INFLUENCE OF TIME OF EMERGENCE AND PLANT DENSITY ON GROWTH OF HEMP-NETTLE (Galeopsis tetrahit)

1989 ◽  
Vol 69 (1) ◽  
pp. 171-183 ◽  
Author(s):  
ANNE LÉGÈRE ◽  
JEAN-MARC DESCHÊNES
Keyword(s):  
Plant Density ◽  
Plant Biomass ◽  
Biomass Accumulation ◽  
Quebec City ◽  
Total Biomass ◽  
City Region ◽  
Higher Plant ◽  
Peak Period ◽  
Plant Densities ◽  
Broadleaf Species

The effects of time of emergence and plant density on hemp-nettle growth (Galeopsis tetrahit) were measured in natural field populations from the Québec City region and in a greenhouse experiment. In the field, more than 80% of the plants emerged during a peak period of about 2 wk in early May. Few hemp-nettle plants emerged after this peak period. Late-emerging plants produced relatively little biomass compared to plants that had emerged during the early emergence flush. Total biomass accumulation increased with density on three out of four sites. Stands from the lowest density (80 plants m−2) generally produced less biomass than stands of higher plant densities. Average plant biomass production decreased with increasing density. Plants from low density stands displayed a bushy profile compared to the etiolated, single-stemmed plants from high density stands. Mature hemp-nettle stands did not develop strong hierarchical population structures such as found for other annual broadleaf species. Hemp-nettle plants within a stand were distributed rather evenly over a number of height classes. A large proportion of the total biomass was produced by a relatively considerable number of plants 45–59 cm in height rather than by a few dominating individuals.Key words: Hemp-nettle, Galeopsis tetrahit, weed populations, emergence pattern, population density, population structure

scholarly journals Manipulation of Plant Density to Enhance Rice Yield for a Bioregenerative Life-support System

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 884G-885
Author(s):  
K.R. Goldman ◽  
C.A. Mitchell
Keyword(s):  
Life Support ◽  
Plant Density ◽  
Biomass Accumulation ◽  
High Yield ◽  
Higher Plant ◽  
Yield Efficiency ◽  
Panicle Number ◽  
Plant Densities ◽  
Controlled Environments ◽  
Bioregenerative Life Support System

Rice (Oryza sativa L.) is a candidate crop for use in Controlled Ecological Life-support Systems (CELSS) proposed for a lunar or Mars outpost. `Ai-Nan-Tsao' is a promising semi-dwarf cultivar because growth volume is limited and HI (percent edible biomass) is high. Yield efficiency rate (YER: g grain/m3 per day [g nonedible biomass]-) combines edible yield rate (EYR: g grain/m3 per day) and HI to quantify edible yield in terms of penalties for growth volume, cropping time, and nonedible biomass production. Greenhouse studies indicate EYR increases with plant density from 70 to 282 plants/m2. YER and shoot HI are stable across this density range because nonedible biomass accumulation keeps pace with edible. Tiller number and panicle size per plant decreased with increasing plant density, but total tiller and panicle number per unit area increased to compensate. Density trials in rigorously controlled environments will determine if higher plant densities will produce even greater YER. This research is supported by NASA grant NAGW-2329.

scholarly journals Patterns of tillering and grain production of winter wheat at a wide range of plant densities.

1978 ◽  
Vol 26 (4) ◽  
pp. 383-398 ◽  
Author(s):  
A. Darwinkel
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Harvest Index ◽  
Plant Density ◽  
Fold Increase ◽  
Grain Production ◽  
Higher Plant ◽  
Grain Number ◽  
Wide Range ◽  
Plant Densities

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)

scholarly journals Effect of Plant Spacing and Harvest Interval on the Growth Parameters of Moringa oleifera Lam (Periyakulam-1) in Sokoto (Semi-Arid Environment)

2021 ◽  
Vol 4 (3) ◽  
Keyword(s):  
Plant Density ◽  
Animal Feed ◽  
Growth Parameters ◽  
Raw Materials ◽  
Block Design ◽  
Biomass Accumulation ◽  
Arid Environment ◽  
Plant Densities ◽  
Harvesting Intervals ◽  
Range Test

