scholarly journals The Physiological Basis for Yield Differences between Four Genotypes of Groundnut (Arachis Hypogaea) in Response to Drought. III. Developmental Processes

1988 ◽  
Vol 24 (2) ◽  
pp. 215-226 ◽  
Author(s):  
D. Harris ◽  
R. B. Matthews ◽  
R. C. Nageswara Rao ◽  
J.H. Williams
Keyword(s):  
Arachis Hypogaea ◽  
Linear Relation ◽  
Leaf Development ◽  
Harvest Index ◽  
Water Status ◽  
The Other ◽  
Physiological Basis ◽  
Pod Yield ◽  
Effects Of Temperature ◽  
Pod Number

SUMMARYRates of leaf development in four groundnut genotypes were found to depend primarily on temperature, although there was a linear relation between the thermal time to produce one leaf and mean leaf water potential below −0.6 MPa. Flower, peg and pod production was analysed in relation to leaf number, since this integrated effects of temperature and water status.When water was not limited, the ratio of pod number: peg number was about 0.8 for all four genotypes. During drought only one genotype (TMV 2) maintained this value, while for the other genotypes the ratio was approximately 0.15. Genotypes also showed different patterns of development during recovery from drought. TMV 2 maintained relatively high values of partitioning factor throughout the pod-filling period, resulting in the largest harvest index and pod yield. Kadiri 3 achieved the second largest harvest index and pod yield by maintaining production of pegs during drought and only forming pods when stress was relieved.

scholarly journals The Physiological Basis for Yield Differences between Four Genotypes of Groundnut (Arachis Hypogaea) in Response to Drought. I. Dry Matter Production and Water Use

1988 ◽  
Vol 24 (2) ◽  
pp. 191-202 ◽  
Author(s):  
R. B. Matthews ◽  
D. Harris ◽  
R. C. Nageswara Rao ◽  
J. H. Williams ◽  
K. D. R. Wadia
Keyword(s):  
Water Availability ◽  
Harvest Index ◽  
Dry Matter ◽  
Central India ◽  
The Other ◽  
Soil Water Depletion ◽  
Physiological Basis ◽  
Matter Production ◽  
Tap Root ◽  
Major Variation

SUMMARYFour genotypes of groundnut grown with limited irrigation in a medium depth Alfisol in Central India transpired similar total amounts of water (220–226 mm) over the season, but produced different amounts of shoot dry matter (390–490 g m−2). The extraction front of Kadiri 3 moved most rapidly down the soil profile which may have enabled it to maintain the fastest rates of transpiration when soil water depletion was greatest. Tap root extension rates of Kadiri 3 in the first 32 days after sowing were also the fastest. NC Ac 17090 was more efficient than the other genotypes in extracting water immediately after irrigation from the upper 40 cm of the soil, but this had little value in determining the pattern of water availability in this experiment. Differences in the water extraction characteristics of these genotypes explain little of the variation in dry matter:water ratio, and do not account for the major variation in harvest index associated with drought.

scholarly journals Groundnut (Arachis hypogaea) genotypes tolerant to intermittent drought maintain a high harvest index and have small leaf canopy under stress

2011 ◽  
Vol 38 (12) ◽  
pp. 1016 ◽  
Author(s):  
P. Ratnakumar ◽  
V. Vadez
Keyword(s):  
Arachis Hypogaea ◽  
Water Uptake ◽  
Yield Components ◽  
Harvest Index ◽  
Root Length Density ◽  
Mild Stress ◽  
Total Water ◽  
Pod Yield ◽  
Arachis Hypogaea L ◽  
Before And After

