Effect of tillage practices, fertilizer treatments and crop rotation on yield of maize (Zea mays L.) hybrids43-48Views:160
This research was conducted at the University of Debrecen Látókép Research Station and is part of an ongoing long-term polyfactorial experiment. The impact of three tillage systems (Mouldboard plowing-MT, Strip tillage-ST, Ripper tillage-RT) and two levels of fertilizer treatments (N80 kg ha-1, N160 kg ha-1) along with a control (N0 kg ha-1) on the yield of maize hybrids (Armagnac- FAO 490 & Loupiac-FAO 380) cultivated in rotation with winter wheat was evaluated during a two-year period (2017–2018).
Amongst the three tillage treatments evaluated, ripper tillage (RT) had the highest average yield (10.14 t ha-1) followed by mouldboard tillage (MT) and strip tillage (ST) with 9.84 and 9.21 t ha-1 respectively. Yield difference between RT and MT was not significant (P>0.05), as compared to ST (P<0.05). Soil moisture content varied significantly with tillage practices and was highest in ST, followed by RT and MT (ST>RT>MT). Yield of RT was 7–9% higher than MT in monoculture plots, while MT reign superior in biculture plots (monoculture: RT>MT>ST; biculture: MT>RT>ST).
A positive interaction between tillage and fertilization was observed, with higher yield variation (CV=40.70) in the non-fertilized (N0) plots, compared to those which received the N80 (CV=19.50) and N160 kg ha-1 (CV=11.59) treatments.
Incremental yield gain from increase fertilizer dosages was significantly higher in monoculture, compared to biculture. There was no significant difference in yield between N160 and N80 in the biculture plots (12.29 vs 12.02 t ha-1). However, in monoculture plots, N160 yield was 23% higher than the N80 kg ha-1 (N160=11.74 vs N80=9.56 t ha-1).
Mean yield of maize in rotation with winter wheat was 28% (2.47 tons) higher than monoculture maize. The greatest benefit of crop rotation was observed in the control plots (N0) with an incremental yield gain of 4.39 tons ha-1 over monculture maize (9.92 vs 5.43 t ha-1).
Yield increased with higher fertilizer dosages in irrigated plots. Fertilizer application greatly increased the yield of maize and accounted for 48.9% of yield variances. The highest yield (11.92 t ha-1) was obtained with N160 kg ha-1 treatment, followed by N80 kg ha-1 (10.38 t ha-1) and N0 kg ha-1 (6.89 t ha-1) respectively.
Overall mean yield difference between the two hybrids was not statistically significant, however, yield of FAO 380 was 3.9% higher (9.06 vs. 8.72 t ha-1) than FAO 490 in monoculture plots, while in biculture plots, FAO 490 was 4.1% higher than FAO 380.
Average yield in 2018 was 13.6% (1.24 t ha-1) higher than 2017 for the same set of agrotechnical inputs, thus, highlighting the significant effect of cropyear.
Armagnac (FAO 490) cultivated in rotation with winter wheat, under ripper tillage and N80 kg ha-1 is the best combination of treatments for optimum yield.
The effect of plant density on maize yield in average and extremely dry years7-16Views:84
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 yield in 2003-2004 and 2007 on meadow soil.
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.
Correlation between the weather in 2017 and the productivity of maize89-93Views:149In our research we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize. The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2; therefore, this experiment was half-industrial. We tested six hybrids with different genetic characteristics and growing seasons. I analysed the correlation between the nutrient supply and the yield of maize hybrids with control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. The yield increasing effect of the fertilizer also depended on the number of plants per hectare to a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants ha-1.In Hajdúszoboszló in 2017, up to October, 445.8 mm of rain fell, which is in line with the average values of 30 years, and is only 45.7 mm less than those. In 2017, the effect of increasing the plant number was slighter. Averaged over the observed fertilizer treatments and hybrids, the yield was 9.10 t ha-1 with 60 thousand plants ha-1, 9.11 t ha-1 with 70 thousand plants ha-1 and 9.12 t ha-1 with 80 thousand plants ha-1. Without fertilization, in most cases, increasing the plant number from 60 thousand plants ha-1 to 70-80 thousand plants ha-1 does not increased the yield but decreased it. With N80+PK treatment the yield changed between 8.90 and 11.27 t ha-1. The effect of increasing the plant number was just slightly observable and did not show a clear tendency. The effect of changing the plant number, even with the highest dosage of fertilizers, could not be detected adequately. In contrast with the plant number, the effect of the different fertilizer treatments was expressly traceable. Compared to the control treatment (treatment without fertilization), with N80+PK fertilizer dosage with 60 thousand plants ha-1 the yield increased by 3.36–4.99 t ha-1. The smallest demonstrable proof, i.e. the LSD5% was 0.22 t ha-1, which means that fertilization, in each case, significantly increased the yield. When analysing the effect of fertilization in the average of the hybrids and the different plant numbers, a yield of 5.61 t ha-1 could be detected, which value was 10.12 t ha-1 with N80+PK treatment and 11.61 t ha-1 with N160+PK treatment. Thus, it can be calculated that compared to the treatment without fertilization, the N80+PK treatment increased the yield by 4.51 t ha-1, while compared to the N80+PK treatment, the N160+PK treatment increased the yield by 1.49 t ha-1. In addition to agrotechnical factors, in maize production, the impact of the crop year is specifically of high importance.The average yield of hybrids (in the average of the different fertilizer treatments) was 6.81 t ha-1 in 2015, 11.86 t ha-1 in 2016 and 9.11 t ha-1 in 2017. When comparing the yield results against the precipitation data, it is clearly visible that the amount of rain fell in the January– October period is directly proportional to the average yield of maize. The effect of the crop year can be defined in a 5.05 t ha-1 difference in the yield.
