ARE THE PLANT DENSITIES CURRENTLY USED FOR CARROT SEED PRODUCTION TOO LOW?

1981 ◽  
pp. 159-166 ◽  
Author(s):  
D. Gray
Keyword(s):  
Seed Production ◽  
Carrot Seed ◽  
Plant Densities

scholarly journals The response of Stecklings Age and Plant Spacing on Carrot Seed Quality and Production

2020 ◽  
Vol 3 (2) ◽  
pp. 71
Author(s):  
Fatiani Manik ◽  
Rasiska Tarigan ◽  
Susilawati Barus
Keyword(s):  
Seed Production ◽  
Field Trial ◽  
Seed Quality ◽  
Block Design ◽  
Plant Spacing ◽  
Randomized Complete Block Design ◽  
Two Factors ◽  
Carrot Seed

The quality of seed needs to be considered in carrot seed production to maintain its productivity. The research aims to find out the response of stecklings age and plant spacing on carrot seed quality and production. This research was held on July 2018 – April 2019 in Berastagi field trial (1340 m MSL). The experiment used Randomized Complete Block Design (RCBD) with two factors, i.e., stecklings age (2 and 3 months) and plant spacing (25, 50, 75, and 100 cm), replicated four times (32 experiment units), 10 plants from each experiment units were taken as samples. The result showed that stecklings age and plant spacing were affected to plant vegetative and generative stages. The combination of 2-month stecklings and 50 cm plant spacing increased the number of secondary umble, if compared to cultivation, which was generally used by the farmer (3-month stecklings and 25 cm plant spacing). The best quality of carrot seed was obtained from the combination of 3-month stecklings and 50 cm plant spacing.

scholarly journals Planting Time Effect on Quality Seed Production of Three Varieties of Carrot (Daucus Carota L.)

2021 ◽  
Vol 23 (2) ◽  
pp. 23-34
Author(s):  
Lutfunnahar ◽  
MF Hossain ◽  
MA Malek ◽  
R Kamrunnahar ◽  
J Hossain
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Block Design ◽  
Time Effect ◽  
Cool Temperature ◽  
Treatment Combination ◽  
Planting Time ◽  
Daucus Carota L ◽  
Randomized Complete Block Design ◽  
Carrot Seed

Crop management like planting time is a crucial factor for maximizing yield especially for seed production. Seed production of carrot is greatly influenced by temperature as it requires adequate periods of cool temperature (vernalization) for flowering and seed production. To find out optimum planting time of carrot steckling for quality seed production the experiment was conducted at the Field Laboratory of Horticulture Farm, Bangladesh Agricultural University, Mymensingh during the period from October 2015 to May 2016.Three planting time viz. 05 January, 15 January and 25 January on the seed production of three carrot varieties viz. BA (Brasillia Agroflora), PA (Prima Agroflora) and NK (New Kuroda) which constituted 9 treatment combinations were included in the experiment. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Planting time had significant effect on most of the parameters studied. The January 05 planting of steckling gave the highest seed yield (527.92 kg ha-1) and the lowest was in January 25 planting of steckling (314.75 kg ha-1). Among the varieties BA gave the highest seed yield (448.73 kg ha-1) and the lowest yield for New Kuroda (395.35 kgha-1.) Considering interaction of planting time and variety the highest seed yield (572.37 kg ha-1) was obtained from the treatment combination of early planting (05 January) with the variety of BA and the lowest (279.77 kg ha-1) was recorded from the late planting (25 January) in variety PA. Hence, BA carrot variety planting on 5 January may be recommended for carrot seed production in Mymensingh region in Bangladesh. Bangladesh Agron. J. 2020, 23(2): 23-34

A comparison of the persistence of Medicago truncatula cv. Paraggio with other annual medics in the Victorian Mallee

1993 ◽  
Vol 33 (4) ◽  
pp. 443 ◽  
Author(s):  
RA Latta ◽  
PE Quigley
Keyword(s):  
Plant Regeneration ◽  
Seed Production ◽  
Medicago Truncatula ◽  
Seed Set ◽  
Agricultural Productivity ◽  
The Other ◽  
Plant Densities ◽  
Seed Reserves ◽  
Annual Medics ◽  
Better Than

The annual medic Medicago truncatula cv. Paraggio has been widely sown in pastures throughout the Victorian Mallee region; however, its ability to persist in cereal pasture rotations is not known. Seed permeability and production, and plant regeneration of Paraggio, were studied in the field over 4 years, and the changes in its seed reserve were examined under 3 different cereal-pasture rotations. When compared with medic cvv. Parabinga, Harbinger, and Jemalong, Paraggio had up to twice the level of permeable seed over the summer-autumn period in 2 years (7-36% v. 2.5-19%). Paraggio produced 336-928 kg/ha of seed over 3 years, and after seed production was halted, it regenerated at densities of 150-1438 plants/m2 over the next 4 years. These results were generally the same as, or better than, the other cultivars. When seed set occurred in 1 and 2 years in the pasture phase of a 2- and 3-year rotation, respectively, Paraggio seed reserves were maintained at >4000 seeds/m2. This study demonstrated that Paraggio resulted in superior plant densities when grown in a number of typical rotations. It persisted satisfactorily and is expected to improve agricultural productivity in shor-tterm cereal-pasture rotations.

