Effect of shallow, rotary cultivation with vertical tines and nitrogen fertilization on the seed productivity of creeping red fescue

2002 ◽  
Vol 82 (4) ◽  
pp. 709-719
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

A field study in the Peace River region of north-western Canada evaluated the effect of shallow rotary cultivation with vertical tines on the seed production of stands of creeping red fescue (Festuca rubra L. var. rubra). At four sites, rotary cultivation treatments (None, Low, Medium and High tine rotor speed) were applied after the harvest of the first and second seed crops, in factorial combination with the time of application of 68 kg ha-1 N fertilizer (Early fall, Late fall, and Split 1:1 early:late fall). In harvest years 2 and 3, the effect of site on seed yield per unit land area was modified by both N and rotary cultivation. In harvest year 2, seed yield at Site 1 was increased greatly by rotary cultivation, regardless of the tine rotor speed, but there was little difference among the four cultivation treatments at the other three sites. In harvest year 3, seed yield was increased with Low, Medium and High rotary cultivation to 6- to 11-fold that without rotary cultivation at Sites 1 and 2 but only to 1.4- to 2-fold at Sites 3 and 4. Seed yield response to rotary cultivation was dependent on site and year, a reflection of the physiological status of the fescue plants at each specific site. Rotary cultivation treatments may have been too detrimental to tiller growth and development for sustaining and enhancing seed yield, particularly at Sites 3 and 4 prior to harvest year 2. There was no consistent pattern of response in seed yield among the four sites to the three N treatments in either harvest year 2 or 3. Although there was a significant (P < 0.001) N × rotary cultivation interaction for seed yield in harvest year 3, the pattern among cultivation treatments was generally similar for each N treatment; compared to no cultivation, the three cultivation treatments more than doubled seed yield to 255–322 kg ha-1 with Early and Split N and increased it 4- to 6-fold to 203–288 kg ha-1 with Late N. There is some potential for rotary cultivation, but the selected treatments were generally too aggressive in suppressing tillers. Key words: Rejuvenation of creeping red fescue, mechanical rejuvenation, rotary cultivation, power-harrowing, grass seed production

2008 ◽  
Vol 88 (3) ◽  
pp. 439-446 ◽  
Author(s):  
N. A. Fairey

In order to address a paucity of information, a study was conducted in the Peace River region of northwestern Canada to determine the effects on seed production of creeping red fescue (Festuca rubra L. var. rubra) of six water treatments [natural precipitation and 100, 125, 150, 175 and 200% of the average, cumulative, long-term precipitation (LTP) of 459 mm yr-1] in combination with four N-fertilization regimes (zero + 102, 34 + 68, 68 + 34, and 102 + zero kg ha-1 N for the first + second crops, respectively). The 2-yr seed yield exceeded 2900 kg ha-1 when N was supplied to just one of the two seed crops, viz. with 150 to 200% LTP when N was applied only to the first seed crop, and with 125 to 150% LTP when N was applied only to the second seed crop. Under the prevailing, long-term, moisture environment at the study site (100% LTP), total seed yield over two production years was greatest (2136 kg ha-1) with 68 + 34 kg ha-1 N. The effects of the water and N treatments on seed yield were not associated with the mass of root organic matter recovered after the harvest of the second seed crop. These results confirm, and begin to quantify, numerous visual observations in the Peace River region that seed yields of creeping red fescue are restricted by insufficient precipitation. Key words: Creeping red fescue, Festuca rubra, grass seed production, nitrogen fertility, water, soil moisture


2000 ◽  
Vol 80 (4) ◽  
pp. 809-811 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

Six trials were conducted on commercial seed fields of creeping red fescue (Festuca rubra L. var. rubra) in the Peace region to evaluate the sensitivity of seed production to the method and time of application of N fertiliser. In each trial, 68 kg ha−1 N was applied using three methods (surface-broadcast, granular, ammonium nitrate 34-0-0; foliar/soil spray of 28-0-0 solution N; soil-injected 28-0-0 solution N) at each of three times (fall, early spring, late spring). No statistically significant (P = 0.05) interaction, or main effect, of method and time of N were revealed for seed yield, fertile tiller density or for several seed quality characteristics. Seed yield varied greatly among trials (142 to 1240 kg ha−1) and averaged 566 kg ha−1. The results indicate that there is considerable flexibility in the method and time of application of N fertiliser for seed production of creeping red fescue in the Peace region, provided it is applied before the commencement of vigorous plant growth in the spring. Key words: Creeping red fescue, Festuca rubra L., nitrogen fertility, grass seed production, grass seed quality


