scholarly journals Matriconditioning of Vegetable Seeds to Improve Stand Establishment in Early Field Plantings

1992 ◽  
Vol 117 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Anwar A. Khan ◽  
James D. Maguire ◽  
George S. Abawi ◽  
Satriyas Ilyas
Keyword(s):  
Field Trial ◽  
Seedling Emergence ◽  
Control Level ◽  
High Water ◽  
Matric Potential ◽  
Snap Bean ◽  
Stand Establishment ◽  
Control Seed ◽  
Emergence Percentage ◽  
Ph Range

A matriconditioning procedure based on the matric properties of Micro-Cel E and expanded vermiculite #5 has proved effective in improving seedling emergence in growth chambers. The major objectives of this study were to examine some physical characteristics of the carriers and their effectiveness as preplant conditioning media in improving stand establishment of vegetable seeds in field plantings. Carrier characteristics included no detectable solute or osmotic potential, low electrical conductivity (0.48-0.04 mmho/cm), high water-retaining capacity (450% to 600%), a pH range of 7.0 to 8.4, and ability to effectively control seed hydration (conditioning) at low matric potential. The seed: carrier: water ratio for seed conditioning ranged from 1:0.3-0.5:1-2 (by weight). In a field trial, conditioning of `Long Imperator' and `Nantes' carrot (Daucus carota var. sativus Hoffm.) seeds reduced the time to 10% of final emergence (T10) by 2.6 to 2.8 days and to 50% of final emergence (T50) by 2.1 to 3.0 days. Conditioning increased the final emergence percentage by 39% in 1-year-old `Long Imperator' compared to 150% in 4-year-old `Nantes' seeds. In another field trial, the effect of conditioning on stand establishment was evaluated in `Jackpot' tomato (Lycopersicon esculentum Mill.), `California Wonder' pepper (Capsicum annuum L.), and `BBL 47' snap bean (Phaseolus vulgaris) seeds. In tomato, conditioning reduced the T10 by 0.9 day, had no effect on T50, and increased the emergence percentage by 86%. In pepper, conditioning reduced the T10 and T50 by 1.5 days and increased the percentage emergence by 30%. In snap bean seeds, conditioning in Micro-Ccl E reduced the T10 and T50 by 0.8 day but adversely affected the percentage emergence. Further reductions in T10 and T50 (1.2 and 1.6 days, respectively) and restoration of percentage emergence to control level occurred upon addition of 0.001 mM GA3 during conditioning. Fungicides added to carrot, tomato, and pepper seeds, with or without conditioning, showed no additional improvements and, in a few cases, adversely affected emergence. A preplant conditioning in Micro-Ccl E, alone or in combination with GA3, smears to be a viable alternative to conditioning! seeds in liquid carriers. Chemical name used: gibberellic acid (GA3)

SELECTION FOR IMPROVED SEEDLING VIGOR IN RUSSIAN WILD RYEGRASS

1984 ◽  
Vol 64 (1) ◽  
pp. 131-138 ◽  
Author(s):  
J. D. BERDAHL ◽  
R. E. BARKER
Keyword(s):  
Seed Weight ◽  
Seedling Emergence ◽  
Field Tests ◽  
Visual Assessment ◽  
Seedling Vigor ◽  
Coleoptile Length ◽  
Stand Establishment ◽  
Psathyrostachys Juncea ◽  
Emergence Percentage ◽  
Selection For

Seedling emergence of 30 open-pollinated progeny lines of Russian wild ryegrass (Psathyrostachys juncea (Fisch.) Nevski. Syn: Elymus junceus Fisch.) ranging in seed weight from 2.1 to 4.5 mg/seed was evaluated in laboratory and greenhouse tests and compared to stand establishment capability in the field. Increases in emergence percentage and coleoptile length associated with increased seed weight diminished when seed weights of parents increased beyond 3.0 mg/seed. Emergence in two field environments was correlated with emergence from a 5-cm planting depth in the greenhouse (r = 0.70** and 0.71** for field tests 1 and 2, respectively) and with coleoptile length (r = 0.51** and 0.64**), but not with emergence under laboratory-induced drought stress of −1.1 MPa matric potential (r = −0.05 and 0.13). Experimental error was high for measurements of forage yields in the establishment year (CV = 38% and 36% for field tests 1 and 2, respectively), and resources required to obtain reliable yields would limit testing to a small number of entries. Preliminary screening of a Russian wild ryegrass population for improved seedling vigor could be accomplished by first eliminating plants with small seed size by visual assessment of seed samples. This could then be followed by selection for increased coleoptile length among progeny lines from those plants with medium or large seed.Key words: Russian wild ryegrass, seedling vigor, stand establishment, seed weight, coleoptile length

scholarly journals Stand Establishment in Plasticulture Systems

1996 ◽  
Vol 6 (3) ◽  
pp. 181-185 ◽  
Author(s):  
Michael D. Orzolek
Keyword(s):  
Seed Germination ◽  
Sweet Corn ◽  
Seedling Emergence ◽  
Warm Season ◽  
Fruit Crops ◽  
Plant Establishment ◽  
Snap Bean ◽  
Stand Establishment ◽  
Growing Seasons ◽  
Soil Temperature And Moisture