Evaluation of the yield and baking quality of winter wheat (Triticum aestivum L.) varieties in different cropyears95-100Views:103
We have investigated the effect of the cropyear, the genotype, the nutrient supply and their interactions on the yield and the quality parameters of three different winter wheat genotypes in three different cropyears. The most disadvantageous influence on the yield averages was caused by the moist weather of 2010, when yield results fell behind the mean of the two other examined years and the nutrient optimum was around low doses. The optimal cropyear turned out to be the ordinary 2011, the best yield results were experienced during this cropyear. Although the drier periods in 2012 decreased the yield values, the varieties could realize high yield maximum values. Considering the yield results, Genius turned out to be the best variety. In respect of the quality traits, 2010 turned out to be the best cropyear in case of all the three varieties. Despite the dry weather of the spring of 2012, the precipitation fell during flowering and ripening phases had positive impact on the grain-filling processes and contributed to the development of better quality. As a consequence of the significantly lower amount of precipitation during the generative phenological phases, the worst quality parameters were realized by the varieties in 2011.
The examination of the agronomy, the amount of yield, and the yield stability of winter wheat varieties61-72Views:77
Our research was carried out at University of Debrecen Centre for Agricultural Sciences Faculty of Agriculture Institution of Plant Sciences Látókép Research Institute through the breeding year of 2003/2004, 2004/2005 and 2005/2006 using cherrnozem soil. In our research we tested 14 chosen autumn wheat varieties during the three crop years.
The different varieties showed very dissimilar ability of resistance against diseases through the three crop years. We could observe both susceptible and resistant varieties. Susceptible varieties got diseases even in favourable crop years. The observed winter wheat varieties showed higher susceptibility against helminthosporium (21.8%) and leaf rost (16.4%). Among the 14 varieties we experienced the least susceptibility in the case of ‘Gaspard’ and ‘GK Kalász’. The research showed that the disease of fusarium undoubtedly depends on the features of the crop year.
In terms of stem solidity we experienced big differences. Among all the observed winter wheat varieties the mid-late ripening ‘Gaspard’ showed the best results in the average of the three years, only 5.3% was beaten down.
The three ripening group of the winter wheat showed the following average yield in the average of three years: 7065 kg/hectare (early ripening varieties), 7261 kg/hectare (late ripening varieties), 6793 kg/hectare (mid-late ripening varieties). Among all the observed varieties the early ripening ‘Flori 2’ produced the biggest yield (7692 kg/hectare).
During the three crop years we reached very different amounts of yield which means that weather conditions had a telling affect on yield. In 2004 we reached an excellent average yield in all the tree breeding groups because of the favourable weather conditions. In 2005 we had a moderate amount of yield because of the unfavourable weather conditions of winter. The year of 2006 showed the smallest amount of yield which is due to the fact that the plant grew less thick than usually.
There were significant differences among the observed varieties in the term of yield, which can be attributed to dissimilar biological basics.
One of he most important questions is the yield stability of the varieties. We had extremely different results at this field. Speaking in general terms we can state that both weather conditions and genetical abilities have a determining effect on yield. In the case of winter wheat varieties the rate of yield fluctuation was quite big, moving in the interval of 33.7-70.3%. Among all the observed varieties ‘Gaspard’ showed the best yield stability (33.3%).
The effect of plant density to the yield results and the yield components of maize hybrids89-93Views:131
Maize is the crop that is produced on the second largest area in our country, in Hungary. It is planted on nearly 25% of the country’s growing area and it was produced on 1 090 439 hectares in 2016. Despite the continuous development of the biological basis and production
technology, the growth of the yield results is not constant, its fluctuation is significant. It can be even up to 60%, because of the extremity of the years. The exploitation of the yield potential of modern hybrids is possible if we harmonize the effects of the ecological factors and properly applied instruments of agro technology and by these we ensure their interaction to reach a favorable outcome. The applied plant density is an important, well researched, but at industrial level a not enough utilized element of the maize production.
The results of the extensive tests, done between 2009 and 2015, showed that the genotype, the year effect and the plant density are in strong correlation with each other determining the yield results. In the past seven years the examined genotypes reached the highest yield
performance at the highest plant densities. The early hybrids (RM90–95, FAO 200–300) are capable of producing them at higher plant density, while in case of the mid and late maturity varieties the further increasing of the density after reaching the optimum level led to yield depression.
According to our experimental results, the yield is in close positive correlation with the increase of the plant density. The effect of the growing season has great significance in forming the yield results and this determines the applicable plant density too.
