Investigations about the influence of free living nematodes on the yield of strawberry cultures
1987
Kohler, E. (Regierungspraesidium Freiburg (Germany, F.R.). Pflanzenschutzdienst)
Немецкий. At intensive cultivation of strawberries the yield is often decreased by the black root-disease (Schwarze Wurzelfaeule). Beside abiotic factors and other parasites the infestination of freely living nematods is frequently mentioned as cause. Above all Pratylenchus penetrans is esteemed to be very harmful. Therefore in examinations, which were made during three years, the influence of a nematod-population mainly consisting of Helicotylenchus digonicus, Pratylenchus crenatus and also, but by far less, Tylenchorhynchus was reconsidered, especially at strawberries that were not roofed over. For a density of infestination up to 1800 nematods in 250 ml soil the results can be depicted as linear regression. For the sort "Gorella" arose in the average of the years a yield-depression of 1.6 per cent per 100 Helicotylenchus or Tylenchorhynchus in 250 ml soil, Pratylenchus crenatus was less harmful. A critical threshold could not be defined for this species. The yield-depression occurs with a reduction of the number of fruits and a coincident increase of the average weight of the fruits. By that means a part of the loss is compensated again. Sorts that are inclined to get many but small fruits seem to be more efficient in this than "Gorella" with a moderate number of fruits and rather equable weights of the fruits. Chemical decontamination of the soil was more effective on "Gorella" than on "Elvira" and "Senga Fructarina"
Показать больше [+] Меньше [-]Ключевые слова АГРОВОК
Библиографическая информация
Эту запись предоставил ZB MED Nutrition. Environment. Agriculture