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The effect of crop protection and agrotechnical factors on sunflower in the Hajdúság region
39-46Views:88Extreme weather conditions are becoming more and more frequent in the crop years, thus increase the risk of sunflower production.
The objective of researches into plant production is to minimize these effects as much as possible. In this sense, the optimization of
agrotechnological factors is of high importance. Within these factors, the appropriate crop technology (sowing time, crop density)
and optimized, rational crop protection technologies are important, especially in the highly sensitive sunflower cultures. The effect of
sowing time, crop density, and fungicide treatments on the yield of sunflower hybrids was analysed in different crop years in 2008
and 2009. In each case, the infection was highest with the early sowing time and at the highest crop density level (65000 ha-1). When
one fungicide treatment was applied, the rate of infection decreased compared to the control treatment. The further decrease of the
infection rate was less after the second fungicide treatment.
In the humid year of 2008 the crop yield was the highest at 45000 ha-1 crop density level in the control treatment and at 55000 crop
ha-1 crop density level when fungicides were applied. In the draughty year of 2009 the maximum yield was gained at 55000 ha-1 crop
density level in the control treatment and at 65000 crop ha-1 when fungicides were applied. In 2008 and 2009 as regards the crop
yield, the difference between the optimal and minimal crop density levels was higher in the fungicide treatments than in the control
treatment (in 2008: control: 517 kg ha-1; one application of fungicides: 865 kg ha-1; two applications of fungicides: 842 kg ha-1), (in
2009: control: 577 kg ha-1; one application of fungicides: 761 kg ha-1; two applications of fungicides: 905 kg ha-1).
In each and every case, the first treatment with fungicides was more effective than the second. In 2008, the highest yield was
obtained with the third, late sowing time in each fungicide treatment. The differences between the crop yields with different sowing
times was less than in 2009, when the results of the second treatment exceeded those of the first and third treatment in each case. -
Investment funding programs on dairy farms in Hajdú-Bihar County
11-16Views:170The dairy farming sector needs constant modernization of its buildings, machines and technology in order to maintain its competitiveness and productivity. For the greater scale investments, these companies try to apply for state funds in addition to their own financial sources. Therefore, the investment support system plays a great role by improving the competitiveness and modernity of these farms. In the last 10 years, 7 funding programs were available for dairy farms. In this research, 25 dairy farms were interviewed in Hajdú-Bihar County. The examined farms cover more than 50% of the milk production in Hajdú-Bihar County. The survey questions focused on the investment funding program use of farms between 2007 and 2017 and renewable energy investments including all programs. The results show how many tenders were submitted, how many were successfully evaluated and completed. All farms had at least two successfully evaluated projects. A correlation was found between completed projects by farm size and completed projects. The connection of the modernity index of dairy farms and the completed projects was also shown.
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Regional interactions of bioenergy utilization
159-162Views:60The backwardness of the rural areas compared to the cities poses a problem all over Europe. In Hungary, a relatively small size of the population lives in the capital, more than 80% of Hungarians live in rural cities or villages. The tension between the countryside and the cities is rather intensified and the symbiotic correlation would need to be restored. Many people migrate from the countryside, especially young adults, as they have no opportunities to find a job in their hometowns. This phenomenon poses big risks because getting a job is usually difficult everywhere and because fitting into a new environment always involves a lot of difficulties.
Non-renewable energies are restricted and they will not be accessible after reaching a certain limit. People’s everyday activities and the functioning of the economy presuppose the availability of the necessary amount of energy. In the future, a solution that provides the longterm stability of energy for the world will become increasingly necessary. There is a huge potential in bioenergy, more specifically in biomass. The building of biomass plants and putting them into operation creates jobs in the rural spatial environments: a locally available resource that can help in creating the energy safety of the country and the reduction of the dependence on import. The production of energy crops or the crops whose purpose of use is energy could help in strengthening the multifunctional character of agriculture and it can represent a source of income for those living off agriculture under the current uncertain conditions.
