scholarly journals Assessment of Wheat Optimum Density in Dryland Farming by Using Reciprocal Mode

2017 ◽  
Vol 9 (4) ◽  
pp. 539-543
Author(s):  
Salar FARHANGI-ABRIZ ◽  
Shahram TORABIAN

Adjustment of seeding schemes is one of the crop management techniques that most influences grain yield. A field study was undertaken to evaluate the effects of densities on optimum wheat grain yield, biological yield and harvest index by using of reciprocal model. The treatments comprised nine wheat cultivars and five densities (200, 250, 300, 350 and 400 plants m-2 ). Evaluation analysis showed that the performance of the model was reasonable as indicated by close correspondence of simulated biomass accumulation, grain yield and harvest index with measured data. Optimum wheat density based on maximum grain yield was almost 400 plant m-2 for ‘Rasad’, ‘Azar2’, ‘Homa’, ‘Saji’, ‘Koohdasht’, ‘Gohar’ and ‘Ohadi’; however, the optimum density was of 370 and 500 plant m-2 for ‘Nicknejad’ and ‘Zagros’ respectively. As an average, the highest of grain yield belonged to ‘Azar2’ by 414 g/m-2 . Biological and grain yields were dependent on the plant density, and increased when wheat density enhanced from 200 to 400 plants/m-2.

2007 ◽  
Vol 42 (6) ◽  
pp. 817-825 ◽  
Author(s):  
Osmar Rodrigues ◽  
Julio César Barreneche Lhamby ◽  
Agostinho Dirceu Didonet ◽  
José Abramo Marchese

The objective of this study was to assess the impact of genetic breeding on grain yield, and to identify the physiological traits associated to the increment in yield and their related growth processes, for wheat cultivars grown in Southern Brazil, in the past five decades. Seven wheat cultivars released between 1940 and 1992, were compared for physiological aspects associated with grain yield. Grain yield, biological yield, biomass partitioning, harvest index and grain yield components were also determined. The number of grains per square meter was more affected by plant breeding and was better correlated with grain yield (r = 0.94, p<0.01) than with grain weight (r = -0.39ns). The higher number of grains per square meter was better correlated with the number of grains per spike in the modern cultivars than in the older ones. The genetic gain in grain yield was 44.9 kg ha-1 per year, reflecting important efforts of the breeding programs carried out in Southern Brazil. Grain yield changes, during the period of study, were better associated with biomass production (r = 0.78, p<0.01) than with harvest index (r = 0.65, p<0.01).


2009 ◽  
Vol 45 (2) ◽  
pp. 149-163 ◽  
Author(s):  
HAMID REZA MIRI

SUMMARYIn order to understanding the changes in morpho-physiological traits of wheat cultivars released from 1940 to 2000 in Iran and to determine the association of these traits with grain yield, an experiment was conducted with 15 wheat cultivars released over the past 60 years using an randomized complete block design with four replications. The experiment was conducted on an experimental farm of Arsanjan Islamic Azad University in 2005/6 and 2006/7. Results indicated that cultivar grain yield was significantly correlated with year of release over the 60 years (r = 0.878, p < 0.01). Harvest index and biological yield increased significantly with increasing grain yield. The change in the photosynthesis rate was not significant during this period but transpiration rate and stomatal conductance and chlorophyll index increased significantly. Among yield components, grain number per ear increased significantly but increase in ear number was not significant. Plant height decreased significantly in new cultivars. In conclusion the results showed that wheat yield improvement in Iran is associated with increasing harvest index, grain number per ear, transpiration rate, stomatal conductance and decreasing plant height.


