Desiccation of alfalfa for seed production with diquat and glufosinate

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. 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


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


Author(s):  
P.T.P. Clifford ◽  
J.A. Wightman ◽  
D.N.J. Whitford

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


2006 ◽  
Vol 24 (2) ◽  
pp. 63-67
Author(s):  
Jeffrey G. Norcini ◽  
James H. Aldrich ◽  
Frank G. Martin

Abstract Effects of season and fertilization on seed production were investigated for a central Florida ecotype of Leavenworth's coreopsis (Coreopsis leavenworthii Torr. & A. Gray) grown in containers. Since container-grown ecotypes of native, herbaceous species are frequently grown using nutrient regimes lower than those for production of typical garden plants, Osmocote 18N–2.6P–10K (18–6–12;8–9 month formulation) was incorporated into the soilless substrate at one-half the low, low, and medium label rates for container-grown herbaceous plants [1.8, 3.6, and 5.4 kg/m3 (3.0, 6.0, and 9.0 lb/yd3], respectively. Seed were harvested from mature heads (capitulescences) in late May to mid-July, and then again from late July to late October after plants had been cut back and reflowered. Seed yield and quality were greatest for the May–July harvest. Averaged over fertilizer rate, there were 3-fold more filled seed per mature head for the May–July harvest than during July–October. Mature head production was most responsive to increases in fertilizer rate during May–July. Percent germination of viable seed was nearly 90% or more for both harvests, but there were more viable seed for May–July than for July–October (75 vs. 57%). Seed also ripened much more uniformly during May–July then during July–October. Based on these conditions and results, the best time to harvest seed was from May to early July.


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.


1987 ◽  
Vol 11 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Robert C. Hare

Abstract A single foliar spray with either antiethylene compounds or cytokinins shortly after anthesis reduced conelet abortion by half and doubled seed production. Spraying with boric acid plus Cytex® , a relatively economical form of cytokinin derived from seaweed, was equally effective,and addition of certain antiethylene compounds further improved seed yield. South. J. Appl. For. 11(1):6-9.


1986 ◽  
Vol 26 (1) ◽  
pp. 59 ◽  
Author(s):  
MDA Bolland ◽  
WJ Collins

On sandy soil near Esperance, W.A., prevention of burr burial compared with covering developing burrs with sand drastically reduced the seed production of three subspp. of Trifolium subterraneum (brachycalycinum, subterraneum and yanninicum) and of T. israeliticum by reducing burr production and seed weight. However, T. globosum produced similar amounts of seed from unburied and buried burrs. On sandy soil at Shenton Park, Perth, W.A., prevention of burr burial also reduced seed production of T. subterraneum subspp. brachycalycinum and subterraneum, this being due to fewer burrs, fewer seeds per burr and lighter seed. For subsp. brachycalycinum, seed yields were two to five times greater from burrs which developed within loose gravel than from those developed over sand (in which fewer burrs were able to bury) as a result of increased production of burrs, more seeds per burr and heavier seed. However, for subsp. subterraneum seed yields were similar from burrs whether developed over gravel or sand.


2016 ◽  
Vol 6 (1) ◽  
pp. 39
Author(s):  
Y. Zubairu ◽  
J. A. Oladiran ◽  
O. A. Osunde ◽  
U. Ismaila

Study was conducted in 2006 and 2007 cropping seasons at the experimental field of Federal University of Technology, Minna (9o 401N and 6o 301E), in the Southern Guinea Savanna of Nigeria to determine the effects of N fertilizer and the fruit positions on fruit and seed yield of okro. The treatment comprised factorial combination of five nitrogen levels (0, 30, 60, 90 and 120 kg/ha) and five fruit positions on a mother-plant (3, 5, 7, 9 and 10) which were replicated three times and laid in a Randomized Complete Block Design (RCBD). The results indicated that significant taller plants were recorded in the plots that received 120 kg N/ha while shorter plants were recorded in plots that received 0 N/ha in both years of the study. The higher N level of 120 kg/ha and lower fruit position of 3 significantly gave higher number of fruit yield while the yield decreased with decrease in N level and increase in fruit position on the mother-plant. Similarly, heavier fruits were recorded in lower fruit positions and higher N levels. The fruits formed at the lower position 3 and 5 produced more seeds with higher seed weight than those formed at the higher positions. The results also showed that significantly higher seed yield was recorded at N level of 120 kg/ha ?.


1977 ◽  
Vol 57 (3) ◽  
pp. 891-896 ◽  
Author(s):  
K. K. KROGMAN ◽  
E. H. HOBBS

In field plot experiments conducted in southern Alberta over a 6-yr period, highest seed yields of alfalfa (Medicago sativa L. cv. Beaver) were obtained with one or two irrigations in the first half of the growing season. In outdoor lysimeters protected from rain, moisture stress for more than 8 days before seed ripening severely reduced seed production. Under field conditions, stored soil moisture from irrigation during the vegetative stage of growth plus occasional rain in July and August permitted irrigation of alfalfa for seed to be stopped at the bud to early bloom stage (June to early July).


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