Studies on Seed biology, Distribution, and Chemical Control of Smellmelon (Cucumis melovar. agrestis Naudin): An Invasive Weed

2019 ◽  
Vol 33 (1) ◽  
pp. 202-209 ◽  
Author(s):  
Reza Noor-Ziarat ◽  
Mohammad Rezvani ◽  
Naser Bagherani ◽  
W. James Grichar
Keyword(s):  
Chemical Control ◽  
Management Program ◽  
Reproductive Capacity ◽  
Burial Depth ◽  
Invasive Weed ◽  
Sowing Depth ◽  
Seed Biology ◽  
Field Crops ◽  
Series Of Experiments ◽  
Cardinal Temperatures

AbstractSmellmelon is an invasive weed in the Golestan and Mazandran provinces of Iran. In a series of experiments, germination of freshly harvested seeds, cardinal temperatures, plant burial depth, and distribution and chemical control of smellmelon were evaluated to assist us in developing a management program to help growers manage this weed more effectively. The optimal seed germination temperature was estimated at 32.7 C by a two-piece segmented model. Mature fresh seeds of smellmelon exhibited no dormancy, whereas mucilage of the seed negatively affected germination. The greatest seed sowing depth from which seedlings emerged was 5 cm. Geographical distribution of smellmelon occurred up to an elevation of 350 m above sea level, whereas the density of smellmelon decreased at elevations higher than 151 m. Imazethapyr reduced plant growth and the reproductive capacity of smellmelon. Germination of seed from smellmelon plants treated with imazethapyr was significantly reduced compared with seed treated with bentazon or bentazon plus acifluorfen. A combination of tillage of deeper than 5 cm, early planting time, and the use of imazethapyr can reduce smellmelon competition in various field crops.

Plant Development and Seed Biology of Windmillgrass (Chloris truncata) in Southern Australia

Weed Science ◽  
2017 ◽  
Vol 65 (3) ◽  
pp. 395-405 ◽  
Author(s):  
The D. Ngo ◽  
Peter Boutsalis ◽  
Christopher Preston ◽  
Gurjeet Gill
Keyword(s):  
Plant Development ◽  
Light Exposure ◽  
Seedling Emergence ◽  
Chloride Concentration ◽  
Management Program ◽  
Field Conditions ◽  
Burial Depth ◽  
Base Temperature ◽  
Weed Species ◽  
Seed Biology

Windmillgrass is a major weed in agricultural systems in northern Australia, and it has now become more common in southern Australia. Because little information is available on the biology of this weed species in southern Australia, studies were conducted to investigate plant development and seed biology. Under irrigated field conditions in South Australia, windmillgrass required 748 to 786 growing degree days from emergence to mature seed production. Freshly harvested seed had low dormancy with 16% to 40% germination. Seeds required light exposure for germination and less than 2% germination was observed in complete darkness. Seed could germinate over a wide temperature range (10 to 40 C) with maximum germination at 20 to 25 C. At 25 to 30 C, 50% germination occurred within 27.3 to 45.5 h, and the predicted base temperature for germination of the two populations investigated ranged from 9.2 to 11.2 C. The sodium chloride concentration and osmotic potential required to inhibit germination by 50% were 51 to 73 mM and −0.27 MPa, respectively. Seedling emergence was completely inhibited by burial of seed, which is consistent with its absolute requirement for light exposure to begin germination. Under field conditions, there was no clear effect of burial depth on seed viability in the first 2 yr with average rainfall, and seeds were completely nonviable after 12 mo. However, in the third year, with low spring–summer rainfall, buried seeds (37% viability after 14 mo) persisted longer than those left on the soil surface (6% viability after 14 mo). This study provides important information on plant development and seed biology of windmillgrass that will contribute to the development of a management program for this weed species in southern Australia.

Optimising canola establishment and yield in south-eastern Australia with hybrids and large seed

2016 ◽  
Vol 67 (4) ◽  
pp. 409 ◽  
Author(s):  
R. D. Brill ◽  
M. L. Jenkins ◽  
M. J. Gardner ◽  
J. M. Lilley ◽  
B. A. Orchard
Keyword(s):  
Grain Yield ◽  
Seed Size ◽  
Biomass Accumulation ◽  
Simulation Modelling ◽  
Sowing Depth ◽  
Large Seed ◽  
South Wales ◽  
Eastern Australia ◽  
Series Of Experiments ◽  
Seed Characteristics

