Duration of cereal aphid populations and the effects on wheat yield and breadmaking quality

Abstract

SUMMARYField‐caged and open‐plot populations of the aphid Sitobion avenae on winter wheat (cv. Maris Widgeon) were sampled approximately twice‐weekly in the summer of 1978. Cage populations began at growth stage 10.2 (Feekes scale) (Zadoks, G. S. 52); they were removed by spraying with pirimicarb at growth stages 10.54 (71), 11.1–11.2 (77) and 11.2–11.3 (85) respectively. All cage populations reduced mean weight per grain but the effect per aphid unit was lowest in the population of longest duration. Although the aphid index in the open plots was higher than that in the early cage treatment, yield was unaffected. Cage infestations affected the breadmaking quality of the grain: percentage flour extraction was reduced and there was an increase in colour, nicotinic acid content and thiamine (vitamin B1) content of the flour; percentage nitrogen in the flour was unaffected but there was a reduction in baking value and in the high molecular weight glutenin content; infestation also reduced α‐amylase activity. Different aspects of grain quality did not change in parallel with one another or with yield changes and thus damage thresholds will vary according to the yield/quality measure under consideration.

Glutenin and gliadin contents of flour derived from wheat infested with different aphid species

“…Significant yield decrease occurred when the abundance of S avenae reached 20–30 aphids per plant during milk development 29. Lee et al 29 demonstrated that S avenae infestation affected not only yield quantity but the bread‐making quality of flour as well: colour, nicotinic acid content and thiamine content increased and the HMW glutenin content decreased.…”

Effect of secondary plant substances on winter wheat resistance to grain aphid

“…Earlier studies have indicated that the aphid reduces not only yields but also quality of injured grains (George & Gair, 1979;Lee et al, 1981;Malachowska, 1987). Earlier studies have indicated that the aphid reduces not only yields but also quality of injured grains (George & Gair, 1979;Lee et al, 1981;Malachowska, 1987).…”

The effect of aphid infection and cultivar on the protein content governing baking quality of wheat flour

“…Sitobion avenae (Fabricius) infestation affects not only yield but also the bread‐making quality of flour (colour, increased nicotinic acid and thiamine content and decreased high‐molecular‐weight glutenin content) 10…”