Grain Sorghum Frequently Asked questions
What hybrid should I grow?
Pioneer® Seeds Australia has the most extensive range of proven sorghum hybrids in all regions and growing environments. To determine the best grain sorghum hybrid for your growing environment click below.
Which maturity hybrid should I grow?
As a general rule, medium-late maturing sorghums are higher yielding - particularly under conditions of good moisture and nutrients. However, as moisture conditions become more limiting, the earlier-maturing hybrids will have greater yield reliability. Hybrids with medium to medium-quick maturity are likely to flower in 60-65 days when sown early, and 50-55 days when sown later under higher temperatures. Slower-maturing hybrids will generally give higher yields than quick-maturing hybrids when moisture and nutrients are not limiting. When moisture is limiting, the quicker-maturing grain sorghum hybrids may offer better growing reliability. The choice of maturity will therefore depend on conditions at planting (e.g. soil type, stored water) and attitude of the grower to risk.
What is the midge rating system?
All commercial sorghum hybrids are tested by DEEDI with support from GRDC and are assigned official midge resistant (MR) ratings from 1-7. Ratings range from 1 (no resistance) to 8+ (practical field immunity)
What height hybrid should i be growing?
Taller varieties are often higher-yielding but may be more prone to lodging. Hybrids sold by Pioneer® Seeds Australia are not excessively tall so height is not a major consideration.
What head type is desirable?
Open-headed hybrids are desirable in the more humid regions and in areas where sorghum caterpillars are expected to be a problem.
Other diseases (e.g. head smut, leaf blight, grey leaf spot, anthracnose and Johnson grass mosaic virus) can have an effect on yield. Head smut is more likely to be a problem in early planted crops on the Darling Downs and northern New South Wales. The other diseases are more likely to cause problems in later planted crops.
What impact does leaf rust have?
Leaf rust can have a significant effect on grain yield, plant death and lodging so rust-resistant grain sorghum hybrids should be used for later plantings when rust infection can be severe. Early sorghum plantings are rarely affected by the disease.
Other diseases (e.g. head smut, leaf blight, grey leaf spot, anthracnose and Johnson grass mosaic virus) can have an affect on yield. Head smut is more likely to be a problem in early planted crops on the Darling Downs and northern New South Wales. The other diseases are more likely to cause problems in later planted crops.
Is there a benefit in selecting hybrids that have better resistance to ergot?
There are no known clear varietal differences for ergot resistance in commercial varieties sown at recommended times. However, there are some hybrids that produce poor quantities of pollen (and are therefore more susceptible to the disease) if flowering during cool conditions. There is a potential benefit in selecting quicker, low-tillering varieties that are not severely affected by cool conditions if sown late.
Is grain colour important?
It is well established that the colour of the pericarp (outer coat of the grain) - whether it is white, cream, red or bronze - has no effect on the feed value of grain sorghum. White, cream and yellow grains are more susceptible to weathering. Such hybrids should not be planted in the humid coastal regions.
The colour of the grain endosperm, white (clear), heteroyellow (one parent yellow endosperm) or yellow, may have an effect on feed value but world literature is not conclusive on this point.
Is standability (lodging resistance) important?
Lodging is a major problem in many grain sorghum producing areas. The most common cause is moisture stress during grain filling, which causes plant death and may be associated with the development of fungal stalk rots.
Lodging occurs frequently enough on most soils to require the use of hybrids with lodging resistance. Only on deep clay soils with good water reserves or under full irrigation should sorghum hybrids without lodging resistance be considered.
Hybrids with 'staygreen' will improve lodging resistance.
What is staygreen?
'Staygreen' is a plant characteristic that results in less plant death (so less lodging) caused by moisture stress during grain filling. 'Staygreen' also increases yield and grain size under drought conditions
When should I be planting sorghum?
Planting time usually varies from September to January, depending on planting rains and soil temperature early in the season.
Crop failures are likely in central and southern regions from very early plantings in August-September and very late plantings in February-March due to cold conditions. Planting at the early end of the range is preferred to avoid midge problems and to allow the option to double-crop a winter crop if sufficient rainfall is received.
Best yields usually follow October plantings. These crops usually miss insect damage by midge. With late crops, midge will need to be managed by selecting midge-resistant sorghum hybrids and/or with the use of insecticide sprays. Generally, planting mid-season sorghum hybrids is advisable as these hybrids are the best overall performers.
Sorghum ergot disease risk can also be minimised by planting from mid-October to mid-January in southern Queensland so that flowering occurs between mid-December and mid-March, when the probability of ergot developing in sorghum florets is lowest. See sorghum pests and diseases for more detail on this disease and its management.
In Central Queensland, use quick-maturing sorghum hybrids for rain-grown spring plantings. For the main summer planting (late December to mid-February), plant slow-maturing hybrids early and the quicker-maturing hybrids later to improve yield reliability.
What soil temperatures should I be aiming for?
Aim for 15°C and rising. At 15°C sorghum takes 11-14 days to emerge. At 17°C it takes only 7-10 days.
What is the approximate number of seeds/kg?
26,000 to 34,000 (refer to bag label for an exact count).
What is the germination %?
Average 90%. Minimum prescribed 85%. Refer to bag label for the exact figure.
What plant populations should i use?
See individual hybrid product pages on this website for all recommendations.
What seed placement depth should i be using?
50-75 mm into moisture.
It is only necessary to plant seed deep enough to give it moisture to germinate and allow its roots to grow down through moist soil into subsoil moisture, ahead of the drying front.
Is seed treatment needed?
Herbicides containing the active ingredient metolachlor (viz, Dual, Dual Gold, Primextra and Primextra Gold) can seriously damage sorghum plants. When there is need to use these herbicides for in-crop weed control, it is necessary to saften the sorghum seed by pre-plant seed treatment with the seed-saftener, Concep II. Check labels on all seed treatment products for recommended treatment sequences and procedures.
What hybrids are suitable for zero tillage?
All Pioneer® brand hybrids are suitable for zero tillage.
If you’re unsure of any aspect of how to grow sorghum in your cropping environment, contact your local Pioneer® Seeds Australia representative.