THE EFFECTS OF ALFALFA PLANT BUG (HEMIPTERA: MIRIDAE) FEEDING LATE IN THE SEASON ON ALFALFA SEED YIELD IN NORTHERN SASKATCHEWAN

1993 ◽  
Vol 125 (5) ◽  
pp. 815-824 ◽  
Author(s):  
Juliana J. Soroka ◽  
Dorothy C. Murrell
Keyword(s):  
Seed Yield ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Field Cage ◽  
North Central ◽  
Alfalfa Plant ◽  
Adelphocoris Lineolatus ◽  
Alfalfa Seed ◽  
Seed Yields ◽  
Beneficial Arthropod

AbstractA 4-year field cage study was conducted to determine what effects feeding of alfalfa plant bug, Adelphocoris lineolatus (Goeze), late in the season had on alfalfa seed yields. When zero, one, two, or four alfalfa plant bugs were placed in sleeve cages containing stems of alfalfa at the green pod stage of growth, there was a significant decrease in the number of pods per cage and per raceme, the number of healthy seeds, and the weight of seeds with two or four bugs per cage. Increasing the duration of infestation resulted in significant increases in the number of damaged seeds per cage. An insecticide field trial was conducted in north central Saskatchewan in 1988 to determine what effects the occurrence of plant bugs had on seed yields of alfalfa. Alfalfa plant bug, lygus bug (Lygus spp.), pea aphid [Acyrthosiphon pisum (Harris)], and beneficial arthropod populations were monitored from 23 June to 1 September 1988. Seed yields were significantly greater in plots that were treated with trichlorfon in June and in June and August than in plots that were treated in August alone. The implications of a large alfalfa plant bug population late in the season to alfalfa seed production in the area are discussed.

Early and Late-Season Insecticide Applications in Seed Alfalfa: Impact on Pest Species and Yield2

1990 ◽  
Vol 25 (4) ◽  
pp. 548-558 ◽  
Author(s):  
B. D. Schaber ◽  
W. A. Charnetski ◽  
T. Entz
Keyword(s):  
Seed Yield ◽  
Field Studies ◽  
Pest Species ◽  
Seed Formation ◽  
Alfalfa Plant ◽  
Late Season ◽  
Time Of Application ◽  
Adelphocoris Lineolatus ◽  
Pest Insects ◽  
Seed Yields

Alfalfa is grown for seed on approximately 9,500 ha in Alberta, Canada. Pest insects, such as Lygus spp. and the alfalfa plant bug, Adelphocoris lineolatus (Goeze), (Heteroptera: Miridae) can reduce seed yield if they are not controlled. However, little is known of the damage caused by these pest insects during late seed formation and development. Field studies were conducted during 1983 and 1986 to determine the effect of early- and late-season applications of the insecticides trichlorfon and phosmet alone and combined on Lygus spp., alfalfa plant bug and seed yield of alfalfa. Effects were dependent on the time of application, year, and insect species. Lygus spp. densities for late-season trichlorfon treatments were significantly (P < 0.05) lower than the control. Trichlorfon and phosmet had no effect on densities of alfalfa plant bugs in 1983, but some late-season trichlorfon treatments did reduce plant bug densities in 1986. Seed yields in plots receiving late-season trichlorfon were generally greater than in the control in both years.

Preharvest glyphosate in alfalfa for seed production: Effect on alfalfa seed yield and quality

2003 ◽  
Vol 83 (1) ◽  
pp. 189-197 ◽  
Author(s):  
W. E. May ◽  
H. A. Loeppky ◽  
D. C. Murrell ◽  
C. D. Myhre ◽  
J. J. Soroka
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Seed Quality ◽  
Seedling Emergence ◽  
Canada Thistle ◽  
Seedling Vigour ◽  
Yield And Quality ◽  
Alfalfa Seed ◽  
Medicago Sativa L ◽  
Seed Yields

