A corn hybrid that offers a great all-round bundle of agronomic traits and wide adaptability. Produces top quality, high energy silage. HM-152 is suitable for dryland or irrigation, silage or feed grain and ideal for short season environments. Maturity sits between P9400 and Maximus. This is an ideal hybrid variety for high input silage maize in areas with a shortmedium length growing season. Good later planting or earlier harvest option where longer season varieties are normally grown.
- CRM 97
- Conventional hybrid
- Quick maturity
- Leading grain & silage yield potential
- Excellent silage quality
- Shorter season option
- Suitable for medium to high population density
- Consistent performance in central and southern markets
- Ideal for TAS, VIC and Southern NSW, Southern WA
- Late plant option in longer season environments
- High cob % of total yield
- High digestibility
- Excellent starch and sugar content
Corn Attributes Chart
Select two or three hybrids to spread your risk. Growing hybrids of different corn relative maturity (CRM) and various planting times will reduce exposure to risks associated with adverse climatic conditions, especially during tasseling and grain fill.
Guide Map - Reference Key
Heritage Seeds corn hybrids are available with OptiCote™ seed treatment (Vitavax® fungicide and Gaucho® insecticide).
Variety/ Agronomy Management
Sowing Time: Sowing time is governed by soil temperature, soil moisture and targeted flowering date. Commence sowing when the 9am EST soil temperature at sowing depth reaches 12°C and is rising. For irrigated crops, the temperature of water used for pre-irrigation or watering-up can influence sowing time. If watering-up, allow for a 3°C to 4°C drop in soil temperature following watering. The rate of seedling emergence increases with increasing soil temperature. At 12°C emergence will occur in 14 days, whereas at 25°C emergence occurs in 4 to 5 days. Planting into cold soils slows emergence, reduces germination and establishment and increases susceptibility to seedling blight. Low soil and air temperatures slow plant growth and reduce nutrient uptake (especially phosphorus) inducing purpling in some hybrids. Very early-planted paddocks frequently have to be replanted. Note that some hybrids do have better cold tolerance than others.
Row Spacing: Row spacing is commonly 75–110 cm. Width is ultimately determined by the available planter, tractor, harvester and other equipment. Narrow rows are an advantage when there is good in-crop rainfall or irrigation, high fertility and high plant populations. In such conditions, narrower rows will usually
produce slightly higher yields as plants are more evenly spaced. For dryland production in drier areas, single or double skip on 100 cm rows are suggested so that soil moisture is conserved for grain fill. With skip row configurations, use the same target plant population as for solid planting. This means, for example, that in-row plant population in double skip rows will be twice that in solid planting.
Crop Establishment: Apart from moisture stress, poor crop establishment and weed competition are usually the major factors that significantly reduces yields. The following recommendations should help improve crop establishment and crop yields. Uniform establishment and accurate depth placement of seed is essential. Precision planters achieve both of these. Planters should be in small enough sections to follow the paddock undulations with large diameter depth wheels located within the frame and tines or discs mounted on parallelogram planter units. Narrow points or discs are better suited to no-till and minimum-till conditions and work very well in free flowing soils but excessive planting speeds will reduce establishment. In moist seedbeds, the seed should be placed about 5 cm deep. In dry seedbeds using moisture seeking for deep furrow planting, the seed is also placed 5 cm deep. That may be 10–12 cm below the original soil surface. Press wheels are essential not only to improve establishment but also to help control soil insect pests of germinating and emerging corn, including true and false wireworms. Use press wheel pressures of 4 to 6 kg/cm width of press wheel for conventional seedbeds and 6 to10 kg/ cm for no-till and minimum-till seedbeds. Use pressures at the higher end of the range when sowing moisture is marginal, seed is deeply planted or soil insects are present. Use pressures at the lower end of the range when soils are hard setting or surface crusting. Crop establishment is improved when the shape of the press wheel matches the shape of the seed trench.
