Influence of Smooth Pigweed (Amaranthus hybridus) and Common Purslane (Portulaca oleracea) Densities on Lettuce Yields under Different Phosphorus Fertility Regimes

The effects of different populations densities of smooth pigweed and common purslane were determined in field trials conducted in organic soils. `South Bay' lettuce was planted in twin rows on 90-cm planting beds. Weed densities used were 0, 2, 4, 8, and 16 weeds per 6 m of row (5.4 m2). Phosphorus (P) was applied broadcast (1200 kg P/ha) and banded 2 inches below each lettuce row (600 kg P/ha). Lettuce fresh weights were collected 8 weeks after emergence. Data collected indicated that P regime and density had significant effects on lettuce yield and quality. For both weeds, yield decreased as density increased. In all cases, lettuce showed greater yields at a given density when grown with P banded than when P was applied broadcast. Critical density for smooth pigweed for P broadcast was between 2 and 4 plants per 5.4 m2, whereas this critical density occurred between 8 and 16 plants per 5.4 m2 when P was banded. Yield reductions of up to 24.4% and 20.1% occurred at the highest smooth pigweed density for broadcast and banded P, respectively. Two common purslane plants per 5.4 m2 were enough to reduce lettuce yields. Banding P helped lettuce to produce significantly more within each common purslane density. Yield reductions of 47.8% and 44.3% occurred at the highest common purslane density for broadcast and banded P, respectively. Apparently, banding P gives an additional advantage to the crop against smooth pigweed and common purslane.

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Effects of Phosphorus Fertility Regimes and Smooth Pigweed (Amaranthus hybridus) and Common Purslane (Portulaca oleracea) Removal Times on Lettuce Yields

HortScience ◽

10.21273/hortsci.32.3.431b ◽

1997 ◽

Vol 32 (3) ◽

pp. 431B-431

Author(s):

Bielinski M. Santos ◽

Joan A. Dusky ◽

William M. Stall ◽

Donn G. Shilling ◽

Thomas A. Bewick

Keyword(s):

Weed Control ◽

Negative Impact ◽

Organic Soils ◽

Amaranthus Hybridus ◽

Weed Interference ◽

Removal Time ◽

Significant Yield ◽

Lettuce Yield ◽

Common Purslane ◽

Smooth Pigweed

The effects of different smooth pigweed and common purslane removal times and two phosphorus (P) fertility regimes were studied under field conditions. Head lettuce (cv. South Bay) in organic soils low in P fertility. Smooth pigweed and common purslane were grown at a density of 16 plants per 6 m of row (5.4 m2) and five removal times (0, 2, 4, 6, and 8 weeks) after lettuce emergence. Phosphorus (P) was applied broadcast (1200 kg P/ha) and banded 2 inches below each lettuce row (600 kg P/ha). Lettuce fresh weights were collected 8 weeks after emergence. When smooth pigweed was removed after 4 weeks, significant reductions (–17%) were observed for P banding. However, these reductions occurred after 2 weeks if P was broadcast. No significant differences were observed if removal was imposed later for P broadcast, whereas lettuce yields gradually decreased as removal time was delayed. These findings indicate that P banding can counteract the negative impact of smooth pigweed on lettuce and may allow farmers to delay weed control (if necessary) for another 2 weeks without significant yield reductions. Common purslane interference did not cause significant lettuce yield reductions as compared to the weed-free control for 6 weeks when P was banded, whereas this was true for P broadcast up to 4 weeks. Phosphorus fertility regime significantly influenced the period of weed interference of common purslane with lettuce, reducing its impact when P was banded.

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Phosphorus effects on competitive interactions of smooth pigweed (Amaranthus hybridus) and common purslane (Portulaca oleracea) with lettuce (Lactuca sativa)

Weed Science ◽

10.1017/s0043174500089463 ◽

1998 ◽

Vol 46 (3) ◽

pp. 307-312 ◽

Cited By ~ 17

Author(s):

Bielinski M. Santos ◽

Joan A. Dusky ◽

William M. Stall ◽

Donn G. Shilling ◽

Thomas A. Bewick

Keyword(s):