Preharvest applications of glyphosate have been shown to be effective in controlling Canada thistle in annual crops, but may reduce alfalfa seed yield depending on time and rate of application. The objective of this study was to determine the effect of preharvest applications of glyphosate on subsequent alfalfa seed yield and quality. The effects of timing, 1, 26, 51 and 76% alfalfa seed pod maturity, and rate, 0, 440, 880, 1320, and 1760 g a.i. ha-1, of a preharvest application of glyphosate on alfalfa seed yield and quality in the year of application, and regrowth and seed yield in the following year were determined. The rate of glyphosate applied did not affect seed yield in the application year; however, in the following year, growth and seed yield were reduced as rates increased. Delaying the application of glyphosate increased seed yields in the application year, but decreased alfalfa regrowth and flowering the following year. Germination and seedling emergence were not affected by the rate or timing of the glyphosate. A preharvest application of glyphosate at 1760 g a.i. ha-1 at 76% pod maturity is a viable option in the last year of seed production. Key words: Alfalfa (Medicago sativa L.), glyphosate, abnormal seeds, seed quality, and seedling vigour

Effect of plant density and herbicide application on alfalfa seed and weed yields

1991 ◽  
Vol 71 (2) ◽  
pp. 481-489 ◽  
Author(s):  
J. R. Moyer ◽  
R. W. Richards ◽  
G. B. Schaalje
Keyword(s):  
Seed Yield ◽  
Plant Density ◽  
Joint Effect ◽  
Seeding Rate ◽  
Perennial Weed ◽  
Weed Growth ◽  
Alfalfa Seed ◽  
Untreated Check ◽  
Plant Densities ◽  
Seed Yields

Alfalfa was seeded in row spacings of 36, 72 and 108 cm and at broadcast seeding rates of 0.33, 1.0 and 3.0 kg ha−1 on irrigated land at Tilley (1983) and Lethbridge (1984), Alberta to determine the effect of plant density on weed growth and alfalfa seed yield. During the seed-producing years at each location, herbicide treatments were overlaid on seeding treatments in a split-block arrangement to assess the joint effect of herbicides and plant density on alfalfa seed yield. Hexazinone was the main herbicide used for weed control. Alfalfa seed and weeds were harvested for 5 yr following alfalfa establishment. Alfalfa seed yields tended to be maximum with 36-cm row spacings or the 3.0 kg ha−1 broadcast seeding rate, and were similar in row-seeded and broadcast-seeded alfalfa. Dry matter yields of weeds decreased as row spacings decreased or the broadcast seeding rate increased. Hexazinone controlled quackgrass, sow thistle, flixweed and kochia. In the experiment at Tilley with perennial weed infestations, mean alfalfa seed yields from 1984 to 1985 were 20% larger when herbicides were used than in the untreated check. Alfalfa plant densities slightly larger than currently recommended usually produced the largest seed yields and smallest weed infestations. Key words: Medicago sativa, quackgrass, kochia, sow thistle, flixweed, hexazinone

Desiccation of alfalfa for seed production with diquat and glufosinate

1996 ◽  
Vol 76 (3) ◽  
pp. 435-439 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya ◽  
J. Fraser ◽  
K. W. Richards ◽  
N. Foroud
Keyword(s):  
Key Words ◽  
Seed Production ◽  
Seed Yield ◽  
Seed Weight ◽  
Viable Seed ◽  
Hard Seed ◽  
Alfalfa Seed ◽  
Percent Germination ◽  
Medicago Sativa L ◽  
Seed Yields

Recommendations for desiccation of alfalfa do not clearly define the stage at which desiccants should be applied. To obtain this information, diquat and glufosinate were applied to alfalfa (Medicago sativa L) from 1991 to 1994 at various stages of maturity to determine the effect of desiccant and stage of maturity at desiccation on seed yield 1000-seed weight and seed germinability. Alfalfa seed yields, 1000-seed weights, percent germination and percent viable seed were similar after desiccation with diquat and glufosinate. Desiccation when 60–75% of the alfalfa seed pods were brown permitted maximum seed yields. Percent germination increased slightly in seeds that were exposed to weathering under normal conditions until all pods turned brown. Both desiccants adequately desiccated alfalfa for harvesting but desiccation with glufosinate took 2 or 3 d longer than diquat. Desiccants did not reduce alfalfa growth in the spring after application. Key words: Germination, yield, hard seed, seed weight, stage

