SEED INCREASE OF ALFALFA IN GROWTH CHAMBERS WITH MEGACHILE ROTUNDATA F.

1967 ◽  
Vol 47 (6) ◽  
pp. 691-694 ◽  
Author(s):  
D. H. Heinrichs
Keyword(s):  
Seed Yield ◽  
Growth Chamber ◽  
Megachile Rotundata ◽  
Growth Chambers ◽  
Seed Increase

Megachile rotundata F. was successfully used to pollinate a 15-clone experimental alfalfa synthetic in a growth chamber. About 20 female bees pollinated 30 plants (two of each clone) during a period of one month when the alfalfa was blooming. This resulted in a yield of 320 g of seed (approximately 650 kg/ha). The 15 clones differed significantly in the amount of seed produced. The lowest-yielding clone produced only 2.7 g of seed per plant, the highest 17.8 g. The seed yield of the clones tended to follow a similar order in three consecutive tests (r = 0.77, 0.53 and 0.49 between tests).

scholarly journals INTERACTION OF TEMPERATURE AND CO2 ENRICHMENT ON SOYBEAN: PHOTOSYNTHESIS AND SEED YIELD

1987 ◽  
Vol 67 (3) ◽  
pp. 629-636 ◽  
Author(s):  
N. SIONIT ◽  
B. R. STRAIN ◽  
E. P. FLINT
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Photosynthetic Capacity ◽  
Co2 Enrichment ◽  
Carbon Dioxide Enrichment ◽  
Glycine Max L ◽  
Total Growth ◽  
Growth Chambers ◽  
Photosynthetic Responses ◽  
Increasing Temperature

Seed yield and photosynthetic responses of soybean (Glycine max L. Merr. ’Ransom’) were studied in growth chambers at day/night temperatures of 18/12, 22/16, and 26/20 °C and atmospheric CO2 concentrations of 350, 675 and 1000 μL L−1. No seeds were produced at 18/12 °C within any of the CO2 concentrations. Numbers of pods and seeds increased with increasing temperature and CO2 levels. Carbon dioxide enrichment increased seed yield of soybean grown at moderately cool temperatures. This increase was associated with an increase in net photosynthetic rate. Leaf photosynthesis in response to CO2 enrichment increased more at 22/16 °C than at 26/20 °C. Increases in temperature and CO2 levels enhanced total growth of plants but hastened senescence of leaves. The extended photosynthetic capacity at cool temperatures did not result in allocating more dry matter to developing pods. CO2 enrichment at 26/20 °C resulted in greater seed yield increases than CO2 enrichment at lower temperatures.Key words: Soybean yield, low temperature, CO2 × temperature

Effects of ultraviolet on polyphenolics of Umbilicaria americana

1997 ◽  
Vol 75 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Andrew Swanson ◽  
Dianne Fahselt
Keyword(s):  
Visible Light ◽  
Field Experiment ◽  
Key Words ◽  
Phenolic Content ◽  
Spectral Band ◽  
Growth Chamber ◽  
Natural Sunlight ◽  
Rock Face ◽  
Growth Chambers ◽  
Foliose Lichen

The foliose lichen Umbilicaria americana Poelt & Nash was exposed to spectrally altered radiation in three growth chamber experiments and one field experiment. After 1 week in growth chambers the phenolic content (% w/w) increased significantly under a spectral band including visible light and UV-A, and the increase was greater when intensity was higher. Under exposure to both UV-A and UV-B the concentration of phenolics was lower than with UV-A alone and, depending on dosage, approached or achieved control levels. In a population of U. americana on a vertical rock face, the interaction between filter treatments and collection dates had a highly significant effect on phenolic levels (P = 0.01). In thalli protected from UV-B, phenolic levels were higher than in those exposed to natural sunlight in June and October, but the same response was not observed in July and August. Thallus groupings covered by filters that admitted both UV-B and UV-A accumulated less phenolics than controls in August, but on other sampling dates contained the same concentrations. Key words: Umbilicaria americana, UV-A, UV-B, depsides, tridepsides.

