Seed production and dormancy in Rumex crispus. I. The effects of removal of cauline leaves at anthesis

1971 ◽  
Vol 49 (7) ◽  
pp. 1123-1130 ◽  
Author(s):  
M. A. Maun ◽  
P. B. Cavers
Keyword(s):  
Biological Control ◽  
Cross Sections ◽  
Absorptive Capacity ◽  
Seed Weight ◽  
Rumex Crispus ◽  
Severe Reduction ◽  
Weedy Species ◽  
Total Seed ◽  
Important Basis ◽  
Number Of Seeds

Defoliation of the panicle of Rumex crispus L. (curled dock) at anthesis had little effect on the number of seeds (nuts) produced but lead to a very severe reduction in total seed weight per panicle and in the size of individual seeds. In particular the proportion of larger seeds was reduced drastically. The seeds from defoliated plants germinated more rapidly and had less precise requirements for germination than those from untreated plants. They did not suffer any loss of viability. A microscopic examination of cross sections of seeds revealed that seeds from defoliated plants had thinner walls (investing structures). They also exhibited a higher absorptive capacity for water. This information provides an important basis for further studies on the biological control of this weedy species.

VARIATION AMONG BRITISH COLUMBIA AND NORTHERN ALBERTA POPULATIONS OF RASPBERRIES, RUBUS IDAEUS SUBSPP. STRIGOSUS MICHX.

1972 ◽  
Vol 52 (6) ◽  
pp. 1067-1072 ◽  
Author(s):  
M. C. J. VAN ADRICHEM
Keyword(s):  
British Columbia ◽  
Seed Weight ◽  
Fruit Weight ◽  
Winter Hardiness ◽  
Rubus Idaeus ◽  
Specific Character ◽  
Positive Correlation ◽  
Total Seed ◽  
Northern Alberta ◽  
Number Of Seeds

Several population samples of Rubus idaeus subspp. strigosus Michx. (raspberries) were collected in British Columbia and northern Alberta and a number of characters were studied and compared with the cultivar Trent. Significant differences between populations were found for cane length, number of buds per cane, percentage of buds growing, number of inflorescences and flowers per bud, fruit and seed weight. There was a positive correlation between the total seed weight and the number of seeds, and between the total seed and fruit weight. No distinct types could be established based on location or elevation. None of the populations showed significantly better winter hardiness than the cultivar Trent, and although some had a specific character that was superior, none was found to have overall superiority.

Biological Control of Diffuse Knapweed (Centaurea diffusa) and Spotted Knapweed (C. maculosa)

Weed Science ◽  
1982 ◽  
Vol 30 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Donald M. Maddox
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Reproductive Potential ◽  
Control Agent ◽  
Flower Head ◽  
Spotted Knapweed ◽  
Centaurea Diffusa ◽  
Weedy Species ◽  
Diffuse Knapweed ◽  
Number Of Seeds

Diffuse knapweed (Centaurea diffusa Lam.) and spotted knapweed (C. maculosa Lam.) presently infest approximately 1.5 million ha of pasture and rangeland in Washington, Montana, Idaho, Oregon, and California. The serious losses caused on lands where returns from herbicidal control are marginal or less prompted the testing and introduction of two strains of a seed-head fly (Urophora affinis Frlfld.) as a biological-control agent in these states. Over 27 000 flies were released in about equal numbers on both weeds during the years 1974 to 1977 and in 1979 and 1980. The fly became established in all states where it was released. The adult was found to disperse over 76 m from release point from 1974 to 1976, and to reduce the number of seeds per flower head in sampled heads by 80% in northern Washington and over 64% at the Heppner, Oregon site. A newly released moth (Metzneria paucipunctella Zell.) and a root-boring beetle (Spbenoptera jugoslavica Obenb.) are expected to cause additional pressure on these plants. The reproductive potential of the knapweeds is such that more natural enemies will be needed to provide enough stress to reduce these weedy species to an acceptable level.