Intermittent drought, which varies in intensity, severely limits groundnut (Arachis hypogaea L.) yields. Experiments were conducted to assess root development, water uptake, transpiration efficiency, yield components and their relationships, in 20 groundnut genotypes under well watered (WW), and mild (DS-1), medium (DS-2) and severe (DS-3) intermittent stress. Pod yield decreased 70%, 55% and 35% under severe, medium and mild stress, respectively. Pod yield varied among genotypes, and showed significant genotype-by-treatment effects. Root length density (RLD) varied among genotypes before and after stress, although RLD did not discriminate tolerant from sensitive lines. Total water uptake and RLD under water stress had a weakly significant relationship. Water extraction from the soil profile was highest under severe stress. Water uptake varied among genotypes in all water regimes, but correlated with pod yield under WW conditions. The relative harvest index (HI) (i.e. the ratio of the HI under stress to HI under WW conditions) was closely related to the pod yield in all three intermittent stresses (R2 = 0.68 in DS-1; R2 = 0.65 in DS-2; R2 = 0.86 in DS-3) and was used as an index of stress tolerance. Under medium and severe stresses, the relative HI was negatively related to plant leaf weight (R2 = 0.79 in DS-2; R2 = 0.53 in DS-3), but less so under mild stress (R2 = 0.31). The results suggest that under intermittent stress, genotypes with a lower leaf area may use water more sparingly during the drying cycle with less damaging consequences for reproduction and pod.

scholarly journals Effect of Dinitroaniline Herbicides upon Yield and Grade of Five Runner Cultivars1

1993 ◽  
Vol 20 (2) ◽  
pp. 126-128 ◽  
Author(s):  
W. James Grichar ◽  
A. Edwin Colburn
Keyword(s):  
Arachis Hypogaea ◽  
The Other ◽  
Pod Yield ◽  
Herbicide Treatment ◽  
Arachis Hypogaea L ◽  
Herbicide Treatments ◽  
Dinitroaniline Herbicides

Abstract Five runner peanut (Arachis hypogaea L.) cultivars were treated with four dinitroaniline herbicide treatments or a postemergence herbicide treatment to determine the effect on pod yield and grade, percentage sound mature kernels + sound splits (SMK+SS). No yield differences due to the dinitroaniline herbicide treatments were noted in the three year study. Southern Runner and GK-7 were higher in yield in one of the three test years, however, no cultivar yield differences were noted in the other two years. Grades were lower with pendimethalin in the three years; grades of trifluralin, ethalfluralin and benefin-treated peanuts were variable from year to year.

scholarly journals Eclipta (Eclipta prostrata L.) Control in Peanuts (Arachis hypogaea L.)1

1995 ◽  
Vol 22 (2) ◽  
pp. 114-120 ◽  
Author(s):  
J. V. Altom ◽  
R. B. Westerman ◽  
D. S. Murray
Keyword(s):  
Arachis Hypogaea ◽  
Field Experiments ◽  
Butanoic Acid ◽  
Late Season ◽  
Nitrobenzoic Acid ◽  
Pod Yield ◽  
Eclipta Prostrata ◽  
Arachis Hypogaea L ◽  
Herbicide Treatments ◽  
Sequential Treatments

Abstract Field experiments were conducted from 1991 to 1993 to evaluate eclipta, Eclipta prostrata L., control and peanut, Arachis hypogaea L., response to herbicide treatments. Fomesafen {5-[2-chloro-4-(trifluoro-methyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide} applied at cracking was the only preemergence-applied herbicide which provided season-long control (>84%). Herbicides applied postemergence were more effective when the eclipta was less than 5 cm in height. The most consistent early postemergence treatments were bromoxynil (3,5-dibromo-4-hydroxybenzonitrile), bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazm-4(3H)-one 2,2-dioxide], and bentazon + acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} + 2,4-DB [4-(2,4-dichloro-phenoxy)butanoic acid]. Various other early postemergence followed by late postemergence sequential treatments also were equally effective. Minor peanut injury was observed at the early season rating from several herbicides; however, all injury had disappeared by the late season rating. Eclipta control did not consistently improve peanut pod yield.

