The Role of the Hierarchy of the Production Tillers in wheat Cultivar km 5180 under the Effect of Sowing Spaces

Interpapillary spacing is an important aspect of crop management in general, and the choice of row spacing reflects a compromise between improving natural resource capture by the constituent members of the plant in the field. The research was applied during the winter season 2019-2020 to know the role of planting row spacing on the main stem and tillers of wheat cultivar km5180. Use the design of R.C.B.D. In the order of the factorial experiment, the cultivars occupied the first factor, and included V1 the Iraq variety and V2 the KM5180 cultivar. The agricultural distances were the second factor, and the distances included three (S1 = 20) cm, (S2 = 40) cm, and (S3 = 60) cm, spacing between the lines. The results showed the effect of line spacing on most of the studied characteristics of the main stem, as the distance of 60 cm gave a significant superiority in the characteristics (spike length (cm), number of spikes.m2 and biological yield ton. ha), which averaged (13.72 (cm), 32.5 spikes.m2 and 5.7088 ton. ha) successively, as the results showed that the distance of 60 cm exceeded the studied characteristics of the branches (plant height cm, number of spikes m2 and biological yield ton. ha), which averaged (91.31, 301.7 spikes m2 and 10.515 ton. ha) sequentially. The reason for the cultivation distance exceeding (60) cm, the farthest between the lines, is due to the increase in the number of stems bearing spikes and the lack of competition for penetrating light and mineral elements present in the soil between plants, and then the nutrients deposited in all parts of the plant. As for the cultivars, the main stem of the KM5180 cultivar was significantly superior for the characteristics (spike length cm, number of spikes/spike, number of spikes.m2), whose averages were (12.68 cm, 17.500 spikes/spike and 195.50 spikes.m2), respectively, over the Iraq cultivar. We conclude that it is possible to adopt the planting distance of 60 cm and the cultivar KM5180, as it gave the best results in most of the traits included in the research.


Introduction
Cereal crops have been grown in row spacing since the seed was invented to reduce waste in the use of seeds, after noticing in the scientific field the extent to which seeds were lost and the lack of guarantee of regular cultivation.Crops have been grown in lines since the seed was invented to reduce waste in the use of seeds after noticing in the scientific field the extent of seed loss and the lack of regular cultivation.In any case, the best distance between the lines for any crop is proven through applied observations in the experimental field.Although there are many attempts by the researchers to increase the yield by using the optimal cultivation methods (planting row spacing, the seeding rate, and the cultivation of modern varieties with high productivity), so the research came to study the best planting row spacing for the selected cultivar KM 5180 gives the highest growth yield and captures the 1259 (2023) 012112 IOP Publishing doi:10.1088/1755-1315/1259/1/012112 2 best photosynthesis to be reflected on The yield and its components.And trying to answer the question which is better?Does the distance between the wider or narrower lines give higher growth characteristics of the main stem and the Tillers of both cultivars, or vice versa?Within all the distances included in the research, previous studies have consistently studied the planting row spacing and their results varied about the most appropriate planting distance for this crop.In general, the grains are sown at a distance of 17-22 cm row spacing , and they are distinguished by their response to the methods of cultivation and the distribution of plants in different forms, but their difference in the amount of seed is not to a wide extent, and this is due to the nature of branching for most of the grains.The number of tillers will be determined.In fact, due to the lack of studies related to knowing the best planting distance between lines for the cultivation of modern varieties.The above research came to determine the best distance for the selected varieties of the wheat crop, especially the registered variety KM5180, which has a high branching ability that distinguishes it from other varieties.This research is part of an integrated project to study the cultivar KM5180.Therefore, the method of planting on lines is an important factor for the purpose of a better distribution of seeds and for the optimal utilization of available resources.The planting distances and seeding rates affect the amount of light and heat available by the plant, and they are two factors that change according to the season and the geographical location because they affect most of the physiological processes that take place in the plant [1].However, the height of the plant is also of great importance and is closely related to lying down on the one hand and its efficiency in intercepting light on the other hand, as tall plants intercept light more [2].Also, the planting distance between the lines has a great influence on this characteristic.As the average plant height reached 86.4 at a distance of 30 cm compared to a distance of 10 cm if it gave 83.6 cm in a study [3].[4], indicated that the highest mean height was at a distance of 17 cm, which was 95 cm.Moreover, the characteristic of the spike length had little effect on changing the distances between the lines.The results of [5], showed that there was no significant effect of distances (15 and 25) cm on the length of the spike, and it was identical to the results of the study of [3] when using the distance (10 and 30) cm row spacing.The number of spikelets.The spike represents the basic unit of the spike, which is the grain production unit [1].The stage of formation of a maximum of spikelets coincides with the development and growth of the main stem, so most of the represented materials are specialized towards supporting and completing the elongation stage, so a case of abortion and death of the spikelets occurs due to the insufficiency of the materials represented to complete the formation and formation of the spikelets.The availability of appropriate distances to equip the plants with good lighting will make the production of spikelet's at a slower rate and extend for a longer period, which gives a greater number of spikelet's.With regard to the number of spikes, m2 constitutes one of the important factors in the formation of the final carrier of grain crops, and the number of spikes is determined in the early stages of the crop's life, and although it cannot be felt except in a late stage, some people imagine that it is formed in the stage of expelling the spikes, but the truth is Other than that, since the processes that lead to the formation of tillers (in light of which the number of spikes is determined) begin after the establishment and consolidation of plants in the field.As for the role of the row spacing, the distance between the lines gave 20 cm the highest rate of the number of spikes in the wheat crop [6].The biological crop is the final outcome of the photosynthesis process and the beneficial nutrients, and the process of photosynthesis depends on the capacity of the vegetative cover of the crop.which depends on the agricultural operations and the nature of the variety in intercepting and using solar radiation during the growing season, and among the agricultural operations that affect this characteristic is the row spacing.