Competitive Ability ◽

Organic Soils ◽

Weed Species ◽

Population Densities ◽

Replacement Series ◽

Amaranthus Hybridus ◽

Extractable P ◽

Common Purslane ◽

Smooth Pigweed ◽

Water Extractable

Replacement series studies were conducted under controlled conditions to determine the effect of phosphorus (P) rates and population densities on the competitiveness of smooth pigweed and common purslane with lettuce. Densities were 2, 4, and 8 plants per 113 cm2, whereas P rates were 0, 0.4, and 0.8 g PL−1soil. A P-deficient Histosol (0.3 mg water-extractable P L−1soil) was used. High P fertility enhanced the competitive ability of lettuce in smooth pigweed-lettuce mixtures. Smooth pigweed was not responsive to P rates. However, luxurious P consumption by smooth pigweed occurred, reducing the amount of the nutrient available for lettuce absorption. In common purslane-lettuce mixtures, the weed was responsive to P rates, increasing its competitive ability, whereas no increase in lettuce competitive ability was observed. Both weed species were more competitive than lettuce. Competition for P appears to be the main mechanism of common purslane interference on lettuce grown in low-P organic soils. Alternative fertilization strategies (i.e., banded applications) may reduce the effect of smooth pigweed on lettuce.

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Influence of method of phosphorus application on smooth pigweed (Amaranthus hybridus) and common purslane (Portulaca oleracea) interference in lettuce

Weed Science ◽

10.1614/ws-03-069r2 ◽

2004 ◽

Vol 52 (5) ◽

pp. 797-801 ◽

Cited By ~ 4

Author(s):

Bielinski M. Santos ◽

Joan A. Dusky ◽

William M. Stall ◽

Thomas A. Bewick ◽

Donn G. Shilling

Keyword(s):

Portulaca Oleracea ◽

Amaranthus Hybridus ◽

Common Purslane ◽

Phosphorus Application ◽

Smooth Pigweed

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Mechanisms of interference of smooth pigweed (Amaranthus hybridus) and common purslane (Portulaca oleracea) on lettuce as influenced by phosphorus fertility

Weed Science ◽

10.1614/p2002-171 ◽

2004 ◽

Vol 52 (1) ◽

pp. 78-82 ◽

Cited By ~ 9

Author(s):

Bielinski M. Santos ◽

Joan A. Dusky ◽

William M. Stall ◽

Thomas A. Bewick ◽

Donn G. Shilling

Keyword(s):

Root Biomass ◽

Biomass Accumulation ◽

Light Interception ◽

Fertility Rates ◽

Interference Factor ◽

Amaranthus Hybridus ◽

Tissue Content ◽

Common Purslane ◽

Secondary Mechanism ◽

Smooth Pigweed

Greenhouse studies were conducted to assess the intensity of smooth pigweed and common purslane aboveground interference (AI) and belowground interference (BI) with lettuce and to determine primary mechanisms of interference of each species as affected by P fertility rates. Lettuce was transplanted in mixtures with either smooth pigweed or common purslane according to four partitioning regimes: no interference, full interference, BI, and AI. Soil used was low in P for optimum lettuce yields, therefore P was added at rates of 0, 0.4, and 0.8 grams of P per liter of soil. Shoot and root biomass and plant height were measured for each species, as well as P tissue content. The data obtained indicated that smooth pigweed interfered with lettuce primarily through light interception by its taller canopy. A secondary mechanism of interference was the absorption of P from the soil through luxury consumption, increasing the P tissue content without enhancing smooth pigweed biomass accumulation. In contrast, common purslane competed aggressively with lettuce for P. Because the weed grew taller than lettuce, light interception was a secondary interference factor.

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Phosphorus absorption in lettuce, smooth pigweed (Amaranthus hybridus), and common purslane (Portulaca oleracea) mixtures

Weed Science ◽

10.1614/ws-03-053r ◽

2004 ◽

Vol 52 (3) ◽

pp. 389-394 ◽

Cited By ~ 6

Author(s):

Bielinski M. Santos ◽

Joan A. Dusky ◽

William M. Stall ◽

Thomas A. Bewick ◽

Donn G. Shilling ◽

...

Keyword(s):

Portulaca Oleracea ◽

Amaranthus Hybridus ◽

Phosphorus Absorption ◽

Common Purslane ◽

Smooth Pigweed

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Evaluation of Harvest-Aid Herbicides as Desiccants in Lentil Production

Weed Technology ◽

10.1614/wt-d-16-00007.1 ◽

2016 ◽

Vol 30 (3) ◽

pp. 629-638 ◽

Cited By ~ 5

Author(s):

Ti Zhang ◽

Eric N. Johnson ◽

Christian J. Willenborg

Keyword(s):

