By David Jones, CropNuts Broad Acre Agronomist
- This week I take a look at wheat varieties in anticipation of planting
- Our latest trials results highlight importance of Nitrogen and Sulphur in Canola
Still a solid variety. First registered in 2009, Robin is never going to set the world alight but it has one key attribute; consistency. Robin yields well across a range of environments. Provided Rust can be managed with late T3 and T4 fungicides this is still a variety worth growing but it is becoming out classed.
The poor Septoria resistance was very evident last year, and I would suggest that an SDHI fungicide is a must in areas such as Timau or Eldoret. Grain quality is not the best, nor the worst.
Not the most prolific tillering variety, so consider a small dose of early nitrogen to promote tiller numbers, especially on wide row spacings over 25cm (10”).
This is still the most popular variety in Kenya, with the lion’s share of the wheat area in the North Rift. Although it is still very good on Stem Rust it is weak strawed so prone to lodging. In my opinion this limits the potential of any variety; lodged crops do not yield.
The favoured variety in Timau, Kwale has stood the test of time. Watch Yellow Rust in cool, wet periods when it is at Flag Leaf stage especially. Solid on Septoria and rarely grown in Stem Rust areas, the milling quality is good and the variety is unlikely to lodge.
A slow variety to mature, but arguably deals with dry periods better than Njoro 2 and Robin.
Hawk is noticeably earlier maturity than the likes of Kwale and Njoro 2 but still offers very high yield potential. It tends to be slightly taller than Robin but still has good lodging resistance.
Unless the crop is severely stressed the Stem Rust resistance is very good, and our trials suggest the variety has a low response to fungicides in most situations. Grain quality is reasonable.
The variety can tiller excessively; when growing Hawk for the first time consider the seed rate carefully and avoid high doses of early nitrogen.
Very good quality white grain that is sought after by millers. Specific weight in my experience is perhaps slightly lower than others but not significantly.
Like Hawk, Korongo is stiff strawed and resistant to Stem Rust in all but the highest pressure situations. I have seen more leaf trapping from late graminicide applications in this variety than many others, so exercise caution when applying products like Sekator and Attribute.
Tillers well but benefits from fairly stiff straw.
A slightly shorter season wheat with correspondingly lower yields. Useful as an off-season crop, but yields of Korongo and Hawk are often higher. Tall Straw so requires careful nitrogen management.
The overall disease profile is good, similar to Hawk. Reports of sprouting in some years, so needs prioritising at harvest.
A later maturity, high yield potential wheat with a very competitive growth habit. Wren is susceptible to both Stem Rust and Yellow Rust in my opinion, although its leafy growth provides a degree of competition against weeds.
The consensus is that Wren is not particularly well adapted to very high altitude nor very warm environments, which limits its usefulness.
A tall, quicker variety similar to Eagle 10. Yields well in most situations but very susceptible to Fusarium (as photographed below last year near Nakuru) and poorer Stem Rust resistance. If you do grow this variety, high rates of prothioconazole containing fungicides are a must at T3 for Fusarium control.
Eldo Baraka and Muvuno
These are two very interesting new varieties from the University of Eldoret currently in our trials. The noticeable feature is the small heads but high tiller numbers and short, stiff straw which is a very different but useful attribute. It will be very interesting to see how these varieties will cope on 38cm (15”) rows given there markedly different growth habit.
We are awaiting yield results at present but the early maturity is encouraging.
Optimum Nitrogen and Sulphur doses in Canola
I have discussed the importance of getting nitrogen and sulphur right in canola several times in THINK AGRONOMY articles; too little and you lose yield, too much and money is wasted. And the wrong amount of one of the nutrients can compromise the efficiency with which the other is used by the plant.
We have just completed the first of several trials looking at the optimum doses of N and S. This trial was located on pumice soil near Nakuru that showed 58 kg/ha of N available nitrogen and 17ppm of sulphur.
The results showed the response to increasing doses of nitrogen, but no response to Sulphur (the lowest rate had just 5 kg/ha of S) which was a surprise.
What is particularly interesting is that although the sulphur level in the soil was not particularly high, the high Organic Matter level of the site is likely to have released the nutrient to supply what was required by the crop.
A leaf tissue test taken at the 6 leaf stage did show that the plant had adequate sulphur available which we know can help decision making.
All of the trials sites have a treatment looking at timing of application too which is already very interesting; more to follow on that another week.
The full data and dose rates of nutrients are available to Agronomy Service clients, and we look forward to seeing the results from other areas of the country to hone our fertiliser recommendations on different soil types. The key lesson so far;
“If you don’t measure it (leaf and soil), you can’t manage it!”
Till next time!
David Jones is the Broad Acre Specialist at Crop Nutrition Laboratory Services Ltd. (CROPNUTS). David has a keen interest in soils and no till farming systems where he has undertaken work looking into weed levels and changes in soil structure, and has extensive experience in field trials and in the development of precision farming techniques. In his spare time he enjoys playing rugby.