Moringa is a typical representative of multi-purpose tropical tree crop due to the high nutritional value, it is an important source for food to many communities and provides raw materials for animal feed industries. This study investigates the influence of plant densities (15 x 15 cm, 15 x 20 cm, 20 x 20 cm, and 20 x 30 cm) and four (4) harvesting intervals (HI) of 2, 4, 6 and 8 weeks was laid out using Randomized Complete Block Design (RCBD) replicated three times. Data on silvicultural practices were collected and six (6) plants were randomly selected for harvest from each plot which were subsequently separated into leaves, stems and twigs. Fresh and air-dried weights were recorded for analysis. Analysis of Variance (ANOVA) was used for data analysis Duncan’s Multiple Range Test was used to separate the means. Results of the present study show non-significant effects of plant density (p>0.05) between treatments. However, greater number of branches, leaves, height and biomass accumulation was recorded at 8 weeks harvesting interval. A significant interaction effects were recorded between spacing and HI.

scholarly journals Effects of the cropyear and the agronomical factors on agronomical elements of different sweet corn (Zea Mays L. convar. saccharata Koern.) genotypes in long-term experiment

2012 ◽  
pp. 105-110
Author(s):  
Ádám Lente
Keyword(s):  
Plant Density ◽  
Sweet Corn ◽  
Sowing Date ◽  
Higher Plant ◽  
Sowing Time ◽  
Sowing Dates ◽  
Long Term Experiment ◽  
Plant Densities ◽  
Fertilization Level ◽  
The University

In the crop season of 2010 (rainy year), we studied the effect of three agrotechnical factors (sowing time, fertilization, plant density) and four different genotypes on the agronomical characteristics of sweet corn on chernozem soil in the Hajdúság. The experiments were carried out at the Látókép Experimental Farm of the University of Debrecen. In the experiment, two sowing dates (27 April, 26 May), six fertilization levels (control, N30+PK, N60+PK, N90+PK, N120+PK, N150+PK) and four genotypes (Jumbo, Enterprise, Prelude, Box-R) were used at two plant densities (45 thousand plants ha-1, 65 thousand plants ha-1). The amount of precipitation in the season of 2010 was 184 mm higher, while the average temperature was 0.8 oC higher in the studied months than the average of 30 years. Weather was more favourable for sweet maize at the first sowing date, if we consider the yields, however, if we evaluate the agronomical data and yield elements (number of cobs, cob length and diameter, the number of kernel rows, the number of kernels per row) it can be stated that the size of the fertile cobs was greater at the second sowing date due to the lower number of cobs. The largest number of fertile cobs was harvested in the case of the hybrid Enterprise (72367.9 ha-1) in the higher plant density treatment (65 thousand ha-1) at the fertilization level of N120+PK when the first sowing date was applied. The largest cobs were harvested from the hybrid Box-R (cob weight with husks: 516.7 g, number of kernels in one row: 45.7) at the lower plant density (45 thousand plants ha-1) in the second sowing date treatment. Cob diameter and the number of kernel rows were the highest for the hybrid Prelude.

scholarly journals Planting Date and Plant Density Affect Yield of Pungent and Nonpungent Jalapeño Peppers

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 520-523 ◽  
Author(s):  
V.M. Russo
Keyword(s):  
Capsicum Annuum ◽  
Plant Density ◽  
Planting Date ◽  
Row Spacing ◽  
Higher Plant ◽  
Cultural Methods ◽  
Plant Densities ◽  
The Cost ◽  
Transplant Site

There is little known about how cultural methods affect yields of nonpungent jalapeño peppers (Capsicum annuum L.). Seedlings of the nonpungent jalapeño peppers `Pace 103', `Pace 105', `Pace 108', `Dulce', and `TAM Sweet2', as well as the pungent jalapeño peppers `Delicias' and `TAM Jalapeño1', used for comparison, were grown in a greenhouse with either one or two seedlings per cell in transplant trays. Transplanting to the field was in mid-April and mid-June of 2000 and 2001. In-row spacing was 0.46 m between transplanting sites. Density was varied by placing either one or two seedlings at a transplant site with resultant plant densities of 24,216 or 48,432 plants/ha. Marketable and cull yields, on a per hectare basis, were determined. In both years there were more fruit produced, and higher yields (25+% greater), at the higher plant density, especially for the mid-April planting. The exception for the mid-April planting date was `TAM Jalapeño1', which was not different at the two densities. If the increased income from higher yield can compensate for the cost of producing two seedlings in each transplant tray cell, then this technique should be employed when these types of peppers are used in early plantings.

