There are a multitude of maize varieties available. The choice of variety will depend on market requirements, environmental conditions, whether the crop is irrigated and the level of disease resistance required. Varieties are continually changing so ensure you have up-to-date varietal information.
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Maize hybrid characteristics
(Note: The information in this table is supplied directly by seed companies and is not based on DPI&F Queensland data. Final choice of maize hybrids should be made in consultation with seed company representatives.)
Key to maize ratings
(1) End use
- S - starch
- P - processing
- F - feed
- Sil - silage
(2) Husk cover
- TO - tight open
- TC - tight closed
- MO - medium open
- MC - medium closed
- LO - loose open
- LC - loose closed
(3) Disease reaction
- S - susceptible
- MS - moderately susceptible
- MR - moderately resistant
- R - resistant
- NA - not available
(4) Stalk strength (lodging resistance)
- * very poor
- ** below average
- *** intermediate
- **** above average
- ***** very good
(5) CRM (cumulative relative maturity, days)
- 100-112 quick
- 113-115 medium quick
- 116-120 medium
- 121-130 medium slow
- 131+ slow
Selecting a suitable variety
Time to flowering
Under conditions of adequate soil moisture, mid to slow maturing hybrids will produce a higher yield than quick maturing hybrids. Therefore, growers aiming for maximum yields should consider a mid to full season maturity hybrid.
However, where irrigation is limited, a mid-season hybrid may produce more yield per megalitre of water. This may also be the case in fully irrigated situations where it is desired to limit the number of irrigations for economic reasons or to plant a following crop to obtain maximum utilisation of seasonal conditions. In dryland environments, commercial full season hybrids can handle heat and moisture stress and then respond to a break in the weather.
Within the choice of hybrids available, growers, particularly in dryland situations, may wish to reduce the risk of yield loss caused by unfavourable seasonal conditions by planting a number of hybrids, perhaps with a range of maturities.
Cob height
Cob height tends to be correlated with maturity. Longer season hybrids usually have higher-set cobs than quickermaturing hybrids. Excessive cob height, greater than 1.5m can be a contributing factor to root lodging (especially if there is wind and rain around flowering), and to stalk lodging, (particularly if stalk rot has infected the plants). Lodged plants can be slow harvesting and reduce yield.
Husk cover
Husks function to prevent damage from Heliothis (Helicoverpa spp.) larvae, reduce ear/kernel rots (Diplodia, Fusarium) and smuts, and protect the grain from weathering. Therefore, a good husk cover (including tip cover) can be important if insects, disease, and pre-harvest rain are likely to pose threats. However, in areas where quick dry-down is necessary because of a short season, hybrids with light, loose husks may be best adapted.
Standability
Standability (resistance to lodging) is important because it reduces harvest losses and grain damage. Many factors contribute to standability including resistance to stalk rots, good mechanical stalk strength and cob height. Most modern hybrids have good standability but some seasonal conditions (e.g. water stress during grainfill) can cause serious lodging. Always choose hybrids with good to excellent standability.
End use
Hybrids generally have specific grain characteristics which govern their suitability for particular end uses such as milling for grits, stockfeed, silage or other special purpose uses.
Isolation
All white, waxy and popcorn varieties of maize must be grown in isolation (both in distance and time) from other maize varieties, as pollen from other crops will affect the quality of grain produced by these types. Seed companies or grain purchasers may have specific recommendations that need to be followed.
