engleski

The effect of high plant populations on maize biomass production in various growing seasons

Optimum plant population is very important factor for grain yield formation in maize (Zea mays L.) crop. Previous research indicated that higher than optimal plant populations decrease grain yields, but less information is available on the effect of high plant populations on maize biomass production. Therefore, the aim of this study was to investigate the effects of high plant populations on maize grain yields and aboveground biomass. Field experiments were conducted over two growing seasons in north-western Croatia under intensive production management. Maize hybrid PR39F58 was grown at recommended plant population for grain production (80.000 plants ha-1) and two high stand densities (100.000 and 120.000 plants ha-1). Growing season significantly affected grain yield and biomass responses to investigated plant populations. Under more favourable growing conditions of 2008, maize grain yields were larger by 3.07 Mg ha-1 (34, 4%), while biomass production increased by 3.42 Mg ha-1 (20, 7%) compared to the growing season of 2007. These higher grain yields in 2008 were primarily due to heavier 1000-kernel weight and increased harvest index. Plant population had no significant effect on maize yield in the growing season of 2007, although high plant populations were associated with a decrease in 1000-kernel weight and harvest index, as well as with more barren plants per ha. However, in the growing season of 2008, high plant populations had no impact on the number of barren plants, and consequently, the highest plant population significantly increased grain yields in comparison to recommended plant population. In contrast to grain yield responses, biomass production consistently increased with higher plant populations in both growing seasons. Biomass production at the highest plant population averaged 19.18 Mg ha-1, which was by 10, 7% larger than biomass produced at the recommended stand density for grain production. Our findings indicated that maize biomass production might be improved by using plant populations higher than recommended for grain production under rain-fed conditions of north-western Croatia.

maize; plant population; biomass; grain yield; harvest index

nije evidentirano