A well-known American author once said that `a good system shortens the road to the goal’. In farming, our focus has become increasingly centred on implementing a `good system’ of integrated agronomic management to achieve crop productivity and profitability.
Although the winter cropping season is in its early stages in Southern Queensland, it isn’t too early for growers to begin planning for the upcoming summer crop.
Management over the next few months will have a direct influence on summer crop and varietal selection, soil moisture levels, plant back timeframes, pest/disease thresholds and yield.
One of the first measurements to take is the level of stored water. Knowing the level will help determine when to plant and what species.
If stored water is moderate it may pay to wait and store additional water or, alternatively, consider planting a shorter season crop with lower water requirements.
There are several other areas that will have a significant impact on crop productivity in the lead up to the summer season including weed control, disease management and soil nutrition, particularly in fallow country.
Levels of Vesicular Arbuscular Mycorrhizars (VAM) – fungi that attach to the root system, allowing the plant greater access to water and nutrients - are likely to be low in long fallow country and the application of phosphorus would be recommended.
Soil nutrition is one of the most important areas to target for crop productivity as nitrogen (N) deficiency is a major limiting factor when it comes to yield in crops like sorghum.
Soil testing is recommended to estimate levels of nutrients like N which can be affected by a range of factors such as residual N from previous crops, stubble decomposition and mineralisation.
Vigilance both in-crop and on fallow country is vitally important as early detection and control of weeds, pests and diseases will dictate the effectiveness of control treatments and alleviate problems once the summer crop planting window has opened.
Well managed weed control also plays a vital role in the production of profitable crops as weeds can have a significant impact on yield by competing for moisture, nutrients, space and light as well as harbouring diseases.
Most growers understand that weed control needs to be considered on a whole-of-farm basis, being particularly conscious of the cropping and chemical rotations where residual herbicides are applied.
Growers should determine what weed spectrum is present and from there determine what crop type to plant and what chemical treatment is required. Managing herbicide resistance should always be a leading priority as over use of group A and B chemicals will quickly lead to instances of herbicide resistance.
While residual herbicides are an integral part of successful integrated weed management programs, particularly in minimum and zero till operations, their use can hold important implications for the germination and vigour of successive crops and residue issues can affect crop and varietal selection.
Weed control also has important implications for the incidence of stubble pathogens. The focus in the Grains Research and Development Corporation (GRDC) northern region has been on management of crown rot and Root Lesion Nematodes (RLN) in winter cereals and the roles that rotational crops play such as the winter pulses. Research has shown that some of the major diseases are carried on weeds as well as crop residues.
Crop sequences affect the incidence and severity of major diseases of summer crops, especially those diseases which have several summer, and in some instances winter crop hosts such as RLN, Fusarium graminearum, Macrophomina phaseolina and the Sclerotinia species.
Additionally, consideration should be given to soil insects and their effect on eventual plant stand. Monitoring for their presence and the use of seed treatments is recommended.
Growers should consult their agronomists to determine the most appropriate soil, pest and disease management strategy for the coming months. They will also soon have access to a suite of summer crop information with next month’s launch of the GRDC GrowNotes for sorghum, faba beans and sunflower www.grdc.com.au/GrowNotes
Rob Taylor, GRDC Northern Region Panellist, Macalister
0427 622 203
Sarah Jeffrey, Senior Consultant Cox Inall Communications