scholarly journals Impact of flucetosulfuron on weed seed bank in wet seeded rice

2018 ◽  
Vol 10 (3) ◽  
pp. 853-859
Author(s):  
Arya S R ◽  
Elizabeth K Syriac
Keyword(s):  
Seed Bank ◽  
Field Experiments ◽  
Block Design ◽  
Seedling Emergence ◽  
Weed Seed ◽  
Time Of Application ◽  
Seed Bank Dynamics ◽  
Before And After ◽  
Hand Weeding ◽  
The Impact

An experiment was conducted to assess the impact of flucetosulfuron, a new generation sulfonylurea herbicide, on weed seed bank dynamics of wet land paddy field. Field experiments were carried out during two consecutive seasons (Kharif 2016 and Rabi 2016-’17), to assess the bio-efficacy of flucetosulfuron in wet seeded rice which was accompanied by weed seed bank assay. Weed seed bank assay of the soil was carried out before and after the field experiments in both the seasons by the seedling emergence method. The experiment on weed seed bank was laid out in Completely Randomised Block Design (CRD) with 12 treatments replicated thrice. Flucetosulfuron @ 20, 25, and 30 g ha-1applied at 2-3, 10-12, and 18-20 days after sowing (DAS) along with two control treatments viz., hand weeding at 20 and 40 DAS and unweeded control comprised the treatments. The emerging weeds were uprooted at 14 days interval up to a period of two months; categorized as grasses, broad leaved weeds, and sedges and counted. Results revealed that non-herbicidal plots recorded significantly higher count of total emerged weeds compared to herbicide applied plots. In all the herbicide applied plots, effective reduction in weed seed bank could be obtained irrespective of the dose of the herbicide. Regarding the time of application, flucetosulfuron applied at 10-12 and 18-20 DAS recorded significantly lower weed seed bank during both the seasons, compared to its application at 2-3 DAS.

Ecological Studies of the Endangered Rutidosis Leptorrhynchoides .I. Seed Production, Soil Seed Bank Dynamics, Population Density and Their Effects on Recruitment

1995 ◽  
Vol 43 (1) ◽  
pp. 1 ◽  
Author(s):  
JW Morgan
Keyword(s):  
Population Density ◽  
Seed Production ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Fire Regime ◽  
Seedling Survival ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Bank Dynamics ◽  
The Impact

The seasonal dynamics of the soil seed bank of Rutidosis leptorrhynchoides F.Muell. were studied by the seedling emergence technique. Seed longevity in soil was quantified in a seed burial and retrieval experiment. The importance of annual seed production to recruitment was also determined over a 2-year-period, as was the impact of conspecific neighbour density on seed production per inflorescence. Rutidosis leptorrhynchoides appears to form a transient seed bank with little capacity to store germinable seeds in the soil from year to year. No seedlings were observed in soil sampled after the autumn germination pulse and no viable seed was present in the soil within 16 weeks of burial. The rate of seed loss was similar when seed was buried under all intact grassland canopy and in 0.25m2 canopy gaps. It appears that most seeds simply rot in moist soil or are predated by soil invertebrates. Seedling recruitment was at least 15 times greater in plots where natural seed input occurred than where it was curtailed. Less than 10% of seed shed resulted in seedling emergence. It is suggested that recruitment in the large populations studied was limited by germination rather than by microsite availability for seedling survival. Population density had an impact on seed production with sparsely distributed individuals producing fewer seeds per inflorescence than plants from denser colonies, although there was much variation. Sparse plants produced significantly fewer seeds per inflorescence than hand crosspollinated heads suggesting reduced pollinator efficacy in these colonies relative to larger colonies where there was no such difference. Rutidosis leptorrhynchoides is dependent on the maintenance of the standing population for recruitment. Any factors that influence flowering and subsequent seed production will limit the ability of the species to regenerate. Over sufficient time, this could lead to the localised extinction of the species and may explain why R. leptorrhynchoides has failed to reappear in remnants where a suitable fire regime has been re-implemented after a period of management unfavourable to the survival, flowering and regeneration of this species.

