A method for maize hybrids zoning

The article proposes a method for maize hybrids zoning. The theoretically expected yield for each hybrid from each location is calculated according to the following formula: Xt = a1 +a2-a3 +(PC1g x PC1e ). When the theoretical yield of a certain hybrid exceeds the actual yield at a given location, it can be grown to the advantage of that region, as well as the reverse version. An example is attached with calculated theoretical yields of 22 early (FAO 300-400) and 45 mid-early hybrids (FAO 400-500), as a part of the ecological variety testing of Maize Research Institute – Knezha at four locations (Knezha, Pavlikeni, Russe, Pazardzhik) in 2018. The year was chosen as representative for normal maize cultivation, after survey of a twenty-years’ test (ESO) of the Institute’s hybrids (2001-2020). The data analysis shows the following results: In FAO 300-400 group, the most suitable cultivation location is Russe with 13 hybrids (59.0% of all tested); followed by Knezha with 12 hybrids (54.5%); and Pavlikeni and Pazardzhik with 10 hybrids each (45.5%). In FAO (400-500) group the most suitable location is Pavlikeni with 27 hybrids (60.0%); Knezha and Russe with 23 hybrids each (51.1 %); and Pazardzhik – 21 hybrids (46.6%). The proposed method for hybrids zoning creates conditions for a more objective assessment of the places (locations) for priority cultivation of the varieties. The method is applicable to all field crops.