YORKSHIRE FOG SEED PRODUCTION 1. Effects of closing date, nitrogen application and harvest date on seed yield and its components

Author(s):  
M.J. Hill ◽  
R.J. Clements ◽  
B.R. Watkin

Seed production by 'Massey Basyn' Yorkshire fog (Holcus lanatus L.) was greatest (mean 323 kg/ha) with early closing (June 30), but lodging occurred on these plots and commercial harvesting would be difftcult. With later closing (July 31 and August 31), lodging did not occur and average yields of about 250 kg/ha were obtained. Very late closing (September 30) resulted in a severe yield depression. Application of nitrogen fertilizer either at closing or at inflorescence initiation increased seed yields by an average of 30%. Peak seed yields occurred later at harvest time as closing was delayed. With the optim8um combination of treatments, yields of 400 kg/ha were achieved and it is suggested that yields of at least 200 kg/ha could be obtained commercially.

1987 ◽  
Vol 11 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Robert C. Hare

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.


2003 ◽  
Vol 83 (1) ◽  
pp. 189-197 ◽  
Author(s):  
W. E. May ◽  
H. A. Loeppky ◽  
D. C. Murrell ◽  
C. D. Myhre ◽  
J. J. Soroka

Preharvest applications of glyphosate have been shown to be effective in controlling Canada thistle in annual crops, but may reduce alfalfa seed yield depending on time and rate of application. The objective of this study was to determine the effect of preharvest applications of glyphosate on subsequent alfalfa seed yield and quality. The effects of timing, 1, 26, 51 and 76% alfalfa seed pod maturity, and rate, 0, 440, 880, 1320, and 1760 g a.i. ha-1, of a preharvest application of glyphosate on alfalfa seed yield and quality in the year of application, and regrowth and seed yield in the following year were determined. The rate of glyphosate applied did not affect seed yield in the application year; however, in the following year, growth and seed yield were reduced as rates increased. Delaying the application of glyphosate increased seed yields in the application year, but decreased alfalfa regrowth and flowering the following year. Germination and seedling emergence were not affected by the rate or timing of the glyphosate. A preharvest application of glyphosate at 1760 g a.i. ha-1 at 76% pod maturity is a viable option in the last year of seed production. Key words: Alfalfa (Medicago sativa L.), glyphosate, abnormal seeds, seed quality, and seedling vigour


2004 ◽  
Vol 84 (3) ◽  
pp. 791-793 ◽  
Author(s):  
H. T. Kunelius ◽  
K. B. McRae ◽  
G. H. Dürr ◽  
S. A. E. Fillmore

Seed production, plant characteristics and herbage regrowth of three cultivars of Westerwolds ryegrass (Lolium multiflorum Lam.) were determined during 3 production years. Ryegrass was fertilized with nitrogen at 60, 90 and 120 kg ha-1 applied either all at the two- to three-leaf stage or split (3:2) between the two- to three-leaf stage and stem elongation. Seed yield of three cultivars ranged from 742 to 1440 kg ha-1. Nitrogen fertilizer at 90 kg ha-1 resulted in near maximum seed yields. Single and split applications of nitrogen resulted in similar seed yields. Density of fertile tillers ranged from 541 to 911 m-2 among the cultivars and responded linearly to applied N. A positive relationship was detected between the density of fertile tillers and seed yield. Herbage in aftermath averaged 2280 kg ha-1 dry matter, 125 g kg-1 crude protein, 597 g kg-1 neutral detergent fibre and 344 g kg-1 acid detergent fibre. Key words: Lolium multiflorum, Westerwolds ryegrass, nitrogen fertilizer, seed, tiller, spikelet, herbage, herbage composition


1967 ◽  
Vol 7 (24) ◽  
pp. 25 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter

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.


2001 ◽  
Vol 136 (1) ◽  
pp. 75-79 ◽  
Author(s):  
A. T. OMOKANYE ◽  
O. S. ONIFADE ◽  
P. E. OLORUNJU ◽  
A. M. ADAMU ◽  
R. J. TANKO ◽  
...  