Plasticulture enables growers to optimize establishment of vegetable and fruit crops under nonoptimum conditions and in locations with short growing seasons. Generally, warm-season crops such as muskmelon, pepper, and tomato, are established from transplants to decrease the time to maturity in the field. Directly seeding vegetables such as sweet corn, cucumber, and snap bean through plastic allows for optimum soil temperature and moisture to ensure maximum seed germination and subsequent seedling emergence. Mechanized transplanting or seeding of vegetables in plasticulture is available and successful if a firm, flat bed with plastic firmly stretched over the bed is formed and specific crop requirements are followed during establishment. Common mistakes made with plant establishment in plasticulture are discussed.

EMERGENCE AND SEEDLING GROWTH OF INBRED LINES OF CORN AT SUBOPTIMAL ROOT-ZONE TEMPERATURES

1987 ◽  
Vol 67 (2) ◽  
pp. 409-415 ◽  
Author(s):  
A. MENKIR ◽  
E. N. LARTER
Keyword(s):  
Zea Mays ◽  
Seedling Growth ◽  
Root Zone ◽  
Seedling Emergence ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Inbred Lines ◽  
Root Zone Temperature ◽  
Emergence Percentage ◽  
Zone Temperature

Based on the results of an earlier paper, 12 inbred lines of corn (Zea mays L.) were evaluated for emergence and seedling growth at three controlled root-zone temperatures (10, 14, and 18 °C). Low root-zone temperatures, 10 and 14 °C, were detrimental to emergence, seedling growth, and root growth of all inbred lines. Differential responses of inbred lines were observed within each temperature regime. The differences in seedling emergence among lines became smaller with increasing root-zone temperature, while the reverse was true for seedling dry weight. Simple correlation coefficients showed a significantly (P = 0.05) negative association between emergence percentage and emergence index (rate). Neither of these two emergence traits was significantly correlated with seedling dry weights. Seedling dry weights were significantly (P = 0.01) and positively associated with root dry weights. Two inbred lines exhibited good tolerance to low root-zone temperatures, viz. CO255 and RB214. A significant and positive correlation existed between emergence percentage at a root-zone temperature of 10 °C and field emergence in test with the same genotypes reported earlier. Selection at a root-zone temperature of 10 °C for a high percentage of seedling emergence, therefore, could be effective in identifying genotypes capable of germinating in cool soils. Furthermore, the significantly (P = 0.01) positive relationship between seedling dry weights at all root-zone temperatures and those from the field test suggest that strains with vigorous seedling growth in the field could be identified using low root-zone temperature regimes.Key words: Zea mays, root-zone temperature, cold tolerance

scholarly journals Emergence rate of seedlings from hard okra seed coats and seedling growth of some genotypes of West African okra (Abelmoschus caillei)

2019 ◽  
Vol 11 (2) ◽  
pp. 118-122
Author(s):  
P.M. Jonah ◽  
G. K. Farauta ◽  
Y. M. Kwaga ◽  
H. E. Shehu ◽  
N. M. Fakuta ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
West African ◽  
Permeability Barrier ◽  
State University ◽  
Cropping Season ◽  
Emergence Rate ◽  
Emergence Percentage ◽  
Seed Coats

Abstract. In 2017 and 2018 cropping season, field experiment was conducted at the Food and Agricultural Organization and Tree Crop Plantation, Department of Crop Science, Adamawa State University, Mubi using fifteen genotypes of West African okra. The study was undertaken to study the emergence rate of seedlings from hard okra seed coats, seedling growth and their development. The seeds of the genotypes were soaked in NaCl solution for 24 hours to accelerate the breaking of seed dormancy and to ease seed germination. Tough seed coat usually impairs seed germination by establishing a permeability barrier which can interrupt water uptake required for imbibition, radicle and seedling emergence. The combined analysis results revealed a highly significant (P≤0.01) difference among these genotypes with respect to days to first and 50% flowering including days to first harvest. Furthermore, accession 3 (NG/SA/DEC/07/0448) and accession 11 (Yar kwadon) flowered earlier, had shortest days to first harvest, recorded the highest number of seedlings and emergence percentage than the other genotypes studied.