Comparative Response of Conventional and Quality Protein Maize Hybrids to High Population Densities in the Southern Guinea Savanna of Nigeria

2013 ◽  
Vol 2 (1) ◽  
Author(s):  
O B Bello
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Plant Population ◽  
Yield Potential ◽  
High Yield ◽  
Quality Protein Maize ◽  
Population Densities ◽  
Higher Plant ◽  
Guinea Savanna ◽  
Plant Densities

Optimum plant population is very important in enhancing high and stable grain yield especially in quality protein maize (QPM) production. A field trial was therefore conducted to compare the performance of six hybrids (three each of QPM and normal endosperm) at three population densities using a split-plot design at the sub-station of the Lower Niger River Basin Development Authority, Oke-Oyi, in the southern Guinea savanna zone of Nigeria during the 2010 and 2011 cropping seasons. Plant population -1 densities (53,333, 66,666, and 88,888 plants ha ) constituted the main plots and the six hybrids were assigned to the subplots, replicated three times. Our results showed a differential response of maize -1 hybrids to high densities, with plant populations above 53,333 plants ha reduced grain yield, and this is more pronounced in QPM than normal endosperm hybrids. This is contrary to the results observed in many other countries. This might be that the hybrids were selected in low yield potential area at low plant densities, and hence not tolerant to plant density stress. It may also be due to low yield potential of the experimental site, which does not allow yield increases at high plant densities. Though normal endosperm hybrids 0103-11 and 0103-15 as well as QPM Dada-ba were superior for grain yield among -1 the hybrids at 53,333 plants ha , hybrid 0103-11 was most outstanding. Therefore, genetic improvement of QPM and normal endosperm hybrids for superior stress tolerance and high yield could be enhanced by selection at higher plant population densities.

scholarly journals Agronomic and economic viability of intercropping onion and lettuce

2012 ◽  
Vol 30 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Wagner F da Mota ◽  
Rosimeire D Pereira ◽  
Gizeli de S Santos ◽  
Janiele Cássia B Vieira
Keyword(s):  
Economic Performance ◽  
Plant Density ◽  
Economic Viability ◽  
Agronomic Performance ◽  
Higher Plant ◽  
Plant Densities ◽  
Factorial Treatments ◽  
Set Up

The study aimed to evaluate the agronomic and economic performance of intercropping onion and lettuce on four plant densities of each species. The experiment was set up in completely randomized blocks, with four replications and treatments arranged in a 4 x 4 factorial. Treatments resulted from a combination of four (100, 80, 60, and 40% of recommended plant densities in monoculture) plant densities for both lettuce and onion. Intercropping did not affect the agronomic performance of onion or lettuce. Higher plant densities (100% for both vegetables) resulted in higher lettuce and onion yields. The best economic results were observed using (a) onion at 80% of plant density combined with lettuce at 40 and 100% and (b) onion at 100% and lettuce at all densities (40 to 100%).

scholarly journals Times of Trinexapac-ethyl application associated to plant densities in agronomic performance of second-season corn

2021 ◽  
Vol 10 (9) ◽  
pp. e39310914751
Author(s):  
Mariana Alves de Oliveira ◽  
Claudemir Zucareli ◽  
Allan Ricardo Domingues ◽  
Lucas Augusto de Assis Moraes ◽  
Leandro Teodoski Spolaor ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Plant Size ◽  
Kernel Weight ◽  
Agronomic Performance ◽  
State University ◽  
Leaf Architecture ◽  
Higher Plant ◽  
Growing Seasons ◽  
Plant Densities

Plant growth regulators, which can alter the plant size and anatomy, allow the use of cultivars of interest that do not have a modern leaf architecture, making higher plant densities possible. The objective of this study was to evaluate the agronomic performance of second season corn, grown at different plant densities and under Trinexapac-ethyl applications at different stages of crop development. The field study was carried out in two growing seasons (2013 and 2014), at the Fazenda Escola of the State University of Londrina. Fifteen treatments were evaluated in a randomized block, 5 x 3 factorial design, at five plant densities (40,000, 60,000, 80,000, 100,000 and 120,000 plants per hectare), of Trinexapac-ethyl applied in three stages: control (no application), V6 and V9, with four replications. The morphological plant characteristics, the yield components and grain yield were evaluated. Increases in plant density raise the plant height, reduce the number of grains per ear, ear length and 100-kernel weight, and have no influence on grain yield. The application of Trinexapac-ethyl in stage V9 reduces plant and ear insertion height and 100-kernel weight.

scholarly journals Efeito da Mudança da Cobertura em Parâmetros Biofísicos em Cuiabá, Mato Grosso

