scholarly journals Forage seed production: 75 years applying science and technology

2006 ◽  
pp. 15-23
Author(s):  
M.P. Rolston ◽  
R.J. Chynoweth ◽  
A.V. Stewart
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Weed Species ◽  
Department Of Agriculture ◽  
Management Tools ◽  
Production History ◽  
The 1960S ◽  
Seed Crops ◽  
N Rates ◽  
Seed Yields

Forage seed (brassica, grass and legume species) is the delivery vehicle for new plant genetics to the pastoral sector. Seed production technology associated with the release of the first bred pasture cultivars in the 1930s was largely based around horse-drawn reaper and binders and stationary threshing machines. The development of authenticity and quality controls also started in the 1930s with the NZ Seed Certification Scheme. Management inputs were minimal with closing and harvest dates being the major tools available. Over a 75 year period, seed yields have increased, with top growers now achieving seed yields that are three times greater than those reported 50 to 75 years ago. In the 1950s, harvest mechanisation developed rapidly and in the 1970s on-farm seed drying was developed. The availability of nitrogen (N) fertiliser was the first major input available for grass seed growers. The paper follows the science and changing recommendations on N rates and the eventual maximum limit achieved by additional N identified in trials in 2004. From the 1960s onwards, new herbicides have allowed for the control of a wider range of difficult to control weed species, especially the control of other grasses in ryegrass seed crops and broadleaved weeds in white clover. New generation fungicides, insecticides and plant growth regulators have provided improved management tools for increased seed yields. The paper concludes with changes in extension from Government driven (Department of Agriculture) to farmer funded R&D and extension by the Foundation for Arable Research. Keywords: ryegrass, white clover, brassica, seed production, history

scholarly journals GRASS SEED PRODUCTION: WEEDS, HERBICIDES AND FERTILISERS

1985 ◽  
Vol 2 ◽  
pp. 15-22
Author(s):  
M.P. Ralston ◽  
K.R. Brown ◽  
M.D. Hare ◽  
K.A. Young
Keyword(s):  
Seed Production ◽  
Stem Elongation ◽  
Grass Species ◽  
Wild Oat ◽  
Weed Species ◽  
Grass Seed ◽  
Prairie Grass ◽  
Seed Crops ◽  
Seed Yields ◽  
Bromus Mollis

Four weed species (Bromus mollis, Vulpia sp., Poa annua, Steltaria media) occur in 30% or more of all perennial ryegrass seed samples. Of the listed undesirable species, Avena fatua (wild oat) and Hordeum murinum occurred respectively in 5.3 and 3.5% of ryegrass seedlots. Only 6 herbicides are registered for use in grass seed crops in New Zealand, 2 for wild oat, and 4 for broadleaved weeds. The results of research on weed control in seedling and established seed crops (ryegrass, cocksfoot, tall fescue, phalaris, prairie grass) are presented. Fertilisers for grass seed crops discussed are nitrogen (N), phosphorus (P), potassium (K), lime and zinc. Autumn N is commonly used and will increase seed yields in early flowering species (Pestuca rubra, F. arundinacea), but in ryegrass variable results have occurred. Spring N should be applied at stem elongation. No responses to P have been reported for ryegrass, while in established cocksfoot responses to P and K have been reported. Overliming can induce Zn deficiencies, and of the grass species only prairie grass may require lime. Keywords: Lolium, ryegrass, seed production, weed occurrence, Bromus mollis, herbicides, fertilisers, nitrogen, phosphorus, potassium, lime, zinc

scholarly journals Maximising seed production potential in white clover: factors influencing seed set per floret

1996 ◽  
Vol 6 ◽  
pp. 41-44
Author(s):  
R.G. Thomas
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Management Practices ◽  
Seed Set ◽  
Head Development ◽  
Light Intensities ◽  
Ovule Sterility ◽  
Growing Conditions ◽  
High Level ◽  
Seed Yields

The causes of low seed set per floret in white clover (Trifolium repens L.) are reviewed. Three stages of flower head development are distinguished as important for a high level of seed set: a pre-fertilisation stage, a stage of anthesis leading to pollination, and a postfertilisation stage in which seed provisioning occurs. In sunny conditions the percentage seed set is limited at the pre-fertilisation stage by up to 20-30% ovule sterility. Relatively low light intensities during the postfertilisation stage can lead to abortion of a high proportion of fertilised ovules and developing seeds. Experimental results suggest that seed yields under optimal growing conditions can be limited solely by the level of pre-fertilisation ovule sterility and probably cannot be bettered, but further understanding of the seed-provisioning requirements for photosynthate could lead to improved management practices for seed production under conditions of lower light intensities. Keywords: abortion, light intensity, ovule, seed provisioning, sterility, white clover