April sowing of canola is considered optimal for grain yield in many regions of Australia; however, there is often insufficient rainfall in April to sow seed into moisture at the ideal depth of 15–30 mm. We report a series of experiments that investigated the seed characteristics (cultivar type and seed size) that would facilitate successful canola emergence from relatively deep sowing (>30 mm). Ten canola cultivar by sowing depth experiments, each with three hybrid and three open-pollinated cultivars, found hybrid cultivars were able to maintain higher emergence rates and grain yield compared with open-pollinated cultivars from deep sowing. Further investigations in the glasshouse showed that the emergence advantage of the hybrid cultivars was largely due to their inherently large seed size, as increased seed size also improved emergence of open-pollinated canola. Early biomass accumulation also improved with larger seeds. In a field experiment, larger seed size of both hybrid and open-pollinated canola increased early biomass accumulation and final grain yield. Simulation modelling in New South Wales demonstrated the importance of timely sowing of canola, as delayed sowing caused a larger reduction in grain yield than reduced plant population. Although ‘moisture-seeking’ (placing seed into moist soil below a layer of dry soil) reduced the emergence rate of canola, the reduction could be offset by planting large seed (>2 mm diameter). This practice of ‘moisture-seeking’ large-seeded canola should be considered as a strategy to improve the timeliness of establishment and subsequent grain yield of canola when rainfall for crop establishment is marginal yet there is moisture available deeper in the seedbed.

Digital Simulation of the Chemical Control of Ventilation

1973 ◽  
Vol 95 (3) ◽  
pp. 335-339
Author(s):  
H. T. Milhorn ◽  
W. J. Reynolds
Keyword(s):  
Computer Model ◽  
Respiratory System ◽  
Digital Computer ◽  
Chemical Control ◽  
Minute Ventilation ◽  
Digital Simulation ◽  
Transient Responses ◽  
O2 Concentration ◽  
Lower Oxygen ◽  
Series Of Experiments

Experimental human data, obtained for the development and evaluation of a digital computer model of the human respiratory system, are presented. The data are from two series of experiments. In the first series the transient responses of tidal volume, respiratory frequency, minute ventilation, alveolar Pco2 and alveolar Po2 were obtained for several inspired CO2 concentrations (3, 5, 6, and 7 percent). In the second series, transient responses of the same variables were obtained for steps of inspired O2 concentration from room air to several lower oxygen levels (9, 8, and 7 percent). An example of the use of the data for the development and evaluation of a model is indicated.

Postharvest Burial of Drosophila suzukii (Diptera: Drosophilidae) Infested Fruit Waste Reduces Adult Emergence

2019 ◽  
Vol 49 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Holly Hooper ◽  
Matthew J Grieshop
Keyword(s):  
Chemical Control ◽  
Negative Impact ◽  
Adult Emergence ◽  
The United States ◽  
Spotted Wing Drosophila ◽  
Burial Depth ◽  
Lipid Concentration ◽  
Drosophila Suzukii ◽  
Fruit Waste ◽  
Fruit Wastes

Abstract The arrival of spotted wing Drosophila, Drosophila suzukii (Matsumura), to the United States has caused many berry and cherry growers to replace IPM programs with calendar-based broad-spectrum insecticide programs. Alternative management tactics are urgently needed to mitigate the current dependency on chemical control. Postharvest burial is a cultural crop sanitation strategy that has the potential to reduce D. suzukii reproductive habitat and eliminate infested fruit wastes. This study revealed that D. suzukii rarely pupate on the soil’s surface or below 1 cm, but are capable of unburying themselves from depths up to 48 cm. Although zero emergence was not obtained in the field, adult emergence decreased exponentially with deeper burial depths. A burial depth of 24 cm reduced D. suzukii emergence by 97%, although soil texture may influence this optimal burial depth. Soils that had a higher concentration of sand had a negative impact on D. suzukii survival at shallower burial depths. The mechanism behind the reduction in adult emergence from differing burial depths remains unclear as the lipid concentration between emerging D. suzukii was the same regardless of burial depth.

scholarly journals Effect of Environmental Factors on Seed Germination and Early Seedling Emergence of Carolina geranium (Geranium carolinianum)

2018 ◽  
Vol 36 ◽  
Author(s):  
X. LIU ◽  
T. ZONG ◽  
Y. LI ◽  
X. ZHOU ◽  
L. BAI
Keyword(s):  
Control Strategies ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Burial Depth ◽  
Invasive Weed ◽  
Temperature Regimes ◽  
Dark Regime ◽  
Early Seedling ◽  
Effects Of Temperature ◽  
And Control

