Comparing fall and spring seeding of Kochia scoparia on saline soil

1993 ◽  
Vol 73 (4) ◽  
pp. 1055-1065 ◽  
Author(s):  
H. Steppuhn ◽  
D. G. Green ◽  
G. Winkleman ◽  
J. A. Kernan ◽  
E. Coxworth

Kochia scoparia naturally invades distributed soils in the Brown soil zone of the Canadian Prairies and offers potential as a forage crop in saline environments. A 3-yr study conducted on severely saline soil near Swift Current, Saskatchewan, compared kochia production resulting from fall (natural- and implement-seeded) and spring (early- and late-seeded) treatments. Late spring-seeded crops produced, on average, 5.4 t of dry, shoot biomass per ha per yr. Early spring and fall-seeded kochia (naturally or implement-placed) yielded between 5.4 and 10.9 t ha−1. Of the nine comparisons between forage yields from fall and spring seedings, six favored fall over spring, two were equal, and one produced more forage from early spring seedings than from the naturally-seeded fall treatment. The late spring treatment consistently produced the least forage. Fall seedings exhibited a greater potential for forage production because fall-seeded plants usually established early in the growing season and in sufficient number to fully exploit soil and water resources when conditions became favorable and effective rooting depths were not restricted by concentrated salt layers. When drier growing conditions prevailed, the lower plant densities associated with early spring seedings tended to minimize plant competition and foster greater forage production. Key words: Kochia forage, seeding dates, salinity, Kochia establishment, Kochia agronomy

1994 ◽  
Vol 74 (3) ◽  
pp. 267-275 ◽  
Author(s):  
H. Steppuhn ◽  
D. G. Green ◽  
J. E. Knipfel ◽  
E. Coxworth ◽  
J. A. Kernan

Kochia scoparia (L.) Schrad. naturally invades mechanically disturbed soils in the Brown and Dark Brown soil zones of the Canadian Prairies and offers potential as a forage crop in saline environments. A 3-yr study conducted on severely saline soil (~ 11 dS m−1) near Swift Current, Saskatchewan, evaluated the production of kochia forage and plant-N uptake following applications of 0, 56, 112 and 168 kg N ha−1 of ammonium nitrate. The yield response in aboveground, dried forage (Y) followed a curvilinear function based on the quantity of nitrogen applied (N): Y = 4740 + 38.5N − 0.121N2. The N-fertilizer requirement to produce 7500 kg ha−1 of dried forage (96% of the function maximum) equalled 110 kg N ha−1 and reflected average growing conditions at the study site during 1987–89. The kochia assimilated protein N (Kjeldahl) within its tissue in direct proportion to the fertilizer dosage applied, reaching theoretical maxima which varied yearly: 18 g kg−1 in 1987, 12 g kg−1 in 1988 and 22 g kg−1 in 1989. Although NO3-N concentrations increased with each addition of fertilizer N, the maximum accumulation of NO3 N (0.5 g kg−1) among all the tests and treatments was within the safe limit of 1.1 g kg−1 to avoid livestock poisoning. The efficiency with which the fertilizer N was assimilated by the kochia ranged between 44 and 69% over the test years and fertilizer treatments. Key words: Saline soil, N fertilization, kochia forage, soil fertility, salinity