Cotton pollination by honeybees

2002 ◽  
Vol 42 (4) ◽  
pp. 513 ◽  
Author(s):  
J. Rhodes
Keyword(s):  
Honey Bees ◽  
Field Trial ◽  
Seed Weight ◽  
Total Mass ◽  
Seed Mass ◽  
Average Weight ◽  
Single Seed ◽  
Total Seed ◽  
Number Of Seeds

In a field trial, significant increases for the total number of bolls harvested (11.1%), total mass of bolls (16.5%), total lint mass (15.8%), total seed mass (19.7%) and total number of seeds per sample (16.5%) were obtained from plots receiving the highest number of bee visits compared with plots receiving the lowest number of bee visits. Lint-quality examinations resulted in a significant improvement for micronaire and fineness with increased bee visits. Non-significant increases were obtained for the mass of 100 seeds (3.8%), average single seed weight (3.9%), average number of seeds per boll (4.7%) and average weight of lint per boll (5.0%). Caged plots with honey bees had significantly greater total boll mass; total seed mass; and average single-seed weight than caged plots without honey bees.

STUDY OF EFFECT OF EMS, MMS AND GR ON YIELD CONTRIBUTING TRAITS IN URDBEAN, VIGNA MUNGO

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
A. B. SAGADE
Keyword(s):  
Plant Height ◽  
Seed Yield ◽  
Seed Weight ◽  
Inhibitory Effect ◽  
Individual Plant ◽  
Mean Values ◽  
Methane Sulphonate ◽  
Pod Length ◽  
100 Seed Weight ◽  
Number Of Seeds

The study of the effect of three well known mutagens, ethyl methane sulphonate (EMS), methyl methane sulphonate (MMS) and gamma rays (GR) on the yield contributing traits of the urdbean variety TPU-4 were carried out in the M3 generation. Effect of selected mutagenic treatments/doses of EMS (0.02, 0.03 and 0.04 M), MMS (0.0025, 0.05 and 0.01 M) and (GR) (30, 40 and 50 KR) on different yield contributing traits like plant height, plant spread, number of pods per plant, pod length, number of seeds per pod, seed yield per plant and 100 seed weight were analyzed in the M3 populations of the variety TPU-4. Seeds of M2 plants and control were harvested separately and sown to raise M3 population.. Genetic variabilty in the mutagen administered M3 progeny of the urdbean variety TPU-4 was analyzed by employing statistical methods. Data on mean values and shift in the mean of seven quantitative traits was evaluated on individual plant basis. The experimental findings revealed that concentrations / dose of the all these mutagens showed inhibitory effect on plant height, number of pods per plant, pod length and number of seeds per pod. Lower concentrations of mutagens exerted a promotory effect on plant spread, 100 seed weight and seed yield per plant while higher concentrations of these mutagens inhibited them to different extent.

Individual crop size increases predispersal predation by beetles in a tropical palm

2020 ◽  
pp. 1-4
Author(s):  
Morgana Maria Arcanjo Bruno ◽  
Klécia Gili Massi ◽  
Alexander V. Christianini ◽  
John du Vall Hay
Keyword(s):  
Seed Predation ◽  
Positive Influence ◽  
Reproductive Phenology ◽  
Individual Plant ◽  
Crop Size ◽  
Seed Predators ◽  
Plant Trait ◽  
Predispersal Seed Predation ◽  
Total Seed ◽  
Number Of Seeds

Abstract Predispersal seed predation is one of the main causes of seed mortality in plant populations, contributing to decreased plant recruitment. Seed loss has previously been found to be related to crop size. Thus, we examined the influence of individual crop size on predispersal seed predation by beetles in the palm Syagrus flexuosa in the Brazilian savanna. The study was carried out in three tropical woodland savanna sites, where we sampled the total seed crop of 46 fruiting palms and checked the presence of beetle larvae inside all seeds per plant. We observed predispersal seed predation of S. flexuosa from all sites and a high variation in the number of seeds preyed on per individual palm. Crop size had a positive influence on the number of seeds lost to predispersal seed predators. Variations in levels of predispersal seed predation may also be accounted for by the reproductive phenology of S. flexuosa. If fruits are not available at the same time, less resource is available for predators and therefore a high proportion of seeds may be preyed on. Thus, our study demonstrates that an individual plant trait, crop size, is an important predictor of beetle seed damage per palm and a driver of the number of seeds lost to predispersal seed predators.

