Chemical Manipulation of Grass Seed Crops

1985 ◽  
Vol 2 ◽  
pp. 9-14
Author(s):  
J.G. Hampton ◽  
T.G.A. Clemence ◽  
B.L. Mccloy
Keyword(s):  
Seed Yield ◽  
Perennial Ryegrass ◽  
Leaf Tissue ◽  
Yield Potential ◽  
Seed Abortion ◽  
Growth Retardants ◽  
Grass Seed ◽  
Poor Seed ◽  
Seed Crops ◽  
Seed Yields

The seed yield potential established at anthesis in grass seed crops is usually 5-10 times greater than actual seed yields realised at harvest. Losses in seed yield between anthesis and harvest result primarily from the death of fertile tillers and poor seed site utilisation. Lodging has been identified as one of the most important factors reducing seed yields, and the use of growth retardants has significantly increased seed yield in perennial ryegrass and tall fescue. The effects of the growth retardant paclobutrazol on the growth, development and seed yield of perennial ryegrass (Lolium perenne) are presented and discussed. Little is known of the effects of leaf and stem diseases on grass seed yields. Recent research has found that fungicide application can substantially increase seed yield in perennial ryegrass through delaying senescence of leaf tissue. Increased leaf area duration is associated with a reduction in seed abortion, resulting in more seeds per spikelet at harvest. The possibilities for fungicide use in the crop are discussed. Keywords: Seed production, grasses, fertile tillers, seed abortion, growth retardants, paclobutrazol, fungicide, senescence.

scholarly journals The effect of vegetation area size on grass seed yield

2003 ◽  
Vol 48 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Savo Vuckovic ◽  
Aleksandar Simic ◽  
Branko Cupina ◽  
Ivana Stojanovic ◽  
R. Stanisavljevic
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Italian Ryegrass ◽  
Row Spacing ◽  
Meadow Fescue ◽  
Grass Seed ◽  
The World ◽  
Seed Yields

This paper surveys sowing norms (row spacing and seed rate) in both our country and the world, as well as the optimal seed rates in grass seed production. It gives a short overview of row spacings and seed rates applied in our and some other countries. Earlier, grass cultivated for the purpose of seed production was grown on small vegetation area. According to some researches, high seed yields can be achieved by cultivating grass on large vegetation area. Based on the results obtained, it can be concluded that the highest cocksfoot, timothy, meadow fescue, tall fescue seed yield was achieved with plants grown in 50 cm spaced rows employing lower seed rates (8 and 4 kg/ha of seeds). The highest Italian ryegrass and perennial ryegrass seed yield was achieved with plants grown in 20 cm spaced rows employing 20 kg/ha of seeds.

scholarly journals Wild oat control and tolerance of grass seed crops to fenoxaprop-P-ethyl

1999 ◽  
Vol 52 ◽  
pp. 218-222
Author(s):  
M.P. Rolston ◽  
W.J. Archie
Keyword(s):  
Seed Yield ◽  
Perennial Ryegrass ◽  
Untreated Control ◽  
Grass Species ◽  
Wild Oat ◽  
Good Tolerance ◽  
Phalaris Aquatica ◽  
Wild Oats ◽  
Seed Crops ◽  
Seed Yields

Fenoxaprop P-ethyl, a wild oat herbicide was applied to five grass species. Perennial ryegrass was tolerant to 37 g/ha, but there was a trend for a reduction in seed yield at 75 g/ha. Two Bromus species had good tolerance, but Phalaris aquatica seed yields were reduced by 80%. In a second trial, there was no significant effect on seed yield of perennial and hybrid ryegrass to fenoxaprop applied at 56 g/ha. However, there was a trend for 75 g/ha to reduce seed yield in perennial ryegrass. In a perennial ryegrass seed crop, wild oats were very competitive, reducing seed yields from 2600 kg/ha (best herbicide treatment) to 660 kg/ha in the untreated control. Excellent wild oat control was achieved with fenoxaprop at rates of 45 g/ha in August and 56 g/ha in September.

scholarly journals Ryegrass (Lolium perenne) seed yield response to fungicides a summary of 12 years of field research

2009 ◽  
Vol 62 ◽  
pp. 343-348 ◽  
Author(s):  
M.P. Rolston ◽  
B.L. McCloy ◽  
I.C. Harvey ◽  
R.W. Chynoweth
Keyword(s):  
Seed Yield ◽  
Stem Rust ◽  
Field Research ◽  
Reproductive Development ◽  
Yield Response ◽  
Yield Data ◽  
Seed Fill ◽  
Seed Crops ◽  
Seed Yields ◽  
Green Leaf Area

A summary of seed yield data from 19 fungicide trials in perennial and hybrid ryegrass (Lolium spp) seed crops conducted over a 12 year period is presented Seed yields from the best fungicide treatments were increased on average by 25 in forage ryegrass (390 kg/ha) and 42 in turf ryegrass (580 kg/ha) Seed yield increases were associated with the control of stem rust and/or maintaining green leaf area during seed fill In turf ryegrass (susceptible to stem rust) delaying the first fungicide application until stem rust appeared resulted in seed yields that were not different (P>005) from the untreated experimental controls whereas early fungicide applications from the beginning of reproductive development increased seed yield by between 36 and 42 Fungicide mixes of a triazole plus a strobilurin usually gave higher seed yields than using either fungicide type alone

Lodging studies in Lolium perenne grown for seed: 1. Seed yield and seed yield components