Materials and Methods
The research was applied at Experimental Station A affiliated to the College of Agricultural Engineering Sciences -University of Baghdad (Al-Jadriya) during the winter season 2019-2020.(S2 = 40 cm (S), = 60 cm, and a code for varieties V1 = soft wheat variety (Iraq), V2 approved soft wheat variety (KM5180) derived by the first researcher for research and registered for the year 2019 at the Ministry of Agriculture -National Committee for Registration and Accreditation and protection of agricultural varieties.Soil preparation and soil service operations were carried out before planting, such as cleaning and removing the residues of the previous crop, and plowing the experimental land IOP Publishing doi:10.1088/1755-1315/1259/1/0121123 with two perpendicular plows using the reversible plow.The area of the experimental unit is 2x2 m2.Each experimental unit used ten lines for the planting distance between the lines of 20 cm or six lines for the planting distance between the lines of 40 cm and included 4 lines for the planting distance between the lines of 60 cm.A constant seeding rate of 120 km ha was used.An experimental land was fertilized with urea [7].fertilizer (46% N) at a rate of 200 kg.N hectares It was added in four batches, the first at planting, the second at the stage of growth of three complete leaves on the plant, the third batch at the stage of a fig knot on the main stem, and the fourth batch at the stage of growth of the bush, according to a scale [8].Fertilizer was added in two stages, triple superphosphate fertilizer (P2O5).64% at a rate of 100 kg.Ha was added in one batch before thinning, and potassium fertilizer (K2O) was added to the plant [9]. in two growth stages Then, samples of an area of one meter in length were taken for each experimental unit randomly and guarded from its four sides for the purpose of calculating the growth characteristics of wheat.It was preceded by calculating the number of plants in early stages for the distance above, after the plant had two complete leaves on the main stem, as white circular plastic markers were placed on the main stem for the purpose of distinguishing between it and the rest of the formed branches.The growth characteristics of each of the main stem as well as the tillers were measured for each growth characteristic, including plant height (cm), spike length (cm), number of spikes m 2 , number of spikelets.spike, biological yield, ton.hectares and according to the above characteristics for all experimental units within all distances included in the study and for both classes.