Jack pine cone quality and cache sizes of red squirrels in southern New Brunswick, Canada

1997 ◽  
Vol 75 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Michael A. Setterington ◽  
Daniel M. Keppie
Keyword(s):  
New Brunswick ◽  
Pinus Banksiana ◽  
Seed Mass ◽  
Dry Mass ◽  
Jack Pine ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Length Width ◽  
Total Seed ◽  
Number Of Seeds

Relationships between external cone characteristics (length, width, wet and dry mass), cone quality (total seed mass as a proportion of cone mass, total number of seeds per cone, total seed mass per cone), and number of cones in caches were evaluated for caches of jack pine (Pinus banksiana) cones belonging to red squirrels (Tamiasciurus hudsonicus) in two plantations in southern New Brunswick. Cone length and mass were good predictors of the total number of seeds per cone and total seed mass per cone. Length accounted for a small proportion of the variance of total seed mass as a proportion of cone mass. There was no relationship between the number of seeds or total seed mass per cone and the number of cones per cache.

Morphological and physiological traits associated with seed yield in different chickpea (Cicer arietinum L.) genotypes under irrigated andwater‐deficit environments

2011 ◽  
Vol 1 (6) ◽  
pp. 260-267
Author(s):  
Reza Talebi ◽  
Ezzat Karami
Keyword(s):  
Chlorophyll Content ◽  
Water Deficit ◽  
Seed Yield ◽  
Seed Weight ◽  
Significant Negative Correlation ◽  
Physiological Traits ◽  
Positive Correlation ◽  
Chickpea Cultivar ◽  
High Level ◽  
Number Of Seeds

The morpho â€physiological traits associated with seed yield in chickpea (Cicerarietinum L.) were evaluated on thirty five chickpea genotypes under twodifferent water regimes. In optimum condition, the highest correlation wasbelonged to number of seeds/plant and number of pods/plant (0.944**) andin water deficit condition, the strongest correlation of seed yield was observedwith number of seeds/plant (0.875**), number of pods/plant(0.789**) and 100  â€seed weight (0.438**). Physiological traits (RWC, Chlorophylland Carotenoid) indicated low and positive correlation with yield, buthigh positive correlation with other seeds yields related traits in optimumcondition while, under water deficit condition, chlorophyll content and RWChad low and non â€significant negative correlation with seeds yield. Carotenoid,number of seeds/plant and 100 â€seed weight showed more direct positiveeffect on yield in optimum environment and in stress condition, numberof seeds/ plant and 100 â€seed weight showed highest direct effect on seedyield. Results of factor analysis showed that four factors explained 88.54%and 34.5% of the total variance caused in the characters in optimum andwater deficit environment, respectively. In general, the results suggestedthat a chickpea cultivar, for increased yield under non â€stress conditions,should have maximum number of seeds and pods per plant and under stressconditions should have maximum number of seeds and pods per plant andalso keep the high level of RWC and chlorophyll content in their leaves. Thus,identifying these traits as selection criteria in chickpea breeding programmay be useful for breeders to introduce suitable drought resistant chickpeacultivars for arid regions.

scholarly journals Morphological characterization and genetic diversity in lentil (Lens culinaris medikus ssp. Culinaris) germplasm

