Seed production in Brachiaria decumbens and Paspalum plicatulum as influenced by system of residue disposal

1987 ◽  
Vol 38 (5) ◽  
pp. 869
Author(s):  
WW Stnr ◽  
LR Humphreys
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Nitrogen Supply ◽  
Floral Initiation ◽  
Spikelet Number ◽  
Brachiaria Decumbens ◽  
Short Day ◽  
Cotton South ◽  
Defoliation Treatment

Long-established swards of Brachiaria decumbens cv. Basilisk and of Paspalum plicatulum cv. Rodds Bay at Mt Cotton, south-east Queensland, were cut, field dried and burnt, or cut and the residues removed in late November or early January. Burning initially reduced tillering, especially when the interval between cutting and burning was 7 days, but this difference disappeared in P. plicatulum when there was a long interval to floral initiation. A juvenility requirement was evident in the short day P. plicatulum swards, where late burning or cutting delayed floral initiation 11 days relative to early defoliation. Strong compensatory and hierarchical effects on the components of seed yield occurred, and seed yield was similar in cut or burnt treatments, except for 23% decrease in late cut P. plicatulum. Late defoliated B. decumbens yielded 31% more seed than early defoliated swards, due mainly to reduced spikelet number per raceme (branch). Burning slightly increased synchrony of inflorescence exsertion in P. plicatulum and reduced crop lodging, although in a subordinate experiment with P. plicatulum lodging was positively related to level of nitrogen supply rather than to defoliation treatment.

Effect of tiller age and time of nitrogen stress on seed production of Paspalum plicatulum

1973 ◽  
Vol 81 (2) ◽  
pp. 219-229 ◽  
Author(s):  
P. A. Chadhokar ◽  
L. R. Humphreys
Keyword(s):  
Ammonium Nitrate ◽  
Seed Size ◽  
Seed Yield ◽  
Growth And Development ◽  
Nitrogen Nutrition ◽  
Development Stage ◽  
Nitrogen Supply ◽  
Nitrogen Stress ◽  
Floral Initiation ◽  
Final Maturation

SummaryPaspalum plicatulum was grown at Brisbane in boxes of sand receiving basal nutrients and frequent irrigation; weekly levels of ammonium nitrate application were varied according to growth and development stage.The rate of tiller appearance increased to a maximum 40–50 days after sowing and almost ceased thereafter. Tiller leaf number, survival, fertility, inflorescence branching, seeds per raceme and seed size were positively related to tiller age. Young tillers were more sensitive to variations in nitrogen supply than old tillers.Adequate nitrogen nutrition during the vegetative phase from sowing to floral initiation (93 days) increased tiller and hence inflorescence density; increased inflorescence branching was compensated by fewer seeds per raceme. Good nitrogen nutrition during the phase from floral initiation to inflorescence exsertion (142 days) increased survival of late-formed tillers and hence inflorescence density; inflorescence branching, seeds per raceme and seed size were also increased. Nitrogen stress during the final maturation phase did not affect seed yield.

Influence of time and level of urea application on seed production of Paspalum plicatulum at Mt. Cotton, south-eastern Queensland

1973 ◽  
Vol 13 (62) ◽  
pp. 275 ◽  
Author(s):  
PA Chadhokar ◽  
LR Humphreys
Keyword(s):  
Podzolic Soil ◽  
Nitrogen Concentration ◽  
Seed Viability ◽  
Moisture Stress ◽  
Early Summer ◽  
Nitrogen Supply ◽  
Floral Initiation ◽  
Plant Nitrogen ◽  
Cotton South ◽  
Tiller Density

Five levels of urea were applied as single or split dressings in early summer, at floral initiation (about Febraury 14), or at inflorescence exsertion to Paspalum plicatulum cv. Rodds Bay grown in rows on a red-yellow podzolic soil. All components of seed yield-tiller density, tiller fertility, raceme number and seed number, and seed size-were influenced by external nitrogen supply. The effects of adequate nitrogen supply during one development phase usually persisted subsequently when differences in plant nitrogen concentration had disappeared. Nitrogen applications during the vegetative and floral initiation stages were most influential. The efficiency of response varied from 5.6 kg additional crude seed produced per kg N at the 50 kg N ha-1 level to 1.2 at the 400 kg N ha -1 level. High levels of urea (200 or 400 kg N ha-1) induced lodging and poor recovery of seed at harvest during a wet year, accentuated moisture stress during a dry year, but improved seed viability.