THE ISOPIESTIC METHOD APPLIED TO SORPTION ISOTHERMS

1949 ◽  
Vol 27b (2) ◽  
pp. 87-100 ◽  
Author(s):  
S. Barnartt ◽  
J. B. Ferguson
Keyword(s):  
Carbon Tetrachloride ◽  
Linear Relation ◽  
Sorption Isotherms ◽  
Sorption Process ◽  
The Other ◽  
Isopiestic Method ◽  
Simple Criterion ◽  
Water Vapors ◽  
Linear Sections ◽  
Wide Pressure

The isopiestic method has been applied to the sorption of carbon tetrachloride and water vapors by activated coconut shell charcoals. The isopiestic charges were found to be linearly related over wide pressure ranges. Isotherms formed by plotting the isopiestic charges of two charcoals one against the other consisted of three linear sections for both carbon tetrachloride and water. If the pressure isotherm of one charcoal be known, those of other charcoals may be computed from it by weighing relatively few isopiestic charges. Errors inherent in the measurement of equilibrium pressures, as well as those caused by the drift of the pressure isotherms towards higher sorption capacities at a given pressure, are eliminated in the isopiestic method of comparing charcoals. The linear relation between the isopiestic charges affords a simple criterion of rejection for equations proposed to fit the pressure isotherms. It also throws into relief the structural regularities in activated charcoals. The existence of discontinuities m the sorption process, reported by previous experimenters, is supported by the isopiestic data.

scholarly journals Intercropping Short and Long Duration Groundnut (Arachis Hypogaea) Genotypes to Increase Productivity in Environments Prone to End-of-season Droughts

1990 ◽  
Vol 26 (1) ◽  
pp. 63-72 ◽  
Author(s):  
R. C. Nageswara Rao ◽  
K. D. R. Wadia ◽  
J. H. Williams
Keyword(s):  
Arachis Hypogaea ◽  
Short Duration ◽  
Total Biomass ◽  
Season Length ◽  
Water Deficits ◽  
Pod Yield ◽  
Long Duration ◽  
Increase Productivity

SUMMARYThree short duration and one long duration groundnut genotypes, grown either ‘sole’ or as intercrops (in 1:1 ratios of the short duration with the long duration genotypes), were compared in four trials. The intercrop treatments resulted in Land Equivalent Ratios (LERs) of up to 1.25 for pod yield and total biomass despite moderate or severe water deficits at the end of the season. Specific combinations of genotypes were necessary to maximize the LER. The results indicate there is scope for achieving greater productivity in environments with a variable season length by growing late and early genotypes together in an intercrop system.

PHYSIOLOGICAL BASIS OF YIELD VARIATION OF TEA (CAMELLIA SINENSIS) DURING DIFFERENT YEARS OF THE PRUNING CYCLE IN THE CENTRAL HIGHLANDS OF SRI LANKA

2009 ◽  
Vol 45 (4) ◽  
pp. 429-450 ◽  
Author(s):  
W. A. J. M. DE COSTA ◽  
D. M. S. NAVARATNE ◽  
A. ANANDACOOMARASWAMY
Keyword(s):  
Harvest Index ◽  
Biomass Partitioning ◽  
Sink Strength ◽  
Down Regulation ◽  
Physiological Basis ◽  
Area Index ◽  
Yield Decline ◽  
Yield Variation ◽  
Shoot Number ◽  
Significant Yield

SUMMARYThe objective of this study was to elucidate the physiological basis of the significant yield decline that occurs during the fourth year of the pruning cycle of tea. Biomass partitioning, which was hypothesized to be a major factor in causing this yield decline, was measured by destructive harvests of entire tea bushes, in two contrasting, mature, field-grown tea cultivars (TRI 2025 and DT1) at the end of different years of the pruning cycle. In both cultivars, yield showed continuous increases from year 1 to 3, followed by reductions of 44% and 35% in TRI2025 and DT1 respectively in the fourth year. Patterns of biomass partitioning to roots, stems or branches did not correlate with the above yield variation whereas harvest index, canopy leaf area index and mature leaf dry weight showed variations which paralleled the yield variation. The fourth-year decline in harvest index was brought about by reductions in both shoot number per m2 and mean individual shoot weight, which indicate a reduction in sink strength. Both cultivars showed reductions in light-saturated photosynthetic rate of maintenance foliage during the second half of the pruning cycle, indicating reduced source capacity. Hence, a combined reduction of both sink strength and source capacity during the fourth year could have brought about the significant yield reduction in tea. A significant increase of root starch in the fourth year indicated a down-regulation of physiological activities of the bush towards the end of the pruning cycle. Mechanisms responsible for this down-regulation need to be elucidated by further research.