Adverse Effects ◽

Crop Yield ◽

Seed Yield ◽

Yield Loss ◽

Field Trials ◽

Growth Stages ◽

Yield And Quality ◽

Seed Field ◽

Dry Down ◽

General Reduction

Desiccants are currently used to improve lentil dry-down prior to harvest. Applying desiccants at growth stages prior to maturity may result in reduced crop yield and quality, and leave unacceptable herbicide residues in seeds. There is little information on whether various herbicides applied alone or as a tank-mix with glyphosate have an effect on glyphosate residues in harvested seed. Field trials were conducted at Saskatoon and Scott, Saskatchewan, Canada, from 2012 to 2014 to determine whether additional desiccants applied alone or tank mixed with glyphosate improve crop desiccation and reduce the potential for unacceptable glyphosate residue in seed. Glufosinate and diquat tank mixed with glyphosate were the most consistent desiccants, providing optimal crop dry-down and a general reduction in glyphosate seed residues without adverse effects on seed yield and weight. Saflufenacil provided good crop desiccation without yield loss, but failed to reduce glyphosate seed residues consistently. Pyraflufen-ethyl and flumioxazin applied alone or tank mixed with glyphosate were found to be inferior options for growers as they exhibited slow and incomplete crop desiccation, and did not decrease glyphosate seed residues. Based on results from this study, growers should apply glufosinate or diquat with preharvest glyphosate to maximize crop and weed desiccation, and minimize glyphosate seed residues.

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Tea saponin reduces the damage of Ectropis obliqua to tea crops, and exerts reduced effects on the spiders Ebrechtella tricuspidata and Evarcha albaria compared to chemical insecticides

PeerJ ◽

10.7717/peerj.4534 ◽

2018 ◽

Vol 6 ◽

pp. e4534 ◽

Cited By ~ 5

Author(s):

Chi Zeng ◽

Lingbing Wu ◽

Yao Zhao ◽

Yueli Yun ◽

Yu Peng

Keyword(s):

Biological Control ◽

Field Trials ◽

Control Measures ◽

Dependent Manner ◽

Glutathione S Transferase ◽

Tea Plantation ◽

Tea Saponin ◽

Yield And Quality ◽

Significant Damage ◽

Dose Dependent

Background Tea is one of the most economically important crops in China. However, the tea geometrid (Ectropis obliqua), a serious leaf-feeding pest, causes significant damage to tea crops and reduces tea yield and quality. Spiders are the most dominant predatory enemies in the tea plantation ecosystem, which makes them potentially useful biological control agents of E. obliqua. These highlight the need for alternative pest control measures. Our previous studies have shown that tea saponin (TS) exerts insecticidal activity against lepidopteran pests. Here, we investigate whether TS represents a potentially new alternative insecticide with no harm to spiders. Methods We investigated laboratory bioactivities and the field control properties of TS solution against E. obliqua. (i) A leaf-dip bioassay was used to evaluate the toxicity of TS to 3rd-instar E. obliqua larvae and effects of TS on the activities of enzymes glutathione-S-transferase (GST), acetylcholinesterase (AChE), carboxylesterase (CES) and peroxidase (POD) of 3rd-instar E. obliqua larvae in the laboratory. (ii) Topical application was used to measure the toxicity of 30% TS (w/v) and two chemical insecticides (10% bifenthrin EC and 50% diafenthiuron SC) to two species of spider, Ebrechtella tricuspidata and Evarcha albaria. (iii) Field trials were used to investigate the controlling efficacy of 30% TS against E. obliqua larvae and to classify the effect of TS to spiders in the tea plantation. Results The toxicity of TS to 3rd-instar E. obliqua larvae occurred in a dose-dependent manner and the LC50 was 164.32 mg/mL. Activities of the detoxifying-related enzymes, GST and POD, increased in 3rd-instar E. obliqua larvae, whereas AChE and CES were inhibited with time by treatment with TS. Mortalities of E. tricuspidata and E. albaria after 48 h with 30% TS treatment (16.67% and 20%, respectively) were significantly lower than those with 10% bifenthrin EC (80% and 73.33%, respectively) and 50% diafenthiuron EC (43.33% and 36.67%, respectively). The highest controlling efficacy of 30% TS was 77.02% at 5 d after treatment, which showed no difference to 10% bifenthrin EC or 50% diafenthiuron SC. 30% TS was placed in the class N (harmless or slightly harmful) of IOBC (International Organization of Biological Control) categories for natural enemies, namely spiders. Conclusions Our results indicate that TS is a botanical insecticide that has a good controlling efficacy in E. obliqua larvae, which suggests it has promise as application in the integrated pest management (IPM) envisaged for tea crops.