Ecological relationships of wild rice, Zizania spp. 10. Effects of sediment and among-population variations on plant density in Zizania palustris

2002 ◽  
Vol 80 (12) ◽  
pp. 1283-1294 ◽  
Author(s):  
P F Lee
Keyword(s):  
Seed Production ◽  
Wild Rice ◽  
Plant Density ◽  
Reproductive Potential ◽  
Resource Depletion ◽  
Dry Weight ◽  
Asymmetric Competition ◽  
Zizania Palustris ◽  
Nutrient Levels ◽  
Plant Densities

The influence of nutrients and intraspecific variations in growth form were examined for their effect on plant density in stands of northern wild rice, Zizania palustris L. In a field situation, densities of a size-restricted wild rice population increased as nutrient levels in the sediment increased. No self-thinning occurred until the population density exceeded 350 plants/m2. A series of controlled experiments examined whether these wild rice densities were determined by resource depletion and (or) intraspecific competition. As nutrient levels increased under constant plant densities, tillering, dry weight, and seed production increased more for populations with the capacity for higher vegetative and reproductive potential. As plant densities increased under constant nutrient levels, height, weight, and seed production declined but inequality of individual plants increased. When both nutrient levels and population densities were increased simultaneously, seed production per panicle declined at higher densities under unfertilized conditions but was unaffected in the treatment with the highest fertilizer level. It was hypothesized that plant densities under field conditions were the result of an integrated mechanism that was influenced by nutrients and the degree of asymmetric competition characteristic of the population. As nutrient levels increase, plant densities would be expected to decrease for populations with high levels of asymmetric competition and increase for populations with low levels of asymmetric competition.Key words: wild rice, density effects, nutrients, intraspecific variation.

scholarly journals Lack of Evidence of Vertical Transmission of ‘Candidatus Liberibacter solanacearum’ by Carrot Seeds Suggests That Seed is not a Major Transmission Pathway

Plant Disease ◽  
2017 ◽  
Vol 101 (12) ◽  
pp. 2104-2109 ◽  
Author(s):  
Marianne Loiseau ◽  
Isabelle Renaudin ◽  
Pascaline Cousseau-Suhard ◽  
Pierre-Marie Lucas ◽  
Aurélie Forveille ◽  
...  
Keyword(s):  
Real Time ◽  
Seed Production ◽  
Real Time Pcr ◽  
Seed Transmission ◽  
The Other ◽  
Candidatus Liberibacter Solanacearum ◽  
Carrot Seed ◽  
Candidatus Liberibacter ◽  
Bacterial Transmission ◽  
Growing Conditions

‘Candidatus Liberibacter solanacearum’ is a bacterium associated with several vegetative disorders on solanaceous and apiaceous crops. Following the recent detection of the bacterium in carrots in Europe, and particularly carrot plants used for seed production in France, two independent laboratories conducted experiments on the transmission of this pathogen by seed and had discordant results: one study showed no bacterial transmission to plants, and the other showed transmission to carrot seedlings starting from the fourth month of culture. To test the hypothesis that growing conditions affect seed transmission efficiencies, trials were renewed in 2015 on four lots of 500 carrot seeds naturally contaminated with ‘Ca. L. solanacearum’ and two lots of 100 healthy seeds. The plants were grown for 6 months in an insect-proof NS2 greenhouse. Sets of 108 plants from the contaminated lots and 24 plants from the healthy lots were individually analyzed each month using real-time PCR to detect the bacterium. The detection tests on seeds and plants from healthy lots were always negative. During the 6 months of the trial, no plants from the contaminated seed lots tested positive for the bacterium or showed any infection symptoms. These results indicate that transmission of ‘Ca. L. solanacearum’ by carrot seed is rare and difficult to reproduce.

scholarly journals Morphoecological characteristics of grasses used to restore degraded semi-arid African rangelands

2021 ◽  
Author(s):  
Kevin Mganga
Keyword(s):  
Ecological Restoration ◽  
Seed Production ◽  
Dry Matter ◽  
Perennial Grasses ◽  
Grass Species ◽  
Rhodes Grass ◽  
Basal Cover ◽  
Plant Densities ◽  
Chloris Gayana ◽  
Semi Arid