2001 ◽  
Vol 81 (4) ◽  
pp. 693-701 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

A field study in the Peace River region of northwestern Canada evaluated five post-harvest management (PHM) treatments on the seed yield and quality of four grasses, viz. Boreal creeping red fescue (Festuca rubra L. var. rubra), Safari and Tomahawk tall fescue (F. arundinacea Schreber), and Midnight Kentucky bluegrass (Poa pratensis L.). The PHM treatments were: straw removal after seed harvest plus trimming prior to winter; a single propane burn; a double propane burn; power cultivation; and diuron applied in spring. The study was conducted for 3 consecutive harvest years. The grass × harvest year × PHM interaction was not statistically significant (P ≤ 0.05) for any of 10 characteristics, viz. panicle density, time of seed maturity, seed yield (per unit land area and per individual panicle), whole-plant yield, harvest index, seed dockage, 1000-seed weight, specific seed weight, and germination capacity. The grass × harvest year interaction was statistically significant (P ≤ 0.05) for each of the 10 characteristics, primarily because of the differential response of the bluegrass as compared to the fescue grasses. The grass × PHM interaction was statistically significant (P ≤ 0.05) for seed yield of individual panicles, harvest index, seed dockage and 1000-seed weight. The PHM × harvest year interaction was statistically significant (P ≤ 0.05) for specific seed weight only. The main effect of PHM was statistically significant (P ≤ 0.05) for specific seed weight and germination capacity only. The average annual seed yield of the two tall fescue cultivars (1002 and 1171 kg ha–1 for Safari and Tomahawk) was approximately twice that of Boreal creeping red fescue (554 kg ha–1) and four times that of Midnight Kentucky bluegrass (284 kg ha–1). At this northerly latitude (55°N), the effects of any PHM treatment on the seed productivity of these grasses may be limited by the short period of environmental conditions between seed harvest and the onset of winter that are conducive to vegetative and reproductive tiller development. Key words: Post-harvest management, propane burning, mechanical and chemical rejuvenation, grass seed yield, grass seed quality


1996 ◽  
Vol 76 (2) ◽  
pp. 291-298 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

The natural growth habit of creeping red fescue (Festuca rubra L. var. rubra) involves a steady proliferation of tillers, which eventually become too dense to form seedheads. A field study was conducted to evaluate whether seed yield of fescue can be optimized for one, two or three consecutive crops by manipulating the initial population density and arrangement of plants. Individual seedling plants were transplanted at seven densities (1.6, 3.1, 6.3, 12.5, 25, 50 and 100 plants m−2) and three row spacings (20, 40 and 80 cm), and characteristics of seed production were determined for 3 yr (1991–1993). Heading commenced at dates differing by 16 d in the 3 yr and was delayed by up to 7 d as density increased. Seed maturity occurred in a 7-d period in each year (15–22 July). For a single harvest, an initial density of 12–100 plants m−2 on a row spacing of 20 cm or 12–50 plants m−2 on a row spacing of 40 cm is required to optimize yield and produce about 600 kg ha−1 of clean seed. For two consecutive harvests, an initial population density of 6–25 plants m−2 on a row spacing of 20 cm or 6–50 plants m−2 on a row spacing of 40 cm is required to optimize yield and produce a total of about 800 kg ha−1 of clean seed. For producing for either 1 or 2 yr, a density of 12–25 plants m−2 on rows no wider than 40 cm is required to optimize seed yield in each year. The probability of producing a third seed crop decreases markedly as the initial plant density increases and as the row spacing decreases. It is probably uneconomic to harvest more than two consecutive seed crops with current management practices. Key words: Red fescue; Festuca rubra var. rubra, population density, plant spacing, seed production


2003 ◽  
Vol 1 (1) ◽  
pp. 67-74
Author(s):  
D. T. Fairey ◽  
N. A. Fairey ◽  
L. P. Lefkovitch ◽  
J. A. C. Lieverse

AbstractThe agri-climatic adaptation of an alfalfa variety in North America is categorized by its Fall Dormancy Rating (FDR1 = dormant to FDR9 = non-dormant). Presently, only relatively dormant, winter-hardy varieties (FDR1–4) are grown for seed and herbage at the northern latitudes of western Canada. However, there is considerably greater demand for seed of varieties that have FDR ≥ 4. A study was conducted in the Peace River region of north-western Canada to determine the relationship between FDR and seed production of alfalfa with FDR ≥ 4. Trials were established in each of two consecutive years with four varieties representing each of six FDR categories, FDR4–9. Growth characteristics were determined for two successive years of seed crops for each year of establishment. Seed yield (as a percentage of that for FDR4) was 84, 52, 40, 29 and 39% for FDR5 to FDR9, respectively, whereas total biomass at seed maturity was 89,73, 73, 57 and 57% for FDR5 to FDR9, respectively. Seed yield was more sensitive to changes in FDR than total biomass. Short rotations of specific alfalfa varieties with FDR ≥ 4 could be an option for seed growers in the northerly latitudes of western Canada, provided greater financial compensation is given for higher FDR varieties, and provided genetic drift can be retained within acceptable limits.


