104(4)_str40

 

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 104, No. 4 (2017), p. 311–320
DOI  10.13080/z-a.2017.104.040

Physicochemical properties of achenes of buckwheat cultivars affecting the development of grain weevil (Sitophilus granarius L.) and lesser grain borer (Rhyzopertha dominica F.)

Mariusz NIETUPSKI, Jacek KWIATKOWSKI, Agnieszka KOSEWSKA

Abstract

The development of two storage pests, grain weevil (Sitophilus granarius L.) and lesser grain borer (Rhyzopertha dominica F.), was studied on achenes of buckwheat representing two species: common buckwheat (‘Red Corolla’, ‘Karmen’ and ‘La Harpe’) and tartary buckwheat (Olsztyn, Lublin and Chinese accessions). The analysis included most important physical characteristics (thousand seed weight, husk content and thickness), and basic chemical composition of buckwheat seeds and husks (crude ash, crude fibre, total protein and total flavonoids). Based on the assessment of the development parameters of R. dominica and S. granarius, an attempt was made to determine which physicochemical characteristics of buckwheat achenes affected the development of these beetles. The results suggest that buckwheat achenes are a habitat in which both species of beetles can develop albeit at different dynamics. R. dominica found suitable conditions for the development on tartary buckwheat achenes, whereas achenes of common buckwheat proved to be a less favourable habitat. With respect to S. granarius, only single individuals completed their development on achenes of both buckwheat species, which indicates that this food source is a rather unattractive habitat for the lesser grain borer. The physical factor which deterred S. granarius from settling on buckwheat is most probably the thick husk of achenes. However, this feature is not a barrier to the lesser grain borer, and the properties which can contribute to the toughness of food (i.e. the per cent share of husk in the whole achene, husk thickness and content of crude fibre) can be decisive factors in beetles accepting or not a given buckwheat accession. Other traits which significantly affected the development of this pest included higher concentrations of total protein and total flavonoids in seeds.

Key words: physicochemical properties of achenes of buckwheat, storage pests.

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