<p>Progressive loss of productivity and plant diversity is a major in global rangelands. In African rangelands ecosystems, this process is partly attributed to heavy and uncontrolled grazing by livestock and wildlife, leading to land degradation. Therefore, restoring such degraded rangelands is critical for enhancing ecosystem health and securing the livelihoods of millions of people. Active restoration strategies, e.g. reseeding using indigenous perennial grasses has been identified as a viable ecological solution for restoring degraded African rangelands. Grass species indigenous to African rangelands Cenchrus ciliaris L. (African foxtail grass), Eragrostis superba Peyr. (Maasai love grass), Enteropogon macrostachyus (Hochst. Ex A. Rich.) Monro ex Benth. (Bush rye grass), Chloris roxburghiana Schult. (Horsetail grass) and Chloris gayana Kunth. cv Boma (Rhodes grass) were established in a semi-arid rangeland in Africa under natural conditions to compare their morphoecological characteristics and suitability for use in ecological restoration. Biomass dry matter yields, plant densities, basal cover, seed production, tiller densities and plant height were measured. Chloris gayana cv Boma and E. superba produced significantly higher dry matter biomass yields and seed production than other species. High biomass and seed production demonstrate their suitability to support livestock production and replenish depleted soil seed banks, respectively. Enteropogon macrostachyus and C. ciliaris displayed significantly higher values for plant densities, tiller densities and basal cover, also a component of establishment and ecological restoration success. Chloris roxburghiana ranked lowest in all the measured morphoecological characteristics. This may be a strong indicator of ecological site-specific characteristic of C. roxburghiana. Successful restoration of degraded African semi-arid rangelands using indigenous grass reseeding can best be achieved through careful selection of grasses to take advantage of their specific morphoecological characteristics. This selection should primarily be informed by the intended use of the rangeland.</p>

scholarly journals Economic bases of the original carrot seed production in the conditions of Moscow region

2021 ◽  
Vol 650 (1) ◽  
pp. 012071
Author(s):  
A N Khovrin ◽  
L M Sokolova ◽  
A V Kornev ◽  
O A Razin ◽  
M G Ibragimbekov
Keyword(s):  
Seed Production ◽  
Moscow Region ◽  
Carrot Seed

The influence of density and nitrogen in seed production stands of S 37 cocksfoot (Dactylis glomerata L.)

1963 ◽  
Vol 61 (3) ◽  
pp. 361-373 ◽  
Author(s):  
D. A. Lambert
Keyword(s):  
Seed Production ◽  
Plant Density ◽  
Unit Area ◽  
The Third ◽  
Plant Densities ◽  
Dactylis Glomerata L ◽  
High Level ◽  
Seed Yields ◽  
Area Percentage ◽  
Lower Plant

1. Seed production stands of S 37 cocksfoot were obtained with varying plant densities by utilizing two drill widths, removing sections of drill, or over-sowing drilled material. All density treatments were operative at two levels of N, 87 or 174 lb. N per acre per annum.2. Tillers in selected quadrats were labelled at monthly intervals during autumn and/or winter for 3 years. Performances of tiller populations were assessed from these quadrats.3. Seed yields were increased in many cases by reducing plant density from a continuous drill pattern. Increased plant density reduced yields. With plant communities on a 1 ft. square arrangement at the high level of nitrogen, an increase of 33%, or 243 lb. seed, per year over a 3-year period was obtained compared with continuous rows at any level of N. The yield of gapped stands increased over the 3-year period, whilst the yields of continuous rows dropped in the final year.4. Nitrogen significantly increased the yield of cocksfoot, except in the third year, by increasing the weight of seed per ear.5. Tiller numbers per quadrat increased in most treatments over the course of the experiment, both within years and from year to year; seasonal peaks of tillering were apparent. The effect of N on tiller numbers differed each year, presumably due to the state of the populations when the N was applied.6. Higher tiller numbers per plant were obtained with lower plant numbers per unit area. Percentage fertility of tillers was generally higher with lower plant densities, and lower tiller numbers per plant, other factors being equal. The only significant effect of N on fertility was to decrease it in the third year.

scholarly journals Plantain seed production in a radial trial

1990 ◽  
pp. 103-106
Author(s):  
J.S. Rowarth
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Trial Design ◽  
Plant Density ◽  
Plantago Lanceolata ◽  
Production Plant ◽  
Significant Positive Effect ◽  
Plant Vigour ◽  
Plant Densities ◽  
Positive Effect

Plantain (Plantago lanceolata) was grown in a radial trial in order to investigate the effect of plant density on seed production. Plant densities ranged from 278 plants/m2 to 17 plants/m2 in 9 arcs. Plants were monitored and harvested individually, thus giving effective high replication (32). Decreasing plant density had a significant positive effect on seed head production (both numbers and size of head), seed yield and plant vigour. Highest seed yield was associated with a density of 17 plants/m2. Keywords: plantain, seed production, plant density, competition, radial trial design

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