scholarly journals Weed Seed Bank in an Agroforestry System With Eucalyptus in Subtropical Brazil

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
L. DEISS ◽  
A. MORAES ◽  
A. PELISSARI ◽  
V. PORFÍRIO-DA-SILVA ◽  
M.Z. SCHUSTER
Keyword(s):  
Functional Traits ◽  
Seed Bank ◽  
Shade Tolerance ◽  
Block Design ◽  
Seedling Emergence ◽  
Agroforestry System ◽  
Relative Importance ◽  
Weed Seed ◽  
Randomized Block Design ◽  
Eucalyptus Dunnii

ABSTRACT : Trees can modify the weed seed bank composition and distribution in the cropped area of an agroforestry system. This study aimed at analyzing the eucalyptus (Eucalyptus dunnii) effect on spatial distribution, functional traits abundance and weed seed bank botanic composition in an agroforestry system under no-tillage in Subtropical Brazil. The experiment was conducted in a randomized block design with five replications, and five positions between 4.5-year-old eucalyptus double rows [(4x3) x 20 m] as treatments. Soil sampling was performed at 0-20 cm and the method to quantify and identify seeds was the seedling emergence in trays, inside a greenhouse. Weed phytosociological indices (relative density, frequency and importance), functional traits abundance (life cycle, shade tolerance, reproduction, spread and seed form) and seed densities (m-2) of families and species were evaluated; 17 weed families and 49 species were found. The indices that contributed to the relative importance of families and species differed among the positions between rows. Eucalyptus grown as an intercrop changed the composition and size of the weed seed bank, in a different way for functional traits, families and species depeding on the distance from trees.

scholarly journals Relation between Soil Weed Seedbank and Weed Management Practises and Diversity in Farms in Kisii Central Sub County, Nyanza

2020 ◽  
Vol 10 ◽  
pp. 1-14
Author(s):  
Charles N. Nyamwamu ◽  
Rebecca Karanja ◽  
Peter Mwangi
Keyword(s):  
Seed Bank ◽  
Weed Management ◽  
Management Practices ◽  
Soil Seed Bank ◽  
Shannon Index ◽  
Weed Seed ◽  
Weed Species ◽  
Western Kenya ◽  
Weed Diversity ◽  
Hand Weeding

This study sought to determine the relation between soil weed seed bank and weed management practices and diversity in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Weed soil seed bank was assessed from soil samples collected from each of the farms; a sub-sample was taken from a composite sample of ten soil cores of 5cm diameter and 15cm deep and placed in germination trays in a greenhouse. Weed diversity in soil weed seedbank was calculated using the Shannon index (H’). Twelve weed species from 12 genera of nine families were recorded. Diversity of the weed species in soil weed seed bank was (H'=1.48). Weed management practises significantly affected weed species soil weed seedbank reserves. Use of inefficient and ineffective hand-weeding techniques resulted in high weed species diversity and abundance.

scholarly journals Effects of Iodine Agronomic Bio- fortification on selected Physiological Characteristics of Cassava in Calabar, Southeastern Nigeria

2018 ◽  
Vol 5 (4) ◽  
pp. 116
Author(s):  
Ansa, J. E. O ◽  
Binang, W. B.
Keyword(s):  
Protein Content ◽  
Field Experiments ◽  
Starch Content ◽  
Block Design ◽  
Iodine Content ◽  
Physiological Data ◽  
Southeastern Nigeria ◽  
Time Of Application ◽  
Tuber Protein ◽  
Cassava Varieties

