Preharvest glyphosate in alfalfa for seed production: Control of Canada thistle

2003 ◽  
Vol 83 (1) ◽  
pp. 199-204
Author(s):  
W. E. May ◽  
C. D. Myhre ◽  
H. A. Loeppky ◽  
D. C. Murrell ◽  
J. J. Soroka

Canada thistle [Cirsium arvense (L.) Scop.] is increasing in both frequency and density in Saskatchewan alfalfa (Medicago sativa L.) seed fields. Application of preharvest glyphosate is an effective means of controlling Canada thistle in annual crops. This study was conducted to determine the effects of preharvest glyphosate on Canada thistle control and crop tolerance in alfalfa seed fields. Five field experiments were conducted in northeast Saskatchewan between 1995 and 1997 in which preharvest glyphosate was applied at 0, 220, 440, 660, 880, and 1760 g a.i. ha-1 when 60–70% of alfalfa seed pods were brown. Glyphosate did not affect seed yield in the year of application at any application rate, nor germination and subsequent emergence of the harvested seed. Alfalfa regrowth in the year following application declined linearly as the rate of preharvest glyphosate increased. Seed yield was also reduced in the year following glyphosate application. Glyphosate application at 220 g a.i. ha-1 significantly reduced Canada thistle regrowth in the year following application. Canada thistle density decreased in 2 of 4 site years with increasing rates of preharvest glyphosate. Using preharvest glyphosate at rates higher than 220 g a.i. ha-1 in seed alfalfa is not recommended when future seed harvest is planned. However, higher rates of preharvest glyphosate could be used in the final year of seed production to facilitate alfalfa removal. Key words: Preharvest glyphosate, abnormal seeds, seed quality, germination, hard seed and emergence

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


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


1989 ◽  
Vol 3 (1) ◽  
pp. 99-101 ◽  
Author(s):  
Douglas S. Packer ◽  
James M. Krall

The effect of glyphosate applied as a desiccant to field bindweed-infested alfalfa in the final year of seed production was examined in field experiments near Lovelock, NV. Glyphosate at 2.5 and 5.0 kg ae/ha flat fan applied was equal to and/or superior to dinoseb for desiccation of foliage, respectively. Alfalfa seed yield and quality following glyphosate treatment were similar to that of dinoseb-treated alfalfa. Glyphosate treatment reduced some alfalfa and field bindweed stands. A beneficial interaction between low-volume control droplet application (CDA) and glyphosate was not evident.


2002 ◽  
Vol 127 (5) ◽  
pp. 855-859 ◽  
Author(s):  
Haim Nerson

Field experiments were conducted in 1996 and 1997 to examine the effects of plant density on yield and quality of fruit and seeds of muskmelons (Cucumis melo L.). Two open-pollinated cultivars, Noy Yizre'el (Ha'Ogen type) and TopMark (western U.S. shipper type), were grown at plant densities ranging from 0.5 to 16.0 plants/m2 under commercial conditions. The highest marketable fruit yields were achieved with plant densities of 2 to 4 plants/m2. In contrast, the highest seed yields were obtained at 8 to 12 plants/m2. Seed yield index [seed yield (g)/fruit yield (kg)] was used as a parameter to define seed production efficiency. High seed yield was closely related to high value of the seed yield index. High seed yield indexes resulted from high plant densities (up to 12 plants/m2), at which the crops produced many, but relatively small fruit. In all cases, the seed yield per fruit (seed number and seed size) increased with increasing fruit weight. However, the sum of the seed yield of two small fruit was always greater than the seed yield of one, double-sized fruit. There was a clear exception with extremely small fruit (<500 g), which produced both low seed yields and poor seed quality. A positive relationship was found between fruit size and seed size in both cultivars. Nevertheless, relatively small seeds (25 to 30 mg) extracted from relatively small fruit (500 to 1000 g) showed the best performance in terms of germination and emergence percentages and rates, and in the vegetative development vigor of the seedlings.


