Choosing the right wheat variety is one of the most important steps to growing a profitable and reliable wheat crop. Disease resistance, yield, grain quality, sprouting risk, and many other factors should be taken into consideration so that the chances of achieving a high yield and Grade 1 quality with minimal risk and expenditure on inputs. We take a look at the characteristics of some popular varieties, and what to be aware of when growing them in order to give yourself the best chance of a successful crop.
One of the most consistent performers, and when looked after it is still probably the highest yielding variety – but only if looked after. Four fungicide sprays are always required because of the very poor Stem Rust resistance, and we have noticed this season that the variety appears to be breaking down to Yellow Rust too.
Generally, Robin is very stiff and does not produce many tillers so does not easily lodge, and grain quality is ok – specific weight is never the best but even with a week of rain at harvest the bushel weight does not drop significantly and Robin rarely sprouts.
A very high-yield potential variety but in the field it does tend to be less consistent than other varieties, something we have seen in trials too. Like Robin, Hawk has long since broken down to both Yellow Rust and Stem Rust so needs managing carefully. Grain quality is good and sprouting is rarely an issue, but the straw can often go weak in the mid-stem in a delayed, wet harvest.
A relatively fast, early maturing variety which is slightly stronger on Stem Rust than Robin and Hawk but very susceptible to Yellow Rust. Eagle 10 has produced some exceptionally good grain and tends not to sprout, but it does lodge badly so be careful not to plant at too high a seed rate.
A white grain wheat which brings with it excellent grain quality and bushel weight but sprouting risk. Do not grow this in a location where there is a risk of rain at harvest as it will punish you. Korongo does thrive in dry seasons and we have seen some of its best results in trials in droughts. Manage the Stem Rust, but also the Fusarium with a well-timed fungicide at early flowering and it does reward you. On strong, fertile shambas it can lodge so be careful of seed rate and topdressing.
A very high-yielding red wheat, but with serious Fusarium weakness and sprouting risk (it behaves more like a white wheat). Kasuku brings some excellent characteristics like lodging resistance and its yield is often similar to Robin. In a way, Robin and Kasuku compliment each other well as they have different strengths and weaknesses, allowing you to balance the risk on big areas of wheat.
Kasuku must be prioritised at harvest because of the sprouting risk, but also because the bushel weight falls far more quickly than other varieties in a wet season. We consider it to be moderately resistant to Stem Rust but moderately susceptible to Yellow Rust. High seed rates do tend to pay off with Kasuku.
Moderately high yields and reasonable grain quality, fairly weak straw but moderately resistant to Stem Rust. Continues to be a very popular variety for its consistency and ease of management.
A variety of which nobody seems to know the origins, but extremely popular and understandably so. Mwera combines arguably the best all-round disease resistance with some of the highest yields, proving in trials to be on a similar level to Robin and Kasuku.
The ease of managing this variety (tall but stiff straw, no sprouting) makes this a very appealing variety to farmers. The downside is the low vigour and tillering which makes it a relatively uncompetitive variety against grassweeds. Bushel weight tends to be around average.
A relatively tall and late red wheat. A solid all-round performer with average bushel weight, very good Stem Rust, Yellow Rust, Fusarium and Septoria resistance, and standing ability. Its only weakness is yield, which has been 9% lower than Robin over nine trials now.
Moderate yields but very good disease resistance and low sprouting. Another solid variety, let down by generally low specific weights in trials.
A new white wheat from KALRO. This is quite an exciting variety as it combines excellent grain quality with improved standing ability and much better all-round disease resistance than other white wheats such as Korongo or Brambling.
Whilst most farmers are very proficient at planting larger grain seeds such as maize and beans, and even wheat and barley, very small grains such as canola often require a different approach and mindset. Introducing a break-crop into a farm that has grown years of wheat, barley or maize has enormous benefits to profitability, but the crop itself has to make money and this starts with good planning and establishment.
Firstly, the planter should be well maintained; meter rollers all present and in good order, chains oiled and greased, bearings checked and replaced if necessary, and all hoses tightly fixed. Springs and coulter tension to place the seeds in the ground should be set in line with the manufacturer’s handbook, and practice runs with seed and fertiliser carried out to check the depth placement – ideally 1-2cm for canola.
