Zea mays
Description
Morphology
A maize (commonly called corn in many English speaking countries) plant is often 2.50 m in height, (although some plants can grow to over 10 m), and is composed of twenty internodes of 18 cm length on average. One leaf grows from each node, reaching a size of about one meter. On some of these nodes grow what is commonly called the “ears” or “cobs” of the corn, with an average size of 18 cm, each with about 600 kernels.
Maize is an annual, monoecious (with unisexual flowers) grass. Male panicle (tessel) is located on top of the stem, female inflorescence at the leaf axils. It has Protandrous blossom.
Kernels are bear, without lemma. They are relatively large (approx. 150 g per 1000).
Very leafy, with strong tillering, tall and thin stem, some varieties, in particular vulgaris, are used as green forage.
Geography
Culture
Chemical Composition
| In % | Water | Nitrogen | Fat | Soluble carbohydrates | Fibrous carbohydrates | Ashes |
|---|---|---|---|---|---|---|
| Green | 87 | 0.9 | 0.3 | 7.4 | 3.5 | 0.9 |
| Silage | 72 | 2.7 | 1.0 | 16.4 | 6.0 | 1.9 |
| Dry leafy stem | 20 | 5.3 | 1.3 | 41.6 | 25.7 | 6.1 |
| Grains | 13 | 10.1 | 4.6 | 69.1 | 2.0 | 1.2 |
Usage
Maize is mostly cultivated for its grains. It is principally destined for animal feed, then for human consumption, and to lesser extent for industrial use.Maize is an outstanding forage plant, providing high efficiency and high nutritional value. It can be used as green forage or in silage.
As a monoid plant (that facilitates self-fertilisation), it is possible (and very often carried out) to cross the best self-fertilised lines in order to increase the yield ( 20-30 % higher ).
It requires a hot and humid climate, but can be cultivated also in drier regions (Mediterranean basin) when properly irrigated. It grows also in dry crops if planted early (in February – a wet month) provided it achieves a minimum temperature of 9-10 ° C for germination. Dry crops should be carried out in deep and fertile soil with very high water retention.
Techniques
Maize can be grown for grain production (in rows or in pockets) for silage or for green forage.
| Production in rows | Production in pockets | Silage | Green forage | |
|---|---|---|---|---|
| Direction of seedlings | In lines | In all directions, by dibbling | In lines | Broadcasting or in rows |
| Space between rows | 60-80 cm | 50-70 cm (between two bunches) | 50-70 cm | 30-50 cm (if in rows) |
| Space between grains | 10-25 cm | / | 10-25 cm | / |
| Depth of grains | 5-10 cm | / | / | / |
| Amount of grains | 15-50 kg/ha | 18-36 kg/ha | 17-60 kg/ha | 75-150 kg/ha |
| Treatments | Hoeing and thinning (30-40 cm) | Separation of bunches (leaving one to tow plants per pocket), hoeing and softening | Hoeing, no thinning | Harrowing, one to two hoeings |
| Harwest | / | Full maturity | Milk stage, just before full maturity | At the panicle formation |
| Yield | 10-50 q/ha | 200-600 q/ha | ||