The yield of maize is determined by a resultant of components. The main component is the number of ears per plant and the amount of kernels per ear, which is calculated from the number of kernels on an ear and the weight of them. The number of the kernels on an ear is
calculated from the number of rows on the cob multiplied by the number of seeds in one row on the cob. In dry years, at lower yield levels the yield decreases because of the shorter ears, while at the higher levels the number of kernels in a row and the thousand-kernel weight decreases,causing yield depression this way. From our examinations it turned out that the plant density reaction of a genotype is individual, every variety reaches its maximum kernel number per hectare – in other words the maximum yield - in an individual way.
Effect of agrotechnical factors on the yield of the Grolim asparagus (Asparagus officinalis L.) hybrid on acidic sandy soil43-48Views:210
Research of blanched asparagus has begun at the University of Debrecen Institutes for Agricultural Research and Educational Farm Research Institutes of Nyíregyháza in 2011. Establishment of the plantation took place in May 2011. The Grolim hybrid was used in the trial, 16 medium plot trial area has been formed under field conditions, with four repetitions and 36 m2 plot size. In the course of our studies, the effect of different nutriment supply methods (untreated, manure, sheep manure compost, fertilizer) has been analysed on the spear yield of the Grolim asparagus hybrid between 2013 and 2017.
In our studies, the beginning of vegetative growth has been recorded upon the constant presence of 10 °C of average soil temperature in the case of the Grolim asparagus hybrid. The beginning and length of spear harvesting are both influenced by the time and dynamics of initial development in spring. During the analysed period, the dates of spear harvesting were various, the earliest being on 23rd March, 2014 and the latest on 23rd April, 2015; the rest of the three years have been varied within this one month interval. The total of heat units required for the vegetative development of spears has been determined; it provides important information for cultivation practice.
Spear yields turned out to be hectic during the analysed period. In 2013 and 2014, yields have surpassed the amount of 50 kg/harvest period/plot in the case of every treatment version. However, in 2015 a significantly lower specific yield has been recorded due to the unfavourable weather conditions in spring; a yield decline of nearly 50% was recorded in the case of the control treatment compared to the previous years. Yield was also lower in the rest of the fertilization treatments compared to 2014; however, in these cases, the degree of yield decrease was around 5–10%, which suggests the yield stabilising effect of fertilization. In 2016, a slight yield increase was measured in comparison with the base year. In 2017, there was a decline of yield in the control treatment; however, the different fertilization treatments resulted in yield increase as compared to previous years.
On the basis of our studies, it is clear that the best yield results have been provided by the artificial fertilization treatment in all of the five analysed years. It was followed by the sheep manure compost and manure treatments in terms of their effect on spear yield. During the three harvesting periods, the lowest yield on acidic sandy soil was recorded in the case of the control treatment. The most remarkable effect of nutriment treatments has been realised in terms of the decreased deviation of yield results, which perfectly represents the yield stabilising effect of nutriment supply in the case of perennial crops – asparagus – as well, even on a poor nutriment supply characteristic sandy soil.
The Influence of Cropyear on the Yield and Yield Safety of Different Sunflower Hybrids68-73Views:96
The effectiveness of plant production is basically influenced by the ecological, biological and agricultural technical factors. There are many kinds of sunflower hybrids which differres in their adaptability. If we want to increase the efficiency of sunflower production, we have to design different technologies for each hybrid. In the last decade, the range of sunflower hybrids increased exceedingly. This is the reason why we have to do experiments with them and examine what the relationship among genotypes, the environment and the hybrids is.
We made our experiments at the Látóképi Experimental Station of the University of Debrecen. We had 57 hybrids in 2001, and 44 in 2002 and 2003. We used only just those hybrids which were planted in every year.
In 2001 the months at summer were hot and the distribution of rainfall was extreme. In the beginning of the year 2002, the summer was also hot. During the abscessing period, the temperature was under the 30 years average and the rainless period was typical. In 2003, the temperature was extrame and the rainfall during the growing season was dry. The yield average which was determined after the three years in the very early group averaged 3998,9 kg/ha. The best hybrids were the LG 5385 (4273,3 kg/ha) and the Magóg (4134,4 kg/ha). The early group’s average was 4129,4 kg/ha. The best hybrid was the Astor in the early group. The middle group’s average was 4169 kg/ha and the Zoltán had a better yield than average (4238 kg/ha). In the confectionary group the Iregi szürke csíkos (3579,9 kg/ha) reached the best yield and it is above the average to it’s group (3225 kg/ha).
To estimate the results, we used factor analysis. Its results allow us to say that rainfall first and second part of June has a negative influence on yield. Aswith to the yield, yield safety is also important to know, which shows the adaptability of the hybrid.
After examining the CV% in the three years we can say that the most stable hybrids were in the very early group Samanta (10,94 CV%) and the LG 5385 (12 CV%) In the early group, the most reliable hybrids were Altesse RM (6,9 CV%) and the Astor (10,8 CV%) and the end in the middle group the Lympil (10 CV%) and in the confectionary group the Birdy (9,8 CV%) and IS 8004 (12 CV%) were the best.
After examining yield and yield safety, our conclusions are that in the Hajdúsági löszhát, the very early group LG 5385, early group Altesse RM, middle group Lympil and the parandial group IS 8004 hybrid had the highest yield and the best yield stability.
