scholarly journals Peanut Tolerance to Paraquat as Influenced by Seed Size1

1994 ◽  
Vol 21 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Glenn Wehtje ◽  
Barry Brecke ◽  
J. P. Bostick
Keyword(s):  
Seed Size ◽  
Growth Reduction ◽  
Herbicide Application ◽  
Peanut Seed ◽  
Net Return ◽  
Small Seed ◽  
Effect On Yield ◽  
Kg Medium ◽  
The Relationship ◽  
Common Plant

Abstract Studies were conducted over a 2-year period at Headland, Ala. and Jay, Fla. to evaluate the relationship between peanut seed size and tolerance of the resultant crop to normal and excessive rates of the herbicide paraquat (1,1′-dimethyl-4,4′-bipyridinium ion). Three seed sizes, termed small (3340 seeds/kg), medium (2615 seeds/kg), and large (1820 seeds/kg), were planted to achieve a common plant population. While seedling size at emergence reflected seed size, no interaction between seed size and herbicide treatment was detected for crop growth measured as the increase in canopy diameter over a 5-week period following herbicide application. None of the seed sizes resulted in seedlings that were either uniquely sensitive or abnormally tolerant of paraquat. Two sequential applications of paraquat at 0.14 kg ai/ha each was consistently the most damaging treatment as measured in growth reduction, however yield was reduced in only one of four trials. Seed size had an effect on yield in only two of the four trials, and within these two trials the average yield improvement from large seed relative to medium and small seed was only 10 and 12%, respectively. Net return generally was independent of seed size. However, medium-sized seed resulted in maximum net return in two out of the four experiments.

Seed size as a determinant of germination rate in Crepis tectorum (Asteraceae): evidence from a seed burial experiment

1996 ◽  
Vol 74 (4) ◽  
pp. 568-572 ◽  
Author(s):  
Stefan Andersson
Keyword(s):  
Seed Size ◽  
Germination Rate ◽  
Local Population ◽  
Seed Viability ◽  
Seed Burial ◽  
Small Seed ◽  
Crepis Tectorum ◽  
Winter Annual ◽  
Selection For ◽  
The Relationship

The present study of the winter annual Crepis tectorum examines the relationship between seed (achene) size and the extent to which seeds resist germination during the year of their production. I carried out two seed burial experiments, one at an outcrop site occupied by a small-seeded population, and another in an experimental garden with soil from the same field site, with seeds representing the local population and a segregating generation of a cross between two other populations. Using logistic regression with data corrected for seed viability, I found an association between small seed size and failure to germinate in the first autumn. The small seed size characterizing many outcrop populations may have evolved as a response to selection for delaying germination in a habitat subject to unpredictable droughts during the growth season. Keywords: Crepis tectorum, germination, seed bank, seed size.

Introgression of genes for small seed size from Glycine soja into Glycine max

1990 ◽  
Author(s):  
Allen Rubin LeRoy
Keyword(s):  
Glycine Max ◽  
Seed Size ◽  
Glycine Soja ◽  
Small Seed

scholarly journals Land Use Transitions and Farm Performance in China: A Perspective of Land Fragmentation

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 792
Author(s):  
Shukun Wang ◽  
Dengwang Li ◽  
Tingting Li ◽  
Changquan Liu
Keyword(s):  
Large Scale ◽  
Household Survey ◽  
Scale Production ◽  
Land Fragmentation ◽  
Land Transfer ◽  
Large Scale Production ◽  
Speed Up ◽  
Farm Performance ◽  
Effect On Yield ◽  
The Relationship

Land fragmentation (LF) is widespread worldwide and affects farmers’ decision-making and, thus, farm performance. We used detailed household survey data at the crop level from ten provinces in China to construct four LF indicators and six farm performance indicators. We ran a set of regression models using OLS methods to analyse the relationship between LF and farm performance. The results showed that (1) LF increased the input of production material and labour costs; (2) LF reduced farmers’ purchasing of mechanical services and the efficiency of ploughing; and (3) LF may increase technical efficiency (this result, however, was not sufficiently robust and had no effect on yield). Generally speaking, LF was negatively related to farm performance. To improve farm performance, it is recommended that decision-makers speed up land transfer and land consolidation, stabilise land property rights, establish land-transfer intermediary organisations and promote large-scale production.

