Influence of flooding period and seed burial depth on Palmer amaranth (
            
              Amaranthus palmeri
            
            ) seed germination

Abstract Lab and greenhouse studies were conducted to evaluate the effects of chemical treatments applied to Palmer amaranth seeds or gynoecious plants retaining seeds on seed germination and quality. Treatments applied to physiologically mature Palmer amaranth seed included acifluorfen, dicamba, ethephon, flumioxazin, fomesafen, halosulfuron, linuron, metribuzin, oryzalin, pendimethalin, pyroxasulfone, S-metolachlor, saflufenacil, trifluralin, and 2,4-D plus crop oil concentrate applied at 1 and 2× the suggested use rates from the manufacturer. Germination was reduced by 20% from 2,4-D, 15% from dicamba, and 13% from halosulfuron and pyroxasulfone. Dicamba, ethephon, halosulfuron, oryzalin, trifluralin, and 2,4-D decreased the average seedling length by at least 50%. Due to the observed effect of dicamba, ethephon, halosulfuron, oryzalin, trifluralin, and 2,4-D, these treatments were applied to gynoecious Palmer amaranth inflorescence at the 2× registered application rates to evaluate their effects on progeny seed. Dicamba decreased seed germination by 24%, whereas all other treatments were similar to the control. Crush tests showed seed viability was greater than 95%; thus, dicamba did not have a strong effect on seed viability. No treatments applied to Palmer amaranth inflorescence affected average seedling length; therefore, chemical treatments did not affect the quality of seeds that germinated.

Download Full-text

Evaluating Effect of Degree of Water Stress on Growth and Fecundity of Palmer amaranth (Amaranthus palmeri) Using Soil Moisture Sensors

Weed Science ◽

10.1017/wsc.2018.47 ◽

2018 ◽

Vol 66 (6) ◽

pp. 738-745 ◽

Cited By ~ 2

Author(s):

Parminder S. Chahal ◽

Suat Irmak ◽

Mithila Jugulam ◽

Amit J. Jhala

Keyword(s):

Soil Moisture ◽

Water Stress ◽

Seed Germination ◽

Crop Production ◽

Growth Index ◽

The United States ◽

Palmer Amaranth ◽

Maximum Height ◽

Amaranthus Palmeri ◽

Soil Moisture Sensors

AbstractPalmer amaranth (Amaranthus palmeriS. Watson) is the most problematic weed in agronomic crop production fields in the United States. The objective of this study was to determine the effect of degree of water stress on the growth and fecundity ofA. palmeriusing soil moisture sensors under greenhouse conditions. TwoA. palmeribiotypes collected from Nebraska were grown in loam soil maintained at 100%, 75%, 50%, 25%, and 12.5% soil field capacity (FC) corresponding to no, light, moderate, high, and severe water stress levels, respectively. Water was regularly added to pots based on soil moisture levels detected by Watermark or Decagon 5TM sensors to maintain the desired water stress level.Amaranthus palmeriplants maintained at ≤25% FC did not survive more than 35 d after transplanting.Amaranthus palmeriat 100%, 75%, and 50% FC produced similar numbers of leaves (588 to 670 plant−1) based on model estimates; however, plants at 100% FC achieved a maximum height of 178 cm compared with 124 and 88 cm at 75% and 50% FC, respectively. The growth index (1.1×105to 1.4×105cm3plant−1) and total leaf area (571 to 693 cm2plant−1) were also similar at 100%, 75%, and 50% FC.Amaranthus palmeriproduced similar root biomass (2.3 to 3 g plant−1) at 100%, 75%, and 50% FC compared with 0.6 to 0.7 g plant−1at 25% and 12.5% FC, respectively. Seed production was greatest (42,000 seeds plant−1) at 100% FC compared with 75% and 50% FC (14,000 to 19,000 seeds plant−1); however, the cumulative seed germination was similar (38% to 46%) when mother plants were exposed to ≥50% FC. The results of this study show thatA. palmerican survive ≥50% FC continuous water stress conditions and can produce a significant number of seeds with no effect of on seed germination.

