and different potential yields and suggest that the varieties used are equally tolerant. The losses are 6.25 t/ha/20 eggs/g for the 0.40 eggs/g range, 1.67 t/ha/20 eggs/g for the 40–160 eggs/g range, and 2.75 t/ha/20 eggs/g as a mean for the whole range. A maximum loss of 22 t/ha is indicated. Peat soils are less dense than mineral soils but there was no need for adjustment in nematode counts. Losses caused by potato cyst nematodes are better expressed as actual yield losses rather than as percentage decreases.