2007 ◽  
Vol 146 (1) ◽  
pp. 35-47 ◽  
Author(s):  
P. PELTONEN-SAINIO ◽  
S. MUURINEN ◽  
A. RAJALA ◽  
L. JAUHIAINEN

SUMMARYIncreased harvest index (HI) has been one of the principal factors contributing to genetic yield improvements in spring barley (Hordeum vulgare L.), oat (Avena sativa L.) and wheat (Triticum aestivum L.) cultivars. Although high HI demonstrates high-yielding ability when cultivars are compared, it can also indicate challenges to yield formation when comparisons are made across differing growing conditions. The present study was designed to investigate variation in HI among modern cereal cultivars relative to that brought about by a northern environment, to assess whether HI still explains the majority of the differences in grain yield when only modern cereal cultivars are compared, and to monitor key traits contributing to HI. Stability of HI was also investigated with reference to the role of tillers. Twelve experiments (3 years, two locations, two nitrogen fertilizer regimes) were carried out in southern Finland to evaluate 12 two-row spring barley, 10 six-row barley, 10 oat and 11 wheat cultivars. In addition to HI, days to heading and maturity, length of grain filling period, grain yield, test weight and 13 traits characterizing plant stand structure were measured and analysed with principal component analysis (PCA) to detect traits associated with HI and those contributing to stability of HI. Although only modern cereals were studied, differences among cultivars were significant both in mean HI and stability of HI, and HI was associated with short plant stature in all modern cereal species. Also, single grain weight was associated with HI in all species. Differences between, but not within, species in HI were partly attributable to differences in tiller performance. Grain yield was associated closely with HI except in two-row barley. It may be possible to further increase HI of wheat, as it still was relatively low. High HI did, however, not indicate the degree of success in yield determination when environments are compared.


1978 ◽  
Vol 26 (4) ◽  
pp. 383-398 ◽  
Author(s):  
A. Darwinkel

The effect of plant density on the growth and productivity of the various ear-bearing stems of winter wheat was studied in detail to obtain information on the pattern of grain production of crops grown under field conditions. Strong compensation effects were measured: a 160-fold increase in plant density (5-800 plants/m2) finally resulted in a 3-fold increase in grain yield (282 to 850 g DM/m2). Max. grain yield was achieved at 100 plants/m2, which corresponded to 430 ears/m2 and to about 19 000 grains/m2. At higher plant densities more ears and more grains were produced, but grain yield remained constant. Tillering/plant was largely favoured by low plant densities because these allowed tiller formation to continue for a longer period and a greater proportion of tillers produced ears. However, at higher plant densities more tillers/unit area were formed and, despite a higher mortality, more ears were produced. The productivity of individual ears, from main stems as well as from tillers, decreased with increasing plant density and with later emergence of shoots. In the range from 5 to 800 plants/m2 grain yield/ear decreased from 2.40 to 1.14 g DM. At 800 plants/m2 nearly all ears originated from main stems, but with decreasing plant density tillers contributed increasingly to the number of ears. At 5 plants/m2, there were 23 ears/plant and grain yield/ear ranged from 4.20 (main stem) to 1.86 g DM (late-formed stems). Grain number/ear was reduced at higher densities and on younger stems, because there were fewer fertile spikelets and fewer grains in these spikelets. At the low density of 5 plants/m2, plants developed solitarily and grain yield/ear was determined by the number of grains/ear as well as by grain wt. Above 400 ears/m2, in this experiment reached at 100 plants/m2 and more, grain yield/ear depended solely on grain number, because the wt. of grains of the various stems were similar. The harvest index showed a max. of about 44% at a moderate plant density; at this density nearly max. grain yield was achieved. At low plant densities the harvest index decreased from 45% in main stems to about 36% in late-formed stems. However, no differences in harvest index existed between the various ear-bearing stems if the number of ears exceeded 400/m2. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1970 ◽  
Vol 34 (1) ◽  
pp. 33-39 ◽  
Author(s):  
MAT Sohel ◽  
MAB Siddique ◽  
M Asaduzzaman ◽  
MN Alam ◽  
MM Karim