ABSTRACT: Carolina geranium (Geranium carolinianum) is an emerging invasive weed in rape and wheat fields in China. A better understanding of its germination and emergence ecology will enable the development of integrated weed control strategies. In this study, we investigated the effects of temperature, photoperiod, soil water content, salinity, and burial depth, on germination and emergence of Carolina geranium. Germination percentages were over 74% under 15/20 and 20/25 oC night/day temperature regimes. Germination rate was independent of light/dark regime. Increasing salinity reduced germination of Carolina geranium from 81.1% at 0 mM to 0% at 160 mM NaCl. Seeds germination was peaked at 50% soil moisture, but was completely inhibited at < 20% and > 90%. The seedling emergence above 82.2% was observed when seeds were placed at a depth from 0 to 1 cm, and no seedlings emerged from seeds placed at a depth of 7 cm. Current work provide the basic information to effectively prevent and control this invasive weed in Chinese rape and wheat fields.

Seed Germination Ecology of Soldier Thistle (Picnomon acarna): An Invasive Weed of Rainfed Crops in Iran

Weed Science ◽  
2019 ◽  
Vol 67 (2) ◽  
pp. 261-266 ◽  
Author(s):  
Iraj Nosratti ◽  
Sajad Almaleki ◽  
Bhagirath S. Chauhan
Keyword(s):  
Seed Germination ◽  
Crop Yields ◽  
Wide Spectrum ◽  
Seedling Emergence ◽  
Effective Control ◽  
Burial Depth ◽  
Invasive Weed ◽  
Row Crops ◽  
Western Iran ◽  
Soil Burial

AbstractSoldier thistle [Picnomon acarna(L.) Cass.] is widely distributed throughout rainfed fields across western Iran, where it decreases crop yields and interferes with harvest operations. This study was conducted to determine the influence of different factors on seed germination and seedling emergence ofP. acarna. Freshly harvested seeds were dormant and required an after-ripening period for breaking dormancy. Seed germination was greatly promoted by light. Germination occurred over a wide spectrum of constant and fluctuating temperature regimes, ranging from 5 to 35 C, with highest germination at constant (74%) and fluctuating (94%) temperatures of 20 and 20/10 C. Seed germination ofP. acarnawas tolerant to osmotic potential, while salt stress significantly inhibited its germination percentage. pH was not an inhibiting factor for germination ofP. acarnaseeds. Seedling emergence decreased exponentially with an increase in seed burial depth in the soil; at soil burial depths of 4 cm or greater, no seedlings were able to reach the soil surface. The results suggest that significant seed germination ofP. acarnain rainfed fields is possible, and the weed has great potential to spread throughout rainfed systems in western Iran. Based on these results, effective control ofP. acarnacan be achieved by applying interrow cultivation in row crops and deep tillage at seedbed preparation.

Factors Affecting Buffalobur (Solanum rostratum) Seed Germination and Seedling Emergence

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 521-525 ◽  
Author(s):  
Shouhui Wei ◽  
Chaoxian Zhang ◽  
Xiangju Li ◽  
Hailan Cui ◽  
Hongjuan Huang ◽  
...  
Keyword(s):  
Seed Germination ◽  
Light Exposure ◽  
Soil Depth ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Distribution Area ◽  
Burial Depth ◽  
Weed Species ◽  
Continuous Darkness ◽  
Invasive Weed

Buffalobur is a noxious and invasive weed species native to North America. The influence of environmental factors on seed germination and seedling emergence of buffalobur were evaluated in laboratory and greenhouse experiments. The germination of buffalobur seeds occurred at temperatures ranging from 12.5 to 45 C, with optimum germination attained between 25 and 35 C. Buffalobur seeds germinated equally well under both a 14-h photoperiod and continuous darkness; however, prolonged light exposure (≥ 16 h) significantly inhibited the seed germination. Buffalobur seed is rather tolerant to low water potential and high salt stress, as germination was 28 and 52% at osmotic potentials of −1.1 MPa and salinity level of 160 mM, respectively. Medium pH has no significant effect on seed germination; germination was greater than 95% over a broad pH range from 3 to 10. Seedling emergence was higher (85%) for seeds buried at a soil depth of 2 cm than for those placed on the soil surface (32%), but no seedlings emerged when burial depth reached 8 cm. Knowledge of germination biology of buffalobur obtained in this study will be useful in predicting the potential distribution area and developing effective management strategies for this species.