Chemical Control of Dandelion (Taraxacum officinale) and Perennial Sowthistle (Sonchus arvensis) in Alfalfa (Medicago sativa) Grown for Seed

Weed Science ◽  
1980 ◽  
Vol 28 (2) ◽  
pp. 164-167 ◽  
Author(s):  
J. Waddington
Keyword(s):  
Medicago Sativa ◽  
Seed Yield ◽  
Chemical Control ◽  
Growing Season ◽  
Taraxacum Officinale ◽  
Alfalfa Seed ◽  
Visible Effect ◽  
Sonchus Arvensis ◽  
Dichlorophenoxy Acetic Acid ◽  
Seed Yields

Applications of 2,4-D [(2,4-dichlorophenoxy)acetic acid] at 1.1 kg/ha at the start of each growing season severely damaged established alfalfa (Medicago sativaL. ‘Beaver’) and reduced seed yield 32% over a 4-yr period. Dandelion (Taraxacum officinaleWeber) populations were reduced but perennial sowthistle (Sonchus arvensisL.) increased in frequency. Dichlobenil (2,6-dichlorobenzonitrile) applied at 2.1 kg/ha controlled both dandelion and perennial sowthistle. Alfalfa was damaged initially but rapid recovery resulted in an increase in seed yield in 2 yr out of 4. Terbacil (3-tert-butyl-5-chloro-6-methyluracil) applied at 1.1 kg/ha also controlled dandelion and perennial sowthistle. No alfalfa damage was evident and seed yields were increased 34% over a 3-yr period. Seed yield increased 30% where asulam (methyl sulfanilylcarbamate) was applied at 4.5 kg/ha, but there was no visible effect on the growth of either alfalfa or weeds. Simazine [2-chloro-4,6-bis (ethylamino)-s-triazine], propham (isopropyl carbanilate) + PCMC (p-chlorophenyl-N-methyl carbamate), pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide], and diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], did not affect alfalfa seed production significantly, although simazine and diuron did reduce dandelion populations.

ALFALFA PESTS IN SAMARA REGION FOREST-STEPPE

2016 ◽  
Vol 1 (4) ◽  
pp. 28-32
Author(s):  
Перцева ◽  
Elena Pertseva
Keyword(s):  
Field Studies ◽  
Forest Steppe ◽  
Research Station ◽  
Adelphocoris Lineolatus ◽  
Age Related ◽  
The Family ◽  
Different Types ◽  
Alfalfa Seed ◽  
Seed Yields ◽  
Selection Of

The purpose of research is alfalfa yields increasing by crops of different ages in the conditions of forest-steppe of the Samara region. Field studies were carried out in breeding crop rotation of department introduction, selection of feed and oilseeds Volga research station named after P.N. Konstantinov in 2014. Entomofauna alfalfa crops of different varieties and ages were studied mowing butterfly net. More numerous entomofauna was recorded in crops of alfalfa 2011 compared with age-related crops in 2008. Specialized herbivores studied culture were found in the growing season 2014 agrocenoses alfalfa crops – alfalfa tolstonozhka (Bruchophagus roddi Guss), alfalfa semyaed (Tychius flavus), alfalfa weevils (Sitona humeralis Steph.), Alfalfa bug (Adelphocoris lineolatus Goeze), leaf alfalfa weevil larvae (Phytonomus variabilis Hbst.) and larvae of alfalfa bollworm (Heliothis viriplaca Hfn.). Forms relating to herbivores Polyphagous and Oligophagous cereals were also recorded. In addition agrocenoses met: Entomophages predator’s cocktsinellidy (Coccinellidae), different types of spiders (Arachnida) and representatives of the family of grasshoppers (Tettigonioidea). Large foliage of alfalfa plants was recorded under option Population 4. Several smaller foliage of plants observed in crops of alfalfa 2011 compared with planting in 2008. On the 3-year agrocenoses best foliage appeared on variety Guzel which had the lowest figures in the age crops. Alfalfa seed yields mainly depend on the age of the studied agrocenosis culture. Alfalfa crop given harvest seeds in 3.6-4.7 times more than the age-crops in 2008. The highest seed yield was obtained from the varieties of Emerald in 2008 and in 2011.