Research in white clover seed production

1980 ◽  
Vol 1 ◽  
pp. 64-67
Author(s):  
P.T.P. Clifford
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Growth Rates ◽  
Plant Density ◽  
First Year ◽  
Production Plant ◽  
Closing Date ◽  
General Management ◽  
Clover Seed ◽  
Seed Yields

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.

scholarly journals Seed production issues that limit supplies or result in high market prices of dryland legume species

2003 ◽  
Vol 11 ◽  
pp. 161-167
Author(s):  
M.P. Rolston
Keyword(s):  
New Zealand ◽  
Seed Production ◽  
White Clover ◽  
Red Clover ◽  
High Price ◽  
Crop Failure ◽  
Market Prices ◽  
Dryland Crops ◽  
New Research ◽  
Seed Crops

A barrier to the adoption of many dryland legumes by grassland farmers is the lack of supply and/or the high price of seed. Growers face a number of problems in growing dryland legumes for seed, including a high risk of crop failure; alternatives such as wheat, barley and perennial ryegrass seed are lower risk crops. Gross margins for legume seed crops (including white clover) indicate that they have low profitability, at present prices if yields are average. Pollination remains a serious limitation to production, especially for dryland crops that are not well pollinated by honeybees. Both internationally and in New Zealand there has been a major decline in seed production research in the last decade, and little new research has been published on seed production of a range of dryland legumes. Seed production issues limiting yield in a range of dryland seed crops in New Zealand are identified. The paper concludes with suggestions that may help overcome some of these limitations. Key words: economics, lucerne, production constraints, red clover, white clover

scholarly journals Relationship between Sitona lepidus larval numbers and white clover seed production

2001 ◽  
Vol 54 ◽  
pp. 141-146
Author(s):  
P.J. Gerard
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Trifolium Repens ◽  
Negative Impact ◽  
Early Flowering ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Second Year ◽  
Clover Seed ◽  
Seed Crops

Plots of two cultivars of white clover (Trifolium repens) Grasslands Prestige (smallleaved early flowering) and Grasslands Kopu (largeleaved later flowering) were established in coldframe beds Clover root weevil (Sitona lepidus) larval numbers were manipulated to obtain winter larval densities ranging from 0 to over 1000/m2 Increasing winter larval densities increased Prestige seed production (g/m2) when harvested on 28 December and 10 January and the trend was still evident on 24 January No such relationships were found in Kopu for the early and middle harvests but at the late harvest increasing winter larval densities had a negative impact on seed production The results indicate that the effect of clover root weevil larvae on second year clover seed crops may vary substantially between cultivars and may even be positive rather than negative

scholarly journals Phalaris and tall fescue seed production: Volunteer control and herbicide tolerance

1999 ◽  
Vol 52 ◽  
pp. 214-217
Author(s):  
K. Reddy ◽  
M.P. Rolston ◽  
W.J. Archie
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Tall Fescue ◽  
Untreated Control ◽  
Herbicide Tolerance ◽  
Good Tolerance ◽  
Phalaris Aquatica ◽  
Second Year ◽  
Seed Crops ◽  
Seed Yields

Experiments in grass seed crops investigated the control of volunteers in phalaris (Phalaris aquatica) and tolerance of phalaris seed crops to four herbicides and tall fescue (Festuca arundiacea) to eight herbicides. Atrazine at 2040 g/ha gave 94% control of volunteer phalaris and both atrazine at 2040 g/ha and ethofumesate at 2000 g/ha showed good tolerance with phalaris seed yields of 760 and 750 kg/ha compared to untreated control which had a seed yield of 620 kg/ha. Tall fescue seed yields showed good tolerance to terbuthylazine at 750 g/ha, prodiamine at 65 g/ha, chlorpropham at 1200 g/ha, diuron at 1800 g/ha and oxyflurofen at 288 g/ha with seed yields of 2580-2730 kg/ha compared to untreated of 2200 kg/ha. In the second year, burn treatments with metolachlor at 1920 g/ha gave 88 % volunteer control with a seed yield of 1380 kg/ha compared with untreated control of 1090 kg/ha.

scholarly journals MIRlDS IN 'GRASSLANDS MAKU' LOTUS SEED CROPS: FRIENDS OR FOES?

1983 ◽  
pp. 42-46
Author(s):  
P.T.P. Clifford ◽  
J.A. Wightman ◽  
D.N.J. Whitford
Keyword(s):  
Key Words ◽  
Seed Production ◽  
Seed Yield ◽  
Pod Shattering ◽  
Lotus Seed ◽  
Lotus Pedunculatus ◽  
Seed Crops ◽  
Seed Yields ◽  
Insecticide Control