Statistical Analysis
The data were analyzed using the Gene Stat program, where the arithmetic means were compared using the least significant difference method at the 5% probability level in a randomized complete block design (R.C.B.D.) in the order of the factorial experiment and with three replications, according to [10].

Plant Height (cm)
Table No. 1 shows that there are significant differences between the two study factors and the overlap between them for the main leg as a result of the spacing of the rows.The distance of 40 cm was superior by giving the highest mean of 99.81 cm significantly over the rest of the distances.As for the introduced cultivars, the V1 variety gave the highest average of 98.94 cm, outperforming the V2 variety.As for the overlap, the highest average was recorded at 102.32 cm for cultivar V1 at a distance of 40 cm, and it did not differ significantly from cultivar V2 at a distance of 20 cm.The lowest average was 94.33 cm at a row spacing of 60 cm for cultivar V2.As a result of row spacing, plant height decreased in rows wider than Narrow rows while narrow rows lead to competition for food resources.

Spike Length (cm)
The results shown in Table (1) showed that there were significant differences between the two study factors and the overlap between them for the main stem.The distance between lines was 60 cm, the highest average reached 13.72%, significantly superior to 20 and 40 cm, respectively, with an increase rate of 1.97 and 10.64%, respectively.As for the varieties, the V2 variety was significantly superior, giving the highest average of 14.05% over the V1 variety, with an increase of 12.95%.As for the overlap, the highest average was achieved at a distance of 20 cm for cultivar KM5180, which amounted to 14.68 cm, while the lowest average was achieved at 11.25 cm at a distance of 40 cm for cultivar V1, and the percentage of increase between them reached 23.37%.Between the rapidly elongating spike and the growth of other organs such as leaves and roots.

The Number of Spikelets / Spike
The results of Table (1) show significant differences between the cultivars and the overlap between them for the main stem, and the planting spacing between the lines did not show any significant difference between the arithmetic means.The KM5180 variety gave the highest average of 20.28% spikelet / spikelet of the main stem significantly over the V1 variety with an increase of 6.07%.This superiority is due to the genetic nature of the variety.As for the overlap, the highest average of 20.73% spike / spike was achieved at the planting distance of 60 cm for the V2 variety, while the lowest average overlap was 18.13 spike / spike for the V1 variety.spikelets and then get the largest number of spikelets.

The Number of Spikes, m 2
The results of Table (1) show that there are significant differences between the two factors of the study, and the interference did not show any significant difference.It affected the distance between the lines by giving the highest average number of spikes of the main stem m 2 , which reached 132.5 spikes.m 2 at the widest distance of 60 cm between the lines, significantly superior to the narrower 20 cm distance, which amounted to 77.5 spikes.m 2 , with an increase rate of 41.50%.This increase is due to the area regularity available to the plant and a better distribution of rows, which increases the number of cuttings bearing spikes.m 2 for a distance of 60 cm compared to the distance of 20 cm between rows at which the number of spikes of the main stem decreased, with a decrease of 70.96%.These results agree with what was reached by [6].As for the main stem of the cultivars, the KM5180 variety excelled by giving the highest average of 130.6 spikes.m 2 , significantly superior to the V1 variety, which had an average of 87.8 spikes.m 2 for the main stem, with an increase of 32.77%.

The Biological Yield is tons.ha
Table (1) shows that there are significant differences between the two study factors and the overlap between them.As the 60 cm distance excelled by giving the highest weight rate of 5.708 tons.hectares at planting distances (20 and 40) respectively, and the percentage of increase was (50.29 and 17.47)%, respectively.The reason for this increase may be due to the increase in the number and moment of competition for the light carrier and the mineral elements present in the soil between plants, and then the increase in nutrients deposited in All parts of the plant.As for the cultivars, the V2 variety outperformed by giving the highest average of 5.201 ton.ha.Significantly over the V1 variety, the increase rate was 30.05%.The reason for superiority may be due to the genetic nature of the variety, the overlap.The V2 variety, at a distance of 60 cm, achieved the highest average overlap of 6.654 tons.hectares, while the lowest average for V1 was 2.232 tons.ha at a distance of 20 cm .The results were consistent with [11][12][13][14][15][16].
Table 1.Showing the behavior of cultivars with planting distances and their effect on the growth characteristics of the Main Stem.