Initial Development of Soybean as a Bioindicator of the Potential of Leaching 2,4-D In Red Latosol

2018 ◽  
Vol 34 (4) ◽  
pp. 727-733
Author(s):  
Vinícius Melo da Silva ◽  
Tonny José Araújo Da Silva ◽  
Maria Aparecida Peres de Oliveira ◽  
Edna Maria Bonfim-Silva ◽  
Jefferson Vieira José ◽  
...  
Keyword(s):  
Seedling Emergence ◽  
Residual Effect ◽  
Control Treatment ◽  
Depth Range ◽  
Soil Columns ◽  
Initial Development ◽  
Leaching Potential ◽  
Factorial Model ◽  
Emergence Percentage ◽  
Red Latosol

Abstract. The objective of this study was to evaluate the potential of leaching 2,4-D in Red Latosol using soybean as a bioindicator plant, to verify the residual effect of the distribution of the herbicide in the soil on the initial development of the plant. The experimental design is a 5 × 11 × 2 triple factorial model, with 5 treatments of water slides (20, 40, 60, 80 and 100 mm) applied by a rainfall simulator. The depth of 11 layers (0-5, 5 -10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45, 45-50, and 50-55 cm) were mounted on soil columns using two groups (in the absence and the presence of the 2,4-D herbicide dimethylamine by application at a dose of 1500 g a.i. ha-1), with four replicates, making 440 experimental plots. The residual effect of the herbicide was evaluated by seedling emergence speed index, total seedling emergence percentage and plant height evaluation. The results demonstrated that the effect of 2,4-D herbicide distribution along the soil profile induces increases in the initial development of soybean when compared to the control treatment. However, the residual 2,4-D in the soil decreases with 80- and 100-mm sheets that have greater herbicide leaching potential beyond the depth range of the soil columns. Keywords: Residual effect, Seedling emergence, Glycine max.

Effect of hydrogen ion changes on vascular resistance in isolated artery segments

1964 ◽  
Vol 207 (1) ◽  
pp. 169-172 ◽  
Author(s):  
Oliver Carrier ◽  
Meredith Cowsert ◽  
John Hancock ◽  
Arthur C. Guyton
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Perfusion Pressure ◽  
Control Level ◽  
Linear Increase ◽  
Hydrogen Ion ◽  
Isolated Artery ◽  
Ph Range

Isolated arterial segments, 1 cm in length and 0.5–1.0 mm in diameter, were perfused with Tyrode's solution titrated to various levels of pH. Po2, Pco2, and temperature were held at physiological levels; the perfusion pressure was held at 100 mm Hg, and flow was measured by a drop counter. There was a linear increase in flow as the pH was decreased from 7.4, 0.05 units at a time, with an increase of 87% obtained at pH 7.15. As the pH was further decreased, the flow dropped until at pH 6.8 it leveled off slightly above control level. When the pH was raised, there was an initial 35% decrease in flow by the time pH 7.50 was reached, followed by an increase, reaching 50% above control level at 7.65. At still higher pHs a precipitous decrease in conductance occurred, flow leveling off slightly below control level at pH 7.80. Consistent results were obtained on 45 vessels using Tyrode's solution titrated to the desired pH with lactic acid, hydrochloric acid, acetic acid, sulfuric acid, nitric acid, sodium hydroxides, or sodium bicarbonate. These results indicate that vessels have a very narrow pH range in which they maintain physiological tone.

Hemp Dogbane Growth and Control

Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 156-159 ◽  
Author(s):  
Laren R. Robison ◽  
Larry S. Jeffery
Keyword(s):  
Seed Germination ◽  
Soil Type ◽  
Vegetative Growth ◽  
Soil Cover ◽  
Seedling Emergence ◽  
Control Seed ◽  
Cover Soil ◽  
And Control ◽  
Emergence Response ◽  
Made In

Hemp dogbane (Apocynum cannabinum L.) was investigated relative to seed germination, depth of seedling emergence, response to clipping, influence of soil type and fertility on vegetative growth, and herbicidal control. Seed germination in this study was influenced by light and scarification. Seedling emergence was influenced by the amount of soil cover. Soil type and fertility affected vegetative growth. In a greenhouse clipping study, hemp dogbane became perennial 41 days after emergence and by 65 days was producing more than one shoot per plant following clipping. Hemp dogbane was more completely controlled following September application of herbicide than from application made in June.