2014 ◽  
Vol 4 (1) ◽  
pp. 70-76
Author(s):  
KU Ahamed ◽  
B Akhter ◽  
MR Islam ◽  
MR Humaun ◽  
MJ Alam
Keyword(s):  
Seed Weight ◽  
Female Flower ◽  
Morphological Characterization ◽  
Flower Initiation ◽  
Mean Values ◽  
Maximum Value ◽  
Cluster Distance ◽  
The Mean ◽  
100 Seed Weight ◽  
Number Of Seeds

Genetic divergence of 110 lentil germplasm with checks was assessed based on morphological traits using multivariate analysis. Mahalanobis generalized distance (D2) analysis was used to group the lentil genotypes. Significant variations among lentil genotypes were observed in respect of days to 1st flowering, days to 50% flowering, days to maturity, plant height, and number of pods per peduncle, number of pods per plant, number of seeds per plant, 100 seed weight and yield per plant. Considering the mean values, the germplasm were grouped into ten clusters. The highest number of genotypes (17) was in cluster X and lowest (5) both in cluster II and IV. Cluster IV had the highest cluster mean for number of pods per plant (297.08), number of seeds per plant (594.16), 100 seed weight (1.44 g) and yield per plant (8.53 g). Among them, the highest inter-cluster distance was obtained between the cluster IV and I (24.61) followed by IV and III (22.33), while the lowest was between IX and II (1.63). The maximum value of inter-cluster distance indicated that genotypes belonging to cluster IV were far diverged from those of cluster I. The first female flower initiation was earlier in BD-3812 (49 days) in cluster I and cluster IV had highest grain yield per plant (8.53). BD-3807 produced significant maximum number of pods per plant (298.40) in cluster IV. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.21095 Int. J. Agril. Res. Innov. & Tech. 4 (1): 70-76, June, 2014

scholarly journals Heliotropism and water availability effects on flowering dynamics and seed production in Macroptilium lathyroides

2006 ◽  
Vol 28 (2) ◽  
pp. 45-52 ◽  
Author(s):  
Armando Martins dos Santos ◽  
Luis Mauro Gonçalves Rosa ◽  
Lucia Brandão Franke ◽  
Carlos Nabinger
Keyword(s):  
Seed Production ◽  
Water Availability ◽  
Yield Components ◽  
Seed Weight ◽  
Field Capacity ◽  
Leaf Movements ◽  
Independent Effects ◽  
Total Seed ◽  
Macroptilium Lathyroides ◽  
Response To Water

The experiment was carried out in pots in a glasshouse, with one plant per pot and nine repetitions per treatment. The treatments consisted of free or restricted leaves, submited to 90-100% or 60-70% soil field capacity (FC). Only independent effects of water availability or leaf movement were observed on yield components. Plants under well-watered conditions and with freely orienting leaves were taller, and had a larger number of ramifications. The greater development favored the setting of a higher number of inflorescences per plant in these treatments. This behavior resulted in a high number of flowers, green and mature legumes per plant, thus resulting in high seed production which was the most evident response to water availability. Although individual seed weight was higher in the water stress treatment, total seed production was higher for well-watered plants, with no statistically significant effect of leaf movements.

EFFECTS OF METHOD AND RATE OF SEEDING ON YIELD OF BRASSICA NAPUS

1978 ◽  
Vol 58 (2) ◽  
pp. 549-550 ◽  
Author(s):  
J. M. CLARKE ◽  
F. R. CLARKE ◽  
G. M. SIMPSON
Keyword(s):  
Brassica Napus ◽  
Seed Weight ◽  
Brassica Napus L ◽  
Seeding Method ◽  
Number Of Seeds

Broadcast and drill seeding of Brassica napus L. were compared at four seeding rates. Drill-seeded material yielded more than broadcast-seeded material, particularly at the low seeding rates. Broadcast-seeded plants had more branches and pods than drill-seeded plants. Seeding method did not affect number of seeds per pod or 1,000-seed weight.

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