The Effect of 2,4-D on Rapeseed

Weed Science ◽  
1976 ◽  
Vol 24 (4) ◽  
pp. 356-360 ◽  
Author(s):  
M. Betts ◽  
R. Ashford

Field experiments were conducted to compare the effects of 0.07, 0.14, 0.28, and 0.56 kg/ha of 2,4-D [(2,4-dichlorophenoxy)acetic acid] amine on plant growth, seed production, and seed quality when applied at four growth stages of summer rape (Brassica napusL. ‘Zephyr’) and turnip rape (Brassica campestrisL. ‘Span’). At all growth stages, seed yield of turnip rape, was significantly reduced by each additional increment of 2,4-D. The difference in response of the two species may relate in part to differences in spray droplet retention of the leaf surfaces. The herbicide did not affect the germination of harvested seed although treatment with the higher rates at the bolting and flowering stages resulted in the production of some shrivelled seed that was lost on cleaning. Some herbicide treatments caused a marked increase in size of harvested seed. There was a trend towards decreased seed oil content with increasing rate of 2,4-D at the bolting and flowering stages, but oil production losses were mainly reflected through losses in seed yield. The time required for both species to reach maturity increased with increasing rate of herbicide when applied at the vegetative stages. In additional field studies, 2,4-D significantly reduced seed yield in turnip rape when applied at the 3- to 4-leaf stage at 0.035 kg/ha, and 0.018 kg/ha sometimes produced visible effects without noticeable loss in yield.

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


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


Plant Disease ◽  
2020 ◽  
Author(s):  
Tonima Islam ◽  
Cecil Vera ◽  
Jan Slaski ◽  
Ramona Mohr ◽  
Khalid Y Rashid ◽  
...  

Among the diseases that have the potential to cause damage to flax every year, pasmo, caused by Septoria linicola, is the most important. Fungicide application and a diverse crop rotation are the most important strategies to control this disease because there is little variation in resistance among flax cultivars. However, few fungicide products are available to flax growers. Field studies were conducted at four locations in Western Canada in 2014, 2015 and 2016 to determine the effect of two fungicide active ingredients applied singly and in combination: pyraclostrobin, fluxapyroxad and fluxapyroxad+pyraclostrobin; and two application timings (early-flower, mid-flower and at both stages) on pasmo severity, seed yield and quality of flaxseed. The results indicated that among the three fungicide treatments, both pyraclostrobin and fluxapyroxad+pyraclostrobin controlled pasmo effectively, however, fluxapyroxad+pyraclostrobin was the most beneficial to improve the quality and quantity of the seed at most of the site-years. Disease severity in the fungicide-free control was 70%, application of fluxapyroxad+pyraclostrobin decreased disease severity to 18%, followed by pyraclostrobin (23%) and fluxapyroxad (48%). Application of fluxapyroxad+pyraclostrobin also improved seed yield to 2562 kg ha-1 compared with 1874 kg ha-1 for the fungicide-free control, followed by pyraclostrobin (2391 kg ha-1) and fluxapyroxad (2340 kg ha-1). Fungicide application at early and mid-flowering stage had the same effects on disease severity and seed yield; however, seed quality was improved more when fungicide was applied at mid-flowering stage. Continuous use of the same fungicide may result in the development of fungicide insensitivity in the pathogen population. Thus, sensitivity of S. linicola isolates to pyraclostrobin and fluxapyroxad fungicides were determined by the spore germination and microtiter assay methods. Fungicide insensitivity was not detected among the 73 isolates of S. linicola tested against either of these fungicides.


1974 ◽  
Vol 10 (1) ◽  
pp. 45-50 ◽  
Author(s):  
H. A. Habish ◽  
Hassan M. Ishag

SUMMARYField experiments conducted in two localities in two growing seasons on the effect of inoculating haricot bean showed that a local strain of Rhizobium significantly improved nodulation and usually increased the nitrogen content of plants. In three out of four experiments, increases in seed yield were obtained ranging from 20–145 Per cent (significant in two cases). Inoculation was better than 43 kg. N/ha. of combined nitrogen but not better than 86 kg. N. Soil inoculation gave better early nodulation than seed inoculation, but the difference diminished in the later stages of plant growth.