The effects of glyphosate and triclopyr on common bryophytes and lichens in northwestern Ontario

1999 ◽  
Vol 29 (7) ◽  
pp. 1101-1111 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell ◽  
Dale H Vitt
Keyword(s):  
Species Richness ◽  
Community Dynamics ◽  
Herbicide Application ◽  
Northwestern Ontario ◽  
Application Rates ◽  
Open Forest ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
The Relationship

The effects of two silvicultural herbicides (Vision®, Release®) on bryophytes and lichens were studied in a harvested boreal mixedwood ecosystem. A completely randomized design with 115 plots of 1 m2 allowed direct comparison between herbicides and their effects on community dynamics. Regression models were used to analyze the relationship between herbicide application rates (0.71-6.72 kg active ingredient/ha) and changes in bryophyte and lichen abundance and species richness for 2 years following herbicide application. Results showed that bryophyte and lichen abundance and species richness decreased after herbicide treatments. In general, herbicide applications reduced the diversity of forest mesophytes and weedy colonizers to an ecosystem with only a few species of colonizers. A combination of clustering techniques and ANOVA were used to divide bryophytes and lichens into three ecologically defined response groups: herbicide-tolerant colonizers, semi tolerant long-term stayers from dry open forest, and sensitive forest mesophytes.

Evaluation of Different Herbicide Application Methods and Cultivation Effect on Yield and Weed Control of Corn (Zea mays)

2008 ◽  
Vol 7 (4) ◽  
pp. 314-320 ◽  
Author(s):  
A.R. Niazmand ◽  
M. Shaker ◽  
A.R. Zakerin
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Herbicide Application ◽  
Application Methods ◽  
Effect On Yield

Investigations into the Growth Suppressing Effect of Nicosulfuron-Treated Johnsongrass (Sorghum halepense) on Corn (Zea mays)

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 640-644 ◽  
Author(s):  
Nagabhushana G. Gubbiga ◽  
A. Douglas Worsham ◽  
Frederick T. Corbin
Keyword(s):  
Soil Surface ◽  
Root Systems ◽  
Application Rate ◽  
Growth And Yield ◽  
Sorghum Halepense ◽  
Growth Reduction ◽  
Herbicide Application ◽  
Stunted Growth ◽  
Rooting Medium ◽  
Excellent Control

Greenhouse and growth chamber experiments were conducted to determine the reasons for stunted growth and yield suppression of corn noticed sometimes in nicosulfuron-treated corn fields infested with heavy population of johnsongrass. Results indicated that in the absence of johnsongrass, nicosulfuron applied broadcast POST at 35 g ai ha−1had no effect on corn. However, growth reduction of corn occurred when nicosulfuron-treated johnsongrass and corn were allowed to share the same rooting medium with their root systems intermingled. The reduction in growth was even greater when corn foliage or the soil surface were also treated with johnsongrass. The extent of growth reduction of corn growing with nicosulfuron-killed johnsongrass depended on weed density and herbicide application rate. Greater growth reductions occurred at four johnsongrass plants per pot compared to two and at a higher application rate of 100 μg nicosulfuron per plant. In general, johnsongrass killed by nicosulfuron appeared to be more phytotoxic to corn than plants killed by paraquat. Nicosulfuron provided excellent control of johnsongrass and improved corn growth by two to three times that of not controlling johnsongrass, but it could not elevate corn growth to the level obtained when johnsongrass was controlled by paraquat or in the absence of interference from johnsongrass.