Download Full-text

Germination ecology of Rhynchosia capitata: an emerging summer weed in Asia

Planta Daninha ◽

10.1590/s0100-83582013000200002 ◽

2013 ◽

Vol 31 (2) ◽

pp. 249-257 ◽

Cited By ~ 6

Author(s):

H.H. Ali ◽

A. Tanveer ◽

M.A. Nadeem ◽

H.N. Asghar ◽

M.M. Javaid

Keyword(s):

Seed Germination ◽

Soil Depth ◽

Seedling Emergence ◽

Ecological Factors ◽

Moisture Stress ◽

Burial Depth ◽

Seed Burial ◽

Germination Ability ◽

Wide Range ◽

The One

Rhynchosia capitata is becoming an increasing problem in summer crops, such as cotton, soybean, pearl millet and mungbean in many Asian countries. Laboratory and greenhouse studies have been conducted to determine the effects of several environmental factors on seed germination patterns and seedling emergence of R. capitata. We investigated whether the diverse ecological factors such as temperature, light, salinity, moisture stress, pH, and soil depth affected germination and seedling emergence of R. capitata. Germination increased as temperature increased from 25ºC and significantly reduced at 45ºC. Presence or absence of light did not influence germination. Germination of R. capitata was sensitive to increased salt and moisture stress, as well as to seed burial depth. Only 48% of seeds germinated at 150 mM salt concentration compared to 100% in control (distilled water). Similarly, 15% of seeds germinated at an osmotic potential of ‑0.8 MPa compared to 88% at ‑0.2 MPa. The optimum pH for seed germination of R. capitata was 7 (98% germination), but the seeds also germinated at lower level of pH 5 (85%) and at higher level of pH 10 (75%). In seed burial trial, maximum seedling emergence of 93% occurred at 2 cm depth, and seedling did not emerge from a depth of 12 cm. The high germination ability of R. capitata under a wide range of ecological factors suggests that this species is likely to be the one to cause more problems in a near future, if not managed appropriately.

Download Full-text

Seed germination and seedling emergence of three Artemisia species (Asteraceae) inhabiting desert sand dunes in China

Seed Science Research ◽

10.1079/ssr2005230 ◽

2006 ◽

Vol 16 (1) ◽

pp. 61-69 ◽

Cited By ~ 24

Author(s):

Kazuo Tobe ◽

Liping Zhang ◽

Kenji Omasa

Keyword(s):

Seed Germination ◽

Sand Dunes ◽

Seedling Emergence ◽

Light Sensitivity ◽

Burial Depth ◽

Secondary Effects ◽

Seed Burial ◽

Desert Sand ◽

Light Fluence ◽

Artemisia Species

Artemisia ordosica,A. arenariaandA. sphaerocephalaare semi-shrubs inhabiting desert sand dunes in China and often used to rehabilitate desertified areas. Improvement of dune rehabilitation success by sowing requires better understanding of the processes involved in the control of seed germination and seedling emergence in these species. Thus, (1) effects of temperature, light and osmotica (polyethylene glycol-6000) on seed germination, and (2) effects of seed burial depth in sand and irrigation regime on seedling emergence, were studied under controlled conditions. Seeds of the three species required light for germination, and the light fluence needed for germination was dependent on temperature. Seedling emergence of the three species was maximal (70–94%) for seeds sown at a depth of 2.5 mm, and decreased with increasing seed burial depth when the pots were initially and subsequently treated with 16 mm and 3 mm irrigation at 1-d intervals. However, when the pots were initially and subsequently treated with 8 mm and 3 mm irrigation at 2-d intervals, seedling emergence was almost completely suppressed due to water deficiency in sand. It is suggested that the probability of seed germination and seedling emergence of the three species in the field is very limited, because the light requirement restricts seed germination to shallow sand layers where water is lost rapidly due to evaporation. Temperature appeared to have secondary effects on seed germination, by modifying the light sensitivity of seeds.

Download Full-text

The effects of temperature, water availability and seed burial depth on seed germination and seedling establishment of Calobota sericea (Fabaceae)

South African Journal of Botany ◽

10.1016/j.sajb.2018.11.012 ◽

2019 ◽

Vol 121 ◽

pp. 224-229 ◽

Cited By ~ 2

Author(s):

F.L. Müller ◽

L.M. Raitt ◽

L.F. Cyster ◽

C.F. Cupido ◽

M.I. Samuels ◽

...

Keyword(s):

Seed Germination ◽

Water Availability ◽

Seedling Establishment ◽

Burial Depth ◽

Seed Burial ◽

Effects Of Temperature ◽

Temperature Water

Download Full-text

Using semi-natural and simulated habitats for seed germination ecology

10.22541/au.162632670.08797149/v1 ◽

2021 ◽

Author(s):

Simon Kallow ◽

Katrijn Quaghebeur ◽

Bart Panis ◽

Steven Janssens ◽

John B. Dickie ◽

...