2017 ◽  
Vol 42 (3) ◽  
pp. 437-446
Author(s):  
MB Rahman ◽  
MM Hossain ◽  
MM Haque ◽  
NA Ivy ◽  
S Ahmad

Two separate field experiments were conducted at the Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during April to October 2012 (summer season) and October 2012 to March 2013 (winter season) to evaluate and compare the seasonal effect on fruit set, seed yield and seed quality of eggplant. Six eggplant varieties (BARI Begun-1, BARI Begun-5, BARI Begun- 6, BARI Begun-8, BARI Begun-9 and Khotkhotia) were grown separately with proper isolation in both the seasons. Significant variation in fruit set per plant, seed yield per fruit and seed quality of eggplant were observed due to execution of growing seasons. The highest seed yield per fruit was obtained from BARI Begun-6 in both the seasons. Number of fruits per plant, seeds per fruit and 1000-seed weight showed the highest in winter season (October to March) as a result the highest seed yield was obtained from the same season. Winter season also showed the best seed quality attributes like germination (%), co-efficient of germination and vigour index irrespective of variety used. Based on seed yield and seed quality, winter season (October to March) found to be more favourable for quality seed production of eggplant in Bangladesh condition.Bangladesh J. Agril. Res. 42(3): 437-446, September 2017


2008 ◽  
Vol 18 (1) ◽  
pp. 91 ◽  
Author(s):  
P. MÄKELÄ ◽  
M. KOUSA

Meadow fescue (Festuca pratensis Huds.) is grown widely in the Nordic countries in forage grass mixtures. Locally adapted cultivars are preferred for establishment of mixed swards. Meadow fescue seed yield is determined by seed weight, the number of panicle bearing tillers, size of panicles and the number of fertile florets. We aimed to determine the differences in components of seed yield in two different meadow fescue cultivars differing in forage quality; Kalevi, released in 1979, and Fure, released in 1999. Biomass accumulation was monitored, numbers of fertile and sterile florets, and seeds were counted, and the forage quality was analysed. Seed quality was also analysed. Fure was leafier and accumulated more vegetative biomass than Kalevi. Kalevi had significantly more panicles than Fure, although Fure compensated for the lower number of panicles with increased panicle size. There were no differences in number of sterile and aborted florets between cultivars. Based on the results it seems that these two meadow fescue cultivars have a completely different strategy in seed production even though the final seed yield was not markedly different. It is apparent that meadow fescues have good ability to compensate among the components of seed yield. Long-term field experiments should be conducted to investigate the interactions between plant stand ecology, seed production and cultivation technology.;


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


2004 ◽  
Vol 84 (4) ◽  
pp. 939-947 ◽  
Author(s):  
C. L. Vera ◽  
S. S. Malhi ◽  
J. P. Raney ◽  
Z. H. Wang

Industrial hemp (Cannabis sativa L.) has sparked renewed interest in western Canada in recent years, and there is very little research information available on its fertilizer requirements. The objective of this study was to determine the effect of surface-broadcast ammonium nitrate and seedrow placed monoammonium phosphate fertilizers on the production and seed quality attributes of industrial hemp (cv. Fasamo and Finola). Field experiments were conducted on a Black Chernozem silty loam soil at Melfort, Saskatchewan, Canada, in 2000, 2001 and 2002. Increasing N rates significantly increased plant height, biomass, seed yield and seed protein content of hemp in all years. Seed-applied P fertilizer increased plant height in all years, and biomass in 2000, but reduced plant density, biomass and seed yield in 2001 and 2002. Finola consistently had lower plant height, earlier maturity, heavier seeds, and higher seed yield, seed protein content and seed oil content than Fasamo. The average amount of nitrate-N in the 0–60 cm soil was 40 kg N ha-1. Seed yield kg-1 of N was 9.4, 5.9, 4.5 and 3.7 kg ha-1 for Fasamo, and 10.6, 7.7, 6.0 and 4.5 kg ha-1 for Finola, respectively, at 40, 80, 120 and 160 kg ha-1 of soil plus fertilizer N. Key words: Fertilizer, hemp, nitrogen, phosphorus, rainfall, soil extractable P, soil nitrate-N, cultivars


