Preharvest glyphosate in alfalfa for seed production: Effect on alfalfa seed yield and quality

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


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


2020 ◽  
Vol 1 (2) ◽  
pp. 60-64
Author(s):  
Wurentuya ◽  
Lingling Chen

Boron (B) is an essential micronutrient for plant reproductive growth and seed setting. A better understanding of the reasonable application rate of B could provide guidelines for improving seed yield and quality. In this study, we used five B concentrations (0, 400, 800, 1200, and 1600 mg B L-1) to study the effect of foliar application of B on seed yield and quality of alfalfa (Medicago sativa L.) in northern China. Our results indicated that foliar B application increased the pollen number, pollen viability, and dry weight and B concentration of alfalfa reproductive organs. The effect of B on alfalfa seed yield can be attributed to affecting the number of inflorescence and the seeds per pod. Foliar application with 800 mg B L-1 made quantitative and qualitative improvements in seed yield and quality of alfalfa. These results help to explain the positive effects of B on alfalfa seed production.


2000 ◽  
Vol 80 (2) ◽  
pp. 433-439 ◽  
Author(s):  
A. L. Darwent ◽  
K. J. Kirkland ◽  
L. Townley-Smith ◽  
K. N. Harker ◽  
A. J. Cessna

Potential use of preharvest applications of glyphosate in canola (Brassica rapa L.) in western Canada both as a harvest aid and to control weeds prompted this study. Experiments were conducted from 1988 to 1990 at four locations in the region to document the effectiveness of preharvest applications of glyphosate to enhance canola seed and foliage drydown and to measure the effect of such applications on seed yield and quality. Glyphosate was applied in early August to early September at rates of 0.45, 0.90 and 1.70 kg acid equivalent ha−1 to canola with seed moisture contents ranging from 79 to 12%. Seed and foliage moisture drydown were not enhanced by glyphosate treatment. Glyphosate treatments generally had little or no effect on canola seed yields, seed weight, seed germination, green seed content or oil content except when applied when the pods were green and when seed moisture contents were high. Seed/pod moisture was not a reliable indicator of stage of canola development and thus, should not be used alone as an indicator of when preharvest applications of glyphosate can be applied to canola without decreasing seed yield and quality. Key words: Glyphosate, canola, Brassica rapa L., preharvest application, desiccation, seed quality


1980 ◽  
Vol 60 (4) ◽  
pp. 1115-1121 ◽  
Author(s):  
M. F. BETTS ◽  
I. N. MORRISON

Fababean plants were swathed or desiccated with diquat [6,7-dihydrodipyrido (1,2-A:2′, 1′-C) pyrazinediium salt] at four stages of maturity corresponding to the time when 0, 10, 25 and 50% of the pods had turned from green to black. Over the 3 yr of the study no significant differences were observed between seed yields from swathed or desiccated plants. Regardless of whether the plants were swathed or desiccated, yields and seed quality tended to be higher from plants which had 25% or more black pods at the time of treatment. Desiccating before 25% of the pods have turned black may have a more serious effect on reducing seed quality than swathing before the recommended time. By desiccating prematurely, there is a risk of reducing seed quality by significantly increasing the number of discolored or shrivelled seeds.


1987 ◽  
Vol 67 (1) ◽  
pp. 263-266 ◽  
Author(s):  
J. WADDINGTON ◽  
N. MALIK

In two experiments at Melfort using alfalfa (Medicago sativa L. ’Beaver’) seeded at a rate of 2 kg ha−1 with and without a Polish rapeseed (Brassica campestris L. ’Candle’) companion crop seeded at 5.5 kg ha−1, rapeseed yields in the establishment year were maximum when alfalfa and rapeseed were mixed and planted in 15-cm rows. Alfalfa showed no consistent seed yield differences between broadcast seeding, seeding in 15- or 61-cm rows, or seeding with or without the companion crop.Key words: Alfalfa, rapeseed, Brassica campestris, seed production


2015 ◽  
Vol 7 (1) ◽  
pp. 471-476 ◽  
Author(s):  
D.K. Mehta ◽  
Tarun Singh ◽  
Rajesh Kanwar

A study was carried out to evaluate the effect of head decapitation and planting density on plant growth, seed yield and quality of sprouting broccoli, Brassica oleracea var. italica L. using cultivar ‘Green Head’. The twenty treatments comprised of combinations of four head decapitation methods viz., D1 (decapitation of primary head at appearance and harvesting seeds from secondary heads), D2 (decapitation of primary head at marketable stage and harvesting seeds from secondary heads), D3 (removal of secondary heads at appearance and harvesting seeds primary head) and ‘D4’ (No decapitation- control) and five planting densities viz., S1 (60x60 cm), S2 (60x45 cm), S3(45x45 cm), S4 (60x30 cm), and S5 (45x30 cm). Decapitation of primary head at appearance and harvesting seeds from secondary heads (D1) and planting density S3 (45x45 cm) independently as well as in combination gave highest seed yield per plot and per hectare. This combination was also found comparable to other combinations for other characters like days to 50% flowering, days to seed harvesting, plant height at harvesting (cm), number of branches per plant, number of siliqua per plant, siliqua length (cm), number of seeds per siliqua and seed quality parameters. Therefore, it is suggested that decapitation of primary head at appearance and harvesting seeds from secondary heads (D1) in combination with plant spacing of 45x45 cm i.e. D1S3 can be recommended for commercial seed production of sprouting broccoli.