The Evolution of the Colour Sense

1901 ◽  
Vol 47 (199) ◽  
pp. 678-679
Author(s):  
F. W. Edridge-Green
Keyword(s):  
Nerve Impulse ◽  
The Other ◽  
Physiological Basis ◽  
Black And White ◽  
Normal Distance ◽  
Colour Sense ◽  
Two Factors ◽  
Colour Blindness ◽  
The Mind

All the facts which can be gathered from the study of museums or literature point to the conclusion that the sense of light was developed first, then the sense of colour. The tendency has been to regard colour-blindness as “chromic myopia;” but this is not correct unless there is a defective perception of light as well, as shown by the cases which I have recorded. A man may be able to see light of all colours at twice the normal distance, and yet be colour-blind. I specially wish to emphasise the fact that there is no definite relation between light and colour. When light falls upon the eye it sets up a nerve impulse, which is conveyed to the brain. In the impulse itself we have the physiological basis of light, and in the quality of the impulse the physiological basis of colour. My contention is that these two factors are perceived by two entirely different sets of cerebral cells, those devoted to the perception of colour being developed at a later period than those conveying to the mind the sensation of light. All the evidence which can be obtained shows that all objects were first seen as in a photograph, that is, in different degrees of black and white. In the evolution of the colour sense those waves which differ most physically, namely, red and violet, were first recognised as different, the remainder of the spectrum appearing grey. Homer's colour vision was of this class, which represents the degree just preceding total colour-blindness. I have recorded a case of this kind of a man who was colour-blind with one eye, and who was therefore able to tell me exactly how objects appeared with this eye. He said that the spectrum appeared nearly all grey, but with a tinge of red at one end and a tinge of violet at the other; he could see very much better with the colour-blind eye than with the other.

Interactive Effects of Fungicide, Application Timing, and Spray Volume on Peanut Diseases and Yield

2012 ◽  
Vol 13 (1) ◽  
pp. 16
Author(s):  
Joao Augusto ◽  
Timothy B. Brenneman
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Interactive Effects ◽  
Stem Rot ◽  
Soilborne Pathogens ◽  
Application Timing ◽  
Yield Increase ◽  
Late Season ◽  
Pod Yield ◽  
Spray Volume

Fungicide penetration of the peanut (Arachis hypogaea) canopy to target soilborne pathogens is difficult due to the dense foliage present when mid- to late-season applications are made. To assess the effect of application timing and volume on leaf spot and stem rot control as well as peanut yield, pyraclostrobin (0.21 kg a.i./ha) or chlorothalonil (1.26 kg a.i./ha), a systemic and a contact fungicide, respectively, were applied four times on cv. Georgia Green during the day (on unfolded leaves) or at night (on folded leaves) at 187, 243, or 355 liters/ha. Night application of pyraclostrobin, across spray volumes, gave the best stem rot control and pod yield increase. Pyraclostrobin applied during the day at higher spray volumes also slightly increased control of stem rot, apparently by improving canopy penetration. Neither application timing nor spray volume affected leaf spot control with pyraclostrobin. Higher spray volumes for the chlorothalonil applications tended to improve control of early and late leaf spot, possibly by increasing coverage of foliage and stems. Accepted for publication 10 January 2012. Published 20 April 2012.

Sign in / Sign up

Export Citation Format

Share Document