The effect of the sowing time on the yield and oil content of sunflower (Helianthus annus L.) in different crop protection models57-61Views:128
The field research was carried out at the experimental farm of the University of Debrecen at Látókép on calcareous chernozem soil in Hungary. We examined the effects of the sowing time and the fungicide treatment on the yield, oil yield and oil content of two different genotypes of sunflower hybrids (NK Ferti, PR64H42) in 2012 and 2013. We applied three different sowing times (early, average, late) and two different treatment levels of fungicides (control =no fungicides applied, double fungicide protection).
During our research, we received better results in 2013 than in 2012. The application of different planting times affected the yield and oil yield production and the oil content as well. The optimal circumstances for yield and oil yield production were provided by late planting in 2012, while by average planting time in 2013. The highest oil yield results were reached by late plating in both years (except for hybrid PR64H42 in the double treated parcels where average plating time turned out to be more effective). The correlation between the plating time, the yield and oil yield production and the oil content was strong in 2012 (r=0.600**, r=0.639**, r=0.590**). On the other side, in 2013, the correlation was medium between the planting time, the yield production and the oil content.
We applied Pearson’s correlation to analyze the effect of the double fungicide treatment on the yield and oil yield production (2012: r=0.498**, r=0.407**). These results were better in 2013 (r=0.603**, r=0.623**), besides, the double fungicide treatment also increased the oil content (r=0.315**).
Effect of Ferilizer on the Yield of Maize (Zea mays L.)40-46Views:112
The effect of fertilization on the yield of maize was examined on chernoem soil with lime deposits at the experimental station at Látókép of the Center for Agricultural Sciences, University of Debrecen. The yields of maize were evaluated using quadratic regression function, in three years – between 2000 and 2002 – in non-irrigated and irrigated treatments. After calculating the regression equations, by derivation of the functions, we have determined the amount of fertilizers needed for maximum yield.
In the non-irrigated treatments, maximum yield and the active substance amount of fertilizer was as it follows: in 2000, yield of 9,133 t/ha with the application of 384 kg/ha mixed active substance, while in 2002 a yield of 6,289 t/ha with the application 236 kg/ha NPK active substance was achieved. In 2001, due to the favourable precipitation, a yield of 9,864 t/ha was achieved with the application of 245 kg/ha fertilizer. In the case of maximum yield, compared to the unfertilized control, the yield increase was 2,5-5 t/ha. The average increase for 1 kg of NPK fertilizer was 13-19 kg.
We also determined the necessary fertilizer dosage for maximum yield in irrigated treatments. In 2000, 10,003 t/ha with a dosage of 423 kg/ha, in 2001, 11,542 t/ha with a dosage of 277 kg/ha and in 2002, 8,596 t/ha of maximum yield could be achieved with a fertilizer treatment of 277 kg/ha in the examined three years. The yield increase, in irrigated treatments, varied between 3,9-5,9 t/ha so it was greater than in the case of non-irrigated experimetal plots. The yield increase for 1 kg fertilizer varied between 12-21 kg.
Examination of the Effect of Cropyear on the Yield Potential and Yield Stability of Winter Wheat Varieties62-67Views:98
Variety selection is one of the most important, determinative elements of sustainable winter wheat production. Yield potential, and yield stability are the most important elements in the variety selection of winter wheat, but baking quality parameters play an important role, too.
Several winter wheat varieties were tested for yield and yield stability on chernozem soil in the Hajdúság (in the eastern part of Hungary), in the 2001-2002-2003-2004 cropyears. The management factors were the same for all cropyears. 15 varieties in early the maturity group, 14 varieties in the middle maturity group and 4 varieties in the late maturity group were tested in the above mentioned cropyears. The climatic conditions were average in 2001, dry in 2002, extremely dry in 2003, and very favourable in 2004.
We obtained 5298-6183 kgha-1 yield from early maturity varieties, 5683-6495 kgha-1 from middle, 5694-6031 kgha-1 from late ones in the average of four years. The cropyears had strong influence on the yields, even on chernozem soil, and were characterized by excellent water – and nutrient – husbandry. Averaging of cropyears and genotypes, we obtained 6984 kgha-1 in 2001 (average cropyear), 5452 kgha-1 in 2002 (dry cropyear), 3120 kgha-1 in 2003 (extremely dry cropyear) and 8400 kgha-1 in 2004 (optimum cropyear), respectively. The yield differences between the minimum and maximum yields were 885 kgha-1 in early varieties, 812 kgha-1 in middle and 337 kgha-1 in late maturity varieties, respectively. The varieties characterized by high yield potential and the varieties characterized by good yield stability were different, so in variety selection we have to take both genetic traits into consideration. There were positive, significant correlations among the yields of winter wheat varieties (early, middle, late), the temperature of spring months. (March-April), and the rainfall of spring months (March-April) (R2=0,703**-0,768** and R2=0,681**-0,749**, respectively). We found a high negative correlation between the temperature of early summer months (May-June) and the yields of wheat varieties (R2= -0,856**- -0,918**).
According to the results of our experiment, it is very important to harmonize yield potential and yield stability in the variety selection of winter wheat.
The effect of crop year and agrotechnical factors on the yield of various maturity groups of Limagrain maize hybirds19-23Views:124
The Limagrain maize hybrids in different maturity groups were examined at the Látókép Experimental Station of the Centre of Agricultural Sciences and Engineering, University of Debrecen on a calcareous chernozem soil with loam texture, between 2001 and 2007 in a multifactorial long-term field trial. Doses of fertilizers: 1 N:0.75 P2O5:0.88 K2O fixed proportion of NPK doses. The basic dose of nitrogen is 30 kg ha-1. The application of fertilization was 1, 2, 3, 4, and 5 times more than the basic dose, beside of untreated control. The long-term field trial is performed in none irrigated and in irrigated version.
