scholarly journals Spatial arrangement of maize plants aiming to maximize grain yield in the hybrid BRS-3046

2020 ◽  
pp. 1662-1669
Author(s):  
Marcus Willame Lopes Carvalho ◽  
Edson Alves Bastos ◽  
Milton José Cardoso ◽  
Aderson Soares de Andrade Junior ◽  
Carlos Antônio Ferreira de Sousa
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Intercellular Co2 Concentration ◽  
Maximum Yield ◽  
Co2 Concentration ◽  
Spatial Arrangement ◽  
Co2 Assimilation ◽  
Linear Increase ◽  
Planting Density ◽  
Row Spacing

The objectives of this study were to: (i) evaluate the effect of different spatial arrangements on morpho-physiological characteristics and (ii) determine the optimal spatial arrangement to maximize grain yield of the maize hybrid BRS-3046 grown in the Mid-North region of Brazil. We tested two row spacings (0.5 and 1 m) and five plant densities (2, 4, 6, 8, 10 plants m-2), which corresponded to 10 different plant spatial arrangements. Different morphophysiological variables, gas exchange rates and grain yield were measured. The increased planting density led to a linear increase in LAI, regardless of row spacing, while the net CO2 assimilation rate increased until the density of 4 and 6 plants m-2, under a row spacing of 0.5 and 1.0 m, respectively. On the other hand, we found a linear reduction in the stomatal conductance with increasing planting density. The intercellular CO2 concentration and the transpiration rate were higher in the widest row spacing. The instantaneous efficiency of carboxylation, in turn, showed a slight increase up to the density of six plants m-2, then falling, regardless of row spacing. Increasing plant density resulted in a linear increase in plant height and ear insertion height, regardless of row spacing. However, it had an opposite effect on stem diameter. Grain yield, in turn, increased up to 7.3 plants m-2 at a row spacing of 0.5 m and 8 plants m-2 at a row spacing of 1.0 m. This spatial arrangement was considered as ideal for achieving maximum yield

Plant density and yield of grain maize in England

1973 ◽  
Vol 81 (3) ◽  
pp. 455-463 ◽  
Author(s):  
E. S. Bunting
Keyword(s):  
Grain Yield ◽  
Water Content ◽  
Field Experiments ◽  
Plant Density ◽  
Unit Area ◽  
Maximum Yield ◽  
Spatial Arrangement ◽  
Practical Significance ◽  
Plant Densities ◽  
The Difference

SUMMARYResults from 10 field experiments are reported. Inra 200, the standard variety in official maize grain trials in Britain, was grown in six of the trials; comparative information was obtained on a range of competitive commercial hybrids and an experimental, early flowering, hybrid. The final plant densities most commonly involved ranged from 5 to 20 plants/m2, with extremes of 2 and 30 plants/m2. The effects of spatial arrangement were also considered in multifactorial or systematic designs; in general, yields increased slightly with more even spacing but no evidence was adduced that spacing, within the limits likely to be encountered in commercial practice, would significantly modify interpretations of density effects.In all varieties tested, a satisfactory model for the response in yield of grain to changes in plant density was 1/y = a + bx + cx2, where y = grain yield/plant and x = density. Estimated parameter values, however, were not the same for all varieties and significant genotype × density interactions were obtained.Grain yield/unit area in Inra 200 was maximal at densities of 8–10 plants/m2, but the response curve did not have a pronounced peak; differences in average yieldat densities ranging from 6 to 14 plants/m2 were less than 6%, and yield at 20 plants/m2 was about 80% of the maximum. Other flint × dent hybrids grown commercially for grain in northern areas (Anjou 210, L.G. 11, Warwick SL 209) reached maximum grain yield/unit area at lower densities (6–8 plants/m2), and the decline in yield with increasing density was much more marked than in Inra 200. In contrast, an earlier flowering, shorter growing, experimental hybrid (ARC 51 A) did not reach maximum yield until density was raised to 14 plants/m2, and was even more tolerant of high plant densities than Inra 200. With increasing plant density the number of ears/plant declined, falling below 1–0 in Inra 200 at densities in excess of 10 plants/m2, and averaging about 0–8 at plants/m2. Over the range 6–20 plants/m2 shelling percentage was reduced by no more than 4%, but water content of the ear (grain plus rachis) increased significantly with density. In the very early hybrid, ARC 51A, the difference in water content of the ear at 6 and 20 plants/m2 was less than 3%, but in Inra 200 it averaged about 8% and in varieties less tolerant of high densities it was often ofthe order of 15%. These results could be related to the delaying effects of increasing density on time of silk emergence. Relatively, time of pollen shed was little affected by density changes. In Inra 200 the difference in time between mid-anthesis and mid-silk was about 7 days more at 20 plants/m2 than at 6 plants/m2 while in Anjou 210 and Kelvedon 59A the comparable increase was 14 days.The practical significance of the findings is discussed in relation to current grain and silage maize production practices, and to future breeding and testing programmes in Northern Europe.