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The effect of sowing date and plant density on the yield of maize (Zea mays L.) under different weather conditions
205-208Views:294Maize has high productivity and produces huge vegetative and generative phytomass, but this crop is very sensitive to agroecological (mainly to climatic, partly to pedological conditions) and agrotechnical circumstances. In Hungary, maize is grown on 1.1–1.2 million hectares, the national average yields vary between 4–7 t ha-1 depending on the year and the intensity of production technology. The longterm experiment was set up in 2015–2016 on chernozem soil in the Hajdúság (eastern Hungary). The maize research was set up on chernozem soil at the Látókép MÉK (Faculty of Agricultural and Food Sciences and Environmental Management) research area of the University of Debrecen. We examined the following commonly used hybrids of Hungary: SY ARIOSO (FAO 300), P9074 (FAO 310), P9486 (FAO 360), SY Octavius (FAO 400), GK Kenéz (FAO 410), DKC 4943 (FAO 410). The experiment was set up in three different plant densities. These were 60, 76, 90 thousand plant ha-1. The experiment was set up with three different sowing dates, early, average and late sowing. The yield was measured using a special plot harvester (Sampo Rosenlew 2010), measuring the weight of the harvested plot and also taking a sample from it. As a next step, we calculated the yield (t ha-1) of each plot at 14% of moisture content to compare them to each other. We evaluated the obtained data using Microsoft Excel 2015.
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The effect of the dates of shoot selection and shoot tip removal on the growth of William’s pear trees
65-70Views:78Increasing the intensity of production in the case of pear can be the solution to satisfy the market demand forr high-quality fruit. The aims in this technology are the canopy treatments and the maintainance of consistently high quality yields in the long run. The experiments were performed with cv. William’s pear, a cultivar grown on large areas in Hungary. To create the optimal canopy shape for earlier fruiting, we performed shoot selection and the cutting back of shoot tips. Our results show, that both pruning methods – applied at 3 different dates – decreased the number of short fruiting parts (spurs), and increased the number of vegetative shoots. The sole exception was from this the effect of shoot tip removal when done at the earliest date.
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Evaluation of egg quality parameters of two Hungarian ostrich populations
51-57Views:216The aim of our study was to evaluate the quality parameters, porosity and weight loss of eggs deriving from the two most significant ostrich farms in Hungary. Quality parameters included weight, length, width, shape index, egg volume, surface area, circumference and shell volume. The effect of storage conditions in both farms and the incubation technology on egg weight loss in farm “A” were also examined. The research objective was to impart a comprehensive knowledge on egg quality parameters of the main ostrich populations in Hungary and to compare the trios and the farms with each other and the international literature. We could reveal significant differences between trios in all egg quality traits. In conclusion, the shorter and the narrower the eggs were, the more spherical shape they had. Narrower eggs showed smaller surface area, volume, circumference and shell volume and vice versa. Eggs from farm “B” indicated significantly greater width, shape index, surface area, circumference and shell volume than farm “A”. A significant difference was observed in weight loss during storage between the farms. Weight loss in farm “A” was a multiple of farm “B”. In farm “B” there was a weak, positive correlation between storage period and weight loss (r=0.22, P≤0.05), in farm “A” it was not significant (P=0.52). There was no relationship between the initial egg weight and weight loss either in farm “A” or farm “B” (P=0,21, P=0,69). A slight positive correlation could be noted between egg porosity and weight loss (r=0.24, P≤0.05). Pores count presented here was less than the international results. Poultry eggs contain the most pores at the blunt end, less via the equator and the least at the pointed end. In ostrich egg we found more pores via the equator against the blunt end. To draw more precise conclusions, further investigation should be carried out on porosity. Considering the fact that the length of storage period and the weight loss during incubation are in strict correlation with hatchability, we intend to extend our research aims to these traits.
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Some methodological aspects of animal behaviour during beef cattle grazing
31-35Views:115Ethology, the research field of animal behaviour, during the past half century developed into an independent science and became more important in recent years as the farming industry has turned toward quality production. Farm animals respond for every environmental factor. Essential to know the answers to avoid unpleasant economic consequences. Based on the shepherds’ experience, this science has merged with modern technology, constantly expanding and searching new methods. According to the literature the article summarizes the observation methods in cattle grazing. This paper introduces the beginnings and shows the future trends. Finally we share personal experiences as the Hungarian Grey cattle grazing behaviour at conditions of Hortobágy, Hungary.
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Portable snapshot spectral imaging for agriculture
221-225Views:252High-resolution proximal and remote sensing applications can consolidate sustainable, prevention- and precision-oriented crop management strategies to decrease production risks. This paper shows significant perspectives, own developments and technical aspects of high resolution remote sensing in the context of field applications. Moreover, we provide an overview of snapshot hyperspectral imaging and potential field video sensors to identify areas of interest for their future development. One of the main conclusions of our paper is that non-scanning snapshot hyperspectral imaging technology may enable researchers to overcome the gap in the “point to image” transition of field sensing, while providing a flexible solution for regular variable-rate applications.