The need for mirid (Calocoris norvegicus Gmel.) control to improve seed yields of 'Grasslands Maku' lotus seed crops was studied over two seasons on a crop near Lincoln, Canterbury. In 1980 seed yields were increased by 40% to 850 kg/ha by the application of bromophos (500 g a.i./ha) in mid-December to remove a population of 30 mirids/20 net sweeps. In 1981, demetonb-methyl (200 g a.i./haj was applied along with a water only control in mid-November, followed by a blanket spray of bromophos in mid-December. There were two separate effects resulting from the use of metasystox. Although demetondmethyl protection gave a higher seed yield/stem for early-formed flowerheads the pattern was reversed for the later-formed flowerheads because early mirid attack increased flowerhead numbers/stem. Laterformed umbels gave a more concentrated span of flowering, which enhanced better timing of harvest of this crop which is prone to pod shattering. The recommendation is to control mirids only in mid-December using bromophos. an insecticide that is relatively bee safe. Key Words: Seed production, Lotus pedunculatus, mirids, Calocoris norvegicus, insecticide control

Experimental studies on seed production of tropical grasses in Kenya. 5. The effect of time of nitrogen top dressing on seed crops of Setaria sphacelata cv. Nandi.

1972 ◽  
Vol 20 (4) ◽  
pp. 225-231
Author(s):  
J.G. Boonman
Keyword(s):  
Adverse Effect ◽  
Seed Production ◽  
Rainy Season ◽  
Seed Set ◽  
Experimental Studies ◽  
Late Season ◽  
Main Adverse Effect ◽  
Setaria Sphacelata ◽  
Seed Crops ◽  
Seed Yields

Effects of date of applying top-dressings of N to early-season and late-season seed crops of Setaria sphacelata cv. Nandi were studied in 4 trials in 1967-71. Highest seed yields were obtained when N was applied as soon as possible after the onset of the rainy season; a delay of 4 weeks reduced yields of pure germinating seed by >60%. Total yields of herbage DM and number of heads were also reduced, but to a lesser extent; the main adverse effect was on seed set/head. In late-season crops, applying N 2 weeks after the earliest possible date proved beneficial in 2 out of 3 years. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Effects of site of seed production on seed yields and regrowth of progeny tubers in potatoes

1986 ◽  
Vol 107 (1) ◽  
pp. 83-101 ◽  
Author(s):  
P. J. O'Brien ◽  
E. J. Allen
Keyword(s):  
Seed Production ◽  
Tuber Yield ◽  
Important Determinant ◽  
Potato Production ◽  
Practical Significance ◽  
Maximum Effect ◽  
Field Growth ◽  
Seed Crops ◽  
Seed Yields ◽  
Commercial Harvesting

SUMMARYNine experiments are reported in which effects of site of seed production on dormancy, sprout and field growth of progeny tubers were recorded. The experiments used early varieties, Home Guard (four experiments), Red Craigs Royal (three experiments) and Arran Comet (two experiments) and in each, seed crops were grown with similar husbandry at sites differing in altitude and location in western England and Wales. There was no consistent effect of site of seed production on the timing of the end of dormancy, and the maximum effect in any year was 11 ± 1·2 (S.E.) days. The small effects of site on dormancy influenced initial sprout lengths, and this effect usually persisted up to planting in Home Guard and Red Craigs Royal, although the effects were small in magnitude. There was no effect of site of seed production on sprout lengths at planting or on field growth and yields in Arran Comet. In the other two varieties there was no effect of site of seed production on yield at early harvests, but at later harvests seed from cooler upland sites sometimes significantly outyielded lowland seed. There was, therefore, no evidence to support the view that locally produced seed was advantageous for early potato production. The results, together with those of the concurrent series with maincrop varieties reported by Wurr (1979), show that on half the occasions on which yields were measured covering the whole of the harvesting period, site of seed production had no effect on yields. In these experiments with early varieties effects of site occurred only at harvests later than the commercial harvesting of such old seed. It is therefore suggested that site of seed production is a much less important determinant of tuber yield than hitherto suggested, and of little practical significance.

scholarly journals Chicory seed production: research and practice

1990 ◽  
pp. 91-94
Author(s):  
M.D. Hare ◽  
J.S. Rowarth ◽  
W.J. Archie ◽  
M.P. Rolston ◽  
B.R. Guy
Keyword(s):  
New Zealand ◽  
Seed Production ◽  
Seed Development ◽  
Herbicide Tolerance ◽  
Cichorium Intybus ◽  
Average Yield ◽  
Research And Practice ◽  
Production Research ◽  
Seed Crops ◽  
Seed Yields

'Grasslands Puna' chicory (Cichorium intybus L.) has been harvested for seed in New Zealand since 1984. Seed yields have ranged from 0 to over 700 kg/ha with an average yield of around 200 kg/ha. Data from Manawatu and Canterbury trials were combined with information gained from monitoring 25 Puna seed crops in Canterbury. Results from work on establishment, time of closing, seed development, response to nitrogen, herbicide tolerance and methods of harvesting are reported, and differences between Manawatu and Canterbury in terms of management of Puna seed crops are highlighted. Keywords: chicory, seed production

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