Body temperature responses to exercise in man on restricted food and water intake

1959 ◽  
Vol 14 (2) ◽  
pp. 194-198 ◽  
Author(s):  
F. Grande ◽  
J. E. Monagle ◽  
E. R. Buskirk ◽  
H. L. Taylor
Keyword(s):  
Water Intake ◽  
Sweat Rate ◽  
Control Level ◽  
High Water ◽  
Progressive Increase ◽  
Important Change ◽  
Water Restriction ◽  
Water Group ◽  
Adequate Food ◽  
Ad Libitum

Rectal temperatures (TR) of 12 clinically healthy soldiers were measured in a room at 25.5°C and 40–45% relative humidity during a 1-hour walk on a motor driven treadmill at 3.5 mph and 10% grade, during control with adequate food intake and water ad libitum, and during a period of food and water restriction. The daily water intake during the water restriction period was 900 ml for six of the men, Low Water group (L.W.), and 1800 ml for the other six, High Water group (H.W.). The restriction of water began at the same time as the restriction of food and lasted 5 full days for the L.W. group and 10 full days for the H.W. group. Food was restricted to 1000 calories from carbohydrate, 4.5 gm of NaCl and a multivitamin pill/day for 16 days. Water ad libitum was given throughout the experiment except for the period of water restriction. The L.W. group showed a progressive increase of TR at the end of the walk during the water restriction period with average TR 1.51℃, higher at peak dehydration than in control. In the H.W. group the greatest average increase, 0.46℃, was observed on day 5 of restriction. Administration of water ad libitum brought the work TR back to the control level in the L.W. group, but failed to produce any important change in the H.W. group. The relationship between dehydration, elevation of TR during work and changes in sweat rate is discussed. Submitted on July 24, 1958

Effects of seed covering treatments on the emergence and seedling growth of crisp lettuce drilled with an experimental dibber drill

1985 ◽  
Vol 105 (3) ◽  
pp. 535-541 ◽  
Author(s):  
D. C. E. Wurr ◽  
Jane R. Fellows ◽  
L. P. Bufton
Keyword(s):  
Standard Deviation ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
Agricultural Engineering ◽  
Percentage Time ◽  
Moisture Regimes ◽  
Dry Conditions ◽  
Emergence Percentage

SUMMARYPelleted seed of the crisp lettuce variety Pennlake was sown on five occasions with units from either the experimental dibber drill designed by the National Institute of Agricultural Engineering or a Stanhay S870 drill. There were three dibber-drill treatments: seeds left in open holes or covered with peat–vermiculite or perlite. Seedling emergence and growth from each sowing of the four drill treatments were compared under different moisture regimes.There were large differences between drill treatments in emergence percentage, time to emergence of 50% of the seedlings which emerged (t50) and seedling weight at all sowings but there was a significant effect of drill treatment on the standard deviation of seedling emergence times at only one sowing. Of the dibber-drill treatments, only very occasionally did open holes or perlite cover give significantly better emergence than peat-vermiculite cover, which gave the most consistent results. In general, the dibber drill with peat-vermiculite cover gave significantly faster and higher emergence and heavier seedlings than the Stanhay drill. Differences in percentage seedling emergence tended to be greater under dry conditions.

scholarly journals Fabrication of Eco-Friendly Superabsorbent Composites Based on Waste Semicoke

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2347
Author(s):  
Yongsheng Wang ◽  
Yongfeng Zhu ◽  
Yan Liu ◽  
Aiqin Wang
Keyword(s):  
Acrylic Acid ◽  
Ph Value ◽  
High Water ◽  
Sem Analysis ◽  
Water Absorbency ◽  
Ammonium Persulphate ◽  
Wide Ph Range ◽  
Maximum Water ◽  
Ph Range ◽  
Superabsorbent Composites

A series of novel superabsorbent composites of poly(acrylic acid)/semicoke were prepared by polymerization of acrylic acid using ammonium persulphate as initiator, N,N′-methylenebisacrylamide as crosslinker and semicoke which was the by-product of coal carbonizing as the inorganic components. FTIR and SEM analysis indicated that the superabsorbent composites had been successfully polymerized and the semicoke participated in construction of the 3D polymeric network. Meanwhile, the effects of initiator, crosslinker, semicoke, and neutralization degree, as well as the pH value, were investigated, and the results showed that superabsorbent composites containing 10% of semicoke possessed the maximum water absorbency of 584 g/g in distilled water and 75 g/g in 0.9% NaCl solution. The superabsorbent composites kept the high water absorbency within a wide pH range of 4–11, and still exhibited better re-swelling capability even after seven times. The superabsorbent composite with its excellent performance is a potential water-retaining agent used in agriculture.

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