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Agronomic bases of precision barley production
217-220Views:95To ascertain the importance of individual preciosion factors in achieving yield and quality of malting barley, we established a multifactor
experiment at the research station of the Slovak University of Agriculture in Nitra in 2009 and 2010. Four variants of fertilization, 2 ways of soil cultivation and four varieties 'Bojos’, 'Kangoo’, 'Marthe’ and 'Xanadu’ were observed. From the quality indicators the nitrogen content (%) was observed. The results were statistically analyzed by using a multifactor analysis of variance by using Statistica 8, the program Statgraphics. The difference between years was statistically significant (1.87 t ha-1) in favour of 2010. The difference was also significant between the varieties 'Bojos’ and ’Kangoo’(1.07 t ha-1), respectively. 'Martha’ and 'Xanadu’ as well as 'Kangoo’ (0.56 resp. 0.33 t ha-1). Conventional soil cultivation in
comparison with a minimalization technology, demonstrated a tatistically insignificant increase of yield. Significant differences were obtained between the variants of fertilization. Treatment by using Condit (b-var.) showed a very positive impact in climatic favorable year (2010) with a yield result of 7.42 t ha-1. In comparison with an untreated control, the difference in yield was 0.89 t ha-1. A significant increase of yield was achieved by using the combination of solid fertilizer with foliar fertilizer (LAV + Hakofyt, var.c) 0.47 t ha-1. The crude protein content was statistically influenced by a variety and year. In 2009, the crude protein content was above average (12.38%). Significantly lower attributes were achieved in 2010 (9.90%). From the studied/observed varieties the lowest crude protein content was showed by a variety 'Kangoo’ (1.68%). -
The effect of plant density on the yield of sweet potato
125-128Views:388A field study was conducted in South-East Hungary during the main cropping season of 2016, 2017 and 2018, with the objective of determining the effect of plant spacing on the productivity of sweet potato. Production technology experiments of four repetitions were set up in a randomized block design on sandy soil. The performed treatments consisted of four variations of plant spacing (row distance x plant-to-plant distance): 80 cm x 20 cm, 80 cm x 30 cm, 100 cm x 20 cm, 100 cm x 30 cm. The plant material was the Hungarian registered sweet potato variety ‘Ásotthalmi-12’. Analysis of variance revealed that planting density significantly affected the average yield of storage roots. The highest yield per plant was achieved with the 100 cm x 30 cm (2016, 2017), as well as with the 80 cm x 30 cm (2018) setups. On hectare level, our results showed that the highest plant density of 62,500 plants ha-1 (80 cm x 20 cm setup) could give the highest yield. Comparing the highest tons ha-1 results to those achieved with the plant spacing setups resulting in the highest yield per plant, the differences can be even 13 or 14 tons at hectare level. This finding underlines the importance of choosing the proper planting density towards the higher end.
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The Effect of Sowing Time and Plant Density on the Yield of MaizeHybrids
95-104Views:81The crop technology of maize has two important elements, sowing time and plant density. In 2003 and 2004 we studied the effect of these two factors on the growth and production of maize in an experiment carried out near Hajdúböszörmény.
The soil of the experimental plots was meadow soil.
Weather in both years was differed greatly. 2003 was drought. Neither the distribution nor the quantity of the precipitation were suitable in the growing season for maize. This fact basically determined the results.
In 2004, we could talk about a favorable and rainy season. The distribution and quantity of precipitation was suitable between April and September. The average temperature was also suitable for maize.
Results of the sowing time experiment:
In 2003, we tested seven hybrids at four sowing times. Hybrids in the early maturity group gave the highest yield at the later sowing time, while the hybrids of the long maturity group gave it at the earlier planting time. The yield of PR34B97, PR36N70, PR36M53 hybrids was the best at every planting time. The moisture loss of hybrids in the late maturity group was faster in the maturity season, but the seed moisture content was higher than the hybrids with early sowing time. The seed moisture content was very low due to the droughty year. In two hybrid cases, this value was higher than 20% only at the fourth sowing time.
In 2004, we examined the yield and seed moisture content of nine hybrids. In the favorable crop year, the yield of every hybrid was the highest at the second and third sowing time. Yields of PR34H31 and PR38B85 hybrids were significant. The seed moisture content at harvest was higher than the previous year due to the rainy season. In the case of hybrids sown later, this value was higher by 30%. However, we noticed that this value was lower at the earlier sowing time than at the later.
