Estimating loss in grain yield due to suboptimal plant density and non-uniformity in plant spacing

1990 ◽  
Vol 30 (2) ◽  
pp. 251 ◽  
Author(s):  
LJ Wade
Keyword(s):  
Grain Yield ◽  
Multiple Regression ◽  
Plant Density ◽  
Effective Area ◽  
Regression Technique ◽  
Yield Potential ◽  
Yield Reduction ◽  
Plant Spacing ◽  
Crop Establishment ◽  
Multiple Regression Technique

The percentage loss in grain yield for a crop of raingrown sunflower was quantified, using a multiple regression technique, for 9 combinations of plant density and uniformity in plant spacing. For each combination, partitioning loss in grain yield involved the reduction in grain yield (g/m2), the number of plants involved and the effective area of crop which those plants represented (m2). Relative to an achievable yield potential of 692 kg/ha, any reduction in grain yield was mainly due to the lack of plants at a density less than 5.00/m2 (7.4% yield reduction) and to non-uniformity in plant spacing at a density greater than 5.001m2 (5.6% yield reduction). The multiple regression technique is considered more valuable than other methods because it provides quantitative estimates of per cent loss in grain yield attributable to suboptimal plant density and non-uniformity in plant spacing. The technique should be of value in assessing the effect of poor crop establishment at a site or in evaluating improved crop establishment. A more general relationship capable of predicting per cent loss in grain yield based on data taken at the time of establishment is still required.

Effects of suboptimal plant density and non-uniformity in plant spacing on grain yield of raingrown sunflower

1988 ◽  
Vol 28 (5) ◽  
pp. 617 ◽  
Author(s):  
LJ Wade ◽  
CP Norris ◽  
PA Walsh
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Unit Area ◽  
Yield Potential ◽  
Individual Plant ◽  
Plant Spacing ◽  
Crop Establishment ◽  
Parabolic Relationship ◽  
Percentage Yield ◽  
The Individual

The effects of suboptimal plant density and non-uniformity in plant spacing on grain yield of raingrown sunflower were examined using regression analysis. This involved quantifying the parabolic relationship between grain weight per plant and area per plant. A term for uniformity was added, based on the proximity of neighbouring plants within the row. Multiple regression accounted for 50% of the total variation amongst the 1071 plants analysed. The 3 constants in the regression were considered to indicate the yield potential of the crop, the proportion of space available per plant not utilised at low density, and the proportion of the most scarce resource denied to the individual plant at high density relative to an equivalent plant at even spacing. This technique permitted quantification of the levels of unevenness, and of the percentage yield reductions attributable to suboptimal plant density and to non-uniformity in plant spacing. Reductions in grain yield per unit area were mainly due to a lack of plants at low densities, and to unevenness at high densities. A technique is proposed for surveying crop establishment, and for estimating the percentage yield reductions attributable to the effects of plant density and uniformity in plant spacing over a range of crops. Further experimentation is warranted, to determine whether the percentage yield reductions found for this crop are generally applicable.

scholarly journals ENHANCING WATER AND FERTILIZER SAVING WITHOUT COMPROMISING RICE YIELD THROUGH INTEGRATED CROP MANAGEMENT

2013 ◽  
Vol 11 (2) ◽  
pp. 65 ◽  
Author(s):  
I.P. Wardana ◽  
A. Gania ◽  
S. Abdulrachman ◽  
P.S. Bindraban ◽  
H. Van Keulen
Keyword(s):  
Water Management ◽  
Organic Matter ◽  
Grain Yield ◽  
Rice Yield ◽  
Crop Management ◽  
Yield Response ◽  
Plant Spacing ◽  
Crop Establishment ◽  
Integrated Crop Management ◽  
Establishment Method

