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.

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.

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.

IRRIGATION MANAGEMENT OF ALFALFA FOR SEED

1977 ◽  
Vol 57 (3) ◽  
pp. 891-896 ◽  
Author(s):  
K. K. KROGMAN ◽  
E. H. HOBBS
Keyword(s):  
Soil Moisture ◽  
Medicago Sativa ◽  
Seed Production ◽  
Irrigation Management ◽  
Growing Season ◽  
Moisture Stress ◽  
Field Plot ◽  
Southern Alberta ◽  
Medicago Sativa L ◽  
Seed Yields

In field plot experiments conducted in southern Alberta over a 6-yr period, highest seed yields of alfalfa (Medicago sativa L. cv. Beaver) were obtained with one or two irrigations in the first half of the growing season. In outdoor lysimeters protected from rain, moisture stress for more than 8 days before seed ripening severely reduced seed production. Under field conditions, stored soil moisture from irrigation during the vegetative stage of growth plus occasional rain in July and August permitted irrigation of alfalfa for seed to be stopped at the bud to early bloom stage (June to early July).

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.

Increased seed production of subterranean clover pastures in response to fertilizers supplying calcium

1974 ◽  
Vol 14 (71) ◽  
pp. 749 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Seed Production ◽  
Calcium Concentration ◽  
Field Experiments ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Unit Weight ◽  
Gypsum Plaster ◽  
Total Seed ◽  
Seed Yields

The effects of four common fertilizers containing calcium on seed production in subterranean clover (Trifolium subterraneum) were measured at six locations over five years in a total of fifteen field experiments. Calcium as a sulphate, carbonate or phosphate salt was applied to subterranean clover pastures either at the start of the growing season (autumn) or at flowering (spring). Gypsum, plaster of Paris, or lime gave large increases in seed yield per unit area and also per unit weight of tops. Spring applications of superphosphate increased seed yields in only two out of four experiments. Gypsum applied in spring at 200-500 kg ha-1 was as effective as 2,000 kg ha-1 of lime applied in autumn. Applications of lime in spring were much less effective. Increased seed yields were due to increases in burr yield, seed number per burr, and mean weight per seed. They were usually accompanied by increases in calcium concentration in the seed. Responses in seed production to calcium applications were obtained in all three sub-species of Trifolium subterraneum. In two experiments, newly sown on a soil type on which subterranean clover regeneration and persistence is commonly very poor, applied calcium doubled or quadrupled seed set. In 13 experiments using soils on which subterranean clover had persisted as the major component of the pasture for several years, calcium in the year of application increased the total seed bank by 6 to 31 per cent, and the current seed set by a greater amount.

Seed production and persistence of Carnamah and other early strains of Trifolium subterraneum in the wheatbelt of Western Australia

1967 ◽  
Vol 7 (24) ◽  
pp. 25 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Early Flowering ◽  
The Other ◽  
Factors Affecting ◽  
Seed Yields

Seed production and persistence of the Carnamah, Northam A, Dwalganup, and Geraldton strains of subterranean clover (Trifolium subterraneum L.) were examined in undefoliated swards in the wheatbelt of Western Australia. The early flowering characteristic of Carnamah was not always associated with higher seed yields. Only when there was a well-defined, early finish to the growing season, or when flowering was very much earlier in Carnamah (viz., following an early 'break' to the season), did this strain clearly outyield both Northam A and Geraldton. The seed yield of Dwalganup was generally inferior to that of the other strains. Factors affecting regeneration are discussed. Under low rainfall conditions, poorer germination-regulation of Carnamah, compared with Geraldton and Northam A, would be expected to result in poorer persistence unless offset by higher seed yields in the Carnamah strain.

Effects of phosphorus on seed yields of subterranean clover, serradella and annual medics

1985 ◽  
Vol 25 (3) ◽  
pp. 595 ◽  
Author(s):  
MDA Bolland
Keyword(s):  
Seed Yield ◽  
Subterranean Clover ◽  
Average Weight ◽  
The Third ◽  
Hard Seeds ◽  
Annual Medics ◽  
Alternating Temperature ◽  
Seed Yields ◽  
The Relationship ◽  
Number Of Seeds

In three experiments located near Esperance, Western Australia, the effect of superphosphate phosphorus on seed yields of subterranean clover, serradella and annual medics was measured on newly-cleared soils, using low seeding rates. In two experiments, the relationship between seed yield and the amount of phosphorus applied was linear for subterranean clover and serradella; seed yields increasing by 7-24 kg/ha for each kg/ha of phosphorus applied, depending on species, strain or cultivar, and location. In the third experiment, seed yields of annual medic species also increased markedly with increasing amounts of applied superphosphate phosphorus, this response also depended on species and strain or cultivar, but the responses become less marked with increasing amounts of phosphorus. For the annual medic species, the phosphorus treatments had no effect on average weight of one burr, number of seeds per burr, weight of one seed, or the rate of softening of hard seeds as measured both in a 15/60� alternating temperature oven (one cycle/day) or for samples of burrs collected periodically during summer from the field. For all legumes, the appearance of first flowers was not affected by phosphorus treatment.