The crop year had a more dynamic effect on maize than the sowing time. First of all, the quantity and distribution of precipitation played an important role in respect to yield safety.
Results of the plant density experiment:
We tested the reaction of hybrids at four plant densities (45,000, 60,000, 75,000 and 90,000 stock/ha) every two years. In 2003, the tested seven hybrids reached the highest yield at the 90,000 stock/ha in the face of a droughty year. The effect of forecrop and favorable nutrients caused these results. In the rainy 2004 year, the yield grew linear with the growing plant density. The yield of the best hybrids were 14-15 t/ha at the 90,000 stock/ha.
Such a high plant density (90,000 stock/ha) couldn’t adaptable in farm conditions in rainy season. It is practical to determine the interval of plant density besides the optimum plant density of hybrids which gave correct yield. The farmers have to use the low value of this interval due to the frequent of the droughty years. -
Productivity of thinned black locust (Robinia pseudoacacia L.) stands in Hungary: case studies
181-186Views:113Black locust (Robinia pseudoacacia L.) is one of the most important introduced tree species in Hungary, covering more than 24% of the stocked area and providing approximately 20% of the country’s annual timber cut. Consequently, the research and development activities related to the improvement of the growing technology of black locust are also important, especially in mitigating the negative effects of climate change. The aim of this study was to quantify growth and yield, responses of even-aged 12–31–year–old black locust stand to thinning in Hungary. The study has proved that irrespective of the yield class, age and thinning intensity, thinning could not increase effectively the cumulative volume production. As percentage of the control it has changed between +0.6 and -8.4%. On the other hand, it could increase the stand value based on stem quality index by 10–21%.
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Product orientated sewage sludge composting technologies in the practice of AKSD Ltd.
33-36Views:124In recent years the regulations of the EU unambiguously determine that the biodegradable wastes should be used for biogas production or composting. The direct use of sewage sludge in agriculture is limited by its hazardous microelement content, but it can be used effectively in composting. The limitation parameters can be extinguished with correct compost-mixture and technology variants. The exact determination of the technologies and mixtures result a stable, constant quality product. The compost, as a classified product, is friable structured. The end-product is a
homogeneous mould with good water capacity, does not contain any weed seeds and pathogenic organisms. The compost does not have a acidify effect on the soil. It is an effective fertilizer thanks to its macro and microelement content. -
Comparative examination of the tillage systems of maize on meadow chernozem soil
21-24Views:167Maize production plays a major role in the agriculture of Hungary. Maize yields were very variable in Hungary in the last few decades. Unpredictable purchase prices, periodical overproduction, the increasing occurrence of weather extremities, the uncertain profit producing ability, the soil degradation processes (physical, chemical and biological degradation) and the high expenses are risk factors for producers. Due soil tillage, there is an opportunity to reduce these risks. Based on the experimental database of the Institute of Land Utilisation, Regional Development and Technology of the University of Debrecen, Centre for Agricultural and the KITE Plc., various cultivation systems were examined with maize (Zea mays L.) as indicator plant in Jász-Nagykun-Szolnok country in 2012 and 2013. The sample area can be found in the outskirts of Kenderes on a meadow chernozem soil. On the examined plot, strip-tillage, subsoiling and moldboard ploughing were performed, each on 4.5 ha, respectively.
In general, our findings show, that strip-tillage and subsoiling can be alternative tillage systems beside moldboard ploughing on meadow chernozem soils in Hungary.
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Carcass and the Meat Quality of Hungarian Lambs
65-71Views:108The author investigated 153 lambs of nine genotypes originating from breeding flocks, and 50 lambs originating from production flocks. The investigations were performed between 1995 and 1998. The authors discuss the evaluation of comformation and fat cover according to EUROP standards. The authors also investigate the proportion of valuable meat by genotype, and – out of the internal value indicators – the dry-matter, protein, fat, connective-tissue and hemin contents comparing the flavour, aroma, tenderness, and oven loss of the different genotypes.
The following findings should be highlighted:
♦ The Hungarian Merino breed should be improved, as – according to EUROP standards, more than 70% of these animals were rated as quality „R”.
♦ Hungarian fattening technology has to be preserved, as the lambs reach the desired slaughter weight within a short period of time, and without over-fattening.
♦ Readiness for slaughter, typical of each genotype, has to be defined, and slaughter at proper weight be achieved.
♦ It has to be re-evaluated whether the Hungarian Merino is the only breed which can be used in Hungary, as none of the investigations really proved the special characteristics and significance of this breed.
