Maize is one of Hungary’s major cereals. In the 1970s and 1980s, we were in the frontline regarding yields and genetic advancement. However, yield fluctuation in maize has increased to 50-60% from 10-20% since the 1980s, which was partly caused by the increase in weather extremes due to climate change and by agrotechnical shortcomings.
The agroecological optimum fertilizer dosage was N 40-120, P2O5 25-75, K2O 30-90 kg ha-1 active ingredient at a plant density of 60-90 thousand plants ha-1 depending on the hybrid and the year.
For industrial (bioethanol) production of maize, a new production technology is needed. I tested and selected hybrids appropriate for this purpose and set up fertilization and plant density experiments. The experiment were set up on chernozem soil in 2008.
In bioethanol production, the selection of a high-yielding hybrid with high starch con
The yield safety of maize has not been satisfactory in Hungary for decades. Yield is influenced by the combination of several factors.
In recent years, the frequency of dry years increased and fertilization decreased. These factors call for a rational determination of the plant density.
I studied the relationship between plant density and
In 2003, the weather was dry. In the vegetation period, the amount of precipitation was 78.5 mm lower and the temperature was 0.97 °C higher than the average of 30 years, the number of hot days was 47-60 (days with a temperature higher than 30 °C). However, we obtained favourable results under experimental conditions in 2003 after wheat as a forecrop using the fertilizer Kemira Power.
The weather in 2004 was favourable. In the vegetation period, the amount of precipitation was 93.2 mm higher than the average of 30 years. Although, the distribution of the precipitation could have been more favourable. The yield of the hybrids ranged between 8.87-10.42 t/ha. Among the studied seven hybrids, the early hybrids gave the highest yield at the highest plant density of 90 thousand plants/ha (PR38Y09, PR38A67, PR37D25, PR37M34). However, FAO 400-500 hybrids gave favourable results also at the low plant density of 45 thousand plants/ha (8-9 t/ha). At this plant density, the aeration of the plant stock was better and the hybrids were prone to bringing several cobs. Yield stagnated with increasing plant density (60 thousand plants/ha), then at 75-90 thousand plants per ha, the yield started to increase again.
In 2004 the yield of hybrids was considerably higher than in the previous year. In contrast to yields of 8.87-10.42 t/ha in 2003, yields in 2004 were around 9-12 t/ha.
The yield of the hybrid XO 902 P is above 12 t/ha already at a plant density of 45 thousand plants/ha. It gives maximum yield at the plant density of 90 thousand plants/ha.
The hybrid PR38P92 showed a good response to changing plant density, but its yield was only 9 t/ha at the low plant density value.
In a favourable year, the yield of the hybrids PR38B85, PR37W05, PR37D25, PR37K85 at a plant density of 45 thousand plants/ha 11 t/ha, while at the higher plant density of 90 thousand plants/ha, it ranges around 13-15 t/ha.
Hybrids PR36K20, PR35Y54, PR34H31 have a good individual yield and they are prone to bringing several cobs in favourable years at a low plant density. Their maximum yield at the plant density of 90 thousand plants/ha is almost 16 t/ha.
In 2007, the weather was similar to that of the extremely dry year of 2003. The amount of precipitation in the vegetation period was 41.9 mm lower than the average of 30 years and its distribution was not favourable either.
In the optimum NPK fertilizer treatment at an optimum plant density, the yield of hybrids ranged between 9.32-10.73 t/ha. The highest yields of 10.22-10.73 t/ha were measured for hybrids PR38A79 (FAO 300) and PR35F73 at a relatively low plant density of 60 thousand plants/ha.
In the average of the hybrids, the optimum NPK dosage was N 131, P2O5 82, K2O 93 kg/ha active ingredient.
Maize is one of the most important crops worldwide and also in Hungary, it can be utilized for multiple purposes: as a feedingstuff, for human nutrition and for industrial processing. In the last decades, the per ha yield of maize varied greatly in Hungary, between 2004 and 2006, it was 6.82-7.56 t/ha, while in 2007, it was only 3.6 t/ha. Resul...ting from this, the price of maize became 2-2.5 times higher. The high price hinders bioethanol production. The largest per ton amount of bioethanol, 387 l, can be produced from maize.
In addition to its classical utilization as feed and food, the industrial use (especially for bioethanol production) of maize is increasin.
For industrial production, a new production technology is needed. I tested and selected hybrids appropriate for this purpose and set up fertilization and plant density experiments. The experiment were set up on chernozem soil in 2007.
The applied fertilization treatment was N 120, P2O5 80 uniformly, and five different dosages of potassium: K2O 0, K2O 100 (KCl), K2O 100 (Kornkáli), K2O 200 (KCl), K2O 200 (Kornkáli) kg/ha active ingredient. The applied plant densities were 40, 50, 60, 70, 80, 90 thousand plants/ha.
The yield of maize hybrids in the fertilization experiment ranged between 10.53 – 14.62 t/ha. Both regarding the form and dosage, 100 kg/ha Kornkáli proved to be the best potassium treatment. Regarding the inner content parameters, the highest starch content in the average of treatments was obtained for the hybrid PR36K67: 73.57%, and its yield was also the highest, so this hybrid proved to be the most suitable for bioethanol production. The highest protein content was observed for the hybrids KWS 353 (12.13%), which can be favourable for feeding purposes.
Most of the hybrids gave the highest yield at 80 thousand plants/ha plant density, however, hybrids PR36K67 and Mv Tarján achieved the highest yield at 90 thousand plants/ha.
In bioethanol production, the selection of a high-yielding hybrid with high starch content, a slight reduction of N, increase of potassium, the application of the highest plant densities of the optimum interval, harvest at full maturity (when starch content is the highest compared to protein content) are of great importance.