INDIVIDUAL VARIABILITY OF MAIZE EAR YIELD ON SANDY SOIL IN FIELD-EXPERIMENT

In a long-term maize fertilization experiment set up on calcareous, sa ndy soil in the mid-region of rivers Danube and Tisza, the individual variability of the hybrid NK-PX MSC 20 (hybrid of Martonvasar) was stu died in the respect of ear mass quantity Twenty ears were taken and in dividually measured from each plot in the five series, six treatments (phi K-240, N120P60K240, N120P120K240, N240P60K240, N240P120K240). Bas ed on the tests and evaluations, the results can be summarized as foll ows: The differences between the repetition (soil heterogenity) appear ed also in the individual ear masses. On the average of the fertilizat ion treatments the individual ear yield varied in the repetitions betw een 184 grams and 260 grams. Due to the soil heterogenity between the repetitions, there were significant differences both in fertilization treatments and in the average of those. The standard deviations charac terizing the individual variability, showed inhomogenity, significant differences between the repetitions and soils, respectively. The ferti lization raised significantly the individual ear yield mass from 120 g to 260 grams. The standard deviations, the individual variability of ear masses showed provable deviations on the effect of fertilization. Its extent proved to be the smallest at control and at good supply lev el. The ratio of maximum and minimum ear masses was at the individual measurements within the extreme values of 1:2,5 and 1:6,7. The individ ual variability of a plant (in present case the maize ear mass) is a g enetical basis that may be influenced in cartain limits by external fa ctors (e.g soil) and human activity (e.g. fertilization). Its extent i n the experiment can be altered by increasing the replications and ind ividual number of samplings.