2017 ◽  
Vol 44 (1) ◽  
pp. 13-18 ◽  
Author(s):  
J.A. Arnold III ◽  
J.P. Beasley ◽  
G.H. Harris ◽  
T.L. Grey ◽  
M. Cabrera

ABSTRACT Calcium (Ca) availability in the 0 to 8 cm soil depth often limits peanut yield and influences grade in the southeastern United States. Field experiments were conducted in 2012 and 2013 at the University of Georgia's Coastal Plain Experiment Station, Tifton, GA (CPES) and the Southwest Georgia Research and Education Center, Plains, GA (SWREC) to determine large-seeded (Georgia-06G) and medium-seed sized (Georgia Greener) runner-type cultivar response to gypsum application rates of 0, 560, 1120, 1650 kg/ha. Peanut pod yield and grade (TSMK) were significantly different between locations with 7610 and 6540 kg/ha at CPES and SWREC, respectively. However, there were no differences between peanut cultivars or gypsum rates. Standard germination, seed vigor (cold germination), and seed Ca content analysis were also conducted on subsamples from each plot. Average peanut seed germination was 97% across all samples. No differences were observed for standard germination or vigor testing. Differences in locations were observed for yield, TSMK, percent jumbo, percent medium kernels, and seed Ca content. Peanut cultivar and gypsum application rate had effects on seed Ca concentration. Seed Ca concentration levels were 825 and 787 mg/kg for Georgia Greener and Georgia-06G, respectively. Seed Ca content increased as field gypsum application rate increased at both locations.


2006 ◽  
Vol 86 (3) ◽  
pp. 605-619 ◽  
Author(s):  
S. S. Malhi ◽  
R. E. Karamanos

Deficiency of copper (Cu) in Canadian prairie soils is not widespread, but whenever it occurs it can cause a drastic reduction in seed yield and quality of most cereals, especially wheat. Field experiments conducted in western Canada indicated that broadcast-incorporation of granular Cu fertilizers prior to seeding at 3-5.6 kg Cu ha-1 was usually sufficient to prevent Cu deficiency in wheat, and improve seed yield and quality. At lower rates (< 2.0 kg Cu ha-1), broadcast-incorporation of granular Cu fertilizers was not effective, while surface spray-broadcast followed by incorporation of liquid Cu fertilizers was much more effective in increasing seed yield of wheat in the first year of application. Surface broadcast without incorporation and seedrow-placed granular Cu fertilizers were much less effective in improving seed yield of wheat than their foliar or soil-incorporated applications. In the growing season, foliar applications of Cu at 0.20 to 0.28 kg Cu ha-1 to wheat at the Feekes 6 (first node of stem visible at base of shoot or stem elongation), Feekes 10 (sheath of last leaf completely grown or flag-leaf) and early boot growth stages were very effective in restoring seed yield, while Cu applications at the Feekes 2 (four-leaf) or Feekes 10.5 (complete heading) growth stage did not have a consistent effect to correct damage caused by Cu deficiency. Some Cu fertilizers (e.g., Cu oxide) were less effective than others in preventing/correcting Cu deficiency. Soil application at relatively high rates produced residual benefits in increasing seed yield for a number of years. The sensitivity of crops to Cu deficiency is usually in the order (wheat, flax, canary seed) > (barley, alfalfa) > (timothy seed, oats, corn) > (peas, clovers) > (canola, rye, forage grasses). Stem melanosis in wheat was associated with deficiency of Cu in soil, and the disease was reduced substantially with Cu application. A high level of available P in soil was observed to induce/increase severity of Cu deficiency in wheat. Soil analysis for diethylene triamine pentacetic acid- (DTPA) extractable Cu in soil can be used as a good diagnostic tool to predict Cu deficiency, but there was a poor relationship between total Cu concentration in shoots and the degree of Cu deficiency in crops. Application of Cu fertilizers to wheat on Cu-deficient soils also generally improved seed quality. Key words: Application time, Cu source, foliar application, granular Cu, growth stage, placement method, rate of Cu, seedrow-placed Cu, soil incorporation, wheat


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