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.
The experiment was carried out 6 km from Debrecen, next to the main road 47 on a homogeneous field on brown forest soil. Five corn hybrids were tested in the trial (DKC 4795, DKC 4995, KWS Kornelius, NK Cobalt, PR37 N01) at three different sowing times (early – 5th April, average – 21st April, late – 10th...May). At each sowing time, three different plant densities were applied (modest – 58 500 plants ha-1, average –70 200 plants ha-1, high – 82 300 plants ha-1). The agrotechnics applied
in the experiment satisfied the requirements of modern corn cultivation.
In the study, the best yield result was achieved with the early sowing time out of the three examined sowing times (11 315 kg ha-1), which was significantly different (LSD5%=495 kg) from that of the average sowing time (10 690 kg ha-1), however, there was no statistically justifiable difference between the yield results of the early and the late sowing times. There was a significant difference also between the average and late sowing time. Our results indicate that the different sowing times resulted in a different flowering times. Consequently, the stands of early and late sowing time reached this critical stadium of growth under proper climatic circumstances (precipitation: 39 mm and 136 mm, average temperature at flowering: 18.1 oC and 20.3 oC), while flowering in the case of the average sowing time of 21st April was in the first half of July and the average temperature at flowering was warmer (23.2 oC) with only 10 mm precipitation.
In the experiment, the plant density response was also examined. According to the measured data, four of the five hybrids responded badly to the increasing plant density. We found that the plant density of 58 500 plant ha-1 gave the largest yield results (DKC 4995 11 794 kg ha-1 – NK Cobalt 10 998 kg ha-1, average of five hybrids: 11 430 kg ha-1), while the lowest yields were obtained at the plant density of 82 300 plant ha-1 (KWS Kornelius 11 037 kg ha-1 – NK Cobalt 10 019 kg ha-1, average of five hybrids 10 720 kg ha-1). The difference between the two plant densities was significant (LSD5%=494 kg), however, the 70 200 plant ha-1 plant density did not show any statistical difference from neither the 58 500 ha-1 nor from the 82 300 plant ha-1 stands. When examining the data of the hybrids separately, we found that there was a significant difference between the average yield of the lowest and highest plant densities only in the case of three (DKC 4795, DKC 4995, NK
Cobalt) out of the five hybrids (DKC 4795: 11 757 kg ha-1 – 10 857 ha-1 where LSD5% =816 kg; DKC 4995: 11 794 kg ha-1 – 10 738 kg ha-1 where LSD5%=853kg; NK Cobalt: 10 998 kg ha-1 – 10 019 kg ha-1 where LSD5%=630 kg ha-1), while a significant difference between the second and third plant densities was observed only in one case (DKC 4995: 11 726 kg ha-1 – 10 738 ha-1 where LSD5%=853 kg). In all other cases, there was no statistical difference between the different
In our experiment the reaction of six sunflower hybrids of different genotypes (NK Oktava, ES Biba, ES Diagora, ES Ballistic, EGH 8925, PR 64 H 42) towards plant density has been investigated by different fungicide treatments in the crop-year of 2011 on a chernozem soil.
In the crop-year of 2011 sunflower populations were infected by a
disease according to our results. According to the results of the Pearson’s correlation analysis it has been revealed that stalk breakage and Diaporthe infection stand in a very close (r=0.782**) and middle close (r=0.523**) correlation resp. with plant density. The relationship between fungucude treatments and stalk breakage, just as Diaporthe infection showed to be middle and close respectively. Our results demonstrate the role of stalk and plate diseases (among them Diaporthe) in causing stalk breakage, for we have found a close positive correlation between stalk breakage and Diaporthe infection (r=0.624**) in our analysis.
From the aspect of yield amount the optimal plant density varied between 45 000 and 55 000 plants per hectare. Fungucude treatments enabled not only the use of higher plants densities, but they had a yield increasing effect as well. In the crop-year of 2011 the highest yield (4 559 kg ha-1) on a chernozem soil has been measured in case of the hybrid ECH8925.
The necessity of application of hybrid specific crop production technology has been confirmed not only by trial results but also by the experiences gained from the agricultural practice. For this reason it is essential to test and collect data in field trials about the specific agronomic traits of the corn hybrids belonging to different maturit...y groups and genotypes. Corn hybrids are tested for their responses to sowing time, plant density and fertilizer supply; sensitivity to herbicides; and lately, the resistance to the damages caused by the larvae of corn root worm. Last but not least, mention should be made of the differences in the responses of the corn hybrids to the damages caused by drought stress. Based on the trial results, suggestions for the hybrid specific corn production are compiled and made public for the experts and farmers engaged in corn growing. Corn hybrids may deliver maximum yields on the impact of specific crop production technology only in case if it relies on carefully done general production technology including soil cultivation, seed bed preparation and weed control. Similarly, precision crop production technology may advance the yield increase in economic way if it is constantly drawing on the source of research results.
Maize plant response to plant density is an essential agrotechnical factor used for determining grain yield. Three plant densities (60,000 ha-1, 72,500 ha-1, and 85,000 ha-1) were used in this study to ascertain the effect of photosynthetic parameters and grain yield. Results show a significant difference in the... photosynthetic parameters (SPAD, NDVI, LAI) and plant height for plant density of 85,000 ha-1. Grain yield and stem diameter were not significantly affected between the different plant densities.
The development and implementation of precision agriculture or site-specific farming has been made possible by combining the Global Positioning System (GPS) and the Geographic Information Systems (GIS). Site specific agronomic applications are of high importance concerning the efficiency of management in crop production as well as the protectio...n and maintenance of environment and nature. Precision crop production management techniques were applied at four locations to evaluate their impact on small plot units sown by wheat (Triticum aestivum L.) and maize (Zea mays L.) in a Hungarian national case study. The results obtained suggest the applicability of the site specific management techniques, however the crops studied responded in a different way concerning the impact of applications. Maize had a stronger response regarding grain yield and weed canopy. Wheat was responding better than maize concerning plant density and protein content performance.