1993 ◽  
Vol 73 (4) ◽  
pp. 503-513
Author(s):  
J. M. Carefoot ◽  
R. L. Conner ◽  
J. B. Bole

The effect of timing of application on the recovery of fertilizer N applied to irrigated soft white wheat (Triticum aestivum L.) was investigated in a 3-yr field study and a 1-yr lysimeter study using 15N-labelled urea and ammonium nitrate. Fertilizer N treatments consisted of a check and 90 kg ha−1 applied as preplant N, postplant N or combinations. Under a controlled watering regime in the lysimeter experiment, timing of N application had no effect on plant growth parameters. In the field studies, although grain yield was not affected by N timing, grain N concentration increased from 17.9 to 19.6 g kg−1 as the proportion of postplant N was increased from 0 to 100%. Plant N uptake was greater when all of the N was applied postplant than preplant (means = 124.5 and 114.2 kg ha−1, respectively) in the field studies. Plant recovery of fertilizer N (FNR) by the difference method was greater when all of the fertilizer N was applied postplant (43.7%) man preplant (28.6%) in the field experiments. With a negative apparent added N interaction (ANI), the FNR was less by the difference method than by the 15N method. However, with a positive ANI, FNR was less by the 15N method than by the difference method. There was a greater difference between methods as the proportion of N applied as postplant N increased. Key words: Fertilizer N timing, irrigation, soft white wheat, nitrogation, fertilizer N recovery


Weed Science ◽  
1986 ◽  
Vol 34 (6) ◽  
pp. 953-956 ◽  
Author(s):  
Drew J. Lyon ◽  
Robert G. Wilson

The effects of the dimethylamine salt of dicamba (3,6-dichloro-2-methoxybenzoic acid) and the dimethylamine salt of 2,4-D [(2,4-dichlorophenoxy)acetic acid] on fieldbeans (Phaseolus vulgarisL. ‘Great Northern Valley’) were studied in order to assess the potential hazards of using these herbicides in areas adjoining fieldbean production. Dicamba and 2,4-D were applied to fieldbeans at three different rates (1.1, 11.2, and 112.5 g ai/ha) and four different growth stages (preemergence, second trifoliolate leaf, early bloom, and early pod). Application of 2,4-D preemergence or in the second trifoliolate leaf stage of growth did not reduce seed yield, delay maturity, or reduce germination of seed obtained from treated plants. Dicamba or 2,4-D applied at 112.5 g/ha to fieldbeans in the early bloom or early pod stages of growth consistently reduced seed yield, delayed maturity, and reduced germination percentage. Fieldbeans exhibited a greater overall sensitivity to dicamba than to 2,4-D.


Author(s):  
Tiago Aranda Catuchi ◽  
Rogério Peres Soratto ◽  
Amarildo Francisquini Júnior ◽  
Fernando Vieira Costa Guidorizzi ◽  
Carlos Sérgio Tiritan

Abstract: The objective of this work was to evaluate the nutrition, accumulation of nutrients in residual straw, pure seed yield, and seed quality of the tropical forage grasses 'Mombaça' and 'Xaraés' subjected to topdressing with nitrogen fertilizer management. Field experiments were carried out in the municipalities of Rancharia and Presidente Prudente, in the state of São Paulo, Brazil. The treatments included a control (without N topdressing) and four N fractionation forms at different forage stages: 150 kg ha-1 N, at the vegetative phase (VP); 150 kg ha-1 N, at the beginning of the reproductive phase (RP), between panicle initiation and the prebooting stages; 100 kg ha-1 N, at VP plus 50 kg ha-1 N at RP; and 50 kg ha-1 N at VP plus 100 kg ha-1 N at RP. Fertilization with N as topdressing, regardless of the N fractionation form, increased N concentration in the flag leaf and in residual straw, and the quantities of N accumulated by 'Mombaça' and 'Xaraés' forage grasses. The application of all or most N in the VP increased the quantities of residual straw and of P and K accumulated by the 'Mombaça' forage grasses. The application of all or most N in the RP provided a greater pure seed yield and N use efficiency in both forage grasses. The seed physiological quality of the forages is not affected by fertilization with N topdressing.