The influence of nitrogen nutrition of Desmodium uncinatum on seed production

1973 ◽  
Vol 24 (5) ◽  
pp. 667 ◽  
Author(s):  
TA Gibson ◽  
LR Humphreys
Keyword(s):  
Ammonium Nitrate ◽  
Seed Production ◽  
Seed Yield ◽  
Nitrogen Nutrition ◽  
Floral Initiation ◽  
Plant Nitrogen ◽  
Development Stages ◽  
Whole Plant ◽  
Initiation Stage ◽  
Nitrogen Demand

Desmodium uncinaium cv. Silverleaf was grown in simulated swards well supplied with water and basal nutrients. Nodulated control swards yielded 179 g m-2; whole plant nitrogen accretion was 25 g m-2. The rate of nitrogen uptake decreased during seed maturation and redistribution of nitrogen from leaf, stem, and raceme was inadequate to meet the nitrogen demand of maturing seeds. Ammonium nitrate applied at 16.9 kg nitrogen ha-1 wk-1 from the immediate pre-floral initiation stage or at later development stages increased seed yield by 21 to 31 % according to timing. Applied nitrogen increased the number of racemes differentiated per runner and the size of seeds, and decreased the number of seeds formed per floral node. Components of seed yield such as raceme number per runner, floral nodes per raceme, seeds per node, and seed weight were influenced by position on the plant. The greater part of the ammonium nitrate response was due to increased seed production from the secondary racemes on the larger primary runners.

The effect of defoliation on flowering and seed yield in subterranean clover

1973 ◽  
Vol 24 (2) ◽  
pp. 211 ◽  
Author(s):  
MW Hagon
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Subterranean Clover ◽  
Early Flowering ◽  
Floral Initiation ◽  
Leaf Appearance

The effect of defoliation on flowering and seed production in Woogenellup subterranean clover was studied under sward conditions. Defoliation prior to floral initiation (FI) delayed this event but did not alter the time from sowing to flowering compared with the undefoliated control. However, defoliation between FI and flowering reduced the time from sowing to flowering by 10 days. These findings are discussed in relation to the changes in rates of leaf appearance which resulted from defoliation. Defoliation of the plots either before FI, after FI, or at early flowering did not alter seed yield or any of its components.

scholarly journals Improvement of annual forage and seed production in the sub-humid zone of Nigeria through supplement irrigation

1990 ◽  
Vol 62 (1) ◽  
pp. 63-75
Author(s):  
J. O. Akinola ◽  
A. A. Addo ◽  
K. C. Olufokunbi
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Crude Protein ◽  
Dry Matter ◽  
Experimental Period ◽  
Pennisetum Purpureum ◽  
Brachiaria Decumbens ◽  
Dual Purpose ◽  
Northern Guinea Savanna ◽  
Forage Species

A two-year study was conducted at Shika in the Northern Guinea Savanna of Nigeria to evaluate several perennial and annual forage species for seasonal and total annual herbage and/or seed production. Over the entire experimental period, total dry matter (DM) yields for grasses, perennial and hay-suited annual legumes varied from 27.5 to 79.1, 18.8 to 40.3 and 40.5 to 50.5 t/ha, to which irrigation contributed 48 to 66, 50 to 57 and 56 % respectively. Irrigated grass crude protein (CP) contents averaged 5.3 and 9.9 %; and legume CP contents 16.1 and 18.8 % for the May and December harvests while rainfed grass CP contents ranged from 7.7 % (August) to 10.9 % (October), the corresponding legume values being 18.7 and 20.9 %. Irrigated cropping accounted for 55 to 56 % of the 9 207 to 12 461 kg/ha seed yield recorded in dual purpose legumes. It was inferred that on the basis of total herbage yield, distribution of yield and responsiveness to irrigation Pennisetum purpureum, Brachiaria decumbens, Cajanus cajan Acc UQ 50 or 3D 8104 and S. guianensis cv Cook proved to be promising; reasonable seed yield levels were obtained from C. cajan 3D 8104, Glycine max Acc. 49-14 and M 216 and Vigna unguiculata Acc Ivu 1283, whether irrigated or rainfed. The potential of irrigation is discussed in relation to feed, food and livestock production.

scholarly journals Effects of stage of defoliation on seed production and growth of Stylosanthes humilis

1970 ◽  
Vol 10 (46) ◽  
pp. 577 ◽  
Author(s):  
DS Loch ◽  
LR Humphreys
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Seed Size ◽  
Seed Yield ◽  
Seed Set ◽  
Leaf Growth ◽  
Floral Initiation ◽  
Stylosanthes Humilis ◽  
Poor Seed ◽  
Defoliation Treatment

Stylosanthes humilis swards grown at Brisbane in irrigated boxes were defoliated (about 60 per cent removal of tops) at floral initiation, first flower appearance, or advanced flowering stages ; seed yield was 45, 16, and 14 per cent respectively of seed yield in undefoliated swards. Decreased yields were primarily due to poor seed set of florets, were also associated with reduced inflorescence density and floret number per inflorescence, and occurred despite increases (in some defoliation treatments) in seed size, leaf growth rate, and differentiation of leaves and branches. Total seasonal plant growth was independent of defoliation treatment.

