Seed-setting in subterranean clover (Trifolium subterranean L.). III. The effect of plant density

1961 ◽  
Vol 12 (1) ◽  
pp. 10 ◽  
Author(s):  
JJ Yates
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Plant Density ◽  
Plant Cover ◽  
General Pattern ◽  
Strain Differences ◽  
Subterranean Clover ◽  
Seed Setting ◽  
Below Ground ◽  
Australian Wheat

Various aspects of seed production in a number of strains of subterranean clover sown at fire seeding rates at two sites in the Western Australian wheat-belt were investigated. Dry matter yields and percentage leaf in the foliage were also recorded. Percentage leaf increased with plant density in the earlier-maturing, stemmy strains, so that differences amongst strains diminished as density increased. The differences amongst strains in number of inflorescences when grown as single plants were largely eliminated under dense sward conditions, so that the two main factors in seed production were number of seeds per inflorescence and mean seed weight. The proportion of burrs above and below ground varied widely amongst strains, and was influenced by plant density in some strains. It is postulated that the extent of burr burial depends on the interaction between strain, environment, and condition of the surface soil. Burr burial improved the efficiency of seed-setting, particularly in the more severe environment. Strain differences in seeds per inflorescence below ground were relatively small, but within each strain, values were higher in the more favorable environment. The efficiency of seed-setting above ground differed considerably amongst strains and between the two environments, and tended to increase with plant density particularly in the earlier-maturing strains. Correlations were established between seeds per inflorescence above ground and the amount of plant cover in these strains. An artificial covering of wood-wool also improved seed-setting above ground. Mean seed weight followed the same general pattern as seeds per inflorescence.

The influence of maturity grading on total yield and seed production in strains of Trifolium subterraneun L. grown as single plants and in swards

1959 ◽  
Vol 10 (3) ◽  
pp. 305 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Soil Moisture ◽  
Seed Production ◽  
Plant Density ◽  
Total Yield ◽  
Subterranean Clover ◽  
Reverse Situation ◽  
Production Pattern ◽  
Seed Yields ◽  
The Relationship ◽  
Early Strain

A large number of strains of subterranean clover was grown as single plants and in swards in a series of 1-year experiments. The relationship between the interval from seeding to flowering ("maturity grading") and the production pattern varied according to plant density. In the case of single plants, both total yields and seed yields increased linearly with increasing maturity grading. With swards, on the other hand, total yields showed scarcely any relation to increasing maturity grading – there was a slight decline, in fact – while seed production fell rapidly. Hence the early strain Dwalganup gave the lowest seed yields as single plants, but the highest seed yields in swards, whereas the reverse situation held for the late strains Wenigup and Tallarook. The main factor responsible for the differences in these production patterns was considered to be available soil moisture supply. It was shown that in the few cases where soil moisture was severely limiting in spring for single plants, yields levelled off (and seed yields even declined) at higher maturity gradings. Three points are discussed at some length: the influence of environment on the seed yield of strains grown as single plants, the effect of plant density on the ratio seed weight/total weight, and production in relation to maturity grading in swards.

The effect of withholding water during flowering on seed production in Trifolium subterraneum L

1977 ◽  
Vol 28 (2) ◽  
pp. 301 ◽  
Author(s):  
P Andrews ◽  
WJ Collins ◽  
WR Stern
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Seed Weight ◽  
Marked Reduction ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Strain Response ◽  
Long Duration ◽  
Prolonged Stress ◽  
Practical Implications

An experiment was conducted in a glasshouse to study the effects of withholding water during flowering on seed production in subterranean clover. Two strains, Northam A (long duration of flowering) and Geraldton (shorter duration) were grown as swards in boxes, defoliated weekly until flowering, and subjected to the following watering regimes: T1, a control; T2, water withheld over the whole of the flowering period; T3 and T4, water withheld for short periods only, during flowering. Regular determinations were made of soil water, leaf water potential and inflorescence number. Seed yield and some of its components were measured in all treatments. The prolonged stress (T2) reduced seed yield by about 80% in both strains. Rates of inflorescence production, duration of flowering and individual seed weight were also reduced. The shorter stress treatments (T3, T4) had no effect on seed yield in the longer-flowering cultivar Northam A, but in cv. Geraldton, T4 caused a marked reduction in seed yield. The practical implications of this differential strain response are discussed.