scholarly journals Paclobutrazol and white clover seed production: a non-fulfilled potential

1996 ◽  
Vol 6 ◽  
pp. 35-39
Author(s):  
J.G. Hampton
Keyword(s):  
Seed Yield ◽  
White Clover ◽  
Unit Area ◽  
Variable Response ◽  
Reproductive Growth ◽  
Seed Yield Components ◽  
Vegetative And Reproductive Growth ◽  
Clover Seed ◽  
Yield Responses ◽  
Seed Increase

Seed yield in white clover depends largely on the number of ripe inflorescences per unit area, and the plant growth regulator paclobutrazol has been used in an attempt to both increase and concentrate inflorescence production, and hence increase seed yield. However results reported from both New Zealand and Europe have been inconsistent, with seed yield responses ranging from highly significant increases to no effects. The current high cost of the chemical ($1280/ha) requires a seed increase of over 300 kg/ha to ensure an economic return. Similarly no consistent effects of paclobutrazol on white clover vegetative and reproductive growth and development have been established. Possible reasons for this variable response of white clover to paclobutrazol application are presented and discussed. Keywords: inflorescence production, Parlay, reproductive growth, seed yield components, Trifolium repens, vegetative growth

scholarly journals Growth, Pod, and Seed Yield, and Gas Exchange of Hydroponically Grown Peanut in Response to CO2 Enrichment

HortScience ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 49-52 ◽  
Author(s):  
K. Stanciel ◽  
D.G. Mortley ◽  
D.R. Hileman ◽  
P.A. Loretan ◽  
C.K. Bonsi ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Seed Yield ◽  
Harvest Index ◽  
Co2 Enrichment ◽  
Branch Length ◽  
Growth And Yield ◽  
Positive Effects ◽  
Growth Chambers ◽  
Total Seed ◽  
Hydroponically Grown

The effects of elevated CO2 on growth, pod, and seed yield, and gas exchange of `Georgia Red' peanut (Arachis hypogaea L.) were evaluated under controlled environmental conditions. Plants were exposed to concentrations of 400 (ambient), 800, and 1200 μmol·mol–1 CO2 in reach-in growth chambers. Foliage fresh and dry weights increased with increased CO2 up to 800 μmol·mol–1, but declined at 1200 μmol·mol–1. The number and the fresh and dry weights of pods also increased with increasing CO2 concentration. However, the yield of immature pods was not significantly influenced by increased CO2. Total seed yield increased 33% from ambient to 800 μmol·mol–1 CO2, and 4% from 800 to 1200 μmol·mol–1 CO2. Harvest index increased with increasing CO2. Branch length increased while specific leaf area decreased linearly as CO2 increased from ambient to 1200 μmol·mol–1. Net photosynthetic rate was highest among plants grown at 800 μmol·mol–1. Stomatal conductance decreased with increased CO2. Carboxylation efficiency was similar among plants grown at 400 and 800 μmol·mol–1 and decreased at 1200 μmol·mol–1CO2. These results suggest that CO2 enrichment from 400 to 800 μmol·mol–1 had positive effects on peanut growth and yield, but above 800 μmol·mol–1 enrichment seed yield increased only marginally.

Low dosages of gamma irradiation of seed increase the growth and yield of two cultivars of sunflower

1981 ◽  
Vol 59 (11) ◽  
pp. 2152-2157
Author(s):  
S. R. A. Shamsi ◽  
R. Roohi ◽  
A. Nisa
Keyword(s):  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Helianthus Annuus ◽  
Seed Yield ◽  
Vegetative Growth ◽  
Growth And Yield ◽  
Significant Stimulation ◽  
Seed Increase ◽  
Mature Seeds ◽  
Stimulation Of

Seeds of cv. Restoler and Noor of sunflower (Helianthus annuus L.) were subjected to 0.5 to 50 krad 60Co gamma radiation (1 rad = 10 mGy) and grown to maturity in a greenhouse. Two low dosages, i.e., 1 krad in cv. Restoler and 3 krad in cv. Noor, caused statistically significant stimulation of vegetative growth and seed yield (both total number and weight). For cv. Noor, 3 krad also significantly stimulated the weight of an individual seed. Significant declines in the yield of mature seeds occurred only at critical dosages of > 10 to 20 krad.