The goal of the study was to analyze the effect of precipitation (environment factor) in one hand, and to evaluate the effect of fertilization and irrigation (agrotechnical factors) on the yield of maize hybrids in different maturity groups in the other hand. At the same time I studied the effect of interaction of different factors on the yield of maize.
Analysis the yield of Limagrain hybrids revealed: the years considerably affected the level of the yield. In dry years the yield was 1.351 t ha-1 less, than in rainy years. As the effect of fertilization the yield increased, the statistically proved biggest increment was at level of 90 kg N ha-1. Evaluating the maturity groups, FAO 300 hybrids reached higher level of yield.
In non irrigated conditions in the average of the seven years 60 kg N ha-1 was sufficient to reach the maximum yield. The efficiency of fertilization on yield in irrigated version increased, 120 kg N ha-1 assured the reliable level of yield.
Without irrigation in comparison to the results of FAO 200 group, with the growth of FAO numbers the yield is increasing in all cases. The most significant increase was at FAO 300 (3.562 t ha-1). With irrigation the greatest difference in yield was in FAO 400 (+2.720 t ha-1) compared to FAO 200.
The effect of production area on the development of yield producing factors of maize (Zea mays L.) hybrids of different genotypes67-72Views:123
Maize yield amount development is determined by the given crop year and the genotype of the applied hybrid, but beside these also by the applied agrotechnical factors, in particular by sowing technology. The development of yield amount and yield producing factors of five maize hybrids of different genotypes has been studied in a small-plot field experiment by the application of different row spacings and plant density variants. The production of the individual plants shows decreasing tendency parallel to the increasing plant density, however, this decrement is compensated by the higher number of plants per unit production area. Individual plant production is determined by the development of yield producing factors, such as the length and the diameter of cobs, just as by the thousand seed weight – that were studied in the present research work as well.
In the present research work the decreasing row spacing resulted in a yield increment of 0.67 t ha-1 (4.53%) in 2013, while in contrast in 2014 yield was decreased by 1.75 t ha-1 (14.87%). The high amount of precipitation in March was determinant in 2013: it filled up the soil water stock and balanced the negative effect of the inadequate amount and distribution of precipitation during the vegetation period for the yield. Lower extent of yield increment (0.6 t ha-1) was registered in 2014 in case of the row spacing of 76 cm than in the previous year. In case of a row spacing of 45 cm the difference between the two crop years was 3.1 t ha-1. The highest impact on the yield production factors was found in all treatment combinations in case of the applied hybrid among the three studied treatment factors. In the crop year of 2014 the effect of plant density on cob diameter and thousand seed weight could be revealed as well. In case of the cob diameter significant difference was found between the plant densities of 70 000 and 90 000 plants ha-1, just as between the populations with densities of 50 000 and 90 000 plants ha-1. In case of the thousand seed weight significant differences could be found by the application of plant densities of 70 000 and 90 000 plants ha-1. The highest values of the studied yield producing factors were measured in case of the plant densities of 50 000 and 70 000 plants ha-1; increasing the plant density to 90 000 plants ha-1 resulted in rather decreasing values.
Evaluation of long term experiments from a new aspect55-60Views:108
During our work, we developed a new, simple method to show the effects of fertilization on yield, which can both be applied over the long term as well as in series of independent experiments.
During the testing of this method, at the experimental farm of the Debrecen University Center for Agricultural Sciences at Látókép on a chernozem soil with lime deposits, we examined the fertilizer reaction of maize hybrids between 1989 and 1994. The treatments were: winter tillage, plant density of 70-80 thousand, unfertilized, N 120, N 240 kg/ha fertilized treatments, long term experiments using Dekalb 524 and Volga SC hybrids in long term experiments.
Four parameters are shown in the model. In the examined period TRmax represents the greatest yield in the fertilized treatments, NT the yield in unfertilized treatment, k the „efficiency of fertilizer” to NT and b the depression-coefficient, where the expected value is zero. The expected grain yield of the fertilized treatments (Y), in the function of the unfertilized grain yield (x) is the following:
The parameters were determined using the Monte Carlo method, in the optimizing process the sum of deviation square was minimized. The correct conformation of the functions was determined by the greatness of the R-value and the standard error. We found that during six years of testing, the tendency of fertilization efficiency was similar in the case of both hybrids. There was an unfavorable weather interval and, in these years, the yields were low, fertilization did not have an effect and moreover, in extremely bad conditions resulted in an obvious yield decrease. With the improvement of conditions, which in the case of our country means an increase in precipitation, the efficiency of fertilization increases and reaches its peak at 13-14 t/ha. At this point, the yield increasing effect of fertilization is 4-4,5 t/ha. If the yield of the unfertilized treatments increases from 8-9 t/ha, then the efficiency of the applied fertilizer decreases.