scholarly journals Paclobutrazol Improves Sesame Yield by Increasing Dry Matter Accumulation and Reducing Seed Shattering Under Rainfed Conditions

2021 ◽  
Author(s):  
Muhammad Zeeshan Mehmood ◽  
Ghulam Qadir ◽  
Obaid Afzal ◽  
Atta Mohi Ud Din ◽  
Muhammad Ali Raza ◽  
...  
Keyword(s):  
Leaf Area ◽  
Seed Production ◽  
Seed Yield ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
Total Biomass ◽  
Dry Matter Accumulation ◽  
Seed Shattering ◽  
Rainfed Conditions ◽  
Leaf Greenness

AbstractSeveral biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L−1, P2 = 200 mg L−1, P3 = 300 mg L−1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L−1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.

Increase Longleaf Pine Seed Yields by Inhibiting Conelet Abortion

1987 ◽  
Vol 11 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Robert C. Hare
Keyword(s):  
Boric Acid ◽  
Seed Production ◽  
Seed Yield ◽  
Longleaf Pine ◽  
Foliar Spray ◽  
Seed Yields

Abstract A single foliar spray with either antiethylene compounds or cytokinins shortly after anthesis reduced conelet abortion by half and doubled seed production. Spraying with boric acid plus Cytex® , a relatively economical form of cytokinin derived from seaweed, was equally effective,and addition of certain antiethylene compounds further improved seed yield. South. J. Appl. For. 11(1):6-9.

Interference and Seed Production by Common Lambsquarters (Chenopodium album) in Soybeans (Glycine max)

Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 113-118 ◽  
Author(s):  
S. Kent Harrison
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Chenopodium Album ◽  
Soybean Seed ◽  
Dry Weight ◽  
Threshold Level ◽  
Yield Reduction ◽  
Significant Treatment ◽  
Weed Biomass ◽  
Common Lambsquarters

Multiple regression and response surface plots were used to analyze the effects of common lambsquarters population density and interference duration on weed growth and soybean seed yield. Under favorable growing conditions in 1986, weed biomass production at all population densities and interference durations was four to five times that produced in 1987, under less favorable conditions. However, there was no significant treatment by year interaction for soybean seed yield reduction by common lambsquarters, and production of each kg/ha weed biomass resulted in an average soybean yield reduction of 0.26 kg/ha. Utilizing 5% yield loss as an arbitrary threshold level, the regression equation predicted a common lambsquarters density threshold of 2 plants/m of row for 5 weeks of interference after crop emergence and 1 plant/m of row for 7 weeks. Seed production by individual common lambsquarters plants was highly correlated (r=0.92) with weed dry weight, and seed production ranged from 30 000 to 176 000 seeds/plant.

INFLUENCE DES CULTIVARS ET DES STADES DE PRÉLÈVEMENT DE LA PREMIÈRE POUSSE SUR LA PRODUCTION DE SEMENCE DE TRÈFLE ROUGE

1990 ◽  
Vol 70 (4) ◽  
pp. 1071-1080 ◽  
Author(s):  
LUCIUS BELZILE
Keyword(s):  
Seed Germination ◽  
Seed Production ◽  
Seed Yield ◽  
Trifolium Pratense ◽  
Red Clover ◽  
Kernel Weight ◽  
Climatic Conditions ◽  
Cultivar Group ◽  
Stage Of Development ◽  
Clover Seed

For five years, the effect of cultivars and vegetative stage of cutting were measured on red clover (Trifolium pratense L.) seed production. The first group of cultivars included Hungaropoli, Ottawa and Lakeland harvested in 1981 and 1982. The second group included Arlington, Florex and Prosper I harvested in 1984, 1985 and 1987. The total annual seed yield differed within cultivars and the highest seed yield was obtained with Hungaropoly and Florex. In the first cultivar group, the tetraploid Hungaropoly obtained a kernel weight higher than the diploids Lakeland and Ottawa. In the second group of cultivars, all diploids, Arlington yielded the highest kernel weight. The percentage of seed germination of Hungaropoly was higher than Lakeland and Ottawa while for Florex it was slightly higher than Arlington and Prosper I. A prior vegetative cutting is essential for good seed yield. In the absence of vegetative cutting seed weight seemed improved. The stage of development at which vegetative cutting is done has little influence on percentage seed germination. These results have shown that despite the strong effect of climatic conditions on seed production, the choice of the optimum stage for vegetative cutting and a well adapted cultivar are important aspects in successful seed production.Key words: Red clover, seed production, cultivar, stage of cutting

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