b"Achieving maximized and stable yield for farmers is also the corn-breeding goal for Corteva Agriscience. To achieve this under ever-changing environmental conditions, we have to actively phenotype and select for resiliency to biotic and abiotic stress like pests, disease, temperature and reduced precipitation, says Heffner. These efforts also enable our goal of continuously improving agri-culture's environmental footprint by increasing the input-to-output ratio; that is: achieving more with less.Lideas paramount breeding targets are also overall yield and its stability, with a priority on hybrids that are better able to tolerate heat and drought stress. Bettinger adds that for silage, digestibility is a key target that is also taken into factor. At DSP, silage and grain yield, as well as silage quality in terms of digestible organic matter and starch, are dominant breed-ing goals. However, Camp explains that there is a special challenge for maize production (and therefore maize breeding) in Switzerland is its very restricted allowable nitrogen application regime. On average, a Swiss farmer will not apply more than 130 kg of nitrogen per hectare, he says. The genetic yield potential of modern maize hybrids cannot be fully exploited by this restriction. Therefore, the capacity to transform nitrogen as efficiently as possible into yield is probably more important here than in other markets. ANNUAL YIELD INCREASEAll companies report achieving an annual corn yield increase of about one per cent or a little higher, due to genetics but also advances in growing practices. Bettinger adds that over the last decade, the highest yield increases were in the early grain maturities with the proliferation of dent germplasm.A yield of 17.0-17.5 t/ha for maize is no longer a record in Ukraine. Of course, the best genetics in the best hybrid choice for a par-Photo: Company MAIS. ticular soil type and growing region will offer the greatest potential of high yields, but Knczl says it goes beyond yield. Wise use of genetics is based on a thorough knowledge of ecological factors, he says. Which, once fully mapped, can be applied in a complex way to all elements of cultivation technology to meet the crops growing demands whilst using fewer resources. On the subject of resources, Beaufum notes that the commod-ity price of corn in any given year can affect the amount of fertilizer and other inputs a farmer will use, which in turn has a large impact on the final yield thats achieved. High moisture growing areas of Europe not surprisingly pro-duce the highest yields. Halechko notes that in high moisture areas in Ukraine, a yield of 17.0-17.5 t/ha for maize is no longer a record. But of course, not all areas have had steady and plentiful rain over the last few years, and yields have reflected this.YEARS TO MARKET, NOW AND IN FUTUREThough annual yield gain for corn is similarly reported to be around one per cent by the main European corn-breeding firms, there is a range in the years needed to develop and release new corn hybrids. The time required is highly variable, says Beaufum. Breeding cycles are around five years, whilst certain traits can take longer. At DSP, Camp reports that it takes seven to eight years from the first selfing for new inbred line development to the commercial launch of a successfully registered hybrid. For Corteva, it takes at least seven years before a new hybrid is ready to market after the company first conducts adequate in-field phenotyping and seed volume increases to deliver a reliable seed supply at scale. However, Heffner looks to the future and points out that those timelines may change: Advances in breeding like genomic selec-tion continue to reshape our strategies and accelerate breeding cycle times.In Parts 2 and 3 of this corn breeding series, we will look at how new technologies are enabling corn breeding to speed up and have more impact on corn production, as well as germplasm sourc-Jean-Bruno Beaufum ing, breeding for disease and pest protection, market alignment strategies, and what corn will look like 20 years from now. 8ISEED WORLD EUROPEISEEDWORLD.COM/EUROPE"