Field experiments were conducted between November 2011 and May 2014 at the Crop Science Teaching and Research Farm of the University of Calabar, (Southeastern rainforest agro-ecological zone of Nigeria) to determine the effectiveness of Iodine agronomic fortification of cassava. The field experiment was a 2x3x4 factorial experiment arranged in randomized complete block design replicated three times, conducted using two cassava varieties,( TME 419 and TMS 30555); four iodine rates( 0, 2.5, 5.0 and 10.0) kg/ha KI; applied at 8, 10 and 12 WAP. Physiological data were obtained by determination of Iodine content [in cassava tuber]; tuber cyanide content (HCN); Carbohydrate content of tuber; starch content of tuber and tuber protein contents. Iodine absorption and retention in cassava tuber flesh was significantly positively correlated with Iodine doses at the times of application (p0.05 and 0.01). TME 419 retained more Iodine in tissues than TMS 30555 and recorded highest correlation co-efficient at 10WAP. Iodine doses and time of application did not significantly control (P≥0.05) contents of cyanide, carbohydrate and starch in cassava tubers. Protein content was significantly varied in cassava varieties and rate and time of Iodine application influenced tuber protein content. TME 419 produced more tuber protein, Iodine doses of 2.5kg/ha KI and 0kg/ha KI had higher protein content than 5kg and 10kg/ha KI. Application at 8WAP and 10WAP were not significantly different. For favourable physiological cassava characteristics, 2.5kg/ha KI is recommended applied 10 weeks after planting (WAP).

The impact of diversification of a rice–wheat cropping system on crop productivity and soil fertility

2002 ◽  
Vol 139 (4) ◽  
pp. 405-412 ◽  
Author(s):  
V. K. SINGH ◽  
B. B. SHARMA ◽  
B. S. DWIVEDI
Keyword(s):  
Soil Fertility ◽  
Green Manure ◽  
Protein Production ◽  
Field Experiments ◽  
Block Design ◽  
Crop Productivity ◽  
Research Centre ◽  
Wheat Crop ◽  
Cropping Intensity ◽  
The Impact

Field experiments were conducted at the Crop Research Centre of Govind Ballabh Pant University of Agriculture and Technology, Pantnagar during 1996/97 and 1997/98. Each experiment comprised 10 crop sequences: (a) wheat–rice, (b) chickpea–rice, (c) lentil–rice, (d) pea–rice, (e) wheat–mungbean green manure–rice, (f) wheat–Sesbania green manure–rice, (g) wheat–fodder–rice, (h) chickpea–fodder–rice, (i) lentil–fodder–rice and (j) pea–fodder–rice, in a randomized block design with four replications. The crop sequences were compared in terms of economic rice equivalent yield (REY), protein production, apparent nutrient balances and effect on soil fertility status. Amongst crop sequences involving two crops each year (200% cropping intensity), chickpea–rice gave highest REY and protein production. Of the sequences involving three crops each year (300% cropping intensity), chickpea–fodder–rice and wheat–fodder–rice were superior to others. The P balances were positive for all sequences, whereas K balances were generally negative except for sequences involving green manure legumes. Green manuring with Sesbania or mungbean helped restore soil fertility, indicating the advantage of green manure for higher productivity and sustainability of rice–wheat system. Chickpea–rice and chickpea–fodder–rice appeared promising alternatives to rice–wheat crop sequence.

scholarly journals Seed bank modelling of volunteer oil seed rape: from seeds fate in the soil to seedling emergence

2013 ◽  
Vol 31 (2) ◽  
pp. 267-279 ◽  
Author(s):  
E. Soltani ◽  
A. Soltani ◽  
S. Galeshi ◽  
F. Ghaderi-Far ◽  
E. Zeinali
Keyword(s):  
Oilseed Rape ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Burial Depth ◽  
Soil Seed Banks ◽  
Seed Bank Dynamics ◽  
Autumn And Winter ◽  
Lower Slope

Studies were conducted to estimate parameters and relationships associated with sub-processes in soil seed banks of oilseed rape in Gorgan, Iran. After one month of burial, seed viability decreased to 39%, with a slope of 2.03% per day, and subsequently decreased with a lower slope of 0.01 until 365 days following burial in the soil. Germinability remained at its highest value in autumn and winter and decreased from spring to the last month of summer. Non-dormant seeds of volunteer oilseed rape did not germinate at temperatures lower than 3.8 ºC and a water potential of -1.4 MPa ºd. The hydrothermal values were 36.2 and 42.9 MPa ºd for sub- and supra-optimal temperatures, respectively. Quantification of seed emergence as influenced by burial depth was performed satisfactorily (R² = 0.98 and RMSE = 5.03). The parameters and relationships estimated here can be used for modelling soil seed bank dynamics or establishing a new model for the environment.

