scholarly journals GAS EXCHANGE, CHLOROPHYLL CONTENT AND LEAF AREA INDEX OF OKRA AT SIX IN-ROW PLANT DENSITIES

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 689E-689
Author(s):  
Wayne F. Whitehead ◽  
Bharat P. Singh
Keyword(s):  
Gas Exchange ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Significant Variation ◽  
Plant Density ◽  
Net Photosynthesis ◽  
Area Index ◽  
Canopy Position ◽  
Plant Densities

The effect of in-row plant densities on gas exchange, chlorophyll content and leaf area index of okra (Abelmoschus esculentus (L.) Moench) was studied. The six in-row plant densities ranged from 8 cm to 48 cm (D1 - D6). On 11 and 27 July 1990, the photosynthetically active radiation (PAR), transpiration (E), net photosynthesis (Pn) and chlorophyll content (Chl) at top- and mid-canopy levels and leaf area index (LAI) were measured. Mid-canopy PAR was 86 ± 6% less than that of the top-canopy and E, Pn and Chl at mid-canopy were respectively 55, 90 and 10% lower than those of the top-canopy. The interaction of plant density with canopy position was significant for E and Pn. The highest E and Pn, (12.28 mmol m-2 s-1 and 22.01 μmol CO2 m-2 s-1, respectively) were recorded at the D5 top-canopy. In-contrast, the lowest E and Pn, (4.17 mmol m-2 s-l and 1.23 μmol CO2 m-2 s-1, respectively) at the D6 mid-canopy were recorded. The LAI also exhibited significant variation among plant densities with a range of 4.65 to 4.97 for D5 and D3, respectively. These results indicate that 40 cm in-row density was the most suited for gas exchange of okra.

scholarly journals Study of plant physiological parameters in winter oilseed rape (Brassica napus var. napus f. biennis L.) production on chernozem soil

2016 ◽  
pp. 111-115
Author(s):  
Éva Vincze ◽  
Péter Pepó
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Oilseed Rape ◽  
Plant Density ◽  
Sowing Date ◽  
Winter Oilseed Rape ◽  
Sowing Time ◽  
Area Index ◽  
Relative Chlorophyll Content

We made plant physiology examinations in Arkaso winter oilseed rape hybrid substance: relative chlorophyll content (SPAD) and leaf area index (LAI) measurements. The experiment was set in University of Debrecen Agricultural Sciences Center at Látóképi Experimental Station in four replications, in two different sowing times (I. sowing date on 08/22/2014 and II. sowing date on 09/09/2014 sowing againhappened because of the incomplete germination in the second subtance 01/10/2014) Three different plant density 200, 350 and 500 thousand ha-1, under the same nutrient supply, 45 cm row spacing. The experiment was green crop of winter wheat. The relative chlorophyll content (SPAD) and leaf area index (LAI) measurements were made in seven different times. We measured the maximum value of chlorophyll content in the first sowing time at 500, and the second sowing time at 350 thousand ha-1 plant density. The measurement results proved that there was a linear relationship between the number of plants and the LAI. The maximum leaf area index values we measured in both the sowing time at 500 thousand ha-1 reached.

scholarly journals Evaluating the effect of plant population densities and nitrogen application on the leaf area index of maize in a reclaimed wetland in Kenya

2016 ◽  
Vol 8 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Catherine Waithira Njuguna ◽  
Hellen Wangechi Kamiri ◽  
John Robert Okalebo ◽  
Wilson Ngetich ◽  
Syphilline Kebeney
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Density ◽  
Block Design ◽  
Nitrogen Application ◽  
Maize Production ◽  
Area Index ◽  
High Plant Density ◽  
Plant Densities ◽  
Set Up