Plant Height (cm) for Tillers
Table (2) showed that there were significant differences between the two study factors and the overlap between them for the branches.The distance of 60 cm gave the highest mean for the branches, which reached 91.31 cm, with a significant increase rate of (1.43, 4.78)%, respectively, over the narrower distances (20 and 40) cm, respectively.As for the branches of the cultivars, the V1 variety was superior in plant height, reaching 90.15, significantly over the V2 variety, with an increase of (1.62)%.
As for the overlap, the 60 cm treatment for class V1 showed the highest average of 94.53 cm, while the lowest average overlap was when the 40 cm treatment for class V1 amounted to 84.80 cm.

Length of Spike(cm) Tillers
Table (2) shows that there are significant differences between the two branches of the study.The narrower line spacing was superior in giving the highest average of 13.05 cm, significantly superior to the longer distances of 40 and 60 cm, respectively, which gave 10.86 and 12.05, respectively.As for the cultivars, the V2 variety outperformed by giving the highest average of 12.68 cm.There was no interference between the study factors.No moral effect.

The Number of Spikelet / the Spike has Tillers
Table (2) shows that there are significant differences between the varieties and the overlap between them, and the spacing between the lines did not have any significant effect.As for the branches of the cultivars, the cultivar KM5180 had a significant superiority of 17.50 spikes/spike, superior to the cultivar V1.This superiority may be due to the genetic susceptibility of the cultivar.
As for the interaction between the two factors of the study, the highest average of the overlap was 18.33 spikes/spike at 40 cm line spacing for variety V2, and it did not lag significantly when treating 20 cm for variety V1, while the lowest average was at a planting distance of 40 cm for variety V1, which was 16.10 spikes/spike.(2) showed that there were significant differences between the spacing between the lines and the overlap between the two study factors.While no significant differences appeared between the cultivars.The distance between the lines 60 gave the highest average number of spikes for the primary branches, which amounted to 301.7 branches bearing the spike.m2,significantly superior to the narrower distances, and with an increase rate of (34.54 and 72.65)%, respectively, for the planting distances (40 and 20) cm, respectively.As for the overlap, the highest average was 315.0 spikes.m 2 for the branches of the V2 variety for a distance of 60 cm, while the lowest value of overlap was 70.0 spikes m 2 for the branches of the V2 variety for the narrowest planting distance of 20 cm.

The Biological Yield is ton.ha for the Primary Tillers
Table (2) shows that there are significant differences between the two factors of the study and the interaction between them.The distance of 60 cm gave the highest mean of 10.515 tons.hectares was significantly superior to the cultivating distances, with an increase of 38.44 and 67.31% for the planting distances of 20 and 40 cm, respectively.As for the cultivars, the V1 cultivar was significantly superior to the V2 cultivar, due to the cultivar's genetic nature and the ability of branching to give the highest number of spikes, which is reflected in the increase in the accumulation of dry matter and thus the biological yield.These results agree with the findings of the researchers [17][18][19][20][21][22].

Conclusion
We conclude that the planting distance between the lines of 60 cm provides the appropriate space for optimal interception of light for the purpose of photosynthesis.The distance between the lines affected the wheat crop and its components in the 2019-2020 planting season.For the main stem and branches.Row spacing mainly affected the yield and its components in the study area, then the average height of grain yield and biomass of 60 cm was recorded.In conclusion, the wheat planted with spaced distances had an effect on the growth characteristics of wheat, just as the different genotypes of wheat behaved differently due to the difference in the ability to branch.The performance of cultivars with a high branch rate was better in the widest rows, and on the contrary, in the cultivars with fewer branches, the distance between the narrower rows was better for them.Row spacing allows for optimal production and provides better crop canopy and space for crop management under this practice and crop engineering.

Table 2 .
Showing the behavior of cultivars with planting distances and their effect on the growth characteristics of the Tillers.