Most likely, the k and b parameters depend on the soil of the experimental location (nutrient and water management) and on the amount of pplied fertilizer and the characteristics of the hybrid. With the increase of fertilizer dosage the k-parameter also increases. The greater value though does not obviously mean a more favorable situation. It is true that in medium and good years this means great fertilizer efficiency, but in low or extreme precipitation conditions it also means greater risk. With the increase of the k-parameter, the yield deviation also increases which, from a cultivation point of view, is quite unfavorable. If the value of the b-parameter is other than, zero then the effect is clearly unfavorable, because with the increase of this value, the yield decrease is also greater. The fertilizer reaction of the two examined hybrids can be well characterized by these two hybrids.
Examining the six years, our created model estimated the effect of fertilization on the yield accurately and with a high degree of safety. Both in highly unfavorable and extremely good years, it gave an exact estimate. In our opinion, it can be used well to evaluate the effects of fertilization on yield in the future.
Evaluation of reaction to plant density of sunflower hybrids by regression and Kang’s stability analysis101-109Views:89
The world production area and the total production of sunflower has significantly been growing. The harvested yield was 23.4 and 21.1 million ha in 2005 and 2001, respectively. The total sunflower seed production has also unexpectedly increased.
Although sunflower is produced on lower quality soils in Hungary, in 2005 the average harvested yield was 2.43 t ha-1, which was the highest in the world.
Sunflower is a typical commercial plant and fits well in the crop structure. Since in terms of acreage the most significant crops are corn and cereals, the partial monoculture cultivation cannot be avoided. Sunflower production is a way to eliminate this problem, therefore it has an important role both in cultivation and ecological points of view.
Accordingly, sunflower has an important role in reducing the monoculture cultivation of some plants, as well as increasing biodiversity. Sunflower well adapts to Hungary’s climatic conditions and its production is easily practicable in our country.
The reaction of sunflower hybrids on crop density change is different. Some hybrids are more some are less sensitive to this parameter. In different crop years, the crop density optimums of the different genotypes are also different. In Hungary, the yield and quality is primarily determined by fungal infections, while viruses and bacteria are less important.
The research was conducted at the Látókép farm and Regional Research Institute of the University of Debrecen, Centre of Agricultural Sciences. The research institute is situated by Road 33,15 km from Debrecen in the Hajdúság. The duration of the experiment was seven years, 10 hybrids were examined in each year.
Two hybrids used every year, Aréna/PR and Alexandra/PR hybrids were tested by Kang’s stability analysis. We found that Alexandra/PR was most balanced at every levels of crop density. Both hybrids performed most stable yield at 65000 ha-1 crop density level and less balanced at 35000 ha-1 crop density level. As a result of improved environmental conditions, the yield increase of Aréna/PR was higher than that of Alexandra/PR.
Our regression analysis found that the maximum yield of Lympil, Louidor, Hysun 321, PR63A82 and PR64A63 hybrids were harvested at 47000-60000 plant ha-1 crop density level. The statistical analysis showed that the highest yield was harvested from Lympil and Hysun 321. As regards the crop yield, the most stable hybrids were Louidor and Lympil. The optimum crop density interval of Rigasol/PR and Larisol (58000 plant ha-1) was wider than that of Diabolo (46000 plant ha-1). The maximum yield of Larisol was higher at the optimal crop density level. As regards yield, Diabol was the most stable hybrid.
The statistical analysis on the stability of the yield of Alexandra/PR and Aréna/PR showed that Aréna/PR is more stable, and its optimal crop density level is lower than that of Alexandra/PR.
The effect of NPK fertilization and the number of plants on the yield of maize hybrids with different genetic base in half-industrial experiment103-108Views:175
In our research we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize.
The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2, this it was a halfindustrial experiment. We tested six hybrids with different genetic characteristics and growing seasons. I analysed the correlation between the nutrient supply and the yield of maize hybrids with control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. Yield increasing effect of the fertilizer also depended on the number of plants per hectare at a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants/ha.
In Hajdúszoboszló, in 2015 the amount of rainfall from January to October was 340.3 mm, which was less than the average of 30 years by 105.5 mm. This year was not only draughty but it was also extremely hot, as the average temperature was higher by 1.7 °C than the average of 30 years. In the critical months of the growing season the distribution of precipitation was unfavourable for maize: in June the amount of rainfall was less by 31mm and in July by 42 mm than the average of many years.
Unfavourable effects of the weather of year 2015 were reflected also by our experimental data. The yield of hybrids without fertilization changed between 5.28–7.13 t ha-1 depending on the number of plants.
It can be associated also with the unfavourable crop year that the yield of the six tested hybrids is 6.33 t ha-1 in the average of the stand density of 60, 70 and 80 thousand plants per hectare without fertilization, while it is 7.14 t ha-1 with N80+PK fertilizer treatment. That increase in the yield is only 0.81 t ha-1, but it is significant. Due to the especially draughty weather the yield increasing effect of fertilizers was moderate. In the average of the hybrids and the number of plants, increasing the N80+PK treatment to N160+PK, the yield did not increase but decreased, which is explicable by the water scarcity in the period of flowering, fertilization and grain filling.
The agroecological optimum of fertilization was N 80, P2O5 60 and K2O 70 kg ha-1. Due to the intense water scarcity, increased fertilization caused decrease in the yield. As for the number of plants, 70 000 plants ha-1 proved to be the optimum, and the further increase of the number of plants caused decrease in the yield.