scholarly journals The Seed-Hull Weight Ratio as an Index of Peanut Maturity1,2

1977 ◽  
Vol 4 (2) ◽  
pp. 47-50 ◽  
Author(s):  
Harold E. Pattee ◽  
Johnny C. Wynne ◽  
James H. Young ◽  
Fred R. Cox
Keyword(s):  
Seed Weight ◽  
Quantitative Method ◽  
Weight Ratio ◽  
Maturity Index ◽  
Peanut Seed ◽  
Seed Maturity ◽  
Harvest Dates ◽  
Arachis Hypogaea L ◽  
Seed Hull ◽  
The Relationship

Abstract A simple, quantitative method was developed to determine peanut (Arachis hypogaea L.) maturity. The method is based on the changing seed-hull weight ratio during maturation of the fruit. The ratio or maturity index was determined for fresh as well as air-dried pods, and these ratios correlated well with a physiological maturity index. The relationship between arginine maturity index and the air-dried seed-hull maturity index (DMI) was also determined, and the two indexes were negatively correlated. The DMI values across nine planting and eight harvest dates over a 2-year period showed that DMI could be applied to estimate average peanut seed maturity under field harvest conditions. The two peanut varieties tested, Florigiant and Florunner, were found to differ in maxmum DMI values. The study also showed that peanut seed weight increased with maturity then decreased after full maturity.

Susceptibility of mungbean varieties to the bruchid species Callosobruchus maculatus (F.), C. phaseoli (Gyll.), C. chinensis (L.), and Acanthoscelides obtectus (Say.) (Coleoptera:Chrysomelidae)

2000 ◽  
Vol 51 (1) ◽  
pp. 85 ◽  
Author(s):  
C. J. Lambrides ◽  
B. C. Imrie
Keyword(s):  
Seed Size ◽  
Seed Coat ◽  
Callosobruchus Maculatus ◽  
Acanthoscelides Obtectus ◽  
Oviposition Deterrents ◽  
Bruchid Resistance ◽  
Small Seed ◽  
Biochemical Resistance ◽  
Acanthoscelides Obtectus Say

Twenty-six mungbean varieties and accessions were screened for resistance to 4 bruchid species (Coleoptera : Chrysomelidae). On the basis of the percentage of seeds damaged all Australian commercial mungbean varieties tested here were highly susceptible to strains of Callosobruchus maculatus and C. chinensis, the 2 species that cause most damage worldwide to mungbean in storage. In addition, 3 accessions of wild mungbean appeared to have bruchid resistance. The texture layer present on the seed coat of some mungbean varieties and small seed size may act as oviposition deterrents. Consequently, these assays for determining resistance to bruchid infestation may not be suitable for identifying biochemical resistance of some mungbean genotypes.

Seed mass and early survivorship of tree species in upland clearings and shelterwoods

1998 ◽  
Vol 28 (9) ◽  
pp. 1307-1316 ◽  
Author(s):  
D F Greene ◽  
E A Johnson
Keyword(s):  
Leaf Litter ◽  
Power Law ◽  
Tree Species ◽  
Picea Glauca ◽  
Mineral Soil ◽  
Seed Mass ◽  
High Survivorship ◽  
Small Seed ◽  
Negative Exponential ◽  
The Relationship

We examined recommended sowing densities of 25 North American tree species (26 observations) to measure the relationship between juvenile survivorship and seed mass in large clearings and shelterwoods. Two models for expressing the relationship (simple power law or a cumulative negative exponential adjusted to account for rodent-repellent application and seedbed type) all showed that survivorship is highly dependent on seed mass. For a small seed, mineral soil and thin humus confer roughly equally high survivorship. Leaf litter is very poor, and undisturbed thick moss appears to be the worst possible organic seedbed on upland sites. An examination of 30 records of Picea glauca (Moench) Voss survivorship (3- to 6-year-old cohorts) on mineral soil revealed substantial intraspecific variation with only 50% of the values within twofold of the predicted value.

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