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.


1988 ◽  
Vol 110 (3) ◽  
pp. 455-463 ◽  
Author(s):  
P. S. Cocks

SummaryThree experiments which measured seed production and seed survival of annual medics (Medicago spp.) were conducted at Tel Hadya in north Syria. In Expts 1 and 2, conducted in consecutive years, the effects of rate and date of sowing on seed yield and its components were measured, while in Expt 3, the residual seed under summer grazing was monitored. In all three experiments seed permeability was observed at frequent intervals in summer and autumn. Selected ecotypes of three native medics (Medicago rigidula (L.) All., M. rotata Boiss. and M. noeana Boiss.) were compared with cultivars of M. truncatula Gaertn. and M. polymorpha (L.).Seed production was greatest at sowing rates of 20–40 kg/ha. The native species produced more seed (up to 1000 kg/ha) than the cultivars (less than 500 kg/ha), although not significantly so in the case of the late-flowering ecotype of M. noeana. Seed yields of 500–1000 kg/ha were considered to be sufficient to perpetuate the pastures, but even higher seed yields are desirable.Seed yield was closely related to number of pods in all ecotypes and, in Expt 2, up to 95% of flowers failed to produce mature pods. Flowers were more likely to mature at high sowing rate (256 kg/ha), in striking contrast to flower production itself which was greatest at sowing rates of less than 30 kg/ha. Flowers produced early in the season (before mid-April) were far more likely to give mature pods than late-produced flowers.In late October, seeds of the native species were less permeable (10%) than those of the cultivars (30%), although their permeability was similar to that of the cultivars in Australia. In the three experiments the seasonal pattern of permeability varied, although there was a tendency for seeds to gain permeability in autumn. In Expt 1 there was a strong suggestion that the change from impermeability to permeability was reversible.Ewes grazing mature pods gained weight, apparently as long as pod availability exceeded 10 kg/ha. It was clear that the condition of ewes was not a good guide to appropriate stocking rate for persistence of pastures, and that farmers will have to use other methods to assist them in grazing management.


1996 ◽  
Vol 76 (3) ◽  
pp. 435-439 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya ◽  
J. Fraser ◽  
K. W. Richards ◽  
N. Foroud

Recommendations for desiccation of alfalfa do not clearly define the stage at which desiccants should be applied. To obtain this information, diquat and glufosinate were applied to alfalfa (Medicago sativa L) from 1991 to 1994 at various stages of maturity to determine the effect of desiccant and stage of maturity at desiccation on seed yield 1000-seed weight and seed germinability. Alfalfa seed yields, 1000-seed weights, percent germination and percent viable seed were similar after desiccation with diquat and glufosinate. Desiccation when 60–75% of the alfalfa seed pods were brown permitted maximum seed yields. Percent germination increased slightly in seeds that were exposed to weathering under normal conditions until all pods turned brown. Both desiccants adequately desiccated alfalfa for harvesting but desiccation with glufosinate took 2 or 3 d longer than diquat. Desiccants did not reduce alfalfa growth in the spring after application. Key words: Germination, yield, hard seed, seed weight, stage


1980 ◽  
Vol 1 ◽  
pp. 64-67
Author(s):  
P.T.P. Clifford

White clover seed yields from crops derived from pure autumn broadcast sowings harvested in the first year after sowing were improved by increasing sowing rate from 3 to 6 kg/ha. On moisture-retentive soils or where irrigation was available, mid-November closings gave highest seed yields for crops derived from either spring undersowings of cereals or as ryegrass mixtures taken for ryegrass seed in the first year from sowing. Closing a month earlier gave similar yields if 30 cm rather than 15 cm row spacings were used. Harvest should be no later than one month from main flowering to reduce the numbers of seedheads lost. General management should aim to promote good primary stolon growth rates over the month prior to mid-December if high flowerhead densities are to be obtained. Therefore excessive grazing before closing and poor timing of herbicide spraying for grass control should be avoided. Keywords: Trifolium repens, seed production, plant density, closing date, pollination, seed harvesting, management.