The author summarizes the findings of the investigation in five tables. -
Effect of sowing time and planting space on change of yield and protein content of white lupine (Lupinus albus L.)
85-89Views:164The hinge of the lupine crop cultivation technology is the sowing time and the determination of the breeding area. According to the literature the early sowing (as soon as possible to go to the soil) and larger growing area is recommended for seed production. Based on the results of our 2 years experiment, the effect of sowing time and different spacing is important on yield of white lupine, and the effect of the sowing time is more significant. A decrease in the yield was observed after later sowings. The yield and the rate of its decreasing was varied in one year and among different years depending on wheather condition and sowing time.
The role of sowing time is significant for protein content of seeds. The average protein content decreased due to the later sowings in 2014, while 2015 the protein content of seeds in early sowing time and of plants sowed 4 weeks later was similar. We measured less protein content in the 2. sowing time sowed 2 weeks later than the first one. In the studied years the average protein content of seeds from different row spaces were not different.
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Önitatók konstrukciós és hidromechanikai vizsgálata
52-57Views:103Our research aimed to examine Hungarian automatic drinking system constructions and hydromechanics under laboratory conditions and in operation with special emphasison the small volume, valve types.
Considering that no Hungarian standard of automatic drinking system examination and qualification exists, on the basis of technical literature, the new examination method of automatic drinking systems has been elaborated.
For laboratory measurements, a universal measuring bench was assembled which is applicable to the hydromechanic testing of all automatic drinking systems (cattle, sheep, pig).
Summary of the laboratory measurements:
Upon comparison of the flow capacity of the valves, in the case of same opening values (h/dn), the rubber spring valve of SZI type automatic fountain has the highest flow capacity, although in the case of 100 kPa pressure even this type has only 15-16 l/min value which hardly surpasses the lower limit of the desired 15-25 l/min range.
The loss coefficients of the valves, on investigating in the range 100-200 kPa, showed the lowest value (2,2-5,8) with the steel spring self drinking device.
Summary of the operational investigations:
In the long term operational investigations, the rubber stripped valve and the rubber spring automatic fountains had the most favourable operational reliability values: K4=0,98 and K4=0,94, respectively.
From the aspect of animal operation of the valves, all the Hungarian types are frontal operated, thus such system automatic valve drinking devices can be used only in long and moderately long stands, directed toward the animal.
On the basis of hydromechanical and construction examinations of the Hungarian tied cattle production technology the construction modification of the rubber spring valve of SZI type automatic drinking fountain, which is the most frequantly used in this country, was carried out. Due to design modifications the valve parameters improved significantly.
The goals of the accomplished valve modification were
ζ'sz – loss coefficient to be reduced
q – flow capacity to be increased -
Conceptional Model of Regional Agricultural Water Management System
199-209Views:107Our study focuses on the water management improvement of the Hajdúsági-löszhát (loess ridge). The Hajdúsági-löszhát (loess ridge) is an intensive agricultural area. At the same time, the problem of increasing water demand is still not solved, so towards of safety production irrigation should be improved. To realise this should be known not even agricultural water demands but industrial and urban ones as well, thus a complex water management system is required to be worked out.
In the first part of the research, the water demand in the area is mapped, then a conceptional model of the Hajdúsági-löszhát’s (loess ridge’s) water management system is created. After collecting data the water management scenario is summarized in a real time model splitted into five periods.
During the research, the instruments of spatial informatics (GIS) are used to get acquainted with the variation of the hydrological parameters in space and time. To understand and simulate the different decision making processes and to choose the right decision alternative, a decision support system is created with the use of spatial informatics data.