scholarly journals IMPACT OF TYROSINE AND GLUTAMINE ACIDS ON YIELD AND SOME CHEMICAL CONSTITUENTS OF HIBISCUS SABDARIFFA PLANTS UNDER DIFFERENT SOWING DATES

2021 ◽  
Vol 21 (no 1) ◽  
Author(s):  
Hekmat K. M. Ali ◽  
Abdelrahman E. Awad ◽  
Mohammed A. I. Abdelkader
Keyword(s):  
Amino Acids ◽  
Field Experiments ◽  
Tap Water ◽  
Chemical Constituents ◽  
Block Design ◽  
Anthocyanin Content ◽  
Hibiscus Sabdariffa ◽  
Total Chlorophyll ◽  
Sowing Dates ◽  
The Impact

Two field experiments were carried out at experimental farm of Faculty of Agriculture, Zagazig University, Egypt, during the two summer consecutive seasons of 2018 and 2019. To study the impact of sowing dates and some amino acids on the roselle (Hibiscus sabdariffa L.) yield in terms of number of fruits per plant, dry sepal’s yield per plant and per feddan as well as its chemical constituents in terms of total chlorophyll (SPAD) and anthocyanin (mg/100g as dry weight) contents. A split-plot experiment was carried out in the field based on a randomized complete block design with three replications. The main plot was four sowing dates (15th April, 1st May, 15th May and 1st June) and the sub-plot was five amino acids treatments (tap water as control, tyrosine and glutamine acids each at 100 or 200 ppm concentrations). The results showed that the early in sowing from June1 to April 15 increased fruit number per plant, dry sepals yield per plant (g) and per feddan (kg) as well as total chlorophyll content and anthocyanin content. Also, all the values of the studied parameters were significantly increased when the roselle plants sprayed with glutamine acid at 200 ppm compared to control. In final, planting roselle seeds in 15th April and sprayed with 200 ppm glutamine four times per season manifests to enhance yield and is adequate for fulfilling the highest anthocyanin contents in sepals of roselle under Sharkia Governorate conditions.

scholarly journals Changes in the Weed Seed Bank in Long-Term Establishment Methods Trials under Rice-Wheat Cropping System

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 292
Author(s):  
Prashant Sharma ◽  
Manoj Kumar Singh ◽  
Kamlesh Verma ◽  
Saroj Kumar Prasad
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Weed Management ◽  
Soil Depth ◽  
Block Design ◽  
Cropping System ◽  
Field Trials ◽  
Management Program ◽  
Weed Seed ◽  
Design Factor

The rice–wheat cropping system in the Indo-Gangetic Plains is the backbone of food security in India. In the 1990s, due to the scarcity of resources, the traditional Crop Establishment (CE) method shifted from Conventional Till Puddle Transplanted Rice (CTPTR) to CT Direct Seeded Rice (CTDSR) and Zero-Till DSR (ZTDSR) in paddy; and in wheat, from Conventional Till Wheat (CTW) to Zero Till Wheat (ZTW), with residue retention in rice (RRR) or in both rice and wheat (RRRW). Shift in CE methods led to change in Weed Seed Bank (WSB) dynamics and ultimately affected the weed management program. After five years of field trials, soil samples were drawn as per 2-factors factorial randomized block design. Factor-I comprised 4-CE methods, whereas factor-II consisted of 3-soil depths (0–10, 10–20 and 20–30 cm). Results showed CTPTR-CTW and ZTDSR-ZTW (RRRW) record the highest seed bank (SB) of grasses, sedges and BLWs as total weeds, in general; and predominant weeds like Echinochloa spp., Ammania baccifera, Commelina benghalensis and Digitaria sanguinalis, in particular. It also showed the higher species richness (DMg) and Shannon–Weaver (H’) indices. CTDSR-CTW and CTDSR-ZTW (RRR) show the lowest WSB and at par with Shannon–Weaver (H’) index; further, lowest species richness (DMg) under CTDSR-CTW. Species Evenness (J’) and Simpson index (λ) vary non-significantly with CE methods. Furthermore, 0–10 cm soil depth showed the highest SB of different category of total weed, predominant weeds as well as higher values of DMg, H’, and λ; whereas reverse trend was observed in Whittaker Statistic (βW). Interaction between CE methods and soil depth revealed most of WSB lying on the top layer in case of ZTDSR-ZTW (RRRW) and CTDSR-ZTW (RRR); while CTPTR-CTW showed almost uniform WSB distribution, and in case of CTDSR-CTW, a gradual decrease in WSB with soil depth.