Seed production from three annual species of Trifolium on sandy soils in the wheat belt of Western Australia

1969 ◽  
Vol 9 (36) ◽  
pp. 92 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Soil Moisture ◽  
Seed Production ◽  
Western Australia ◽  
Plant Density ◽  
Subterranean Clover ◽  
Soil Conditions ◽  
Seeding Rate ◽  
Relative Water ◽  
Plant Densities ◽  
Seed Yields

Seed production and persistence of subterranean, cupped, and rose clovers were examined over a period of three years in undefoliated swards, at several plant densities, in the wheat belt of Western Australia. Subterranean clover, although earlier flowering, was outyielded by the other two species in the two driest years. No major differences were found between species in relative water content of leaves during periods of soil moisture deficit. Moreover, species differences in soil moisture exploitation were small. A high proportion of inflorescences failed to set seed in subterranean clover. This reproductive defect, which is associated with restricted inflorescence burial due to dry soil conditions, was thought to be the main reason for the poorer seed yield in this species. Despite low seed yields in the establishment year, plant density after the first year did not seriously limit seed yields, even at the lowest seeding rate, in any of the three species.

Studies in oil-seed crops: II. An assessment of the interrelationships between plant development and seed production in linseed (Linum usitatissimum)

1954 ◽  
Vol 45 (1) ◽  
pp. 3-9 ◽  
Author(s):  
G. E. Blackman ◽  
E. S. Bunting
Keyword(s):  
Seed Production ◽  
Plant Development ◽  
Seed Weight ◽  
Plant Density ◽  
Level Density ◽  
Spatial Arrangement ◽  
Nutrient Level ◽  
Capsule Production ◽  
Seed Crops ◽  
Number Of Seeds

Records of plant development in some twenty-five multifactorial experiments were collected with the object of analysing the effects of nutrient level, density, spatial arrangement and variety on seed production in linseed. By sampling techniques estimates were made of plant density, the extent of basal branching, the number of capsules per stem, the number of seeds per capsule and the seed weight. The expected plot yields, calculated from these data, were in good agreement with the harvested yields.In factorial trials, involving additions of nitrogen, phosphorus and potassium, only a change in the nitrogen level increased the yield of seed, and this gain was largely determined by an increase in the production of capsules and not by any alteration in either the number of seeds per capsule or the seed weight.Over a range of density of thirty to eighty plants per square foot the number of capsules produced per plant was inversely correlated with density. When the distance between drills was maintained at 6–7 in. and the density varied by changing the seed rate then—on an area basis—both capsule production and seed yield were rarely affected since the product of plant number and capsules per plant remained relatively constant. On the other hand, if the rate of seed delivery in the drill was kept the same and the distance between the drills was the variable for density then with a narrow width of drill (4 in.) the increase in plant density more than offset the fall in capsules per plant.Further experiments comparing drilling and crossdrilling did not wholly confirm the importance of spatial arrangement. There was, however, evidence that at densities over eighty plants per square foot, besides a further reduction in capsules per plant, the number of seeds per capsule was depressed. Varieties were characterized by differences in seed size, the number of seeds per capsule, capsules per plant and the ability to produce more capsules at high levels of nitrogen. The superiority of the yielding capacity of Royal could be ascribed to the high rate of capsule production. Such varietal differences in capsule production have not been reported previously, and since the number of capsules per plant is greatly influenced by varying density, the common practice of basing selection on spaced plants, may not give a true assessment of capsule formation at densities optimal for seed production.