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The effects of fertilization on the protein related properties of winter wheat

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/52/2102 ◽

2013 ◽

pp. 67-69

Author(s):

Mariann Móré ◽

Zita Burján ◽

Zoltán Győri ◽

Péter Sipos

Keyword(s):

Field Trials ◽

Quality Parameters ◽

Plant Production ◽

Mineral Fertilization ◽

Yield And Quality ◽

Gluten Content ◽

Protein Properties ◽

Set Up ◽

The University ◽

Gluten Index

The yield and quality of wheat are mainly determined by the plant production system, thus we studied the effect of mineral fertilization. The field trials were set up in 1983 at the Látókép Research Institute of the University of Debrecen. We examined effect of different Nfertilizer doses (60 kg ha-1 N/P/K, 120 kg ha-1 N/P/K) on Lupus, Mv Toldi and GK Csillag's protein properties in 2012. During the tests, three quality parameters were determined: wet gluten content (%), wet gluten spread (mm/h) and gluten index (%). In the experiment the effect of different doses of N-fertilizers significantly influenced by the wet gluten content and gluten index of Lupus.

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Efficacy of Bentazon and MSMA as Affected by a Humic Acid-Type Polymeric Polyhydroxy Acid Adjuvant

Weed Science ◽

10.1017/s0043174500079121 ◽

1987 ◽

Vol 35 (2) ◽

pp. 237-242 ◽

Cited By ~ 4

Author(s):

Chester G. McWhorter ◽

Gene D. Wills ◽

Robert D. Wauchope

Keyword(s):

Glycine Max ◽

Humic Acid ◽

Sorghum Halepense ◽

Xanthium Strumarium ◽

Amaranthus Hybridus ◽

Acid Type ◽

Monosodium Salt ◽

Treated Leaf ◽

Methylarsonic Acid ◽

Smooth Pigweed

Foliar applications of14C-bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] with PPA (polymeric polyhydroxy acid) at 1 or 2% (v/v) or nonoxynol (9.5 POE) [α-(p-nonylpheny1)-ω-hydroxypoly(oxyethylene)] at 1% (v/v) or mixtures of PPA and nonoxynol did not increase absorption or translocation of14C-bentazon in soybeans [Glycine max(L.) Merr. ‘Lee 74′] or common cocklebur (Xanthium strumariumL. # XANST). PPA alone at 1 to 2% (v/v) did not significantly affect absorption or translocation of14C-bentazon in smooth pigweed (Amaranthus hybridusL. # AMACH), but PPA with nonoxynol significantly increased translocation out of the treated leaf. Both PPA and nonoxynol decreased absorption and movement of14C-MSMA [monosodium salt of methylarsonic acid] out of the treated leaf of johnsongrass [Sorghum halepense(L.) Pers. # SORHA]. In greenhouse research, PPA at 0.25 and 0.5% (v/v) did not increase the level of control of common cocklebur obtained following postemergence applications of bentazon at 0.24 and 0.48 kg ai/ha. Similarly, PPA at 0.25 and 0.50% (v/v) did not increase the toxicity of MSMA at 0.3 and 0.6 kg ai/ha to either johnsongrass or common cocklebur.

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Triazine-Resistant Smooth Pigweed (Amaranthus hybridus) Control in Field Corn (Zea maysL.)

Weed Technology ◽

10.1017/s0890037x00027846 ◽

1993 ◽

Vol 7 (2) ◽

pp. 431-436 ◽

Cited By ~ 12

Author(s):

Eric D. Birschbach ◽

Mark G. Myers ◽

R. Gordon Harvey

Keyword(s):

Amaranthus Hybridus ◽

Complete Control ◽

Field Corn ◽

Herbicide Treatments ◽

Smooth Pigweed

Studies were conducted for 3 yr to evaluate herbicides and herbicide combinations for triazine-resistant smooth pigweed (TR-AMACH) control in field corn. Of the PRE treatments, combinations of atrazine plus acetochlor, metolachlor plus dicamba, and atrazine plus alachlor provided the most complete control of this weed (77 to 81%). The best early postemergence (EP) combination was pendimethalin plus atrazine plus dicamba (93% control). Pyridate plus atrazine applied POST provided a four-site average of 98% control. The most effective sequential herbicide treatments consisted of either metolachlor or pendimethalin PRE followed by POST treatments containing either pyridate, thifensulfuron, bromoxynil, or dicamba.

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