Top Tips for choosing your variety
Going out and talking with farmers who use similar management techniques and with similar soils is often is a good first step and can help you make a head start, says the former Nuffield scholar who grows corn for ethanol, soya beans for oil and a good food/flour quality winter wheat for export.
Mr Vince says: “Comparing notes and discussing what worked favourably – and what didn’t work – gives you some useful insights.” GM-crops are now widely grown across Canada, and as Mr Vince grows only non-GM crops, he has to cast his net increasingly wide to find farming colleagues with similar systems to his.
Once he has a broad idea, he starts to work out the genetics and how well they may perform in the geography of his local area. Seed companies often have yield data on corn and soybeans from plots right across the country. Wheat, however, is a different story. Many growers still propagate their own seed-stock, so the seed companies invest less time on wheat as they will not get the same return on investment that they receive for other crops.
“This results in a lack of real data so you have to rely more on word of mouth,” says Mr Vince. Once decisions on genetics have been made, he brings a number of them back and starts on-farm trials to compare them with other varieties.
“We look at neutral ones to see how they perform against hybrids, and then using them as a benchmark to compare them with other hybrids.”
If they work well, he gradually increases exposure, building his own on-farm evaluations which give him reliable information to work from. “As you move to growing the variety across wider acreage, you get more data sets so you can see the net result over time.” This is then compared verbally with other farmers in his network to see if they are keeping pace with other varieties in similar environments; a five to ten per cent difference is perfectly acceptable, he says. “Soil varies farm to farm, and field to field, so collecting your own information is the best way of assessing a variety.”
Rainfall can also dictate varietal performance; so knowing the exact conditions and management systems can also help make the best informed decisions.
With his extensive knowledge of agronomy, Mr Vince emphasises the importance of varietal tolerance and resistance; an area where hybrids often shine.
Yields can be hard hit with a Phytophthora, a soil-borne fungus which causes root rot if a susceptible variety is grown. “We know we have this pathogen in the soil, so checking the variety you are looking at has the relevant resistance gene is crucial.” Other important yield-robbing pathogens include soybean cyst nematodes. The nematode infects the roots of soybean eating on the nitrogen-fixing nodules of the bean. Signs of infestation include chlorosis of the leaves and stems, root necrosis, poor root and shoot growth.
Wheat tends to be more susceptible to leaf diseases; stripe rust (also known as yellow rust) can play havoc with yields, with losses up to 25 per cent, says Mr Vince, who does not like to use fungicides, but recognises the need to control these pathogens. “When we can select for natural resistance it is a huge bonus.” But there are other risks too, so it is always better to grow a range of different varieties; weather is different from year to year, so a particular variety which performs very well one year, may not do so well in subsequent years.
Therefore, he looks for soybeans which perform in different row widths; with bush varieties preferring wider rows while the narrower ones prefer less space. “If you use a high seed-rate and water is restricted, you have paid a high price for the seed, but yields plummet.” He recommends, therefore, using lower rates such as 45,000 plants/ha for corn rather than the higher rate of 90,000 plants/ha. When on his Nuffield scholarship, he came across varieties of corn with the ability to grow two ears; when there was sufficient moisture available, there was enough to fill both ears, and, therefore a high yield per plant. In a dry year, one was dominant at
the expense of the other.
In many areas, the aesthetic beauty of the crop is also taken into consideration; but Mr Vince does not think this is at all important. “There is a perception that maize needs to be tall, but there are some very good hybrid varieties out there that are very short; at times tradition clouds judgement and we need to break away from this.”