1994 ◽  
Vol 74 (3) ◽  
pp. 531-537 ◽  
Author(s):  
T. Harrison ◽  
J. T. Romo

Regrowth and production of tillers in smooth bromegrass (Bromus inermis Leyss.) following defoliation to a 5-cm stubble height were monitored throughout the summer and in early spring the following year in central Saskatchewan. After defoliation, while smooth bromegrass was vegetative, forage began accumulating in 45–75 growingdegree-days (GDD) when moisture was favorable. Regrowth ranged from 34 to 84 g m−2. Plants also produced ≤ 51 g m−2 of regrowth when defoliated at or before culm elongation in a year with above-average precipitation. In two dry years, regrowth was minimal and plants did not regrow after defoliation in the later vegetative growth stages; however, new leaves were produced within 110–140 GDD. Following defoliation at early vegetative growth stages, 1030–1180 GDD were needed to reach maximum regrowth. Total annual production was either unaffected or reduced by defoliation. Total annual production ranged from 35 to 139 g m−2, with yields lowest when defoliated in early May or early June and highest when herbage was removed in mid-May or near flowering and seed production. When plants were defoliated during vegetative growth most tillers were produced the following spring, whereas when plants were defoliated during reproductive phases the majority of tillers emerged in the fall. The year after defoliation, the density of tillers (871–951 m−2) was not significantly different among treatments. Regrowth following defoliation cannot be related to a particular growth stage, but rather it depends on growing conditions. If smooth bromegrass is defoliated once and rested until the next year, it should be recovered by early spring and its productivity should be unaffected. Key words: Etiolated growth, forage production, grazing management, regrowth, rest requirement, tillering


2016 ◽  
Vol 67 (9) ◽  
pp. 1000 ◽  
Author(s):  
Marco Mariotti ◽  
Alessandro Masoni ◽  
Iduna Arduini

With the view to extending the cultivation of common buckwheat to Mediterranean environments, we investigated the responses of two varieties to three sowing times, early spring, late spring and late summer, in rainfed and irrigated conditions. Plants were harvested at two ripening stages for forage production and at maturity for grain yield. The crop cycle lasted 82–88 days independent of sowing time, whereas the thermal time was ~1000 degree-days in early spring and late summer sowings, and 1200 degree-days when sown in late spring. Forage yield increased up to 75% between ripening stages. Early spring was the best sowing time for forage (4 t ha–1 dry weight) and grain yield (2 t ha–1 dry weight) in rainfed conditions. Late spring sowings give the highest forage yield when irrigated (6 t ha–1 dry weight), but were not suitable for producing grain, for the adverse effect of high summer temperatures on seed set and seed filling. Late summer sowings produced acceptable grain yield (1.5 t ha–1 dry weight), whereas short days and low temperatures limited forage production. Thus, in Mediterranean environments, buckwheat could be profitably introduced as a minor summer crop, sown in early spring for grain production and in late spring for forage production.


2021 ◽  
pp. 1-17
Author(s):  
Leo Roth ◽  
José Luiz C. S. Dias ◽  
Christopher Evans ◽  
Kevin Rohling ◽  
Mark Renz

Garlic mustard [Alliaria petiolata (M. Bieb.) Cavara & Grande] is a biennial invasive plant commonly found in the northeastern and midwestern United States. Although it is not recommended to apply herbicides after flowering, land managers frequently desire to conduct management during this timing. We applied glyphosate and triclopyr (3% v/v and 1% v/v using 31.8% and 39.8% acid equivalent formulations, respectively) postemergence to established, second-year A. petiolata populations at three locations when petals were dehiscing, and evaluated control, seed production and seed viability. Postemergence glyphosate applications at this timing provided 100% control of A. petiolata by 4 weeks after treatment at all locations whereas triclopyr efficacy was variable, providing 38-62% control. Seed production was only reduced at one location, with similar results regardless of treatment. Percent seed viability was also reduced, and when combined with reductions in seed production, we found a 71-99% reduction in number of viable seed produced plant-1 regardless of treatment. While applications did not eliminate viable seed production, our findings indicate that glyphosate and triclopyr applied while petals were dehiscing is a viable alternative to cutting or hand-pulling at this timing as it substantially decreased viable A. petiolata seed production. Management Implications Postemergence glyphosate and triclopyr applications in the early spring to rosettes are standard treatments used to manage A. petiolata. However, weather and other priorities limit the window for management, forcing field practitioners to utilize more labor-intensive methods such as hand-pulling. It is not known how late in the development of A. petiolata these herbicides can be applied to prevent viable seed production. Since prevention of soil seedbank replenishment is a key management factor for effective long-term control of biennial invasive species, we hypothesized late spring foliar herbicide applications to second year A. petiolata plants when flower petals were dehiscing could be an effective management tool if seed production or viability is eliminated. Our study indicated that glyphosate applications at this timing provided 100% control of A. petiolata plants by 4 weeks after treatment at all locations, whereas triclopyr efficacy was inconsistent. Although both glyphosate and triclopyr decreased viable seed production to nearly zero at one of our three study locations, the same treatments produced significant amounts of viable seed at the other two locations. Our findings suggest late spring glyphosate and triclopyr applications should not be recommended over early spring applications to rosettes for A. petiolata management, as our late spring application timing did not prevent viable seed production, and may require multiple years of implementation to eradicate populations. Nonetheless, this application timing holds value in areas devoid of desirable understory vegetation compared to no management practices or mechanical management options including hand-pulling when fruit are present, as overall viable seed production was reduced to similar levels as these treatments.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 689
Author(s):  
Samantha Cannazzaro ◽  
Silvia Traversari ◽  
Sonia Cacini ◽  
Sara Di Di Lonardo ◽  
Catello Pane ◽  
...  