scholarly journals Gas exchanges in peach palms as a function of the spad chlorophyll meter readings

2011 ◽  
Vol 33 (spe1) ◽  
pp. 267-274 ◽  
Author(s):  
Maria Luiza Sant'anna Tucci ◽  
Valéria Aparecida Modolo ◽  
Norma de Magalhães Erismann ◽  
Eduardo Caruso Machado
Keyword(s):  
Intercellular Co2 Concentration ◽  
Co2 Concentration ◽  
Co2 Assimilation ◽  
Photosynthetic Photon Flux Density ◽  
Linear Increase ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Gas Exchanges ◽  
Complementary Method ◽  
Spad Readings

The close relationship between the chlorophyll-meters readings and the total chlorophyll and nitrogen contents in leaves, has allowed their evaluation both in annual and perennial species. Besides, some physiological events such as the CO2 assimilation have also been estimated by chlorophyll meters. This work was carried out aiming to evaluate the gas exchanges of peach palms as a function of the chlorophyll SPAD-Meter readings. Three year-old peach palms from Yurimaguas, Peru were studied in Ubatuba, SP, Brazil, spaced 2 x 1 m in area under a natural gradient of organic matter which allowed four plots to be considered, according to the peach palms leaves colors, from light yellow to dark green. The SPAD readings and the stomatal frequency of leaflets were evaluated. The photosynthetic photon flux density (PPFD, μmol m-2 s-1), the leaf temperature (Tleaf, ºC), the CO2 assimilation (A, μmol m-2 s-1), the stomatal conductance (g s, mol m-2 s-1), the transpiration (E, mmol m-2 s-1) and the intercellular CO2 concentration (Ci, μmol mol-1) were evaluated with a portable infrared gas analyzer (LCA-4, ADC BioScientific Ltd., Great Amwell, U.K.). A linear increase in the CO2 assimilation as a function of the SPAD readings (y = -0.34 + 0.19x, R² = 0.99), indicates that they can be a rapid and cheap complementary method to evaluate in peach palms some important physiological events, such as CO2 assimilation.

scholarly journals Optimizing Planting Density and Impact of Panicle Types on Grain Yield and Microclimatic Response Index of Hybrid Rice (Oryza sativa L.)