SURVIVAL OF Bradyrhizobium japonicum IN CANADIAN PRAIRIE SOILS

1989 ◽  
Vol 69 (1) ◽  
pp. 23-30 ◽  
Author(s):  
L. D. BAILEY
Keyword(s):  
Protein Content ◽  
Seed Yield ◽  
Bradyrhizobium Japonicum ◽  
Growth Chamber ◽  
Prolonged Storage ◽  
Canadian Prairie ◽  
Prairie Soils ◽  
Commercial Mixture ◽  
Early Maturing ◽  
Glycine Max L

The study was conducted to determine whether Bradyrhizobium japonicum can over-winter in Canadian prairie soils, and whether prolonged storage in soil exposed to various environmental conditions affects its nodulating activity. In 1984, Maple Amber, an early-maturing Canadian soybean cultivar was grown in the field on two soils that had never been contaminated with B. japonicum. Two single strains and a commercial mixture of four strains were used as inoculants. In 1985, the soils were cropped again to soybean, but the 1984 inoculated plots were split to permit noninoculated and inoculated treatments. In both years, the inoculants increased seed yield and protein content over the noninoculated treatments. Plants grown on soils inoculated in 1984, but not in 1985, had no nodules, indicating that the Rhizobia did not survive over the winter; seed yield and protein content were similar to plants grown on soils that were never inoculated. Further, the two strains of B. japonicum, 61A148 and 61A196 were more effective than the multistrain inoculant, producing more nodules and greater seed yield, but similar protein content. In the fall of 1984, soil was removed from the inoculated and noninoculated plots and subjected to storage treatments prior to cropping to inoculated soybeans in a growth chamber. Immediate cropping of soils in the growth chamber, following removal from the field, showed that Bradyrhizobia were present at the time of sampling. Prolonged storage in a frozen or severe drying condition completely destroyed the nodulating activity of the Bradyrhizobia and may have killed them; storage in a moist refrigerated state reduced their nondulating activity and may have adversely affected their survival.Key words: Glycine max (L.) Merrill, soybean, Bradyrhizobia nodulation, survival, freezing, drying

Air circulation in growth chambers stunts tomato seedling growth

1992 ◽  
Vol 72 (4) ◽  
pp. 1275-1281 ◽  
Author(s):  
A. Liptay
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Growth Inhibition ◽  
Seedling Growth ◽  
Growth Chamber ◽  
Daily Exposure ◽  
Air Movement ◽  
Movement Effect ◽  
Growth Chambers ◽  
Air Circulation

Air circulation, generally an integral part of environmentally controlled plant growth chambers, inhibited tomato (Lycopersicon esculentum Mill.) seedling growth seismomorphogenically. Tomato seedlings were grown either in a growth chamber having an air movement of 0.5–0.7 m s−1 or in a chamber with no air circulation. Growth inhibition was noticeable with as little as 15 min of daily exposure to air circulation, and a continuous exposure gave the greatest amount of growth inhibition. The air-movement effect on seedling growth was transient and required a continued daily exposure to air movement for growth inhibition. Continuous air circulation inhibited seedling growth to such an extent that in a two-factor experiment (i.e., air movement and water stress) the water-stress effects were completely hidden by the air-movement effect. The results have important implications for tomato plant growth experiments in chambers equipped with air circulation: seedling growth may be affected more by the inherent air circulation in the growth chamber than by an experimental treatment.Key words: Tomato growth inhibition, air movement, seismomorphogenic, short seedlings

scholarly journals CAN PLANTS DETECT SMALL DIFFERENCES IN IRRADIANCE OBTAINED BY VARYING THE REFLECTANCE PROPERTIES OF THE GROWTH CHAMBER WALLS?