Abstract Maize is the main staple food in Kenya with over 90% of Kenyans relying on it. While the annual national consumption is increasing, the production of this crop has been on the decline in the last two decades. Maize production in Kenya fell by 33.4% in 2013 with Nyeri among the counties said to be grappling with the production of this crop. Land pressure is one of the major causes of decreased availability of food as well as soil depletion and encroachment upon fragile ecosystems such as wetlands. Nitrogen is a key nutrient in the production of maize, and its deficiency is a major factor limiting its production. This study investigated the effect of N application at 120 kg N/ha and maize density on the Leaf Area Index in reclaimed wetland soils in an experimental set-up comprising a randomized complete block design with three replications. The research was carried out in Nyeri County, Kenya. Leaf Area Index (LAI) was determined using the given SunScan formula. Measurements were done continuously until crop physiological maturity. Results indicated that the leaf area index increased with nitrogen application and reduced with spacing for most treatments. There were no significant differences between the two methods (Copy Method and SunScan). Leaf Area Index (LAI) was high in treatments containing nitrogen and high plant density. It was concluded that high plant density gives high LAI. 50 cm * 12.5 cm (-N) and 50 cm * 12.5 cm (+N) are the recommended plant densities for the site.

scholarly journals Narrow and twin-row plantings do not increase maize yield

2020 ◽  
Vol 38 (3) ◽  
pp. 342-349
Author(s):  
Luís Sangoi ◽  
Amauri Schmitt ◽  
Marcos Cardoso Martins Júnior ◽  
Hugo François Kuneski ◽  
Antonio Eduardo Coelho
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Nitrogen Content ◽  
Leaf Area ◽  
Plant Density ◽  
Block Design ◽  
Plant Distribution ◽  
Area Index ◽  
Plant Densities ◽  
Row Space

Reducing row space and sowing in twin rows of maize (Zea mays L.) allow more equidistant plant distribution at the same density. The objective of this research was to evaluate the effect of these two management practices on the nitrogen content of the index leaf, the leaf area index at silking, and the grain yield of maize at different plant densities. The experiment was carried out in Lages, Santa Catarina State University, in southern Brazil during the growing seasons 2016-2017 and 2017-2018. A split-plot arrangement of a randomized complete block design was used. Two plant densities (7 and 9 plants m-2) were distributed in the main plot, and five row spaces (0.4, 0.6, 0.8, 1.0 m and twin rows 0.6 m apart with 0.18 m between rows) were evaluated in split-plots. Physiological traits and grain yield were determined on the maize hybrid P30R50YH. The experiments were sown on 10/20/2016 and 10/21/2017. Kernel yields were higher at the plant density of 9 plants m-2 than at 7 plants m-2. The row space did not affect the nitrogen content of the index leaf, the crop leaf area index at silking, and the maize grain yield. The increment of plant density was more effective than the use of narrow and twin rows to enhance P30R50YH  hybrid grain yield.

scholarly journals Changes in plant density dependence of leaf photosynthesis of maize (Zea mays L.) hybrids, 1959 to 1988

1991 ◽  
Vol 71 (1) ◽  
pp. 1-11 ◽  
Author(s):  
L. M. Dwyer ◽  
D. W. Stewart ◽  
M. Tollenaar
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Zea Mays L ◽  
Plant Density ◽  
Leaf Photosynthesis ◽  
Area Index ◽  
Photosynthetic Rates ◽  
Plant Densities

Understanding of the physiological basis for increased maize (Zea mays L.) yields over the last three decades may contribute to future genetic improvement. Recent maize production systems have tended to increase plant densities to maximize grain yield. The objective of this field study was to determine if there were changes in the response of leaf photosynthetic rates to increasing plant densities in four hybrids grown in Ontario from 1959 to 1989. The four hybrids, numbered from the oldest to most recent hybrid ((1) Pride 5, (2) United 106, (3) Pioneer 3978 and (4) Pioneer 3902) were grown at 20 000, 80 000 and 130 000 plants ha−1. Leaf photosynthetic response to irradiance (PRI) and crop growth rate (CGR) were measured near silking and during late grainfilling, leaf area index (LAI) was measured near silking and total grain yield was measured after maturity. The LAIs of recent hybrids tended to be larger than for old hybrids at comparable plant densities. Leaf photosynthetic rates declined in all hybrids at increasing densities, but the decline occurred at lower LAIs in the older hybrids. As a result, despite the higher LAIs of recent hybrids, they showed an equal or higher PRI at all plant densities. The higher PRI of recent hybrids was correlated with higher CGRs and grain yields. These results suggest that increases in optimum plant density for grain and increases in yield may be attributable, in part, to higher PRI at elevated LAIs in recent hybrids. Key words: Leaf area index, plant density, leaf photosynthesis, Zea mays L.