Non-thermal plasma (NTP) appears a promising strategy for supporting crop protection, increasing yield and quality, and promoting environmental safety through a decrease in chemical use. However, very few NTP applications on containerized crops are reported under operational growing conditions and in combination with eco-friendly growing media and fertigation management. In this work, NTP technology is applied to the nutrient solution used for the production of gerbera plants grown in peat or green compost, as an alternative substrate to peat, and with standard or low fertilization. NTP treatment promotes fresh leaf and flower biomass production in plants grown in peat and nutrient adsorption in those grown in both substrates, except for Fe, while decreasing dry plant matter. However, it causes a decrease in the leaf and flower biomasses of plants grown in compost, showing a substrate-dependent effect under a low fertilization regime. In general, the limitation in compost was probably caused by the high-substrate alkalinization that commonly interferes with gerbera growth. Under low fertilization, a reduction in the photosynthetic capacity further penalizes plant growth in compost. A lower level of fertilization also decreases gerbera quality, highlighting that Ca, Mg, Mn, and Fe could be reduced with respect to standard fertilization.


2010 ◽  
Vol 24 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Vince M. Davis ◽  
Greg R. Kruger ◽  
Bryan G. Young ◽  
William G. Johnson

Horseweed (Conyza canadensis) is a common weed in no-till crop production systems. It is problematic because of the frequent occurrence of biotypes resistant to glyphosate and acetolactate synthase (ALS)-inhibiting herbicides and its ability to complete its life cycle as a winter or summer annual weed. Tactics to control horseweed while controlling other winter annual weeds routinely fail; herbicide application timing and spring emergence patterns of horseweed may be responsible. The objectives of this experiment were to (1) determine the influence of fall and spring herbicides with and without soil residual horseweed activity on spring-emerging glyphosate-resistant (GR) horseweed density and (2) evaluate the efficacy and persistence of saflufenacil on GR horseweed. Field studies were conducted in southern Indiana and Illinois from fall 2006 to summer 2007 and repeated in 2007 to 2008. Six preplant herbicide treatments were applied at four application timings: early fall, late fall, early spring, and late spring. Horseweed plants were counted every 2 wk following the first spring application until the first week of July. Horseweed almost exclusively emerged in the spring at both locations. Spring horseweed emergence was higher when 2,4-D + glyphosate was fall-applied and controlled other winter annual weeds. With fall-applied 2,4-D + glyphosate, over 90% of the peak horseweed density was observed before April 25. In contrast, only 25% of the peak horseweed density was observed in the untreated check by April 25. Starting from the initiation of horseweed emergence in late March, chlorimuron + tribenuron applied early fall or early spring, and spring-applied saflufenacil at 100 g ai/ha provided greater than 90% horseweed control for 12 wk. Early spring–applied saflufenacil at 50 g ai/ha provided 8 wk of greater than 90% residual control, and early spring–applied simazine provided 6 wk of greater than 90% control. When applied in late spring, saflufenacil was the only herbicide treatment that reduced horseweed densities by greater than 90% compared to 2,4-D + glyphosate. We concluded from this research that fall applications of nonresidual herbicides can increase the rate and density of spring emerging horseweed. In addition, spring-applied saflufenacil provides no-till producers with a new preplant herbicide for foliar and residual control of glyphosate- and ALS-resistant horseweed.