Nutrition: Good yields of grain or silage require high levels of soil fertility. The amount of nitrogen, phosphorus and potassium required in fertiliser applications is dependent on previous cropping and fertiliser history, age of cultivation, fallow conditions and yield targets. The overall removal of nutrients is greater in silage compared to grain crops, particularly for potassium. Continuous removal of these nutrients without replacement leads to declining soil fertility. Defining a target yield and its expected nutrient removal is the basis of building a nutrition program for corn. Corn takes up only small amounts of nutrients until 4 weeks after planting when nutrient uptake rapidly increases. More than 90% of potassium uptake occurs between 4 and 7 weeks after planting, when less than half of the final above ground dry matter has been produced. Nitrogen uptake also increases rapidly with 55% of uptake occurring in the short window from 7 weeks after planting until the end of silking. Nitrogen uptake is virtually complete 2 weeks after flowering. Phosphorus uptake is complete 4 weeks after flowering. The timing of fertiliser application is extremely important. Crop accumulation of nitrogen, phosphorus and potassium is rapid in the early stages of growth. Banding fertiliser at sowing ensures that the crop can access nutrients from the very early stages of root development. Referred to as the ‘pop-up effect’, seedlings are observed to develop at a faster rate when sown with banded fertiliser. An added advantage of band applied fertiliser over broadcast fertiliser is that the nutrients remain in available forms for a longer time. Banding fertiliser at sowing is possible with most modern precision planters. Apply mixed fertilisers (nitrogen, phosphorus and potassium) in a band 5 cm to the side of the seed and 5 cm below it. This placement prevents damage to the seedling by fertiliser burn which is a risk if the seed and fertiliser are in direct contact. Zinc fertilisers are needed for corn grown on heavy alkaline soils as deficiencies commonly occur. Zinc can be broadcast at 10–20 kg Zn/ ha and incorporated at least 3 months prior to planting. This application rate should last for five to six years, as zinc is relatively immobile in the soil. Lower rates are sufficient on lighter textured soils.
Irrigation: Well irrigated corn crops use water very efficiently, commonly yielding 16–18 kg grain/ ha/mm of water. Trial work has recorded efficiencies in excess of 20 kg of grain/ha/ mm of water. Irrigation water use efficiency is affected by crop agronomy, irrigation system efficiency and seasonal conditions – primarily evaporation and in-crop rainfall. In generating yield responses to applied water it is as critical to avoid waterlogging stress as it is to avoid stress from moisture deficits.
Water Budgeting: When planning a corn crop it is important to consider the area that can be fully watered, as corn is less tolerant of moisture stress than other summer crops. At Gunnedah, Northern NSW – budgeting 7 ML of irrigation water applied to the field/ha will satisfy crop water requirements in four out of five years. In the Murrumbidgee Valley, Southern NSW - irrigation water use ranges from 6 to 10 ML applied to the field. The average budget is 8–9 ML/ha.
Peak water use: High water use occurs from tassel appearance through to early dent grain maturity. Approximately 70% of the crop’s total water use will occur in this window between 5 and 12 weeks after planting. During this time cob initiation, flowering, pollination and kernel set occur.Peak water use occurs during the 3 weeks following silking (weeks 10–12). The greater the canopy, the greater the water use during this period. Taller, denser crops will use more water as they intercept more light and are exposed to more wind.
Weed Management: Corn is most susceptible to weed competition in the early stages of growth until the crop reaches 0.8m in height, approximately 8 weeks after planting. Effective weed control through this period is essential for high yields, particularly in dryland crops. Maintaining weed control beyond this stage is important for harvestability and preventing contamination of the grain sample. An integrated approach to weed management is recommended. Herbicide resistance is an emerging
problem in most grain producing areas. Producers should target their weed control carefully so that the correct rate and time of application is achieved. This is particularly important for harder to kill weeds such as barnyard grass, liverseed grass, fleabane, bindweed and wild oats.
Herbicides: Due to the impact of early competition, the weed control program should include pre-plant or post-plant preemergent herbicides targeting both grass and broadleaf weeds. Efficient and economical herbicides are available for the common weeds of corn, however some residual herbicides may have plant back restrictions that limit their suitability.
Disease Management: Many diseases in corn can be overcome by selecting resistant hybrids. Additionally, good farm hygiene, including washing down equipment and controlling weeds and volunteers, can minimise disease spread from crop-tocrop and season-to-season. While diseases are important to corn production because of their potential to reduce yield, the marketing of grain can be severely restricted by the presence of disease, adding further to the need to choose hybrids carefully. Key diseases that can affect corn include Turcica leaf blight or Northern leaf blight (Exserohilum turcicum), boil smut or common smut (Ustilago maydis), dwarf mosaic virus, cob and stalk rots (Aspergillus, Fusarium and Gibberella spp.), wallaby ear and rust (Puccinia sorghi). For broader disease management programs, please consult advisors from the various State government primary industry departments or experienced commercial agronomists/consultants in the relevant growing areas.