Plant density effects on growth, yield, leaf area index and light transmission on intercropped maize and Vigna unguiculata (L.) Walp. in Nigeria

1982 ◽  
Vol 99 (1) ◽  
pp. 19-23 ◽  
Author(s):  
M. O. A. Fawusi ◽  
S. B. C. Wanki ◽  
D. Nangju
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Field Experiments ◽  
Plant Density ◽  
Light Transmission ◽  
Growth Yield ◽  
International Institute ◽  
Similar Response ◽  
Area Index ◽  
Plant Densities

SUMMARYIn field experiments at the International Institute of Tropical Agriculture in Nigeria, two cow-pea cultivars, TVU-1209 and FARV-13 and a composite maize cultivar were intercropped at plant densities of 10000, 20000, 30000 and 40000 plants/ha in a split-plot design. There were four replications of each density. Results showed that increasing cow-pea plant density increased the number of days to flowering but decreased the numbers of branches and of leaves per plant in both monoculture and mixture. Different varietal responses to plant density were observed for other growth measurements. While TVU-1209 yielded the highest dry matter at 20000 plants/ha in monoculture and mixture, FARV-13 did so at 40000 plants/ha in monoculture and at 20000 in mixture. Some yield components decreased while others were unaffected by increasing plant density. Similar response pattern was observed for maize. Both leaf area index and light interception were greater in FARV-13 than in TVU-1209.

Estimation of leaf area index and leaf chlorophyll content in Sporobolus densiflorus using hyperspectral measurements and PROSAIL model simulations

2020 ◽  
Vol 42 (4) ◽  
pp. 1181-1200
Author(s):  
Estefanía Piegari ◽  
Juan I. Gossn ◽  
Francisco Grings ◽  
Verónica Barraza Bernadas ◽  
Ángela B. Juárez ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Area Index ◽  
Model Simulations ◽  
Leaf Chlorophyll Content ◽  
Leaf Chlorophyll

scholarly journals Comparative Yield, Fiber Quality and Dry Matter Production of Cotton Planted at Various Densities under Equidistant Row Arrangement

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 232
Author(s):  
Nangial Khan ◽  
Fangfang Xing ◽  
Lu Feng ◽  
Zhanbiao Wang ◽  
Minghua Xin ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Plant Density ◽  
Fiber Quality ◽  
Biomass Accumulation ◽  
Lint Yield ◽  
Planting Density ◽  
Area Index ◽  
High Plant Density

The number of cotton plants grown per unit area has recently gained attention due to technology expense, high input, and seed cost. Yield consistency across a series of plant populations is an attractive cost-saving option. Field experiments were conducted to compare biomass accumulation, fiber quality, leaf area index, yield and yield components of cotton planted at various densities (D1, 1.5; D2, 3.3; D3, 5.1; D4, 6.9; D5, 8.7; and D6, 10.5 plants m−2). High planting density (D5) produced 21% and 28% more lint yield as compared to low planting density (D1) during both years, respectively. The highest seed cotton yield (4662 kg/ha) and lint yield (1763 kg/ha) were produced by high plant density (D5) while the further increase in the plant population (D6) decreased the yield. The increase in yield of D5 was due to more biomass accumulation in reproductive organs as compared to other treatments. The highest average (19.2 VA gm m−2 d−1) and maximum (21.8 VM gm m−2 d−1) rates of biomass were accumulated in reproductive structures. High boll load per leaf area and leaf area index were observed in high planting density as compared to low, while high dry matter partitioning was recorded in the lowest planting density as compared to other treatments. Plants with low density had 5% greater fiber length as compared to the highest plant density, while the fiber strength and micronaire value were 10% and 15% greater than the lowest plant density. Conclusively, plant density of 8.7 plants m−2 is a promising option for enhanced yield, biomass, and uniform fiber quality of cotton.

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