Frequency, depth and rate of phosphorus fertilizer application effects on alfalfa seed yields

2014 ◽  
Vol 94 (7) ◽  
pp. 1149-1156 ◽  
Author(s):  
Tiejun Zhang ◽  
Junmei Kang ◽  
Zhongxiang Zhao ◽  
Wenshan Guo ◽  
Qingchuan Yang
Keyword(s):  
Seed Yield ◽  
Fertilizer Application ◽  
Application Rate ◽  
P Uptake ◽  
Environmental Benefits ◽  
Phosphorus Fertilizer ◽  
Alfalfa Seed ◽  
P Application ◽  
Seed Yields ◽  
Annual Application

Zhang, T., Kang, J., Zhao, Z., Guo, W. and Yang, Q. 2014. Frequency, depth and rate of phosphorus fertilizer application effects on alfalfa seed yields. Can. J. Plant Sci. 94: 1149–1156. Efficient phosphorus (P) management is important for alfalfa (Medicago sativa L.) seed production and is necessary in order to alleviate the negative environmental effects of excess P application. The study was conducted on both very low-P and optimum-P soils to evaluate the effects of two frequencies (annual and triennial applications), two depths (7–8 and 15–16 cm), and three rates (15, 30, and 45 kg P ha−1) of P fertilization on seed yield, total P uptake (TPU), P-use efficiency of applied P (PUE), and recovery of P fertilizer (PR). There was a zero-P control. Under the model of annual application, the highest seed yields were obtained with the rates of 30 or 45 kg P ha−1. Under the model of triennial application, however, the seed yield decreased linearly with increasing rates in the first year. Averaged across frequency and depth, PUE and PR decreased linearly but TPU increased linearly with increasing P application rate. Triennial application of 45 kg of P led to higher mean seed yield than annual application of 15 kg of P, and its PUE and PR values were higher than triennial application of 90 and 135 kg of P. However, on low-P or optimum-P soil, annual application of 30 or 45 kg of P resulted in the highest mean seed yields compared with low PUE and PR. Thus, triennial application of a low P rate leads to a high alfalfa seed yield and has potential economic and environmental benefits.

Quackgrass (Elytrigia repens) Interference and Control in Seed Alfalfa (Medicago sativa)

1993 ◽  
Vol 7 (1) ◽  
pp. 58-64 ◽  
Author(s):  
James R. Moyer ◽  
G. Bruce Schaalje
Keyword(s):  
Seed Yield ◽  
Hyperbolic Model ◽  
Threshold Density ◽  
Economic Threshold ◽  
Elytrigia Repens ◽  
Southern Alberta ◽  
Herbicide Treatments ◽  
Alfalfa Seed ◽  
Seed Yields ◽  
And Control

Alfalfa seed yield and quackgrass density were measured in seven irrigated fields in southern Alberta to assess the effect of quackgrass on seed yield. Six herbicides were tested to determine their effect on quackgrass growth and accompanying alfalfa seed yield. The effect of quackgrass on seed yield was adequately described by a hyperbolic model. Quackgrass densities of 50 and 100 heads per m2reduced seed yields by 56 and 74%, respectively. The economic threshold density was 3 quackgrass heads per m2. The most effective herbicide treatments, quizalofop and propaquizafop, resulted in good initial quackgrass suppression and yield increases similar to those predicted by the hyperbolic model.

scholarly journals Anti-pest protection of two-year old alfalfa grown for seeds

2021 ◽  
pp. 170-180
Author(s):  
A. V. Tyshchenko ◽  
O. D. Tyshchenko ◽  
G. M. Kuts ◽  
O. O. Piliarska ◽  
N. M. Galchenko
Keyword(s):  
Water Supply ◽  
Seed Yield ◽  
Irrigated Agriculture ◽  
Active Ingredients ◽  
Insecticide Treatment ◽  
Alfalfa Weevil ◽  
Alfalfa Plant ◽  
Lambda Cyhalothrin ◽  
Alfalfa Seed ◽  
Active Substances

