Yield records and crop breeding strategies: reflections on the past and future perspectives

Every farmer has heard the rumours of their neighbors’ exceptionally high yields come harvest time and has learned to digest these rumours critically and skeptically. However, this year the rumours happened to be true! Statistics Canada has recently announced that this past year Quebec’s corn growers saw their biggest yields yet, weighing in at an average of 10.6 tonnes per hectare (Ménard, 2016). Amidst the excitement we may experience in the face of this agronomic achievement, it is important to take a step back and reflect on the conditions that have led us to reach these exceptional yields. Additionally, we should take the time to wonder what will be the future conditions that will drive crop improvement for years to come.

The first important thing to note is that there is not only one single driving factor that has led to these increases in yields. On the contrary, it has been a cumulative effort across multiple disciplines that has led to these significant yield performances. In fact, increased fertilizer use, more efficient chemical pesticides, large mechanical equipment and improved cultural practices such as earlier planting and narrower rows have all been attributed to some degree to being a contributor to these yield increases (Troyer and Good, 2008). However, there is one factor that seems to play a slightly more important role than some of the others. In fact, genetic improvements to corn crops have been estimated to be the cause of approximately 51% of yield increases in some regions (Qin et al., 2016).

One of the main reasons plant breeding has had such a large effect on yields is the result of breeding for increasing plant density tolerance (Qin et al., 2016). Plant density tolerance encompasses a large amount of traits that help plants in situations of high plant competition. These traits could include drought tolerance, hybrid vigour and resistance to high pest pressure. Instilling plants with these traits ensures hardy plants that will be resistant to a multitude of conditions. This is of vital importance, since in order to obtain the desired high yields at the end of the season, the plant must not only survive until the end of the season, but produce enough biomass to obtain the high yields we are looking for.

The final question is: are these increases in yields sustainable? Can we expect to see yields like this ten or twenty years into the future? Luckily for us, traits that allow plants to be tolerant to high densities also happen to make them more resilient in the face of uncertain climatic conditions. With climate change on the horizon, this is something that should not be overlooked. Nonetheless, it is also important for us to always be looking for other areas where we can be improving not only our plant breeding but also our general agronomic practices. This is especially important as we do not know today what our goals will be in the future. Perhaps in the coming years, the success of our crops will not be measured by the yields we obtain, but rather we will evaluate our performance based on our ability to produce high quality crops using low resources. In such cases, perhaps we would measure soil health or soil water quality as indicators of our performance. Whatever the future may hold, it is certain to be a challenge for the agricultural industry as a whole. However, our shared knowledge and ever improving technologies hold a lot of promise for us.

 

Ménard, M. 2016. Récolte record de maïs au Québec. La Terre de Chez Nous.

Qin, X., Feng, F., Li, Y., Xu, S., Siddique, K.H.M., and Liao, Y. 2016. Maize yield improvements in China: past trends and future directions. Plant Breeding. 135: 166-176.

Troyer, A.F. and Good, D. 2005. At last, another record corn crop. Journal of Crop Improvement. 14: 175-196.

3 responses to “Yield records and crop breeding strategies: reflections on the past and future perspectives”

  1. charlottebourgetrousseau says:

    A very well-written piece! As a start, I really liked your catchy introduction that really got me interested in reading the rest of your text. I liked how you invite your reader to take a step back and reflect on the various factors that may be played a part in the exceptional yields. You really set the table for your following analysis. When you discuss how instilling plants with specific traits make the plant more resistant to environmental conditions, I would have like to read about what were the actual conditions in the summer of 2016. Was it dry? Hot? What were the plant traits that helped them specifically last year to achieve such good yields? Also, when you discuss how traits that allow plants to be tolerant to high densities make them more resilient as well, it would have been nice to have a concrete example here to illustrate your point. I particularly liked how you later on broadened up your analysis with your take on sustainability and agronomic practices. Your article was interesting and you definitely came off as a respectable, reliable source of information.

  2. Stéphanie Bélanger-Naud says:

    Très bon article. La problématique est très bien expliquée et il est facile de comprendre l’effet contradictoire des producteurs face à leur désir de toujours vouloir des rendements de plus en plus élevés. En effet, la majorité des producteurs aujourd’hui évaluent leurs performances par leurs rendements au champ. Par contre, ceci peut avoir des répercussions sur l’environnement et la durabilité de notre agriculture, ce qui a très bien été expliqué dans l’article. La tendance actuelle est à l’agriculture durable, et ce n’est pas en atteignant les plus hauts rendements que nous allons arriver à nourrir le monde; au contraire nous risquons plus de dégrader nos sols et d’épuiser nos ressources si elles ne sont pas bien gérées.
    Par contre, il est aussi important de considérer l’aspect économique de ces rendements record, ce qui n’a pas été couvert dans cet article, puisque l’objectif des producteurs ne devrait pas être d’atteindre les plus hauts rendements, mais bien d’être le plus rentable possible. C’est une chose d’avoir de bons rendements, mais à quel coût? Il serait intéressant de faire une recherche sur la rentabilité de ces rendements record pour les producteurs, autre que le prestige d’avoir eu le meilleur rendement de leur région.

  3. Julie Major says:

    Good intro, draws attention. The reference by Qin et al. applies to China…I could see how the results would apply more broadly as well, but I bet similar papers have been published with a north-American focus? You mention hybrid vigor as a trait…that’s not really accurate in my view. I enjoyed the outlook into the future, and the discussion of what our objectives might be then…

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