Author(s):  
Ozlem Alan ◽  
Damla Kanturer ◽  
Alison A. Powell ◽  
Hulya Ilbi

Dill seed production was investigated over two seasons, comprising a spring growing cycle (SGC) and an autumn growing cycle (AGC). The effects of growing cycle on phenological traits, yield and quality of dill seeds formed on different umbels of the mother plant were investigated. Significant differences were noted in the flowering period, seed yield and quality parameters. The SGC resulted in a shorter time from sowing to bolting and flowering initiation compared with the AGC. Plant height, number of umbels/plant, number of umbelets/umbel, umbel diameter, umbel length and seed weight/plant increased in the AGC. In contrast, decreased germination at 20/30°C and at 13°C, and increased mean germination time at 20/30°C in AGC indicated lower seed quality compared with SGC. Primary umbels produced the best yield and higher quality seeds, followed by the secondary umbels while tertiary umbels gave poor yield and quality seeds in both SGC and AGC. In conclusion, AGC was advisable for higher seed yield, but SGC resulted in higher seed quality compared with the AGC. This highlights the need to select a suitable growing cycle to guarantee high seed yield and quality for each seed production environment.


2015 ◽  
Vol 16 (2) ◽  
pp. 56-62 ◽  
Author(s):  
Esteban Rios ◽  
Ann Blount ◽  
Philip Harmon ◽  
Cheryl Mackowiak ◽  
Kevin Kenworthy ◽  
...  

Seed production is a critical component in agricultural systems based on bahiagrass and ergot has been reported to significantly reduce seed quality in tetraploid cultivars. Seed yield and quality are important traits to evaluate in the advanced breeding lines developed at the University of Florida. Resistance to ergot was assessed in seven tetraploid bahiagrass breeding lines and the cultivar Argentine. Tebuconazole and pyraclostrobin also were evaluated for managing ergot and increasing seed quality. Argentine and two tetraploid hybrids (Hyb1 and Hyb2) showed the highest levels of ergot severity and incidence. Three wild-type bahiagrass lines (WT-2, WT-4 and WT-5) performed significantly better than Argentine and could be considered resistant to ergot. Anthesis was the critical stage in relation to ergot infection, and a single application of tebuconazole at anthesis reduced ergot severity; however, neither fungicide was able to reduce ergot incidence. Tebuconazole and pyraclostrobin improved seed set, and reproductive efficiency was 2.4% higher after the application of tebuconazole. The slight increase in reproductive efficiency following fungicide application may not be economically justifiable for seed production in bahiagrass. Three advanced tetraploid breeding lines (Hyb1, WT-3, and WT-5) exhibited adequate seed production to be considered for cultivar release. Accepted for publication 24 February 2015. Published 17 April 2015.


Author(s):  
K. Lokesh ◽  
. Basavegowda ◽  
Mallikarjun Reddy ◽  
. Siddaram ◽  
P. D. Suhas ◽  
...  

Aim: To identify the best planting time for obtaining higher seed yield and quality of Soybean in off season. Study Design: Randomized completely block design (RCBD) Place and Duration of Study: Agricultural Research Station, Halladkere, Bidar, Karnataka between 2016 and 2017. Methodology: A field experiment was conducted at Agricultural Research Station, Halladkere, Bidar to find out the best off season planting time for quality seed production of Soybean. The certified seeds of soybean varieties, JS-335 and Dsb-21 were sown with recommended package of practices at appropriate field condition from November to February at every fortnight with a spacing of 30 cm X 10 cm. The quality parameters related to seed were carried out in the laboratory of seed science department. Further, soybean seeds were treated with fungicide (carbendazim 25% + mancozeb 75%) at the rate of 3 gram per kg of seeds. Results: From the present investigation, it was observed that among the different sowing dates, soybean varieties (JS 335 and DSb 21) sown during 1st fortnight of November recorded significantly higher plant growth parameters as well as seed yield followed by 2nd fortnight of November during off season. Further, climatic factors like rainfall, maximum and minimum temperature and relative humidity played a major role in the off season to produce higher seed yield and quality of Soybean. Conclusion: Among various sowing dates, November 1st Fortnight sowing resulted in highest seed yield with better seed quality in both cultivars (JS-335 and Dsb-21) of soybean.


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