Effect of burr burial on seed production of Trifolium subterraneaum subsp. brachycalycinum and other annual legumes

1986 ◽  
Vol 26 (1) ◽  
pp. 59 ◽  
Author(s):  
MDA Bolland ◽  
WJ Collins
Keyword(s):  
Seed Production ◽  
Sandy Soil ◽  
Seed Weight ◽  
Trifolium Subterraneum ◽  
Annual Legumes ◽  
Seed Yields

On sandy soil near Esperance, W.A., prevention of burr burial compared with covering developing burrs with sand drastically reduced the seed production of three subspp. of Trifolium subterraneum (brachycalycinum, subterraneum and yanninicum) and of T. israeliticum by reducing burr production and seed weight. However, T. globosum produced similar amounts of seed from unburied and buried burrs. On sandy soil at Shenton Park, Perth, W.A., prevention of burr burial also reduced seed production of T. subterraneum subspp. brachycalycinum and subterraneum, this being due to fewer burrs, fewer seeds per burr and lighter seed. For subsp. brachycalycinum, seed yields were two to five times greater from burrs which developed within loose gravel than from those developed over sand (in which fewer burrs were able to bury) as a result of increased production of burrs, more seeds per burr and heavier seed. However, for subsp. subterraneum seed yields were similar from burrs whether developed over gravel or sand.

Effects of Plant Density and Thinning on High-Yielding Dry Beans (Phaseolus vulgaris) in Mexíco

1977 ◽  
Vol 13 (4) ◽  
pp. 325-335 ◽  
Author(s):  
Aguilar M. Immer ◽  
R. A. Fischer ◽  
Joshue Kohashi S.
Keyword(s):  
Phaseolus Vulgaris ◽  
Leaf Area ◽  
Seed Weight ◽  
Plant Density ◽  
Plant Competition ◽  
Growth And Yield ◽  
Positive Relation ◽  
Dry Beans ◽  
Leaf Area Duration ◽  
Pod Number

SUMMARYThe influence of leaf area and inter-plant competition on the growth and yield of a crop of high-yielding dry beans (Phaseolus vulgaris L.) in central Mexico was studied, using density and thinning treatments. The highest seed yield (4210 kg/ha at 14% moisture) was obtained with the highest density (28·8 plants/m2). Thinning showed that pods/plant was sensitive to inter-plant competition between 36 and 78 days after seeding (first flower at 50 days), but seeds/pod, and especially seed weight, were not sensitive. It is suggested that the close positive relation between yield and leaf area duration derives from the influence of photosynthate supply upon pod number.

Differentiation of reproductive traits between central and peripheral populations of Allium wallichii Kunth

2021 ◽  
Author(s):  
Hanqing Tang ◽  
Demei Hu ◽  
Chao Zhang ◽  
Juan Yang ◽  
Mengda Xiang ◽  
...  
Keyword(s):  
Pollen Germination ◽  
Plant Density ◽  
Peripheral Populations ◽  
Seed Setting ◽  
Peripheral Population ◽  
Reproductive Characteristics ◽  
Central Population ◽  
Floral Visitors ◽  
Different Populations ◽  
Seed Setting Rate

The differentiation of reproductive characteristics not only exists between different populations, but also may exist within populations. In this work, the differences between the central and peripheral populations were experimentally compared and analyzed in terms of biodiversity index, plant traits, anthesis, pollen germination, floral visitors, seed setting rate, and ploidy. The results showed that the diversity and richness of other plant species, in the central population were significantly lower than those in the peripheral population, but the plant density was much higher than in the peripheral population. The plant anatomical traits, anthesis, pollen germination, floral visitors, seed setting rate, and ploidy were significantly different between central population and peripheral populations. The term increasing rate (IR) is proposed as a means of comparing morphologies in different organs. IR differences in vegetative characteristics were more stable, while those in reproductive characteristics differed significantly. For the central population, the effect of the intraspecific reproductive competition and pollinator selection on plants may significant, and morphology was differentiated in terms of reproductive characteristics. Plants in the peripheral populations were visited by many more pollinators than in the central population, and all pollinators visited infrequently. The reproductive characteristics of plants in the peripheral populations may therefore only be weakly affected by pollinator selection. The reproductive characteristics of plants in the peripheral population may weakly affected by the selection of pollinators and the variation was small. In conclusion, morphological differentiation among the different populations was associated with differences in vegetative and reproductive characteristics.

