engleski

Grain yield and quality of maize hybrids grown on acid soil

Acid soils are limiting factor for achieving high maize yield, along with other factors such as soil fertility, genotype and growing season characteristics. The aim of this research was to evaluate the impact of soil acidity, genotype and growing season on the maize grain yield and quality in terms of protein, oil and starch contents. The field experiment was set up at the beginning of May 2011 on the acid soil in the east Croatia (45° 29' N and 18° 14' E). Based on chemical analyses, soil from experimental plot has very acid reaction (pHKCl 4.77) and low levels of organic matter (1.75%) while high level of mobile phosphorus (33.67 mg 100 g -1) and potassium (42.23 mg 100 g -1) according to AL-method were found, due to prior rich mineral fertilization. Basic plot was 14 m2 (two rows of 10 m length). Ten maize hybrids belonging to different FAO groups originating from Croatia were sown (H1 – Drava 404 ; H2 – OS 430 ; H3 – OSSK 444 ; H4 – OS499 ; H5 – OSSK 515 ; H6 – OS 5717 ; H7 – OSSK 552 ; H8 – OSSK 596 ; H9 – OSSK 602 and H10 – OSSK 617). Maize was manually harvested at the end of September 2011. Grain yields were calculated on 14% grain moisture basis. Protein, oil and starch in the maize grain were determined by Near Infrared spectroscopic method on Foss Tecator (Infratec 1241 Grain Analyzer). Statistical analyses were performed by the ANOVA and t-test using LSD at 0.05 and 0.01 probability levels. 2011 growing season was less favorable for maize growth. Total precipitation during maize growing season (April to September) was only 257 mm or 43% lower in comparison with long term mean (453 mm). At the same time, mean air temperatures was for 1.5 °C higher compare to the long term mean (19.0 °C and 17.5 °C, respectively). In this research grain yield of maize was relatively low. Average grain yield was only 4.93 t ha-1 with variations among hybrids from 4.02 t ha-1 to 6.25 t ha-1. Majority hybrids achieved grain yield of about 4 t ha-1, what is quite below theirs potential. Main reason for low grain yields was great percentage of sterile plants which was in average 35%, what is consequences of unfavorable weather conditions during silking and pollination. Statistical analyses have shown significance in terms of protein, oil and starch content. The highest protein content (10.58%) was achieved by hybrids of earlier maturity group in comparison with last three hybrids in the research (8.70%) what was statistically proved. Average grain oil content was 3.26% with less pronounced variations among hybrids from 2.83% to 3.58%. Genotype effect on starch content was also significant with a realized average of 71.3%. Two hybrids (H2 and H3) was achieved only 69.7% starch content in maize grain while other two hybrids (H9 and H10) had 72.9% or 3.2% higher starch content. Based on this preliminary research we can assumed that some hybrids can achieve better yield and grain quality on the same field conditions on acid soil.

acid soil ; maize hybrids ; grain yield ; grain quality

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