Evaluation of year effect on the yield in maize (Zea mays L)

The year effect on the yield in maize was tested on hybrid Pioneer 3732 SC using its 14-year yield series. The years were characterized by climatic parameters. From the precipitation values, the precipitation fallen during the period from the harvest of forecrop till the sowing of maize (winter half year) and fallen during the vegetation period were involved in analysis, as well as from the temperature values the monthly average temperatures during the vegetation period and the average temperature of the vegetation period. The dependent variables tested were the kernel yields of treatments without and with (120 kg Na/ha) fertilization. Based on the correlation matrix of the factors tested,it was stated that there was a weak negative correlation between precipitation during vegetation period and the monthly average temperatures, and betwen the average temperature of vegetation period and the kernel yield. While the precipitation fallen in the period from harvesting of forecrop till sowing, and during the vegetation period showed a positive correlation with the kernel yield. Based on the results of fertilization treatments, each millimetre of precipitation fallen during the winter half year resulted in 29 kg/ha kernel yield, during the vegetation period in 18 kg/ha, on an average 23 kg/ha kernel yield. This means for each precipitation millimetre 39,8 kg/ha total dry-matter, considering 15% kernel moisture- content and 50% harvest index. Consequently, on the average during the 14 years 251 g precipitation was available to produce 1 g dry matter.