<p>Water and fertilizer scarcity amid the increasing need of rice production challenges today’s agriculture. Integrated crop management (ICM) is a combination of water, crop, and nutrient management that optimizes the synergistic interaction of these components aiming at improving resource use efficiency, i.e. high productivity of water, land, and labor. The objectives of the study were to investigate the effects of crop establishment method, organic matter amendment, NPK management, and water management on yield of lowland rice. Five series of experiments were conducted at Sukamandi and Kuningan Experimental Stations, West Java. The first experiment was focused on crop establishment method, i.e. plant spacing and number of seedlings per hill. The second, third, and fourth experiments were directed to study the effect of NPK and organic matter applications on rice yield. The fifth experiments was designed to evaluate the effect of water management on rice yield. Results showed that 20 cm x 20 cm plant spacing resulted in the highest grain yield for the new plant type rice varieties. Organic matter and P fertilizer application did not significantly affect grain yield, but the yield response to P fertilization tended to be stronger with organic matter amendment. Split P application did not significantly increase grain yield. The use of a scale 4 leaf color chart reading resulted in a considerable N fertilizer saving without compromising rice yield. Intermittent irrigation technique saved water up to 55% without affecting yields, resulting in a 2-3 times higher water productivity.</p>

Grain nitrogen concentration differences among three sorghum hybrids with similar grain yield

1999 ◽  
Vol 50 (2) ◽  
pp. 137 ◽  
Author(s):  
A. Kamoshita ◽  
M. Cooper ◽  
R. C. Muchow ◽  
S. Fukai
Keyword(s):  
Grain Yield ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Grain Filling ◽  
Yield Potential ◽  
Yield Reduction ◽  
N Availability ◽  
N Accumulation ◽  
N Concentration ◽  
Grain Nitrogen

The differences in grain nitrogen (N) concentration among 3 sorghum (Sorghum bicolor (L.) Moench) hybrids with similar grain yield were examined under N-limiting conditions in relation to the availability of assimilate and N to grain. Several manipulation treatments [N fertiliser application, lower leaves shading, thinning (reduced plant population), whole canopy shading, canopy opening, spikelet removal] were imposed to alter the relative N and assimilate availability to grain under full irrigation supply. Grain N concentration increased by either increased grain N availability or yield reduction while maintaining N uptake. Grain N concentration, however, did not decrease in the treatments where relative abundance of N compared with assimilate was intended to be reduced. The minimum levels of grain N concentration differed from 0.95% (ATx623/RTx430) to 1.14% (DK55plus) in these treatments. Regardless of the extent of variation in assimilate and N supply to grain, the ranking of hybrids on grain N concentration was consistent across the manipulation treatments. For the 3 hybrids examined, higher grain N concentration was associated with higher N uptake during grain filling and, to a lesser extent, with higher N mobilisation. Hybrids with larger grain N accumulation had a larger number of grains. There was no tradeoff between grain N concentration and yield, suggesting that grain protein concentration can be improved without sacrificing yield potential.

scholarly journals Threshold Tolerance of New Genotypes of Pennisetum glaucum (L.) R. Br. to Salinity and Drought

Agronomy ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 230 ◽  
Author(s):  
Kristina Toderich ◽  
Elena Shuyskaya ◽  
Zulfira Rakhmankulova ◽  
Roman Bukarev ◽  
Temur Khujanazarov ◽  
...  
Keyword(s):  
Grain Yield ◽  
Crop Production ◽  
Plant Density ◽  
Pennisetum Glaucum ◽  
Germination Rate ◽  
Malonic Dialdehyde ◽  
Carotenoid Biosynthesis ◽  
Soil Salinization ◽  
Yield Potential ◽  
Grain Yields

With continued population growth, increasing staple crop production is necessary. However, in dryland areas, this is negatively affected by various abiotic stresses, such as drought and salinity. The field screening of 10 improved genetic lines of pear millet originating from African dryland areas was conducted based on a set of agrobiological traits (i.e., germination rate, plant density, plant maturity rate, forage, and grain yields) in order to understand plant growth and its yield potential responses under saline environments. Our findings demonstrated that genotype had a significant impact on the accumulation of green biomass (64.4% based on two-way ANOVA), while salinity caused reduction in grain yield value. HHVBC Tall and IP 19586 were selected as the best-performing and high-yielding genotypes. HHVBC Tall is a dual purpose (i.e., forage and grain) line which produced high grain yields on marginal lands, with soil salinization up to electrical conductivity (EC) 6–8 dS m−1 (approximately 60–80 mM NaCl). Meanwhile, IP 19586, grown under similar conditions, showed a rapid accumulation of green biomass with a significant decrease in grain yield. Both lines were tolerant to drought and sensitive to high salinity (above 200 mM NaCl). The threshold salinity of HHVBC Tall calculated at the seedling stage was lower than that of IP 19586. Seedling viability of these lines was affected by oxidative stress and membrane peroxidation, and they had decreased chlorophyll and carotenoid biosynthesis. This study demonstrated that ionic stress is more detrimental for the accumulation of green and dry biomass, in combination with increasing the proline and malonic dialdehyde (MDA) contents of both best-performing pearl millet lines, as compared with osmotic stress.

