Comparison of growth and productivity of the low morphine poppy Papaver somniferum L. cv. Mieszko depending on the sowing date

A single-factor field experiment was conducted in 2008 and 2009. The aim of this study was to evaluate the low-morphine poppy cv. Mieszko which was sown at three different dates: I-early, II-optimal, III-delayed. The results of the experiment demonstrate that there is no difference between morphological traits at characteristic growth stages. Plants in the population varied in the number of poppy heads (from 1 to 6). Plant productivity in the crop depended on the sowing date and growing year. Sowing poppy at the early and optimal date allowed more productive individuals that produced poppy heads with a higher unit weight to be obtained in the crop population. The most productive plants in the crop formed 3 or more poppy heads per plant. The results of experiment proved that the date of poppy sowing had a significant effect on plant growth and, as a consequence, on yield, in spite of the fact that it is a no-cost agrotechnical factor. For utilitarian reasons, efforts should be made to do sowing at the optimal time