Keyword(s):

Seed Germination ◽

Natural Habitat ◽

Crop Wild Relatives ◽

The Philippines ◽

Maximum Temperature ◽

Marginal Effect ◽

Burial Depth ◽

Natural Habitats ◽

Seed Burial ◽

Soil Temperatures

1. Ecologically meaningful seed germination experiments are constrained by access to seeds and relevant environments for testing at the same time. This is particularly the case when research is carried out far from the native area of the studied species. 2. Here, we demonstrate an alternative - the use of glass houses in botanic gardens as simulated-natural habitats to extend the ecological interpretation of germination studies. Our focal taxa were banana crop wild relatives (Musa acuminata subsp. burmannica, M. acuminata subsp. siamea and M. balbisiana), native to tropical and subtropical Southeast Asia. Tests were carried out in Belgium, where we performed germination tests in relation to exposure to sun and foliage-shading, seed burial-depth in different heated glass house compartments, as well as seed survival and dormancy release in the soil. We anchored the interpretation of these studies by also conducting an experiment in a semi-natural habitat in the species native range (M. balbisiana - Los Baños, the Philippines), where we tested germination responses to exposure to the sun and shade. Using temperature data loggers, we determined temperature dynamics suitable for germination in both these settings. 3. In semi-natural and simulated-natural habitats, seeds germinated in response to exposure to direct solar radiation. Seed burial-depth had a significant but marginal effect by comparison, even when seeds were buried to 7cm in the soil. Temperatures at sun-exposed compared to shaded environments differed by only a few degrees Celsius. Maximum temperature of the period prior to germination was the most significant contributor to germination responses and germination increased linearly above a threshold of 23°C to the maximum temperature in the soil (in simulated natural habitats) of 35°C. 4. Glass houses can provide useful environments to aid interpretation of seed germination responses to environmental niches.

Download Full-text

Seedbank Persistence of Palmer Amaranth (Amaranthus palmeri) and Waterhemp (Amaranthus tuberculatus) across Diverse Geographical Regions in the United States

Weed Science ◽

10.1017/wsc.2018.27 ◽

2018 ◽

Vol 66 (4) ◽

pp. 446-456 ◽

Cited By ~ 6

Author(s):

Nicholas E. Korres ◽

Jason K. Norsworthy ◽

Bryan G. Young ◽

Daniel B. Reynolds ◽

William G. Johnson ◽

...

Keyword(s):

United States ◽

Seed Viability ◽

Soil Surface ◽

The United States ◽

Palmer Amaranth ◽

Soil Conditions ◽

Burial Depth ◽

Amaranthus Palmeri ◽

Seed Damage ◽

Amaranthus Tuberculatus

AbstractKnowledge of the effects of burial depth and burial duration on seed viability and, consequently, seedbank persistence of Palmer amaranth (Amaranthus palmeriS. Watson) and waterhemp [Amaranthus tuberculatus(Moq.) J. D. Sauer] ecotypes can be used for the development of efficient weed management programs. This is of particular interest, given the great fecundity of both species and, consequently, their high seedbank replenishment potential. Seeds of both species collected from five different locations across the United States were investigated in seven states (sites) with different soil and climatic conditions. Seeds were placed at two depths (0 and 15 cm) for 3 yr. Each year, seeds were retrieved, and seed damage (shrunken, malformed, or broken) plus losses (deteriorated and futile germination) and viability were evaluated. Greater seed damage plus loss averaged across seed origin, burial depth, and year was recorded for lots tested at Illinois (51.3% and 51.8%) followed by Tennessee (40.5% and 45.1%) and Missouri (39.2% and 42%) forA. palmeriandA. tuberculatus, respectively. The site differences for seed persistence were probably due to higher volumetric water content at these sites. Rates of seed demise were directly proportional to burial depth (α=0.001), whereas the percentage of viable seeds recovered after 36 mo on the soil surface ranged from 4.1% to 4.3% compared with 5% to 5.3% at the 15-cm depth forA. palmeriandA. tuberculatus, respectively. Seed viability loss was greater in the seeds placed on the soil surface compared with the buried seeds. The greatest influences on seed viability were burial conditions and time and site-specific soil conditions, more so than geographical location. Thus, management of these weed species should focus on reducing seed shattering, enhancing seed removal from the soil surface, or adjusting tillage systems.