2021 ◽  
Author(s):  
Guotao Yang ◽  
Xuechun Wang ◽  
Farhan Nabi ◽  
Hongni Wang ◽  
Changkun Zhao ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Grain Yield ◽  
Hybrid Rice ◽  
Plant Density ◽  
Oryza Sativa L ◽  
Planting Density ◽  
Response Index ◽  
Lower Position ◽  
High Plant Density

AbstractThe architecture of rice plant represents important and complex agronomic traits, such as panicles morphology, which directly influence the microclimate of rice population and consequently grain yield. To enhance yield, modification of plant architecture to create new hybrid cultivars is considered a sustainable approach. The current study includes an investigation of yield and microclimate response index under low to high plant density of two indica hybrid rice R498 (curved panicles) and R499 (erect panicles), from 2017 to 2018. The split-plot design included planting densities of 11.9–36.2 plant/m2. The results showed that compared with R498, R499 produced a higher grain yield of 8.02–8.83 t/ha at a higher planting density of 26.5–36.2 plant/m2. The response index of light intensity and relative humidity to the planting density of R499 was higher than that of R498 at the lower position of the rice population. However, the response index of temperature to the planting density of R499 was higher at the upper position (0.2–1.4%) than at the lower position. Compared with R498, R499 at a high planting density developed lower relative humidity (78–88%) and higher light intensity (9900–15,916 lx) at the lower position of the rice population. Our finding suggests that erect panicles are highly related to grain yield microclimatic contributors under a highly dense rice population, such as light intensity utilization, humidity, and temperature. The application of erect panicle rice type provides a potential strategy for yield improvement by increasing microclimatic conditions in rice.

scholarly journals Increasing population density reduces soybean yield components and productivity

2021 ◽  
Vol 37 ◽  
pp. e37042
Author(s):  
Marcelo De Almeida Silva ◽  
Ana Carolina De Santana Soares ◽  
Melina Rodrigues Alves Carnietto ◽  
Alexandrius De Moraes Barbosa
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Spatial Arrangement ◽  
Plant Population ◽  
Row Spacing ◽  
Individual Plant ◽  
Growth Type ◽  
Soybean Yield ◽  
Plant Densities ◽  
Plant Yields

Studies addressing the interaction of different spatial arrangement in soybean are needed in order to achieve management that leads to higher grain yield associated with rational seed use. The objective of this work was to evaluate the yield components and productivity of an undetermined growth type soybean as a function of different row spacing and plant densities. The treatments consisted of three row spaces (0.25, 0.35 and 0.45 m) and three plant population densities (30, 40 and 50 plants/m²). There was no interaction of row spaces and plant population on soybean yield. Regarding the overall spacing average, the grain yield of the population of 30/m² plants was higher than the productivity of the populations of 40 and 50/m² plants. The largest populations reduce plant sizes due to greater competition between plants. In addition, smaller populations promote higher individual plant yields due to the increase components of the production. This characteristic is defined as the ability of the plant to change its morphology and yield components in order to adapt to the conditions imposed by the spatial arrangement.

Growth and Physiology Vary Little Among North American, an Asian, and a North American x Asian Hybrid Ash in a Common Garden in Ohio, U.S.A

2019 ◽  
Vol 45 (3) ◽  
Author(s):  
Laurel Haavik ◽  
Daniel Herms
Keyword(s):  
Photosystem Ii ◽  
North American ◽  
Intercellular Co2 Concentration ◽  
Emerald Ash Borer ◽  
Common Garden ◽  
Co2 Concentration ◽  
Interspecific Variation ◽  
Co2 Assimilation ◽  
Agrilus Planipennis ◽  
White Ash

The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) invasion of North America has increased interest in ash (Fraxinus, Oleaceae) phylogeny, ecology, and physiology. In a common garden in central Ohio, we compared the performance of three North American ash cultivars that are highly susceptible to EAB (F. pennsylvanica ‘Patmore,’ F. americana ‘Autumn Purple,’ and F. nigra ‘Fall Gold’), one North American species that is less susceptible to EAB (F. quadrangulata), and two taxa that are resistant to EAB (F. mandshurica and F. mandshurica × F. nigra ‘Northern Treasure’). During the 2015 growing season, we measured diameter growth, foliar N concentration, specific leaf area, and on four dates (two with adequate and two with low precipitation) we measured CO2 assimilation rate (A), stomatal conductance (gs), intercellular CO2 concentration (Ci), photosynthetic nitrogen use efficiency (PNUE), variable fluorescence (Fv’/Fm’: efficiency of energy harvested by open photosystem II reaction centers), and the fraction of photons absorbed by photosystem II that were used for photosynthesis (ɸPSII). F. pennsylvanica grew fastest and on most sampling dates was superior in physiological performance (A, gs, and ɸPSII). Generally, however, there was little interspecific variation in growth and physiology among the different ash taxa tested, as all performed well. This suggests that the EAB-resistant F. mandshurica and F. mandshurica × F. nigra hybrid, as well as the moderately resistant blue ash, are as physiologically well-suited to growing conditions in the Midwestern United States as green and white ash cultivars that had been widely planted prior to the EAB invasion.