1990 ◽  
Vol 70 (3) ◽  
pp. 611-618 ◽  
Author(s):  
R. PINNISCH ◽  
P. B. E. McVETTY

Hybrid summer rape (Brassica napus L.) seed production blocks were established at two locations in Manitoba in 1986 and 1987 to examine the effect of distance from the pollen source on seed yield, (both total and hybrid) and percent hybridity of seed produced on rows of a male sterile line of the open pollinated population B. napus cultivar, Marnoo, possessing the pol cytoplasmic male sterility inducing cytoplasm. A 10:1 ratio of male sterile line (A-line) to pollen parent was employed. Leaf cutter bees (Megachile rotundata F.) were used as the pollen vector between the two parents. In 1986, no significant differences in total seed yield were found among A-line rows, while in 1987, significant differences in total seed yields of A-line rows were found. Differences in hybrid seed yields among A-line rows were significant for all locations and years. Leaf cutter bees were found to be effective pollinators of the A-line plants. Less than half and less than a third of the seed produced on the A-line rows in 1986 and 1987, respectively, was hybrid seed. The high percentage of non-hybrid seed present in the seed lot may have been due to incomplete male sterility of the Marnoo A-line population. Total seed yields, hybrid seed yields and percent hybridity all declined linearly as distance from the pollen source increased. Improvement in the degree of male sterility of the Marnoo A-line population and/or a reduction in the 10:1 ratio of parents, and subsequent maximum A-line row to R-line row distance, will be necessary if hybrid summer rape seed production using this pol CMS A-line is to be commercially viable.Key words: Brassica napus L., CMS, hybrid, hybridity


Author(s):  
Mary Abukutsa-Onyango ◽  

Slenderleaf is one of African Leafy Vegetables that has been grown and consumed in Kenya for a long time, its young leaves and shoots are used as a cooked vegetable. Slenderleaf acts as an agent to promote suicidal germination of Striga, a parasitic plant that is a major problem weed for maize and millet growers. One of the major constraints in its production has been poor quality seed and lack of technical packages for optimal production. Although slenderleaf has high germination percentage that occurs within 5 days, there is hardly any information on nitrogen nutrition and the longevity of slenderleaf seed and factors affecting them. The objectives of this study therefore were: to investigate the effect of nitrogen rates on growth, leaf and seed yield of Crotalaria brevidens and to study the effect of storage period on germinability of Crotalaria brevidens. Seeds of slenderleaf were obtained from Maseno University, Botanic garden and subjected to germination tests and then planted in the field in a well prepared seed bed at Maseno University experimental plots at a spacing of 30x30cm. The design of the experiment was RCBD with 6 treatments and three replications and each plot measured 1.5 x 2m. The treatments included six nitrogen rates (0, 10, 20, 40, 80 and 100 kg N per hectare). Measurements on plant height, number of leaves, number of branches and number of flowering plants were taken regularly. Seeds were harvested, processed and seed yield determined and the seeds from the various treatments were kept in airtight containers and stored at room temperature in September 2003. Germination tests were carried out by placing 50 seeds from each treatment randomly selected into a Petri-dish lined with a wet filter paper every 6 months commencing September 2003 for a period of two years and germination percentage determined. Results indicated that nitrogen rates did not have a significant (p>0.05) effect on growth, leaf and seed yields. Seed yields varied from 0.42 to 0.59 kg/m2. Nitrogen rates had no significant (p>0.05) effect on the germination percentage in the period of storage. In September 2003, the mean germination percentage was 96.8% while in September 2005 it was 95%. The findings of this study indicate that Nitrogen application may not always be necessary for growing slenderleaf and seed can be stored for 2 years without loss of germinability and viability


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