Factors affecting grain crop seed germination

Page last updated: Tuesday, 28 November 2023 - 2:20pm

Please note: This content may be out of date and is currently under review.

Grain pests (insects and disease)


Many grain pests preferentially eat out grain embryos, lowering the percentage of seeds which germinate.

Freshly-harvested cereal grain usually has a temperature around 30°C, which is an ideal breeding temperature for storage pests

Effect of grain temperature and moisture on stored grain insect and mould development (Source: Kondinin Group)
Grain temperature (°C) Insect/mould development Grain moisture content (%)
40-55 Seed damage occurs, reducing viability -
30-40 Mould and insects prolific >18
25-30 Mould and insects active 13-18
20-25 Mould development is limited 10-13
18-20 Young insects stop developing 9
<15 Most insects stop reproducing, mould stops developing <8

For more information refer to Insect pests of stored grain and GRDC factsheets Identification of stored grain pests and Grain storage pest control guide.

Rust-red flour beetle
Rust - red flour beetle (Tribolium castaneum)


Fungal diseases affecting grain viability include fusarium head blight and white grain disorder (caused by Tiarosporella spp.) Both of these are quite rare and occur when wet springs promote infection during flowering.

White grain affected wheat can be clearly differentiated from healthy grains (Photo: M. Evans, SARDI).

Contact information

Helen Spafford
+61 (0)8 9166 4074