2020 ◽  
Vol 13 (3) ◽  
pp. 1324
Author(s):  
Altemar Lopes Pedreira Junior ◽  
Marcelo Sacardi Biudes ◽  
Nadja Gomes Machado ◽  
Andreia Godoy Rocha Arruda ◽  
Luiz Octavio Fabricio Dos Santos ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Plant Density ◽  
Urban Forest ◽  
Plant Biomass ◽  
Satellite Image ◽  
Forest Fragment ◽  
Biophysical Parameters ◽  
Higher Plant ◽  
Mato Grosso

Técnicas de sensoriamento remoto possibilita monitorar e identificar alterações que ocorrem na superfície terrestre, sejam elas ocasionadas por fenômenos naturais ou ação antrópica. O monitoramento dessa dinâmica tornou-se um importante instrumento de pesquisa, pois as transformações ocorridas na cobertura do solo alteram as trocas de radiação entre a superfície a atmosfera. Assim, o objetivo deste trabalho foi analisar os parâmetros biofísicos da superfície em diferentes uso e ocupação em Cuiabá. Foram utilizadas imagens do satélite Landsat 5 durante o ano de 2009. As estimativas dos parâmetros biofísicos foram produzidas a partir de uma camada vetorial com nove pixels sobre cada área. Essas áreas foram classificadas como área de solo exposto, área urbana, vegetação rasteira, área reflorestada, fragmento de floresta urbana e vegetação densa. O índice de vegetação da diferença normalizada (NDVI) apresentou variação de acordo com a cobertura do solo, sendo observado os maiores valores nas áreas com vegetação mais densa. Os maiores valores de albedo foram encontrados nas áreas com pouca ou ausência de vegetação. A Ts foi maior nas áreas com maior grau de antropização e baixa quantidade de vegetação. O Rn foi maior nas áreas com maior densidade vegetal e menor nos pontos com maior antropização. Enfim, os locais com maior quantidade de biomassa vegetal apresentaram maiores valores de NDVI e Rn, além de menores valores de αs e Ts. Effect of Coverage Change on Biophysical Parameters in Cuiabá, Mato Grosso A B S T R A C TRemote sensing techniques make it possible to monitor and identify changes that occur on the earth's surface, whether caused by natural phenomena or anthropic action. Monitoring these dynamics has become an important research tool, since the transformations in the ground cover alter the radiation exchanges between the surface and the atmosphere. Thus, the objective of this study was to analyze the surface biophysical parameters in different use and occupation in Cuiabá. Landsat 5 satellite images were used during 2009. Estimates of biophysical parameters were produced from a vector layer with nine pixels over each area. These areas were classified as exposed soil area, urban area, undergrowth, reforested area, urban forest fragment and dense vegetation. The normalized difference vegetation index (NDVI) varied according to soil cover, with the highest values being observed in areas with denser vegetation. The highest albedo values were found in areas with little or no vegetation. The Ts was higher in the areas with higher degree of anthropization and low amount of vegetation. Rn was higher in areas with higher plant density and lower in areas with greater anthropization. Finally, the sites with the highest amount of plant biomass presented higher NDVI and Rn values, as well as lower αs and Ts values.Keywords: Anthropization, Satellite image, Urbanization.

The influence of sowing rate and row spacing on the plant density and yield of red beet

1985 ◽  
Vol 104 (3) ◽  
pp. 615-624 ◽  
Author(s):  
L. R. Benjamin ◽  
R. A. Sutherland ◽  
D. Senior
Keyword(s):  
Plant Density ◽  
Unit Area ◽  
Total Yield ◽  
Row Spacing ◽  
Higher Plant ◽  
Density Maximum ◽  
Maximum Value ◽  
Red Beet ◽  
Plant Densities ◽  
The Mean

SummaryThree experiments examined the effects of sowing rate and between-row spacing on the plant density and yield of red beet.The proportion of seeds which produced mature plants decreased when the mean distance to the nearest neighbour was less than 5 cm. In these experiments, this distance was governed by within-row spacing. Thus, plots with narrow-spaced rows achieved a higher plant density than those with wide-spaced rows, when sown with the same weight of seed.Total yield of beet per unit area decreased with increasing plant density. Maximum yields per unit area of small beet were achieved at high plant densities, whereas maximum yields of large beet were achieved at low plant densities. The effect of between-row spacing on yield was much smaller than that of density, and was important only for crops harvested early. Shoot yield per unit area was measured in two experiments and was not affected by row spacing in either. Shoot yield was not affected by plant density in one experiment, but, in the other, tended to a maximum value with increasing plant density.

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