1978 ◽  
Vol 90 (2) ◽  
pp. 261-267 ◽  
Author(s):  
P. D. Hebblethwaite ◽  
A. Burbidge ◽  
D. Wright
Keyword(s):  
Seed Development ◽  
Lolium Perenne ◽  
Seed Yield ◽  
Perennial Ryegrass ◽  
Yield Components ◽  
Field Experiments ◽  
Unit Area ◽  
Seed Yield Components ◽  
Seed Yields ◽  
Number Of Seeds

SummaryThe effects of lodging on the seed yield of S. 23 and S. 24 perennial ryegrass were investigated in a series of field experiments from 1973 to 1976. Natural lodging severely reduced seed yield in all years as a result of a decrease in the number of seeds per unit area. Controlled lodging at different stages of crop growth produced more variable results, indicating that lodging may affect both pollination and seed development. Disturbance of the crop during anthesis in order to aid pollination did not improve seed yields, possibly as a result of damage incurred.

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 RYEGRASS SEED CROPS

1990 ◽  
Vol 5 ◽  
pp. 40-46
Author(s):  
K.R. Brown ◽  
G. Lill ◽  
J. Mccartin ◽  
D. Jarman ◽  
B. Mccloy ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Large Scale ◽  
Arable Crops ◽  
Key Factor ◽  
High Yields ◽  
Seed Crops ◽  
Seed Yields

Perennial ryegrass seed has been one of the most profitable large scale arable crops in the long term, where good yields have been maintained. The key factor in producing high yields of quality ryegrass seed is to take a 'specialist crop' approach. By following the principles given here, specialist growers are achieving consistent seed yields of 1500 kg ha".

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

Effects of herbicides on wallaby grass (Danthonia spp.). 2. Established plants

1994 ◽  
Vol 34 (6) ◽  
pp. 759 ◽  
Author(s):  
GM Lodge ◽  
MG McMillan
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Early Spring ◽  
Dry Matter Yield ◽  
Annual Grass ◽  
South Wales ◽  
Seed Crops ◽  
Seed Yields

Three experiments were conducted at Tamworth, New South Wales, in 1990-92 to assess the effects of a range of broadleaf and grass herbicides, 6 rates of glyphosate and paraquat + diquat, and 4 rates of 2,4-D amine and diuron on the phytotoxicity, dry matter yield, inflorescence number, and seed yield of established Danthonia (wallaby grass) plants. Phytotoxicity was scored visually on a 0-5 scale (0, no phytotoxicity; 5, 100%). Danthonia dry matter yields were not affected (P<0.05) by any herbicide tested, except glyphosate applied at 2360 g a.i./ha. Phytotoxicity was highest for the glyphosate treatment (1440 g a.i./ha) in that study. All rates of glyphosate, and paraquat + diquat rates >250 + 150 g a.i./ha reduced (P<0.05) inflorescence number compared with the unsprayed control. Paraquat + diquat had no significant effect on seed yield, but glyphosate rates >360 g a.i./ha reduced (P<0.05) seed yield compared with the control. In 1992, no damage was observed on 2,4-D amine treatments and phytotoxicity scores were low (<2) for all diuron treatments. Danthonia inflorescence numbers and seed yields were higher (P<0.05) on plots mown in early spring than on unmown treatments. The lack of effect of herbicides such as diclofopmethyl, simazine, fenoxaprop-ethyl, and diuron on Danthonia dry matter yield, and the low phytotoxicity, indicated that a range of chemicals may be used on established Danthonia swards to control perennial and annual grass weeds. Seed yield was more affected than dry matter yield by herbicide, and paraquat + diquat should be used in preference to glyphosate on seed crops.

scholarly journals Adaptation of Lentil to the Mediterranean Environment. I. Factors Affecting Yield Under Drought Conditions

1993 ◽  
Vol 29 (1) ◽  
pp. 9-19 ◽  
Author(s):  
S. N. Silim ◽  
M. C. Saxena ◽  
W. Erskine
Keyword(s):  
Drought Stress ◽  
Flowering Time ◽  
Seed Yield ◽  
Ground Cover ◽  
Farming Systems ◽  
Yield Potential ◽  
Mediterranean Environment ◽  
Early Maturity ◽  
Selection For ◽  
Seed Yields

SummaryLentil frequently suffers from drought stress towards the end of the growing season in rainfed Mediterranean farming systems. This study aimed to quantify the contribution of yield potential under irrigated conditions and of drought escape to the adaptation of lentils to drought, and to identify traits of value in selection for adaptation to a rain-fed Mediterranean environment. Twenty-five diverse lentil lines were sown under both irrigated and rainfed conditions in the 1987/88 and 1988/89 seasons in northern Syria. In 1987/88 the total seasonal rainfall was 403 mm and average rainfed biomass and seed yields were 5.0 and 1.8 t ha-l, respectively. In contrast, in 1988/89 the total season rainfall was 180 mm and average biomass and seed yields were only 0.67 and 0.12 t ha-1, respectively. Early vigour (estimated as a visual score) and percentage ground cover were strongly associated with final biomass, and were of value in predicting economic yield (seed + straw). Early maturity was correlated with seed yield. In the dry season 1988/89, 49% of the variation in seed yield among lines was accounted for by variation in flowering time. Drought escape was clearly the key response to drought. For severely drought-prone areas, selection for early flowering is therefore required. Variation in flowering time and seed yield under irrigated conditions accounted for 62% of seed yield variation under drought stress.

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