The effect of sowing time on the yield and the variance of the seed moisture content a harvest of maize (Zea mays L.) hybrids39-49Views:87
Sowing 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.
Hybrid-specific nutrient and water use of maize on chernozem soil51-54Views:109
The field research was set up on chernozem soil at the Látókép AGTC KIT research area of the University of Debrecen. The study focused on yield, water utilization, nutrient reaction and the amount of yield per kg fertilizer of corn hybrid NX 47279 in 2011 and 2012. Based on the yield results it can be concluded that the largest yield in 2011 was 15 963 kg ha-1 at level N120+PK, while in 2012, the maximum yield amounted to 14 972 kg ha-1 at level N90+PK. Surplus yield per kg fertilizer proved that in 2011 level N30+PK resulted in the highest surplus yield (42.3 kg kg-1) compared to the control treatment. In 2012, yield growth was 18.0 kg kg-1 compared to the control treatment. We measured at level N60+PK 17,5 kg kg-1 compared to at level N30+PK, at the N90+PK 17,7 kg kg-1 compared to at level N60+PK. level N30+PK kg kg-1, 17.5 kg kg-1 at level N60+PK and 17.7 kg kg-1 at level N90+PK compared to the control treatment.
The effects of agrotechnological factors on winter wheat yield in humid cropyear162-167Views:76
The effects of crop rotation, nutrien supply and crop protection technologies, as well as the appearance of the main ear- and leafdiseases
(powdery mildew, helminthosporium leaf spot, leaf rust, fusarium) were studied on the crop yields of winter wheat variety MV
Pálma during the 2009/2010 crop year. The experiments were conducted in triculture (pea – wheat – corn) and biculture (wheat – corn), at
five nutrition levels, with the use of three crop protection technologies (extensive, conventional and intensive) at the Látókép Research Site of
the University of Debrecen, Centre of Agricultural Sciences. Our results proved that the appearance of leaf- and ear-diseases were
significant in the wheat cultures during the 2009/2010 crop year, because of the rainy, warmer than usual weather, the lodging, and the huge
vegetative mass developed. The most severe infections by the four examined diseases after pea and corn pre-crops were observed at
extensive crop protection levels, when fertilizers were used at the highest dose.
Following corn pre-crop, in the case of all the three crop protection technologies the maximum rate of wheat yield results were achieved
at N150+PK level. The highest yield was reached at intensive crop protection level (6079 kg ha-1). In triculture, in case of all the three crop
protection technologies the maximum yields were achieved at N50+PK level; in extensive technology 5041 kg·ha-1 yield, in conventional
technology 6190 kg ha-1 yield was realised, while in the intensive technological model the yield was 7228 kg ha-1.
The relationship between yield and fertilizer amounts, the rate of pathogen contaminations, crop protection technologies and pre-crops
was defined with correlation analysis in case of different crop rotations during the 2009/2010 crop year. Based on the results of the
experiment, we found that in stands after corn pre-crop strong positive correlation was established between the crop protection level and the
crop yield (0.543), the nutrient levels and the emergence of the four examined pathogens, and between the nutrient levels and the yield
(0.639). Extremly strong positive correlation was observed between crop protection and yield (0.843) in triculture. Strong positive
correlation was detected between the nutrient levels and the presence of the four examined pathogens, as well as between nutrient and
lodging (0.688). Strong negative correlation was between the crop protection level and the four examined diseases both in biculture and
Examination of the impact of sowing technology models on the ear, constiuent and yield parameters of the yield formation elements of maize hybrids of different genotypes17-23Views:108
Production year 2012 has been characterised by climatic extremities. The weather of this year can be considered very contradictory in terms of maize production. The droughty conditions of the winter and spring months had a negative effect on both germination and starting vigour. The favourable weather of May-July created ideal conditions for intensive growth and generative processes; however the lack of precipitation in August and September had a damaging effect on the development of yield composing elements and grain saturation processes as well. Under such circumstances, the sowing date models caused significant differences in the yield and quality of the hybrids belonging to different growth periods. The growing period of the maize hybrids has been shortened as a result of the unfavourable climatic conditions.
The Effect of Fertilization and Irrigation on Maize(Zea mays L.) Production26-29Views:102
In a long-term field experiment set up at the Látókép experimental station of the Center of Agricultural Sciences of Debrecen University, the data of the last five years (1995-1999) were analyzed to determine the crop production factors with the greatest influence on maize production and the relationship and interactions between irrigation and fertilization.
In the extremely dry year of 1995, fertilization was found to cause substantial yield depression in the absence of irrigation. According to results of analysis of variance, fertilization significantly reduced the maize yield by 40-90% compared to control plots. Under irrigated conditions, there was a considerable increase in the maize yield, the yield surplus being 4.4-9.4 t ha-1, depending on the nutrient supply level.
During the period from 1996-1999, when rainfall conditions were favorable for maize, fertilization significantly increased the maize yield even without irrigation over the average of the four years. The yield surplus due to fertilization was 3.9-4.6 t ha-1, depending on the fertilization rates. The maximum yield surplus was obtained on plots fertilized with 120 N kg ha-1, while at the rate of 240 N kg ha-1 the maize yield did not differ significantly from this value. During the period examined, corn yield was significantly higher at all three nutrient supply levels as the result of irrigation than in the non-irrigated treatment. As in the case of non-irrigated conditions, the highest fertilizer dose did not result in a substantial yield increase. An analysis of the interaction between fertilization and irrigation indicated that the yield-increasing effect of fertilization was not significantly different under irrigated and non-irrigated conditions. The significant year x irrigation interaction was confirmed by the fact that the yield surplus (1.3-2.3 t ha-1) differed greatly from the irrigation effect recorded in 1995.