Effect of plant density on grain yield and yield stability of sorghum hybrids differing in maturity

1990 ◽  
Vol 30 (2) ◽  
pp. 257 ◽  
Author(s):  
LJ Wade ◽  
ACL Douglas
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Maximum Yield ◽  
Yield Stability ◽  
Early Maturity ◽  
Yield Level ◽  
Wide Range ◽  
Plant Densities ◽  
The Stability ◽  
Sorghum Grain

The extent and significance of the maturity x density interaction in dryland grain sorghum, and its implications for yield stability, were examined for 3 hybrids over 6 locations. Site mean grain yield ranged from 0.44 to 4.96 t/ha. Early maturity was superior in environments truncated by water stress, while late maturity was superior in favourable environments. Mid-season maturity provided greater stability of grain yield. Maximum yield by each hybrid at each yield level did not differ significantly from yield at a density of 75 000 plants/ha. The highest grain yields should be obtained with plant densities of 50000-100000 plants/ha under rainfed conditions, where yield expectations range from 0 to 5.0 t/ha. The results demonstrate the stability of sorghum grain yield over a wide range of plant density and crop maturity. Regression analysis aided data presentation and interpretation.

scholarly journals Performance of cotton genotype TCH 1819 to high density planting system under winter irrigated condition at the Western agroclimatic zone of Tamil Nadu

2021 ◽  
Vol 13 (SI) ◽  
pp. 130-134
Author(s):  
R. Sowmiya ◽  
N. Sakthivel
Keyword(s):  
Tamil Nadu ◽  
Plant Density ◽  
Unit Area ◽  
Maximum Yield ◽  
Winter Season ◽  
Plant Population ◽  
Growth And Yield ◽  
Row Spacing ◽  
Area Index ◽  
Cotton Genotype

Plant population is an important attribute in crop management practice. Increasing the plant density by decreasing the crop row spacing was an alternative strategy to optimize crop profit. Hence, the field trial was conducted at Tamil Nadu Agricultural University, Coimbatore, during the winter season of 2017 – 18 to study the effect of row spacing on the growth and yield of cotton genotype TCH 1819. The experimental design was Randomized Block Design (RBD) with seven spacing treatments viz., T1: 60 x 15 cm (1,11,111 plants ha-1), T2: 60 x 20 cm (83,333 plants ha-1), T3: 75 x 15 cm (88,888 plants ha-1), T4: 75 x 20 cm (66,666 plants ha-1), T5: 75 x 30 cm (44,444 plants ha-1), T6: 90 x 15 cm (74074 plants ha-1), T7: 90 x 20cm (55,555 plants ha-1) and was replicated thrice.  Plant densities showed a significant (p=0.05) difference for all the characters studied.  The higher plant density of 1,11,111 plants (60 x 15 cm) observed significantly (p=0.05) maximum plant height (103.14 cm), Leaf Area Index (LAI) (4.35), Dry Matter Production (DMP) (8125 kg/ha), Crop Growth Rate (CGR) (6.58 g/m2/day), root length (41.46 cm), root dry weight (14.94 g/plant), and chlorophyll index (48.24).  The number of sympodial branches per plant (17) and bolls per plant (22 bolls) was found significant in the wider spacing of 75 x 30 cm.  The narrow spacing of 60 x 15 cm noted the highest seed cotton yield (2565 kg/ha), net return (R65706.62), and B: C (2.32) ratio, followed by the spacing of 75 x 15 cm due to more plant density per unit area (m2).  So, maximum yield in cotton can be achieved by decreasing the row spacing and increasing the plant population per unit area.