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from July to December 2004 to evaluate the effect of hill spacing on the performance of BRRI dhan40 and BRRI dhan41 as Transplant aman crop. The experiment consisted of five hill spacings viz., 5cm. 10cm, 15 cm, and 25 cm where row to row spacing of 25 cm was kept constant for all treatments. The experiment was laid out in randomized complete block design with four replications. The 25 cm x 5 cm hill spacing produced the tallest plant, highest total number of tillers/hill, bearing tillers/hill lowest number of non-hearing tillers/hill, grain yield and harvest index, while 25 cm x 5 cm hill spacing produced the highest number of sterile spikelets/panicle, straw yield and biological yield. BRRI dhan41 produced higher grain yield (4.7 t/ha) which was the contribution of higher number of grains/panicle and heavier grain weight. Lower yield (4.51 t/ha) was recorded in BRRI dhan40.Key Words: Varietal performance; T. aman rice; hill density.DOI: 10.3329/bjar.v34i1.5750Bangladesh J. Agril. Res. 34(1) : 33-39, March 2009


2020 ◽  
Vol 3 (1) ◽  
pp. 233-239 ◽  
Author(s):  
Sampurna Bartaula ◽  
Urbasi Panthi ◽  
Anil Adhikari ◽  
Mohan Mahato ◽  
Darbin Joshi ◽  
...  

A field experiment was conducted to evaluate the plant height, yield and yield attributes of wheat under different tillage practices and nitrogen level at Dang, Nepal during winter season 2018-19. The experiment was laid out in split plot design with two tillage practices viz. zero tillage and conventional tillage as main plot factor and four level of N viz. 50 kg ha-1, 75 kg ha-1, 100 kg ha-1and 125 kg ha-1 as sub plot factor and each replicated thrice.  The result revealed that there is no significant relation between tillage practice and plant height of wheat while N level significantly affect the plant height. 125 kg N ha-1 recorded the highest plant height (110.7 cm). Zero tillage recorded the highest effective tiller m-2 (254) and grain yield (3.3 t ha-1) whereas spike length, grain spike-1, biological yield and harvest index were not significant with tillage practices. Regarding the N level, 125 kg N ha-1 recorded the highest effective spike m-2 (279), spike length (10.6 cm), grain spike-1 (48), thousand grain weight (46.3 g), grain yield (3.6 t ha-1) and biological yield (9.4 t ha-1). 50 kg N ha-1 recorded the highest harvest index (42.9%). The interaction between the tillage practice and nitrogen level showed the significant effect on grain yield and harvest index where as other parameters showed non-significant relation. The zero tillage with 125 kg N ha-1 recorded the highest grain yield (3.9 t ha-1).


2018 ◽  
Vol 5 (3) ◽  
pp. 313-320
Author(s):  
Israt Jahan ◽  
Sarder Md Altaf Hossain ◽  
Md Anwarul Islam ◽  
Joynulalam Talukder

The research was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, to investigate the effect of time of split application of potassium on the yield of three transplanted (T) aman rice varieties. Rice varieties were BRRI dhan39, BRRI dhan40 and BRRI dhan41. Potassium was applied at the rate of 80 kg K ha-1. Experimental plot size was 5m2 (2.5m ×2.0m). Four split application of potassium [K1= Control (No K application), K2= 40 g K plot-1 at 15 DAT (days after transplanting), K3= 20 g K plot-1 at15 DAT+20 g K plot-1 at 30DAT, K4= 10 g K plot-1 at 15 DAT+ 10 g K plot-1 at 25DAT+ 10 g K plot-1 at 30 DAT+ 10 g K plot-1 at 45 DAT] were considered as treatments. From the experiment it was found that split application of potassium had no significant effect on plant height, length of panicle, thousand grains weight. It was evident that two splits application of potassium i.e., 20 g K plot-1 at 15 DAT+20 g K plot-1 at 30 DAT with BRRI dhan41 gave maximum no. of tiller hill-1, effective tiller hill-1, grains panicle-1, grain yield and straw yield, biological yield and harvest index. But varieties differed among themselves in terms of yield contributing characters and yield, and BRRI dhan41 performed the best. Therefore, based on the findings of the present study, it may be concluded that for obtaining higher yield BRRI dhan 41 can be grown following application of potassium at the rate of 80 kg ha-1 in two equal split at 15 and 30 days after transplanting Res. Agric., Livest. Fish.5(3): 313-320, December 2018