Top tip – canola seeds can be hard to see to check the depth, so put some light wheat grains in the bottom of the hopper on a trial-run so that you can see the depth (they need to be light grains or cleanings so that you can see if they are blowing out of the furrow if the fan speed is too high.
Aim for a fine, level, and firm but not compact seedbed. The planter should be able to cover almost all of the seeds and not be bouncing over un-even bumps and holes. Remember that the planter will do some cultivation, but aim for the largest clod of soil to be the size of the palm of your hand, and some fine soil surrounding the seed. Too fine leads to capping and erosion.
Once calibrated – typically around 2-4 kg/ha for canola – the depth should be regularly checked particularly as soil types change across a field which can lead to the planter going too deep or shallow.
If you are dry planting, check the seed is into dry soil. If you are confident that there is enough moisture, try to keep it by rolling afterwards with a flat roll or a ring roller (this improves seed-to-soil contact too, helping rapid and even germination and will improve the effectiveness of herbicides).
As a general but very good rule, 8kph is as fast as you want to go in most cultivated soils – the more the machine bounces the less seed will actually get to where you want it! If you are driving at 6kph and the planter is still blowing seed out of the ground, you probably need to do another cultivation with the harrows to level the soil.
Whilst checking for seed depth this is also a great time to scout for Cutworms which can cut the crop off as it tries to emerge. You rarely have much time to react to Cutworm, so many farmers base the decision to spray based on field history and past experience, applying a deltamethrin or lambda-cyhalothrin at or before planting.
It was once said that “A wise person gets more from their enemies than a fool from their friends”. If we consider Brome as our enemy and what it is telling us about our farming system, we have a lot to learn.
There are an awful lot of farms that are struggling to grow a crop of wheat or barley because of Brome – and Ryegrass – outcompeting the crop. The options to control these to try and improve the yield and profitability of the crop fall into three categories, but there is, frankly very little good news in the first two.
Herbicides remain the most obvious, short-term answer for doing something to reduce grass weeds and their effect on the crop. Pendimethalin is the most obvious, and while it does not appear to do a great deal it still reliably gives around 50% control of Brome and Ryegrass (look at any spray miss and count the seed heads).
Flufenacet, whilst temporarily unavailable in Kenya does add significantly to pendimethalin for Ryegrass (it doesn’t do much on Brome) but needs cool and damp conditions to thrive. Certainly not a product for areas below around 2,200m.
Triallate was very effective, once registered in Kenya as Avadex, and tends to be very effective against numerous Brome species in other parts of the world. I wonder if anyone will try to re-register the product here as it is highly effective.
Post-emergence options are limited, not least in barley where no options exist. Pyroxsulam has almost completely stopped working on most Brome populations that I see, Propoxycarbazone is very variable in its control and can cause significant leaf trapping and stunting
Iodosulfuron (+/- mesosulfuron) is occasionally effective, but once again resistance is very widespread as is the case with all Group B grass weed herbicides. Do not forget that these products are in fact very good growth regulators on wheat and do a lot of harm to the crop; if they are not controlling the weeds then they are doing more harm than good by suppressing the crop.
Non-chemical in-crop measures are limited to creating a more competitive crop with narrow rows and higher seed rates – which brings other problems such as lodging – or going to the other extreme and planting on wide rows to allow an inter-row mechanical weeder. This takes a lot of skill and patience, as well as dry weather, and is still of limited usefulness.
Delaying planting will help by allowing a flush of Brome which can be sprayed off with glyphosate before planting. This will inevitably compromise the crop however, as it will be grain filling later in dryer and warmer conditions, so with high Brome populations this is only really practical if you can switch from a long-rains to a short rains season. Ultimately the answer lies in crop rotation, which we will discuss in future newsletter.
Till next time,
Think Agronomy is brought to you by Cropnuts and the Centre of Excellence for Crop Rotation. We share the same vision for sustainable, dryland farming across Africa, and Think Agronomy is our independent voice to promote profitable, climate-resilient farming through better management of soil health, systems-based agronomy, crop diversification, and farm mechanization.
David is an independent agronomist in Kenya and a member of the Association of Independent Crop Consultants. David gives independent advice based on scientific trials and experience. Currently works with the Centre of Excellence for Crop Rotation.
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