Download Full-text

Germination of Fresh Horse Purslane (Trianthema portulacastrum) Seeds in Response to Different Environmental Factors

Weed Science ◽

10.1614/ws-d-11-00002.1 ◽

2011 ◽

Vol 59 (4) ◽

pp. 495-499 ◽

Cited By ~ 18

Author(s):

Jihyun Lee ◽

Bhagirath S. Chauhan ◽

David E. Johnson

Keyword(s):

Seed Germination ◽

Environmental Factors ◽

Seedling Emergence ◽

Soil Surface ◽

The Philippines ◽

Integrated Weed Management ◽

Burial Depth ◽

Seed Burial ◽

Soil Burial ◽

Two Populations

Horse purslane, a C4 species, is a branched, prostrate, and annual weed of upland field crops throughout the tropics. Experiments were conducted to determine the influence of various environmental factors on seed germination and seedling emergence of two populations of horse purslane. Seeds were collected from rice fields of the International Rice Research Institute (the IR population) and from sorghum fields of the University of the Philippines (the UP population); the two sites were 5 km apart in Los Baños, Philippines. Germination response of both populations was greater at 30/20 C and35/25 C day/night temperatures than they were at 25/15 C alternating day/night temperatures. Germination of both populations was greater in the light/dark regime than in darkness. In dark, depending on the temperature, seed germination of the UP population ranged from 37 to 62%, whereas seed germination of the IR population was < 20%. Exposure to 5 min at 117 and 119 C for the IR and UP populations, respectively, reduced germination to 50% of maximum germination. Osmotic potential of −0.26 MPa inhibited germination to 50% of the maximum for the UP population, whereas the corresponding value for the IR population was −0.37 MPa. Seeds placed on or near the soil surface had maximum emergence, and emergence declined with increase in seed burial depth. Seedling emergence of the UP and IR populations was 74% and 13%, respectively, for seeds placed on the soil surface. For both populations, no seedlings emerged from a soil burial depth of 6 cm or more. Germination and emergence responses to light and seed burial depth differed between the two populations of horse purslane. Residues on the soil surface of up to 6 Mg ha−1 did not influence seedling emergence of either populations. Knowledge gained in this study could contribute to developing components of integrated weed management strategies for horse purslane.

Download Full-text

Seed germination ecology of Conyza sumatrensis populations stemming from different habitats and implications for management

PLoS ONE ◽

10.1371/journal.pone.0260674 ◽

2021 ◽

Vol 16 (12) ◽

pp. e0260674

Author(s):

Yanyun Xu ◽

Junyong Ye ◽

Ahlam Khalofah ◽

Ali Tan Kee Zuan ◽

Rehmat Ullah ◽

...

Keyword(s):

Seed Germination ◽

Osmotic Potential ◽

Seedling Emergence ◽

Environmental Cues ◽

Burial Depth ◽

Maternal Environment ◽

Seed Burial ◽

Germination Traits ◽

Germination Indices ◽

Semi Arid

Conyza sumatrensis (Retz.) E. H. Walker is an obnoxious weed, emerging as an invasive species globally. Seed germination biology of four populations of the species stemming from arid, semi-arid, temperate, and humid regions was determined in this study. Seed germination was recorded under six different environmental cues (i.e., light/dark periods, constant and alternating day and night temperatures, pH, salinity, and osmotic potential levels) in separate experiment for each cue. Populations were main factor, whereas levels of each environmental cue were considered as sub-factor. The impact of seed burial depths on seedling emergence was inferred in a greenhouse pot experiment. Seed germination was recorded daily and four germination indices, i.e., seed germination percentage, mean germination time, time to reach 50% germination, and mean daily germination were computed. Tested populations and levels of different environmental cues had significant impact on various seed germination indices. Overall, seeds stemming from arid and semi-arid regions had higher seed germination potential under stressful and benign environmental conditions compared to temperate and humid populations. Seed of all populations required a definite light period for germination and 12 hours alternating light and dark period resulted in the highest seed germination. Seed germination of all populations occurred under 5–30°C constant and all tested alternate day and night temperatures. However, the highest seed germination was recorded under 20°C. Seeds of arid and semi-arid populations exhibited higher germination under increased temperature, salinity and osmotic potential levels indicating that maternal environment strongly affected germination traits of the tested populations. The highest seed germination of the tested populations was noted under neutral pH, while higher and lower pH than neutral had negative impact on seed germination. Arid and semi-arid populations exhibited higher seed germination under increased pH compared to temperate and humid populations. Seed burial depth had a significant effect on the seedling emergence of all tested populations. An initial increase was noted in seedling emergence percentage with increasing soil depth. However, a steep decline was recorded after 2 cm seed burial depth. These results indicate that maternal environment strongly mediates germination traits of different populations. Lower emergence from >4 cm seed burial depth warrants that deep burial of seeds and subsequent zero or minimum soil disturbance could aid the management of the species in agricultural habitats. However, management strategies should be developed for other habitats to halt the spread of the species.

Download Full-text