scholarly journals Plant Density Effects on Single-head Broccoli Production

HortScience ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 50-52 ◽  
Author(s):  
Lewis W. Jett ◽  
Ronald D. Morse ◽  
Charles R. O'Dell
Keyword(s):  
Brassica Oleracea ◽  
Plant Density ◽  
Consumer Demand ◽  
Spatial Arrangement ◽  
Unit Weight ◽  
Row Spacing ◽  
Exclusive Production ◽  
Plant Damage ◽  
Plant Densities ◽  
High Yields

There is a strong consumer demand for single-head broccoli (Brassica oleracea L. var. italica) that yields more florets per unit weight than bunching broccoli. Two spatial arrangements (single vs. twin row) and five plant densities (10.8, 7.2, 5.4, 4.3, and 3.6 plants/m2) were examined for single-head broccoli production. Spatial arrangement had no significant effect on any measured attribute, although the twin-row arrangement resulted in less plant damage with each harvest. For exclusive production of quality, single-head broccoli with high yields of marketable florets, 3.6 plants/m2 (46-cm within-row spacing) should be used.

scholarly journals PLANT DENSITY AND FIELD GERMINATION OF WINTER TRITICALE DEPENDING ON VARIETY AND NORMAL SEEDING SEEDS

2018 ◽  
Vol 13 (4) ◽  
pp. 83-86
Author(s):  
Леонид Шашкаров ◽  
Leonid Shashkarov ◽  
Светлана Толстова ◽  
Svetlana Tolstova
Keyword(s):  
Plant Density ◽  
Maximum Yield ◽  
Stand Density ◽  
Weather Conditions ◽  
Planting Density ◽  
Seeding Rate ◽  
Southeastern Part ◽  
Winter Triticale ◽  
Field Germination ◽  
Plant Stand

The article deals with the issues of plant density and field germination of winter triticale on gray forest soils of the southeastern part of the Volga-Vyatka zone depending on the variety and seeding rates. The question of establishing the optimum density of sowing, the area of food for grain crops served as the object of study by many researchers. The urgency of the issue of creating optimal sowing density is explained by the fact that the factors that determine the magnitude of the yield are constantly changing. The plant stand density and field germination of winter triticale are significantly influenced by the weather conditions formed during the growing season of winter triticale plants. With an increase in seeding rates, the plant stand density and seeding rate increases, respectively, is important for the formation of a given density of productive stalks. In production, these elements of technology are often underestimated and often unjustifiably overestimate the seeding rate, which is absolutely unnecessary, since the really possible yield is achieved at an optimal seeding rate with minimal seed consumption. The winter triticale seeding rates, both in Russia and in the world as a whole varies from 2 to 8 million viable seeds per hectare. The urgency of the issue of creating optimal sowing density is explained by the fact that the factors that determine the magnitude of the yield are constantly changing. Until now, there is no consensus on the dependence of planting density on the degree of fertility. Some researchers believe that nutrient-rich soil requires less seed for maximum yield. Under these conditions, the plants develop better, they bush more, the maximum yield can be obtained with a lower seeding rate. The opposite opinion that it is necessary to sow thicker on rich soils has become widespread, especially in recent years. Advocates of the bottom conclusion explain their point of view by the fact that fertile soil has a greater supply of food and moisture, therefore, more plants can be grown on the same area, which means that the seeding rate should be increased [1,2.3,4.5,6,7]. Research results indicate that winter triticale with increasing seeding rates increases plant density and field germination of winter triticale plants.

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