2007 ◽  
Vol 58 (3) ◽  
pp. 265 ◽  
Author(s):  
Catherine P. Borger ◽  
Abul Hashem

Applying glyphosate followed by a mixture of paraquat + diquat in the same season for pre-planting weed control may reduce the risk of developing resistance to either herbicide. Glasshouse and field experiments at Merredin and Beverly, Western Australia, were conducted over 2 seasons to determine the best herbicide application sequence, growth stage of annual ryegrass at which to apply the 2 herbicides, and application time and interval to be allowed between applications for optimum control of annual ryegrass (Lolium rigidum Gaud.). Annual ryegrass plants were treated at 3 growth stages with either glyphosate 540 g a.i./ha alone, paraquat + diquat 250 g a.i./ha alone, glyphosate followed by paraquat + diquat 250 g a.i./ha, or paraquat + diquat 250 g a.i./ha followed by glyphosate 540 g a.i./ha (the double knockdown treatment). The herbicides were applied at different times of the day, with varied intervals between herbicides when applied in sequence. The glasshouse experiment showed that herbicides in sequence more effectively killed annual ryegrass plants at the 3–6-leaf stage than a single application of either herbicide. Field experiments showed that applying glyphosate followed by paraquat + diquat provided 98–100% control of annual ryegrass plants when applied at the 3- or 6-leaf stage in 2002 and at all 3 growth stages in 2003. Generally, the sequence of paraquat + diquat followed by glyphosate was less effective than the reverse sequence, although the difference was not large. Averaged over 2 seasons, herbicides in sequence were most effective when the first herbicide was applied at the 3- or 6-leaf stage of annual ryegrass. An interval of 2–10 days between applications of herbicides was more effective than 1 day or less. The application time did not significantly affect the efficacy of double knockdown herbicides on annual ryegrass plants under field conditions.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1171
Author(s):  
Andrzej Brachaczek ◽  
Joanna Kaczmarek ◽  
Malgorzata Jedryczka

Winter oilseed rape (Brassica napus L.) is the main source of domestic oil in central and northern Europe, bringing profits to farmers, but the plants are often damaged by stem canker, caused by two fungal species belonging to the genus Leptosphaeria. Due to environmental concerns, the benefits of fungicide applications must outweigh disadvantages. The aim of this work was to determine the effect of stem canker on seed yield and its quality and find out the best timing of fungicide application. The multi-year field experiments were done at two sites in south-west Poland, where the disease is regarded as a serious problem. The fungicide treatments with the azole-containing preparation followed the same scheme each year; a single application was made at one-week intervals, starting in late September through mid-November for a total of eight treatments. Seed yield, oil and protein content, mass of thousand seeds as well as indole-and alkenyl-glucosinolate contents in seeds were statistically unrelated with the incidence and severity of phoma leaf spotting and stem canker symptoms. The significant decrease of the seed yield was observed in three (site × year combinations) of eight, in which phoma leaf spotting and stem canker were severe. Yield loss was noted only in years with warm and wet autumns, when cumulative mean temperatures between BBCH14 and BBCH19 plant growth stages exceeded 60 °C and precipitation in this period exceeded 110 mm of rain. Under these conditions, fungicide treatments were highly effective when they were done between BBCH15–BBC16 growth stages (5–6 true leaves).


Author(s):  
S. Kavitha ◽  
P. Srimathi

Background: Black gram is the important pulses crop, grown throughout the country; gives low seed yield mainly due to poor management and low soil fertility. Development of suitable technology is essential to enhance productivity. Seed priming is one such effective technology which enhance rapid and uniform emergence to achieve high vigour, leading to better stand establishment and yield. The current research aimed to study micronutrient seed priming and rhizobium coating on seed germination, seedling vigour, crop growth and seed yield in black gram.Methods: Blackgram seeds were primed with 10 different micronutrient solutions with different concentrations and evaluated for its quality parameters to find out suitable seed priming technique. Seeds from two best priming treatments were coated with rhizobium @ 30g/kg of seed and evaluated for its production potential and resultant seed quality under field condition.Result: Seed priming with 0.5% ZnSO4 at 1/3rd seed to solution ratio for 3 hours recorded higher germination (96%) and vigour index (3811) than control which recorded 84% seed germination and 2528 of vigour index under laboratory experiment. Field experiments revealed that, seeds primed with 0.5% ZnSO4 and coated with rhizobium @ 30g per kg of seeds improved seed yield by 13.2% over control. 


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