1992 ◽  
Vol 119 (3) ◽  
pp. 297-301 ◽  
Author(s):  
S. K. Roy ◽  
P. K. Biswas

SUMMARYMaize was grown al the Regional Agricultural Research Station, Hathazari, Bangladesh during 1988/89 and 1989/90 to study fodder yield, cob growth and grain yield together with the contribution of pre-silking stem reserves to grain. Population densities were 33300, 44400 and 66600 plants/ha. Plants were either detopped after silking and pollen shedding, keeping 0, 2 or 3 leaves above the cob, or were left entire.The results showed that the maize crop could successfully be detopped for fodder with little or no adverse effect on grain yield. Fodder yield increased with increased plant density and among the detopping treatments the highest fodder yield was obtained when the plants were detopped just above the cob. Cob growth followed a sigmoid pattern and the highest dry weight per cob was obtained from the lowest plant density and from entire plants. The number of cobs/m2 increased with increased plant density but detopping treatments did not give any significant difference in relation to densities. The number of grains/cob was highest with 33300 plants/ha but, among the detopping treatments, plants detopped just above the cob had the lowest number of grains/cob in both years. Weight of 1000-grain decreased with increasing plant density but it was increased by detopping plants just above the cob during 1988/89, although it was decreased in 1989/90. The highest apparent translocation of pre-silking reserves was obtained using densities of 44400 plants/ha but detopping treatments did not show any consistent effect, although the highest apparent translocation (20%) and harvest index (58%) were obtained from plants detopped just above the cob.


2003 ◽  
Vol 140 (4) ◽  
pp. 395-407 ◽  
Author(s):  
R. E. RUSKE ◽  
M. J. GOODING ◽  
S. A. JONES

Field experiments were conducted over 3 years to assess the effect of a triazole fungicide programme, and additions of strobilurin fungicides to it, on nitrogen uptake, accumulation and partitioning in a range of winter wheat cultivars. Commensurate with delayed senescence, fungicide programmes, particularly when including strobilurins, improved grain yield through improvements in both crop biomass and harvest index, although the relationship with green area duration of the flag leaf (GFLAD) depended on year and in some cases, cultivar. In all years fungicide treatments significantly increased the amount of nitrogen in the above-ground biomass, the amount of nitrogen in the grain and the nitrogen harvest index. All these effects could be linearly related to the fungicide effect on GFLAD. These relationships occasionally interacted with cultivar but there was no evidence that fungicide mode of action affected the relationship between GFLAD and yield of nitrogen in the grain. Fungicide treatments significantly reduced the amount of soil mineral N at harvest and when severe disease had been controlled, the net remobilization of N from the vegetation to the grain after anthesis. Fungicide maintained the filling of grain with both dry matter and nitrogen. The proportionate accumulation of nitrogen in the grain was later than that of dry matter and this difference was greater when fungicide had been applied. Effects of fungicide on grain protein concentration and its relationship with GFLAD were inconsistent over year and cultivar. There were several instances where grain protein concentration was unaffected despite large (1·5 t/ha) increases in grain yield following fungicide use. Dilution of grain protein concentration following fungicide use, when it did occur, was small compared with what would be predicted by adoption of other yield increasing techniques such as the selection of high yielding cultivars (based on currently available cultivars) or by growing wheat in favourable climates.


Author(s):  
Shantanu Das ◽  
Debojit Sarma

Thirty rice genotypes of local and exotic origin were analyzed to ascertain the genotypic and phenotypic correlation among 21 morpho-physiological and yield traits and their direct/ indirect contribution to grain yield under <italic>boro</italic> season. The result revealed that grain yield per plant had significant positive correlation with biological yield (0.927**, 0.766**), harvest index (0.748**, 0.658**), days to first flowering (0.459*, 0.377*), panicle length (0.501**, 0.445*), grains per panicle (0.576**, 0.484**) and 1000 grain weight (0.573**, 0.460*) at both genotypic and phenotypic levels. Path coefficient analyses at both genotypic and phenotypic levels revealed high positive direct effect of biological yield (0.7181) and harvest index (0.6382) on grain yield per plant. Thus direct selection for grain yield per plant and indirect selection through these characters would be effective to improve yield in <italic>boro</italic> rice.


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