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 656b-656
Author(s):  
Donald T. Krizek ◽  
Roman M. Mirecki ◽  
Alton L. Fleming
Keyword(s):  
Shoot Elongation ◽  
Growth Chamber ◽  
Photon Flux ◽  
Controlled Environment ◽  
Wall Surface ◽  
Photosynthetic Photon Flux ◽  
Fluorescent Lamps ◽  
Environment Study ◽  
Growth Chambers

A controlled-environment study was conducted in separate growth chambers with the wall surface covered either with white enamel paint (WEP) or polished aluminum (PA). `Williams' soybean were grown under 1500 mA cool white fluorescent lamps and internodes measured at 7, 14, and 21 days. Photosynthetic photon flux (PPF) levels in the center of each chamber were set at 320 μmol m-2 s-1 with a quantum sensor. Means ± SD for PPF levels in the WEP and PA chambers were 286 ± 28 and 307 ± 11 μmol m-2 s-1, respectively. This increase in mean PPF and decrease in variance of PPF in the PA chamber was reflected in: a) a decrease in hypocotyl, first internode, and total shoot elongation: and b) an increase in enlargement of the primary and the first trifoliolate leaves. These findings demonstrate that plants can detect small differences in irradiance within a growth chamber and suggest the advantages of using a highly polished wall surface to improve uniformity of irradiance and reduce variability in growth.

THE EFFECT OF SPRING BURNING OF SEED ALFALFA FIELDS ON LEAF CHARACTERISTICS AND ON MANDIBULAR WEAR OF FEMALE LEAFCUTTER BEES [MEGACHILE ROTUNDATA (F.)] (HYMENOPTERA: MEGACHILIDAE)

1993 ◽  
Vol 125 (5) ◽  
pp. 881-886 ◽  
Author(s):  
B.D. Schaber ◽  
E.G. Kokko ◽  
T. Entz ◽  
K.W. Richards
Keyword(s):  
Image Analysis ◽  
Seed Yield ◽  
Consistent Difference ◽  
Analysis Method ◽  
Megachile Rotundata ◽  
Image Analysis Method ◽  
Leaf Characteristics ◽  
Leafcutter Bee ◽  
Seed Yields

AbstractIncreased seed yields often result when alfalfa fields are burned in spring. The main pollinator of seed alfalfa in Alberta is the alfalfa leafcutter bee, Megachile rotundata (F.), that cuts pieces of leaves to build thimble-like cells. One hypothesis for increased seed yield is that alfalfa leaves from burned fields may be easier for the bees to cut. Cutting of leaf pieces causes progressive wear to the mandibles, which could decrease bee efficiency, resulting in reduced pollination and lower seed yields. An image analysis method was used to measure the mandibular wear of leafcutter bees from burned and unburned alfalfa fields. No consistent difference in the amount of wear between bees foraging in burned or unburned fields was found.

EFFECTS OF ROOT TEMPERATURE AND A SUSPECTED PHYTOTOXIC SUBSTANCE ON THE GROWTH OF ALFALFA

1970 ◽  
Vol 50 (3) ◽  
pp. 307-311 ◽  
Author(s):  
J. D. McELGUNN ◽  
D. H. HEINRICHS
Keyword(s):  
Soil Fertility ◽  
Differential Effect ◽  
Root Zone ◽  
Growth Chamber ◽  
Root Temperature ◽  
Suitable Temperature ◽  
Phytotoxic Effect ◽  
Growth Chambers ◽  
Phytotoxic Substance

Two alfalfa cultivars, Rambler and Alfa, were grown at two soil fertility levels to assess a phytotoxic effect of two soils on the growth of alfalfa in a growth chamber at three root-zone temperatures. Different root-zone temperatures (10, 15, and 20 C) produced no differential effect on the characteristic unthrifty growth of alfalfa and therefore cannot be recommended as a tool to aid in the assessment of the condition. However, best growth of herbage and roots occurred al 15 C, which appears to be the most suitable temperature for growth of alfalfa in growth chambers. Addition of fertilizer did not amend the phytotoxic soil effect and the two cultivars reacted in a near-equal manner to the condition.

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