The effect of and interaction between the biological bases and the agrotechnical factors on maize yield83-87Views:141The effect of and interaction between the biological bases and the agrotechnical factors on maize yield In our research, we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize. The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2; therefore, this experiment was half-industrial. We tested six hybrids with different genetic characteristics and growing seasons.We analysed the correlation between the nutrient supply and the yield of maize hybrids with a control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. The yield increasing effect of the fertilizer also depended on the number of plants per hectare to a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants ha-1.In 2015, the highest yield was produced by hybrid P9241 with N80+PK and 70 thousand plants per hectare. With the N160+PK fertilizer dosage, the same hybrid responded the best, followed by hybrids P9486 and DKC4717. Using the same fertilizer treatment, the 80 thousand plants per hectare population density resulted in decrease in the yield with most of the examined hybrids. In 2016, with the increase in the number of plants per hectare, even with non-fertilised treatment (control treatment), the yield could be increased in the case of each hybrid.Averaged over the different hybrids and fertilizer treatments, applying 80 thousand plants ha-1 instead of 60 thousand resulted in 1.0 ha-1 yield increase. In 2017, the number of plants had a slighter effect. With N160+PK treatment, in most cases no significant difference can be observed. The value of LSD5%: plant number: 0.20 t ha-1, hybrid: 0.28 t ha-1, interaction: 0.48 t ha-1. With N160+PK treatment, the hybrids produced yields between 10.07 and 12.45 t ha-1. When examining the three years in the average of the number of plants, with treatment without fertilisation, the average yield of hybrids reached 7.53 t ha-1. With N80+PK treatment, this value was 9.71 t ha-1 and with doubling the fertilizer dosage, this value increased to 10.42 t ha-1. No economic profit was gained as a result of applying double dosage of fertilizer; therefore, the N80+PK dosage can be considered ideal.
Integrated nutrient supply and varietal difference influence grain yield and yield related physio-morphological traits of durum wheat (Triticum turgidum L.) varieties under drought condition111-121Views:101
The ever-growing world population entails an improvement in durum wheat grain yield to ensure an adequate food supply, which often gets impaired by several biotic and abiotic factors. Integrated nutrient management, such as nitrogen rate × foliar zinc × sulphur fertilization combined with durum wheat varieties were investigated in order to examine the dynamics of yield and yield related physio-morphological traits under drought conditions. The four durum wheat varieties, three-level of nutrient supply (i.e. control, sulphur, and zinc), and two nitrogen regimes (i.e. zero and 60 kg ha−1) were arranged in split-split plot design with three replications. Zinc and sulphur were applied as foliar fertilisation during the flag leaf stage, both at a rate of 3 and 4 liters ha-1, respectively. Results showed existence of genetic variability for grain yield, plant height, NDVI, SPAD and spike density. Foliar based application of zinc and sulphur at the latter stage improved the plant height. Nitrogen fertilized varieties with lower spike numbers showed to better yield formation. Co-fertilization of nitrogen and zinc improved grain yield of responsive varieties like Duragold by about 21.3%. Spikes per m2 were statistically insignificant for grain yield improvement. It could be inferred that the observed positive effect of sulphur, nitrogen and zinc application on physio-morphology and yield formation substantiates the need to include these essential nutrients in the cultivation system of durum wheat.
Impact of environmental changes resulting from different sowing dates on maize yield99-104Views:127
Three Debrecen maize hybrids of different genotypes (Debreceni 285, Debreceni 377 and Debreceni 382) were examined on chernozem soil in a field experiment. During the two years of the experiment (2009–2010), we wanted to get to know how the examined hybrids reach to different sowing dates and what impact early, optimal and late sowing has on yield.
In 2009, balanced soil and air temperature resulted in steady emergence. However, the low temperature in early April and the cooling down in mid-May 2010 caused a delayed emergence.
The grain moisture content at harvesting and the high yield showed a strong crop year effect. In 2010, yield was much lower (1.664 t ha-1) and grain moisture was significantly higher (34%)than in 2009.
In 2009, early sowing resulted in yield decrease (P<0.05), but it also significantly reduced grain moisture at harvesting (P<0.05). Although late sowing slightly increased yield (not significantly), but grain moisture at harvesting increased by 9.2%. In 2010, optimal sowing date was shown to be the best alternative from the aspect of yield, but there was no significant difference in comparison with early and late sowing. Grain moisture at harvesting greatly increased (13.3%).
The Debreceni 382 maize hybrid reacted to sowing dates flexibly, neither early, nor late sowing affected its yield significantly and the grain moisture at harvesting showed 12% increase in the case of the late sowing date. In 2009, maize hybrids Debreceni 285 and Debreceni 377 reached their highest yield in the case of the sowing date which was shown to be optimal (23rd April), while the different sowing dates had no effect on yield in 2010.
The Effect of Sowing Time and Plant Density on the Yield of MaizeHybrids95-104Views:70
The 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.