Steady Genetic Progress, Accelerating Hybrid Renewal
Maize is one of the plants with the most evident genetic progress expression. Compared with other major crop plants around the world, it displays the most dynamic genetic progress.
Steady Genetic Progress, Accelerating Hybrid Renewal
Two interrelated characteristics account for that: maize’s hybrid-producing aptitude and its natural genetic variability, acquired by selection. Maize is also particularly adapted to – and often, a pioneer of – new breeding techniques. Lastly, its status as the first worldwide-grown crop plant justifies the breeders’ considerable investments and research efforts. Thus, companies invest an average 9 percent of their annual turnover in R&D, making the maize seed breeding & selection industry one of the most dynamically-innovative sectors.
Thanks to the quality of its land, its production environment, and its farmers’ high technical competence, France has become Europe’s “laboratory” in terms of new hybrid development. On a market where segmentation and (both grain and feed) hybrid turnover are particularly strong, seed production must show considerable flexibility.
Due to its soil and climate diversity and its growers’ high professional level, the French maize industry is a flexible one and can handle planting a considerably wide range of hybrids. Thus, the country produces an average 1900 commercial hybrids every year.
France is therefore Europe’s main supplier of genetic diversity and contributes to a fine-tuned market segmentation, which provides the growers with a wide range of options enabling them to meet the specific requirements of their farms. Moreover, the maize seed market is characterized by a strong hybrid turnover, which is due to the plant’s hybrid-producing aptitude and to the producers’ growing interest in using the best hybrid breeding and genetic progress products, every year.
Yield and Consistency
These are the most obvious and easy indicators to measure genetic progress. Ever since the introduction of hybrid varieties into Europe in the 1950s, average maize yields have more than doubled – and the tendency carries on. This steady genetic progress reflects an average gain of 1,2 q/ha/year, which is apparent at all yield levels and has been trending upwards for more than 50 years. The improved productivity is coupled with greater yield consistency, resulting from the plants’ greater tolerance to weather factors, pests, and diseases.
Drought Stress Tolerance
For a long time, breeders have been focusing on improving maize’s tolerance to drought. The ongoing yield progress witnessed throughout the world – against the background of a stable maize area – is a case in point. Selection efforts have mostly focused on the flowering stage, which is particularly sensitive to drought and also a decisive stage in yield formation. Modern selection methods – which combine genomics and massive data processing following field observations made in numerous locations – should speed up the process even more. Lastly, the grower should keep in mind that yield improvement comes from a careful combination of seed potential and proper agronomic practices.
Precocity and vigor at the start
The development of European maize lineages (derived from maize plants that had acclimated to Europe since the 17th century) and their crossing with American lineages have made it possible to obtain earlier hybrids with better cold tolerance. Breeding very early hybrids has allowed maize to be grown in northern European areas previously known for their low climate. As a result of the global warming, since 2000, breeding work in Western Europe has been focused on producing hybrids that can be sown earlier, particularly along the Atlantic region. The method – known as the avoidance strategy – aims at helping the plants partly escape water deficits, which have become more and more pronounced at the end of the crop life cycles.
The strategy also allows one to “shift” certain sensitive crop stages away from pest attacks. On the other hand, it makes it critical for growers to choose more robust hybrids, that tolerate slower crop establishments in spring. This is why one cannot view earliness, avoidance, early vigour, and – of course – seed quality as separate concepts. The strategy may also be observed in countries with a continental climate such as the USA.
Disease and Pest Resistance
Maize is one of the crops that receives the fewest chemical treatments. This is due to its native tolerance to fungal diseases. Nevertheless, careful hybrid selection allows one to reduce the plant’s exposure to hazards such as Fusarium or Helminthosporium. The impact of other diseases or pests can be controlled efficiently by carefully choosing one’s hybrids and adjusting one’s agronomic strategies (tillage, sowing and harvesting dates, crop residue mulching, rotation, etc). In some cases, a good combination of hybrid choice and agronomic techniques can lead to highly-effective results (one may in that case speak of resistance), without resorting to phytosanitary products to control pests such as Ostrinia or Chrysomela that might be present or developing.