Insect Management: The successful management of insect pests is important for achieving high grain or silage yields. Growers who maintain awareness of pest activity through regular crop inspections will be better able to decide if and when insect control measures are needed. Infestations of insect pests can occur at any time but crops are most susceptible to damage during establishment and from tasselling until harvest. Insects that can affect corn include African black beetle (Heteronychus arator), armyworm (Spodoptera spp.), black field earwig (Nala lividipes), corn aphid (Rhopalosiphum maidis), cutworm (Agrostis spp.), heliothis or corn earworm (Helicoverpa armigera) red shouldered leaf beetle (Monolepta australis) true wireworm (Agrynus variabilis) and false wireworms (Pterohelaeus darlingensis, P. alternatus, Gonocephalum macleayi) and two-spotted spider mite (Tetranychus urticae). For broader insect management programs, please consult advisors from the various State government primary industry departments or experienced commercial agronomists/consultants in the relevant growing areas.
Harvest Timing: Harvest timing is a compromise between maximum dry matter yield, moisture content and potential feed quality. These factors need to be balanced to ensure the feed will ferment and ensile effectively without spoiling. Ideally, harvest should occur 10–14 days prior to physiological maturity when the maturing grain reaches the milk line score (MLS) of 2.5. When the milk line score is in the range 2–3, dry matter production is near to the maximum and moisture content is 63–67%, which is ideal for fermentation. Feed quality declines rapidly if crops are held over for more than 10–14 days past the optimum harvest time, as dry matter yield is lost and the chopped material becomes difficult to compact, resulting in poor fermentation and ineffective silage. If harvest at the optimum time is delayed due to rain, it may be preferable to hold the crop for grain. At MLS 2.5 the milk line is halfway down the grain. This often coincides with the cob husk turning from green to white and the dying off of lower leaves.
Frosted Crops: After frost damage, the crop will generally have a higher moisture content than is apparent looking at the damaged leaves. Leaves usually constitute 15% of the total dry matter; the remainder of the plant still retains moisture. Frosted corn must be allowed to dry to at least 30% DM.
When frost occurs early in grain fill, the moisture content will be too high for immediate harvest and ensiling and could either be cut and fed as green chop or left standing to dry down. Where high field losses are expected during dry down, a silage additive such as hay or grain could be incorporated with the harvested material prior to ensiling to boost fermentation. When frosts occur close to the intended time of harvest, the crop should be ensiled as soon as possible as leaf loss is likely to be greater and can reduce yield.
Drought-stressed Crops: The effect drought has on yield and forage quality will depend on the timing and severity of the moisture stress. Drought stressed corn can be harvested at a DM content of 30–40%. When a crop grown with high nitrogen inputs becomes droughtstressed, there may be the risk of nitrate poisoning if the crop is grazed or fed as green chop. Ensiling will reduce this risk as nitrate concentrations fall by 40–60% during the first 3–4 weeks of storage. Harvest should be delayed while plants have green leaf if there is a chance of rain.
Cutting height: Nominating an optimum cutting height is difficult due to variations in hybrids and growing conditions. The lower the cutting height, the higher the dry matter yield. However higher cutting heights increase silage quality by increasing the proportion of grain in the chop. Raising the cutting height from 15 cm to 45 cm would reduce yield by 15% and raise digestibility by 2%. The potential for the remaining stubble to assist or hinder the establishment of the next crop in the field should also be considered when nominating a cutting height.
Chop Length: Calibrate machines and aim for an actual chop length of 10–15 mm. Very fine chopping will crack more grain but increase power requirements. If harvesting is delayed (DM >38%) the chop length should be set as fine as possible to aid effective compaction. If forced to harvest early (DM <28%) a longer chop length of 15–20 mm will aid compaction. However harvesting at low DM is not advised as poor fermentation and unacceptable effluent losses can result.
Harvest Timing: Most end users require grain moisture content at 12–14%, with 12% being optimal for storage on-farm. As grain reaches physiological maturity, moisture content is usually 28–34%, which requires significant drying down. Natural dry down is possible until early May, depending on location. Corn can dry at a rate of 0.5–1.0% each day in suitable weather conditions. Once conditions become cool, consideration should be given to harvesting crops at 16–18% moisture content and artificially drying to below 14%. Crops can be left to stand over winter for natural drying to resume in the spring, but this increases the risk of mycotoxin contamination. With access to drying facilities, harvest usually commences at 18% grain moisture content. Most harvesters perform best; losing and damaging less grain, when moisture content is between 18 and 24%. Aeration equipment is not sufficient to dry corn grain.