In addition, considering the potentially right decision alternative, irrigation will be started in practice, an effect and after-effect inquiry will be made, and the results will be analysed, evaluated and summarized. Finally, a suggestion to the most adequate irrigation technology will be made. -
Determination of element contents of commercial and homemade jams
71-75Views:251Various products could be prepared by using fruits as raw materials. In Hungary, the most popular fruit products are spirit, jams, preserves, juices and dried fruits. Jams are made from different fruits, with different fruit content, technology and additives. They can be used for different products or they can be consumed by themselves. These products and their related production processes have great traditions in Hungary. In addition, they are widely used.The aim of our study was to determine the element content of jams and to compare these samples based on their micro- and macroelement content.In this study, 26 fruit jams with different botanical origins were examined. 10 samples were commercial, and 16 samples were homemade products. The determination of micro- and macroelements was carried out by using Inductively Coupled Plasma Mass Spectrometer and Inductively Coupled Plasma Optical Emission Spectrometer. Different element contents were measured [B (249.7), Ca (422.6), Fe (259.9), K (769.8), Mg (280.2), Na (589.5), P (185.9), S (182.0), Al (27), Mn (55), Cu (65), Zn (66), Sr (88), Ba (137)]. Based on element contents, the jams showed statistical differences. -
The effects of curing technology on the rheological and organoleptic features of meat products
139-142Views:87Meat products are important staple foodstuffs owing to their high protein, vitamin and mineral content. Meat plants do not only use traditional production technologies but also develop methods that preserve the nutritional value of meat or improve the texture and organoleptic features of meat products. These features play an important role in the consumer society. Consumers first meet the external features of meat and this experience influences their decisions. Our analyses compared a traditional and a new curing procedure. Besides organoleptic inspections, we analysed texture with a CT3 type Texture Analyser to obtain quantified information on the condition of meat samples in the various curing phases. We used our results to compare traditional and new curing procedures.
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Effect of floor type and bedding system on sows lifespan
155-160Views:108The paper studies two nucleus pig farms in the Great Plain region of Hungary which have same management, same feeding system but different breeding technology (Farm A had solid floor with straw and Farm B had slatted floor without straw). The genetics of sows were crossbred Dutch Large White and Dutch Landrace. The comparative examination was based on the causes of culling according to the different floor type. To the analysis of culling reasons was applied the methods of survival analysis.
In the analysis there were used the Kaplan-Meier method and the Cox Proportional Hazard model to the estimate the difference between the farms. The results of survival analysis showed significant difference (p<0.05) between the lifespan of sows that caused the difference between the survival probabilities of sows culled due to lameness. Furthermore there was showed that the sows kept on solid floor with straw have stayed in production longer than on slatted floor without straw. The hazard ratio was 1.434 that means that the culling due to lameness is 1.434 times higher by the slatted floor without straw facing by solid floor with straw.
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The effect of sowing time on the yield and the variance of the seed moisture content a harvest of maize (Zea mays L.) hybrids
39-49Views:98Sowing time is an important crop technology element of maize. We studied the effect of this factor on the growth and production of maize in an experiment carried out near Hajdúböszörmény, in 2003 and 2004, and near Debrecen, in 2005.
The soils of the experiments were humic gley soil and chernozem. Weather in both years differed greatly. 2003 was drought. Neither the distribution, nor the quantity of the precipitation were suitable in the growing season for maize. This fact basically determined the results.
In 2004 and in 2005, there were favorable and rainy seasons. The distribution and quantity of precipitation were suitable between April and September. The average temperature was also suitable for maize.
In 2003, we tested seven hybrids at four sowing times. Hybrids with a shorter vegetation period gave the highest yield at the later sowing time, while the hybrids with a longer vegetation period gave them at the earlier sowing time. The yield of PR34B97, PR36N70, PR36M53 hybrids were the best at every sowing times. The moisture loss of hybrids in the late maturity group was faster in the maturity season, but the seed moisture content was higher than the hybrids with early sowing time. The seed moisture content was very low due to the droughty year. In two hybrid cases, this value was higher than 20% only at the fourth sowing time.
In 2004, we examined the yield and seed moisture contents of nine hybrids. In the favorable crop year, the yield of every hybrid was the highest at the second and third sowing times. Yields of PR34H31 and PR38B85 hybrids were significant. The seed moisture content at harvest was higher than the previous year, due to the rainy season. In the case of hybrids sown later, this value was higher by 30%. However, we noticed that this value was lower at the earlier sowing time, than at the later.
In 2005, we applied three sowing times. Unfortunately, the results of the third sowing time could not be analyzed, due to the low plant density. The yield of the six hybrids varied from 12 to 14 t/ha at the first sowing time. At the second sowing time, the yields fluctuated and each hybrid had the lowest yield, except the PR37D25 hybrid. At the latest sowing time, the yield of the PR34B97 hybrid was the lowest. However, this low yield was due to damage from the Western corn rootworm (Diabrotica virgifera) imago. The moisture content at harvest of the hybrids varied from 16 to 24% at the first sowing time. Yields at the second sowing time were higher. The low yield of the PR34B97 hybrid coupled with a higher seed moisture content. In addition, the maximum value of the LAI was more favourable at the first sowing time, and ranged between 5-5.5 m2/m2.
The crop year had a more dynamic effect on maize than the sowing time. First of all, the quantity and distribution of precipitation played an important role in respect to yield safety.