Responses of serradella and subterranean clover to phosphorus from superphosphate and Duchess rock phosphate

1985 ◽  
Vol 25 (4) ◽  
pp. 902 ◽  
Author(s):  
MDA Bolland
Keyword(s):  
Rock Phosphate ◽  
Phosphorus Content ◽  
Subterranean Clover ◽  
Fertilizer Application ◽  
Sampling Time ◽  
Eastern Australia ◽  
North Eastern ◽  
Herbage Yield ◽  
Seed Yields ◽  
The Relationship

The responses of yellow serradella, slender serradella and subterranean clover to phosphorus from superphosphate and an apatite rock phosphate from Duchess, north-eastern Australia, were measured in a field experiment near Esperance, W.A. Over the 16 months of the experiment, dry herbage yields depended upon the phosphorus content of dried herbage. For each sampling time, the relationship between dry herbage yield and the phosphorus content of dried herbage was similar for both fertilizers and for all three species. At each rate of fertilizer application, the amount of phosphorus absorbed by the plants from the rock phosphate was less than that from superphosphate, and this limited yield. When fertilized with superphosphate, subterranean clover absorbed less phosphorus than the serradellas for each rate of fertilizer application, and this also reduced yield. Thus less phosphorus from superphosphate was required to produce serradella than was required to produce the same weight of subterranean clover. When fertilized with rock phosphate, 1982 herbage production was in the order: yellow serradella> subterranean clover>slender serradella. 1982 seed yields were: subterranean clover>yellow serradella> slender serradella. 1 983 herbage yields were: slender serradella>yellow serradella> subterranean clover. For herbage yields, for each rate of fertilizer application, this order was also dictated by the amount of phosphorus absorbed by each of the three species.

The evaluation of dual-purpose groundnut (Arachis hypogaea) varieties for fodder and seed production at Shika, Nigeria

2001 ◽  
Vol 136 (1) ◽  
pp. 75-79 ◽  
Author(s):  
A. T. OMOKANYE ◽  
O. S. ONIFADE ◽  
P. E. OLORUNJU ◽  
A. M. ADAMU ◽  
R. J. TANKO ◽  
...  
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Crude Protein ◽  
Production Systems ◽  
Forage Yield ◽  
Dual Purpose ◽  
Whole Plant ◽  
Seed Yields ◽  
The Relationship ◽  
Forage Yields

At Shika in a subhumid environment of Nigeria, a 3-year study was carried out to select newly developed groundnut varieties for use in crop–livestock production systems. The study examined 11 groundnut varieties. Emergence time, plant stands at full emergence, forage and seed yields and yield components were examined. Whole plant samples were analysed for crude protein (CP) content. Varieties ICGV 87123 gave the lowest forage yield and cultivar M517-80I, the highest, with seven varieties recording forage yields above 5 t/ha. The CP content of forage was lowest (14·8%) for variety M576-80I and highest (21·6%) for variety M554-76. Mean seed yield (over 3 years) varied significantly from 0·73 to 1·68 t/ha. Only two varieties had mean seed yield >1 t/ha. The relationship between seed and forage yields was positive and significant (r = 0·529, P < 0·006). Varieties RMP 12, 88-80I and M517–80 were most promising for both forage and seed production.

The effects of frosts on seed production in subterranean clover (Trifolium subterraneum)

1971 ◽  
Vol 11 (49) ◽  
pp. 202 ◽  
Author(s):  
WR Scott
Keyword(s):  
New Zealand ◽  
Seed Production ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
The Past ◽  
Seed Yields

Six cultivars of subterranean clover, Geraldton, Yarloop, Woogenellup, Clare, Mount Barker, and Tallarook, were grown as ungrazed swards at 1,700 feet a.s.1. in the Mackenzie Country of South Canterbury, New Zealand. In this very frosty environment seed yields tended to increase with increasing lateness of flowering although Clare and perhaps Tallarook appeared to be more frost susceptible than the other cultivars. It is suggested that the deleterious effects of frosts in reducing the seed yields of subterranean clover may have been overemphasized in the past and that the trend for seed yields to increase with increasing lateness of flowering can be partially explained by differences in runner production.

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