Effect of soil water content on wild oat (Avena fatua) seed mortality and seedling emergence

Weed Science ◽  
2006 ◽  
Vol 54 (02) ◽  
pp. 255-262 ◽  
Author(s):  
James A. Mickelson ◽  
William E. Grey
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Seed Bank ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Irrigation Treatment ◽  
Seed Banks ◽  
Wild Oat ◽  
Seed Mortality

Field experiments were established in fall 1999 and 2000 near Huntley, MT, to determine the effects of soil water content on wild oat seed mortality and seedling emergence. Four supplemental irrigation treatments were implemented from June through September to establish plots with varying soil water content. Wild oat seed mortality during the summer increased linearly as soil water content increased. For seed banks established in 1999 (1999SB), seed mortality increased, on average, from 36 to 55% in 2000, and 15 to 55% in 2001 as soil water content increased from 6 to 24%. For seed banks established in 2000 (2000SB), seed mortality increased, on average, from 38 to 88% in 2001 and 53 to 79% in 2002 as soil water content increased from 6 to 24%. Increasing soil water content likely increased the activity of microorganisms that cause mortality in wild oat seeds. The increasing seed mortality rates (due to increasing soil water content) resulted in greater annual declines of wild oat seed banks and 2-yr cumulative decline rates. Total season emergence percentage was not affected by irrigation treatment. Results show that weed seed bank decline is more rapid in moist than in dry soils and suggest that management practices that increase or conserve soil moisture will also increase the rate of wild oat seed bank decline.

Seed bank characterization and emergence of a weed community in a moldboard plow system

Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Dawit Mulugeta ◽  
David E. Stoltenberg
Keyword(s):  
Seed Bank ◽  
Field Experiments ◽  
Negative Binomial ◽  
Soil Disturbance ◽  
Weed Seed ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Viable Seeds ◽  
Moldboard Plow

Field experiments were conducted in 1992 and 1993 to characterize the weed seed bank, to determine the influence of moldboard plowing and secondary soil disturbance on the emergence pattern of weeds, and to measure weed seed bank depletion by emergence in a long-term moldboard plow corn cropping system. Viable seeds of common lambsquarters, redroot pigweed, and each of 10 other species accounted for about 85, about 9, and less than 1%, respectively, of the total weed species in the seed bank. A negative binomial distribution described the spatial distribution of viable seeds of 10 species, but not of common lambsquarters or of redroot pigweed. Decreased density of seeds among species was associated with increased aggregation. Secondary soil disturbance increased the rate and magnitude of common lambs quarters emergence in 1992 but did not influence emergence in 1993. Secondary soil disturbance did not influence the magnitude and rate of emergence of redroot pigweed or velvetleaf. Whereas cumulative growing degree days from April through July were similar between years, the amount of rainfall was about 50% less in 1992 than in 1993. Secondary soil disturbance may have increased common lambsquarters emergence by increasing the availability of soil moisture and improving conditions for seed germination during the dry year. Even though seed bank depletion by seedling emergence was relatively low for all species, secondary soil disturbance in creased seed bank depletion of common lambsquarters and redroot pigweed about 7- and 3-fold, respectively, in 1992. Seasonal variation in the amount of rainfall may have influenced the effect of soil disturbance on emergence and seed bank depletion of common lambsquarters, which is the most abundant species in the weed community.

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