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.

The relationship between crop yield (or mean plant weight) of lettuce and plant density, length of growing period, and initial plant weight

1976 ◽  
Vol 86 (1) ◽  
pp. 83-91 ◽  
Author(s):  
M. A. Scaife ◽  
D. Jones
Keyword(s):  
Time Course ◽  
Plant Density ◽  
Unit Area ◽  
Subterranean Clover ◽  
Plant Weight ◽  
Relative Growth ◽  
Growing Period ◽  
Lettuce Growth ◽  
Log Linear ◽  
The Relationship

SUMMARYLettuce obeys the Shinozaki–Kira relationship in which the reciprocal of plant weight is linearly related to plant density. The intercept (a) represents the reciprocal of the weight of an isolated plant and the slope (b) represents the reciprocal of yield/unit area at high densities (the ‘ceiling yield’). This work examines the time course of (a) and (b) in an ‘ideal environment’ in which water and nutrients are non-limiting, and the light/temperature regime is constant.Two pot experiments are described: the first showed that the growth of isolated lettuces follows a logistic expression, which can therefore be substituted for a–1 in the Shinozaki-Kira equation. It was then hypothesized that b–1, the ‘ceiling yield’ would be constant over time. This was confirmed by the second experiment, giving the equationw–1t = w–10 e1–kt × w–1max × bd,in which wt is mean plant weight at time t, w0 and wmax are the initial and final weights of isolated plants, k is the early relative growth rate of such plants, b–1 is the constant ceiling yield, and d is the plant density.Two examples of the use of the equation are given: one shows how it predicts the interaction between seed size and plant density within a species (subterranean clover): the other illustrates how it can be used to explain why lettuce growth appears to be log-linear against time whereas cereal growth is more nearly just linear.

scholarly journals Linking floral biodiversity with nitrogen and carbon translocations in semi-natural grasslands in Lithuani

2015 ◽  
Vol 34 (2) ◽  
pp. 137-146
Author(s):  
Saulius Marcinkonis ◽  
Birutė Karpavičienė ◽  
Michael A. Fullen
Keyword(s):  
Plant Cover ◽  
Chemical Properties ◽  
Above Ground Biomass ◽  
Long Term Effects ◽  
Specific System ◽  
Ground Biomass ◽  
Natural Grasslands ◽  
Below Ground ◽  
Grassland Communities

AbstractThe aim of the present study is to evaluate the long-term effects of long-term piggery effluent application on semi-natural grassland ecotop-phytotop changes (above- and below-ground phytomass production, and carbon and nitrogen allocation in grassland communities) in relation to changes (or variability) in topsoil properties. Analysis of phytomass distribution in piggery effluent irrigated grassland communities showed that dry biomass yield varied from 1.7−5.3 t ha-1. Variability in soil and plant cover created a unique and highly unpredictable site specific system, where long-term anthropogenic influences established successor communities with specific characteristics of above- and below-ground biomass distribution. These characteristics depend more on grassland communities than on soil chemical properties. Families of grasses (Poaceae) dominated the surveyed communities and accumulated most carbon and least nitrogen, while legumes accumulated most nitrogen and lignin and least carbon. Carbon concentrations in above-ground biomass had minor variations, while accumulation of nitrogen was strongly influenced by species diversity (r = 0.94, n = 10, p <0.001) and production of above-ground biomass

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