Maize is a crop which responds well to careful management and it is also influenced by weather conditions during the entire growing season, explains Dr Simon Pope, Crop Protection Manager for Wynnstay.
Dr Simon Pope, Wynnstay crop protection manager, is urging growers to give some careful thought to the nutrition of their maize crops, following days of torrential rainfall in June, to ensure a maximum return on investment in 2019’s harvest.
Growers are advised to re-think their cereal agronomy strategies and use of seed treatments, to ensure the best possible establishment and vigour of crops this autumn, as a result of the neonicotinoid bans.
Growing maize under film could provide producers with benefits worth more than £200 per hectare (ha) compared to conventional methods. According to Wynnstay dairy specialist Mark Price, the improved nutritional value of maize silage grown under film, outweighs the increased growing costs.
When growing high yielding varieties, often other agronomic features such as disease resistance are sometimes overlooked. The fungicides at our disposal today are capable of producing extremely good results, but it is important to apply as much thought to the fungicide programme and timings as to the choice of product, to achieve optimum yield potential.
Over recent years, the emphasis has moved away from reactive fungicide applications to treat visible disease in the crop, and more towards a strategy where prevention is better than cure. To achieve this, the fungicides must be applied at the correct time and early in the development of the disease, or even before infection occurs, with timing influenced by growth stage, weather and the variety’s disease resistance.
Disease resistance The AHDB Recommended List expresses disease ratings on a scale of 1 to 9, with 1 being poor resistance to the disease and 9 being good. Any variety with a resistance rating for a particular pathogen of 7 or below would require careful attention and a strategic approach to disease control.
Out of all the winter wheat varieties on the 2018/19 AHDB Recommended List, only one variety has a septoria tritici rating higher than 7. Therefore, in the wetter west every variety must be considered at risk from septoria infection and all require a robust fungicide programme.
For those varieties with a septoria rating of mid-6 and above,a robust fungicide strategy is still needed, but the timings of the applications can be a little more flexible.
When modern SDHI chemistry is employed for septoria control, supported by an appropriate dose of triazole, we can achieve very acceptable levels of control of the other important diseases at the same time. However, for a variety such as RGT Gravity, which has a mildew rating of 4, an additional specific mildewicide will probably be required.
Choosing the right herbicide programme
With all aspects of agronomy, there is rarely a ‘one size fits all’ solution and flexibility in approach is essential. When planning herbicide programmes there are two key timings to be considered; pre-emergence and post-emergence of the crop and weeds.
The most effective herbicide programmes usually commence with a planned pre-em application of residual herbicide. Depending on the situation and the weed spectrum, if an effective pre-em herbicide is applied, additional weed control later in the season may not be required, therefore saving both time and money.
It is important to work with your agronomist or specialist to develop a herbicide strategy that takes into account soil type, drilling date and the expected weed spectrum.
Application options In winter cereals, one pass with a pre-em containing actives such as flufenacet, diflufenican, flurtamone or pendimethalin will often do a very good job in controlling a broad spectrum of broad-leaved weeds and annual meadow grass, with a second pass sometimes needed to control spring germinating species.
For more problematic weeds such as blackgrass or brome, there should be a pre-planned herbicide strategy in place which adopts the principle of ‘stacking’ several different active ingredients, eachwith a different mode of action. In addition to ‘stacking’ chemistry, a split-timed approach with pre-em and peri-em applications will help to extend the period of residual herbicide activity into the autumn.
For help with planning a cost-effective herbicide strategy, and advice on the best fungicides for the varieties you’re growing, contact your local Wynnstay agronomist or arable specialist to discuss options and timings.
With maize planting only a few weeks away, it’s an ideal time to share some of my top tips for crops to get off to the best possible start.
Although it may seem an obvious starting point, ensuring maize seed is ordered well in advance of planting is more important than ever - particularly with the uncertain future of Mesurol raising a question mark over the availability of treated seed as we near drilling.
Once seed is purchased, the next focus area should be the field in which the maize will be planted.
If the fields haven’t had a soil analysis in the last four years, then now is the time to take some samples and establish the nutritional status of the soil.
Soil pH should be as close as possible to 6.5, and if below this level an application of fast-acting Calcifert should be considered to correct the pH and avoid impacting this season’s crop.
Growers should keep a record of how much slurry or muck has been applied, when considering what additional inputs may be required.
Knowing the N, P and K available from applications of FYM or slurry will allow accurate levels of fertiliser to be applied to meet crop requirements.”
The Wynnstay team of agronomists can help to prepare a nutrient management plan for the season ahead, as well as advise on pre-emergence herbicide programmes. A target drilling date should be established, with the aim of sowing as early as conditions allow.
The base temperature for maize is 10 ͦC so I advise aiming to drill around 20th April, provided that soil and weather conditions allow.
Finally, I would also suggest planning the seed rate ahead of planting, taking into account the individual variety that is being drilled.
Reducing the seed rate can improve crop maturity and boost starch yield but can also impact overall dry matter yields. With modern, early maturing, high yielding varieties such as Reason from Limagrain for example, there should be little need to reduce the seed rate below 110,000 seeds/ha (45,000 seeds/acre).
Maize is a costly crop to grow, both financially and from a management perspective, but it has an extremely high value. Planning ahead and paying attention to detail at this early stage in the season, will pay dividends come harvest.
Click here to find your local Wynnstay specialist or call 01939 210555 for more information. Alterantively, view the maize seed range here.