2009 ◽  
Vol 62 ◽  
pp. 343-348 ◽  
Author(s):  
M.P. Rolston ◽  
B.L. McCloy ◽  
I.C. Harvey ◽  
R.W. Chynoweth

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


1984 ◽  
Vol 35 (4) ◽  
pp. 511 ◽  
Author(s):  
RW Downes ◽  
JS Gladstones

Plants of Lupinus angustifolius cv. Unicrop were raised at 27/22 or 21/16�C dayhight temperatures until flowering. They were then either grown on to maturity at these conditions or moved to the other regime. Branches were removed as they started to develop and leaves were removed at the start of flowering so that 0, 3, 6, 9, 12 upper leaves or all 21 leaves were retained. Conditions before flowering determined potential pod number. Defoliation treatments revealed that under favourably cool conditions all leaves contributed to seed yield but in treatments involving 27/22'C there was no seed yield response to more than about six leaves, emphasizing the significance of environmental conditions rather than current assimilate on pod set and other yield components. In another experiment, plants were raised to flowering at 27/22, 21/16 or 15/10�C before flowering, when all were moved to 21/16�C. Half the plants were allowed to develop branches and on the remainder branch buds were removed. Branch and stem growth appeared to provide severe competition for the development of the primary inflorescence. Though branching was much more pronounced in plants at 15/10�C before flowering than in other treatments, vegetative development exceeded reproductive investment and harvest index was low under these conditions. It was suggested that there appears to be a need to develop and evaluate unbranched or less-branched lupin genotypes.


Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 729
Author(s):  
Alexandru Bogdan Ghețe ◽  
Voichița Haș ◽  
Roxana Vidican ◽  
Ana Copândean ◽  
Ovidiu Ranta ◽  
...  

During the process of maize seed production, in order to ensure the genetic purity of parental forms of hybrid maize, an important work performed is the removal of male inflorescences from plants on mother rows. Hand detasseling has high precision but is labor-intensive. Mechanical detasseling offers the possibility to cover large acreages in a short period of time, but the number of leaves removed has a varying influence on plant performance and seed yield. The aim of this study was to simulate three types of damages on plants similar to those induced through mechanical detasseling and to assess the effects for five inbred lines during the course of three years. Results show that when tassels alone were removed, the average seed yield decreased an average of 4–21%. When two leaves were removed with the tassel, yield decreased an average of 22–31%, while when plants were cut above the main ear, seed yield decreased an average of 31–66%. Environmental conditions influenced seed yield, especially high temperatures during flowering. Yield response to tassel and leaves removal varied between the inbred lines. Genotype controls maize ear and kernel characters, while environmental factors exercise a strong influence on seed yield, due to the succession of years with contrasting weather conditions in a key phenophase. Within the trend of full mechanization in agriculture, identification of inbred lines that cope better with plant damage can assist in optimizing seed production.


1995 ◽  
Vol 9 (2) ◽  
pp. 294-300 ◽  
Author(s):  
A. Lloyd Darwent ◽  
Leonard P. Lefkovitch

In commercial fields of creeping red fescue, spring applications of sethoxydim at 500 g/ha and fluazifop-P at 250 g/ha consistently reduced the heading, and consequently the seed production, of foxtail barley and volunteer bromegrass by ≥90% without affecting crop seed yield, 100-seed wt or germination. The effectiveness of sethoxydim at 500 g/ha and fluazifop-P at 250 g/ha to reduce heading of grass weeds was not affected by tank mixing with metsulfuron at 4.5 g/ha but was reduced when tank mixed with either dicamba plus 2,4-D at 280 plus 560 g/ha or 2,4-D alone at 560 g/ha. Metsulfuron alone, or in tank mixtures with sethoxydim (500 g/ha) or fluazifop-P (250 g/ha), effectively controlled dandelion and volunteer alsike clover (probability of ≥80% control was 0.94 or more). Dicamba plus 2,4-D provided a similar level of volunteer alsike clover control but was less effective on dandelion, while 2,4-D was ineffective on both weeds. Treatments containing dicamba plus 2,4-D reduced crop seed yield and germination, and increased seed weight.


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