HOW TO GROW MAIZE

HOW TO GROW MAIZE

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 quicker-maturing 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.

Planting preparation

 

Soil type

Maize will grow on a wide range of soil types, providing they are well drained. A pH range of 5 - 8 can be tolerated but best growth is achieved in the range of pH 5.6 - 7.5.
Maize does not grow well in saline soils. Yield reductions of 10 - 20+ percent can be experienced if soil extracts contain 2.0 - 4.0 dS/m respectively. Yield decline is likely if irrigation water has a reading of more than 1.5 dS/m. Seedling and flower growth is most sensitive to salinity.

Soil temperature

Soil temperature at planting depth (5-7.5 cm) at 9:00 am should be 12°C or higher, and have been on an upward trend for three or more days.
While seed will germinate at 12°C, growth is often slow and foliage develops a purple colour. Temperatures of 15°C + are safer and result in better growth.

Planting moisture requirement

Dryland maize should be planted on a full soil moisture profile. Irrigated crops should be irrigated pre-plant and then if using flood irrigation not watered until 6 weeks old (pre-tasselling). If conditions are hot and dry, a quick flush 2 - 3 weeks after emergence may be required.
Maize is not tolerant of waterlogging especially during seedling and flowering stages.

Seed details

Seed has both size and shape gradings. Size varies from 4400 seed/kg (small) to 2500 seed/kg (large).
Seed shape consists of rounds or flats. Flat seed is generally best in plate seeders, while round seed is preferred by air seeders. There is no difference between the crops produced by these seed shapes.
Information on the germination percentage and the date the test was conducted should also be with the bag.