Purpose. To evaluate the effectiveness of different insecticides against pests on two-year old alfalfa grown for seeds. Materials and methods. The study was conducted in the experimental field of the Institute of Irrigated Agriculture of NAAS in 2017–2019. The filed experiments were laid out in split plots. The main plots (factor A) were for water supply conditions (no irrigation vs. irrigation); sub-plots (factors B and C) were for application of insecticides. Seeds were sown in wide rows with interrows of 70 cm. Results and discussion. When the two-year old alfalfa canopy (budding onset) was inspected before insecticide treatment, the average numbers of pests were as follows: alfalfa plant bug – 3.0 specimens/10 sweeps, alfalfa aphid – 20.0 specimens/10 sweeps, beet webworm – 3.0 specimens/10 sweeps, alfalfa weevil (imagoes/grubs) – 1.0/3.0 specimens/10 sweeps, and alfalfa seed weevil – 1.0 specimens/10 sweeps. Treatment 1 reduced the pest numbers in the canopy: alfalfa plant bug – by 70.0–93.3%, alfalfa aphid – by 93.0–97.5%, beet webworm – by 80.0–96.7, alfalfa weevil (imagoes/grubs) – by 60.0–90.0%/73.3–93.3%, and alfalfa seed weevil – by 76.0–94.0%, depending on the insecticide. Treatment 2 helped to reduce the pest numbers in the canopy. Insecticide containing active substances chlorpyrifos 500 g/L and cypermethrin 50 g/L applied at a dose of 1.00 L/ha was the most effective. The highest seed yield was achieved after treatment 1 with insecticide containing active ingredients chlorpyrifos 500 g/L and cypermethrin 50 g/L applied at a dose of 1.00 L/ha and treatment 2 with insecticide containing active ingredients chlorantraniliprole 200 g/L and lambda-cyhalothrin 50 g/L applied at a dose of 0.17 L/ha and 0.15 L/ha, respectively. Conclusions. The highest seed yield was achieved after treatment 1 with insecticide containing active ingredients chlorpyrifos 500 g/L and cypermethrin 50 g/L applied at a dose of 1.00 L/ha and treatment 2 with insecticide containing active ingredients chlorantraniliprole 200 g/L and lambda-cyhalothrin 50 g/L applied at a dose of 0.17 L/ha and 0.15 L/ha, respectively

scholarly journals Suitability of NDVI index to pea condition evaluation at diverse phosphorus fertilization

2020 ◽  
Vol 15 (1) ◽  
pp. 35-47
Author(s):  
Janina Gospodarek ◽  
Agnieszka Klimek-Kopyra ◽  
Milena Rusin
Keyword(s):  
Seed Yield ◽  
Vegetation Index ◽  
Acyrthosiphon Pisum ◽  
Standard Dose ◽  
Environmental Variable ◽  
Meteorological Conditions ◽  
Pea Aphid ◽  
Phosphorus Fertilization ◽  
Condition Evaluation ◽  
Ndvi Index

In this 3-year study the suitability of the normalized differenced vegetation index (NDVI) to the evaluation of pea plant infestation by aphids and expected seeds yield was investigated. The effect was assessed in the conditions of the increasing doses of phosphorus fertilization (0, 70, and 140 kg P2O5 ha–1) and in the different pea aphid (Acyrthosiphon pisum Harris) occurrence on six various cultivars of pea. Independent of the dose, the phosphorus fertilization supported the occurrence of aphids on pea plants of Batuta, Model, and Protecta cultivars where in Tarchalska and Mecenas cultivars only the standard dose (70 kg ha–1) showed such effect. NDVI index was not clearly, unambiguously correlated to the intensity of A. pisum occurrence. Such factors as the deficiency or excessive amount of phosphorus, as well as meteorological conditions and the cultivar of host plant had the greater effect on its value than the presence of aphids. All this testifies that the NDVI index is not reliable indicator of aphid occurrence on pea, however it can offer a promising method to select the cultivars under sub-opitmal conditions. The seed yield was strongly related to agronomical factors (fertilization, cultivars) and plant (NDVI) variable, while marginally to environmental variable (aphids).

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