Author(s):  
G.W. Sheath ◽  
R.W. Webby ◽  
W.J. Pengelly

Comparisons of controlling late spring to early summer pasture growth on either easy or steep contoured land with either a fast rotation or continuous grazing policy were made in self-contained farmlets for two years. Pasture control was maintained over more land by controlling steep land first and with continuous grazing. Animal performances (ewes, steers) were generally similar for the mid-November to early January treatment period, and subsequently until May shearing. In the first year better animal performances occurred in "steep control" farmlets during winter and early spring, but this was less evident in the second year. Priority control of steep land during late spring-early summer is recommended because of likely longer-term benefits in pasture composition,density and production. Quick rotation grazing through the period provides a better ability to recognise and manage pasture quantities and should be adopted if summer droughts are anticipated. For well fenced properties in summer-wet areas and with integrated stock grazing, continuous grazing during late spring-early summer may be equally suitable. Keywords: hill country, grazing management, pasture control


Parasitology ◽  
1991 ◽  
Vol 102 (1) ◽  
pp. 147-155 ◽  
Author(s):  
D. Rh. Thomas

SUMMARYNatural populations of 3rd-stage Nematodirus battus larvae were present on pastures in North Wales throughout the year; highest numbers were present in late spring, with smaller peaks occurring in autumn. Inter-site variation was observed in the timing and magnitude of these peaks. Hatching on experimental plots occurred 2 months to 2 years following deposition of eggs. Intraspecific and inter-site variation occurred in the timing, and inter-site variation occurred in the magnitude, of the mass hatch on upland and lowland experimental plots. Arrested 4th-stage N. battus were recovered from Welsh Mountain lambs. Percentage arrest and number of arrested worms was greatest during winter and early spring. The prevalence and intensity of N. battus infection in 1-, 2- and 3-year-old Welsh Mountain ewes was low. The plasticity exhibited in the parasite's life-history is discussed in relation to potential changes in the epidemiology of nematodiriasis.


1993 ◽  
Vol 73 (4) ◽  
pp. 765-778 ◽  
Author(s):  
W. D. Willms ◽  
P. G. Jefferson

The mixed prairie represents the most arid region of the Northern Great Plains in Canada. Approximately 6.5 M ha of the original total of 24 M ha have retained their native character. The native prairie supports about 5.3 M animal–unit–months or about 15% of all beef cattle present on the Canadian prairies. A large portion of the area is dominated by either needle-and-thread (Stipa comata Trin. + Rupr.) or western wheatgrass (Agropyron smithii Rydb.), both cool season grasses, and associated with blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Steud.] a warm season grass. These species define the major plant communities of the mixed prairie and determine their production potential. However, their production is limited by available water during the growing season and by soil nutrients; factors which also influence their species composition. Grazing imposes a significant impact on the grasslands by altering the water and nutrient cycles, through defoliation and reduced plant litter, and eventually by affecting the species composition. Removing litter may reduce forage production by up to 60% and repeated defoliation will favour the more drought tolerant but less productive species. Forage production may be increased by seeding introduced species, which have a greater shoot to root ratio than native grasses, or with fertilizer application. Livestock production may be increased with the use of grazing systems. However, the benefits of each practice on the mixed prairie must be assessed in terms of their cost, their impact on the environment, and the reduced or lost value for other users. Key words: Biomass, above-ground, below-ground, water-use efficiency, reseeding, soil fertility, grazing efficiency


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