scholarly journals Assessment of Genetic Diversity for Drought, Heat and Combined Drought and Heat Stress Tolerance in Early Maturing Maize Landraces

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 518 ◽  
Author(s):  
Nelimor ◽  
Badu-Apraku ◽  
Tetteh ◽  
N’guetta
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Drought Stress ◽  
Grain Yield ◽  
Yield Potential ◽  
Yield Reduction ◽  
International Institute ◽  
Improvement Program ◽  
Maize Varieties ◽  
Drought And Heat Stress

Climate change is expected to aggravate the effects of drought, heat and combined drought and heat stresses. An important step in developing ‘climate smart’ maize varieties is to identify germplasm with good levels of tolerance to the abiotic stresses. The primary objective of this study was to identify landraces with combined high yield potential and desirable secondary traits under drought, heat and combined drought and heat stresses. Thirty-three landraces from Burkina Faso (6), Ghana (6) and Togo (21), and three drought-tolerant populations/varieties from the Maize Improvement Program at the International Institute of Tropical Agriculture were evaluated under three conditions, namely managed drought stress, heat stress and combined drought and heat stress, with optimal growing conditions as control, for two years. The phenotypic and genetic correlations between grain yield of the different treatments were very weak, suggesting the presence of independent genetic control of yield to these stresses. However, grain yield under heat and combined drought and heat stresses were highly and positively correlated, indicating that heat-tolerant genotypes would most likely tolerate combined drought and stress. Yield reduction averaged 46% under managed drought stress, 55% under heat stress, and 66% under combined drought and heat stress, which reflected hypo-additive effect of drought and heat stress on grain yield of the maize accessions. Accession GH-3505 was highly tolerant to drought, while GH-4859 and TZm-1353 were tolerant to the three stresses. These landrace accessions can be invaluable sources of genes/alleles for breeding for adaptation of maize to climate change.

Leaf modification delays panicle initiation and anthesis in grain sorghum

2001 ◽  
Vol 52 (1) ◽  
pp. 127 ◽  
Author(s):  
S. E. Ockerby ◽  
D. J. Midmore ◽  
D. F. Yule
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Reproductive Development ◽  
Grain Sorghum ◽  
Yield Potential ◽  
Green Leaf ◽  
Sufficient Evidence ◽  
Yield Reduction ◽  
Crop Failure ◽  
Green Leaf Area

Water stress at anthesis is the major cause of yield reduction or crop failure in grain sorghum [Sorghum bicolor (L.) Moench] in central Queensland. Rainfall is difficult to predict and it is impractical to substantially alter the timing and amount of water stored in the soil, so we focussed on whether crop ontogeny could be managed, ultimately giving farmers some capability to align anthesis with in-crop rain. It is widely considered that a signal, transported from the leaf to the shoot apical meristem, is integral to the onset of panicle initiation and reproductive development. We hypothesised that modifying the leaves may interrupt the signal and cause a delay in the onset of reproductive development. Delays in sorghum anthesis associated with leaf modification treatments applied before panicle initiation were found to be a consequence of delays in panicle initiation. The longest delays in panicle initiation were obtained by twice-weekly defoliation above the second ligule (15–45 days); delays were shorter when plants were defoliated above the third ligule (10–41 days) or when only the fully exposed leaves were removed (0–13 days), depending on genotype. Although panicle initiation was delayed, leaf initiation continued, so extra leaves were produced. Defoliation of fully irrigated plants, however, generally reduced green leaf area, plant dry weight at anthesis, and grain yield, all by 30–50%. The application of ethephon also delayed anthesis, and changed the pattern but not the area of leaf produced, and did not alter grain yield. In rain-fed agriculture, where grain yields are frequently <50% of irrigated controls, delaying panicle initiation by 2 weeks may provide a better rainfall environment during which anthesis and grain-filling will occur. Reductions in green leaf area, although reducing yield potential, may promote a more balanced use of water between vegetative and grain growth. There was sufficient evidence to indicate that defoliation before panicle initiation could provide simple post-sowing management to achieve this scenario.

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