Effect of Temperature and Moisture on Quinclorac Soil Half-life and Resulting Native Grass and Forb Establishment

2016 ◽  
Vol 9 (4) ◽  
pp. 252-260 ◽  
Author(s):  
Rodney G. Lym
Keyword(s):  
Moisture Content ◽  
Great Plains ◽  
Seedling Growth ◽  
Native Species ◽  
Management Program ◽  
Effect Of Temperature ◽  
Grass Species ◽  
Northern Great Plains ◽  
Invasive Weed ◽  
Native Grass

Quinclorac will control leafy spurge and not injure many established native grasses and forbs. Seeding of desirable species is often required to reestablish native vegetation after an invasive weed-management program, but quinclorac residue may inhibit the reestablishment of native species. Greenhouse studies were conducted to estimate quinclorac dissipation rates in Northern Great Plains soils and the effect of residue on establishment of some native grass and broadleaf plants. Quinclorac 50% dissipation time (DT50) ranged from > 21 to 112 d in four soils from the Northern Great Plains. The quinclorac DT50 was dependent on several factors including soil type, moisture content, temperature, and especially organic matter (OM). Across four different soil textures, quinclorac dissipation generally increased as soil moisture content increased, but moisture had less of an impact in low OM soils. Quinclorac dissipation also increased as temperature increased in the four soils. The most rapid dissipation occurred in soils with higher OM (> 6%), with an average DT50 of < 38 d, at 45% moisture content, held at 16 C. Wild bergamot, purple coneflower, blanketflower, and stiff goldenrod seedling growth were all reduced by quinclorac residue at 6 μg kg−1, the lowest concentration evaluated in the study. The native grass species big bluestem, intermediate wheatgrass, and switchgrass generally were tolerant of quinclorac, but green needlegrass was sensitive, and seedling growth declined as quinclorac residue increased from 6 to 375 μg kg−1. Based on a quinclorac application of 840 kg ha−1 and 150 frost-free d, seeding of sensitive forbs and grasses should be delayed at least 12 mo after herbicide application.

scholarly journals Bioefficacy of entomopathogenic mycoformulations and effect of adjuvants against nymphs of cabbage aphid, Brevicornye brassicae (Linnaeus)

2021 ◽  
Vol 13 (2) ◽  
pp. 530-536
Author(s):  
Karuna Thakur ◽  
Neelam Joshi ◽  
Sudhendu Sharma
Keyword(s):  
Pest Management ◽  
Chemical Control ◽  
Insect Pests ◽  
Management Program ◽  
Environmentally Benign ◽  
Laboratory Studies ◽  
Percent Reduction ◽  
Cabbage Aphid ◽  
Percent Increase ◽  
Cent Mortality

Cabbage aphid, Brevicornye brassicae (Linnaeus) is one of the major insect pests of cabbage. Chemical control is mostly used to manage this pest. The present investigation was conducted to evaluate an environmentally benign approach for the pest management through different entomopathogenic mycoformulations against nymphs of B. brassicae to identify effective mycoformulation. The effect of mycoformulations supplemented with different adjuvants against nymphs of B. Brassicae was also evaluated under laboratory conditions. The bioassay studies of fungal bioformulation against nymphs of B. brassicae recorded maximum cumulative per cent mortality (53.33%) in talc formulation of L. lecanii MTCC 956 and commercial L. Lecanii formulation @12g L-1 and these were at par with each other. Maximum percent reduction of nymphal population over control 54.66 and 51.33 per cent was recorded @12 g L-1in talc formulation of L. lecanii (MTCC 956) and commercial L. Lecanii formulation ten days after treatment respectively. Laboratory studies undertaken to evaluate talc formulation of L. lecanii MTCC 956 lecanii with and without adjuvants against the nymphs of B. brassicae recorded maximum percent increase in mortality over control (7.89%) in L. lecanii formulation + tween80@1%. Results of this study signified that L. lecanii formulation, when supplemented with adjuvants enhanced the growth of L. lecanii and increased mortality of nymphs of B. brassicae and could be used as a part of the integrated pest management program.

Progress on Utilization of Water Hyacinth

2014 ◽  
Vol 1004-1005 ◽  
pp. 881-884 ◽  
Author(s):  
Yun Zhao ◽  
Guang Wei Zhang ◽  
Ying Shen
Keyword(s):  
Water Hyacinth ◽  
Reproductive Capacity ◽  
Nutritional Requirements ◽  
Invasive Weed ◽  
Adverse Environments

Water hyacinth is an invasive weed because of its high reproductive capacity, adaptability, nutritional requirements and resistance to adverse environments. It is impossible to eradicate and difficult to control. Since water hyacinth is mainly composed of lignin, cellulose, hemicellulose and water (around 90%).This paper introduced the current researches and perspectives of the utilization of water hyacinth.

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