Effect of soil temperature, seeding depth and cultivar on wheat tolerance to simulated ethalfluralin carryover

1997 ◽  
Vol 77 (1) ◽  
pp. 181-188
Author(s):  
A. L. Darwent ◽  
L. P. Lefkovitch ◽  
P. F. Mills

Field and controlled environment experiments were conducted at Beaverlodge, Alberta to determine the effect of soil temperature, seeding depth and cultivar on wheat (Triticum aestivum L.) tolerance to ethalfluralin. In one experiment, ethalfluralin was applied and incorporated, and wheat was seeded at several depths in late April/early May when soil temperatures were lowest or in late May when soil temperatures had increased. Mean 3-yr wheat yields decreased by 45% as the rate of ethalfluralin increased from 0 to 0.75 kg ha−1 and by 21% as the depth of seeding increased from 4 to 12.5 cm but the effect of ethalfluralin on yields was similar regardless of the soil temperature (time of seeding). Mean plant density decreased by 55% as the rate of ethalfluralin increased and by 25% as the depth of seeding increased. Reductions in mean plant density from ethalfluralin were slightly greater when seeded into the warmer soils. In another experiment, the effect of ethalfluralin on the yields of three wheat cultivars, Laura, Conway and Biggar was similar, i.e. the cultivar × rate of ethalfluralin interaction was not significant. However, the mean plant density of Biggar, averaged over rates of ethalfluralin, was less than that of the other cultivars in 1 of 2 yr. In a controlled environment experiment, the oven-dry weight and percent emergence of wheat shoots of the cultivars, Katepwa, Laura and Conway, seeded at 1.5 or 4 cm into soils containing ethalfluralin at concentrations of 0 to 4 ppm and maintained at temperatures of 4.5 or 15 °C, were reduced by decreases in temperature and increases in the rate of herbicide and depth of seeding. However, the interaction of soil temperature × rate of ethalfluralin was not significant for the oven-dry weight of the wheat shoots and the reduction in percent emergence of the wheat shoots as the rate of ethalfluralin increased was only slightly greater at 4.5 °C than at 15 °C. These results indicate that soil temperature and cultivar selection have a minor effect on wheat tolerance to ethalfluralin while herbicide concentration and depth of seeding have a major impact. Key words: Ethalfluralin, wheat, seeding depth, soil temperature, cultivar

1979 ◽  
Vol 59 (1) ◽  
pp. 237-240 ◽  
Author(s):  
S. FREYMAN ◽  
W. M. HAMMAN

In a controlled environment experiment, five phenoxy herbicides were sprayed at two rates on 14-day-old winter wheat (Triticum aestivum L. emend Thell ’Norstar’). After 7 additional days of active growth, the plants were cold-hardened for 14 days and then subjected to a freezing test. Four of the herbicides — MCPA amine, 2,4-D ester, 2,4-DB, 2,4-D amine — significantly reduced the cold hardiness of winter wheat whereas diclofop methyl had a minor effect. The reduction in hardiness was greater at the higher rates of application than at the lower rates.


2003 ◽  
Vol 83 (1) ◽  
pp. 89-98 ◽  
Author(s):  
F. J. Larney ◽  
T. Ren ◽  
S. M. McGinn ◽  
C. W. Lindwall ◽  
R. C. Izaurralde

Soil and crop management practices and their effects on surface residue levels can modify soil temperature. Our study investigated the effect of rotation, tillage and row spacing on near-surface (0.025 m) soil temperature under winter wheat (Triticum aestivum L.) in 1993-1994 and 1994-1995. The main treatment was winter wheat rotation: continuous winter wheat (WW); winter wheat-canola (Brassica campestris L.) (WC) or winter wheat-fallow (WF)] with tillage sub-treatments of conventional tillage (CT) vs. zero tillage (ZT) and row spacing treatments of uniform row (UR) vs. paired row (PR) spacing. From fall 1993 to spring 1994, ZT was cooler than CT by 1.2°C on the WC rotation, 1.1°C on WW and 0.4°C on the WF rotation. From fall 1994 to spring 1995, the magnitude of tillage differences was lower on all three rotations with ZT being cooler than CT by 0.1–0.9°C. The magnitude of the row spacing effect on soil temperature was less than that of the tillage effect. Extreme differences in soil temperature due to tillage were generally higher (1.0–4.9°C) on the WW and WC than the WF rotation (0.6–2.5°C) due to the presence of more crop residue. Results demonstrate that while ZT promotes overall cooler soils under winter wheat from fall to late spring, especially on continuously cropped (WW, WC) rotations, it also allows moderation of soil temperatures during extremely cold periods. Key words: Soil temperature, winter wheat, rotation, tillage, row spacing


2016 ◽  
Vol 43 (10) ◽  
pp. 961 ◽  
Author(s):  
Greg J. Rebetzke ◽  
Bangyou Zheng ◽  
Scott C. Chapman

Increases in air and soil temperatures will impact cereal growth and reduce crop yields. Little is known about how increasing temperatures will impact seedling growth and crop establishment. Climate forecast models predict that by 2060, mean and maximum air temperatures in the Australian wheatbelt will increase by 2−4°C during the March–June sowing period, and particularly at lower latitudes. Concomitant increases in soil temperature will shorten coleoptile length to reduce crop establishment, particularly where deep sowing to access sub-surface moisture. Mean coleoptile length was reduced in commercial wheat (Triticum aestivum L.) germplasm with increasing soil temperature (106 mm and 51 mm at 15°C and 31°C, respectively). Coleoptile lengths of modern semidwarf varieties were significantly (P < 0.01) shorter than those of older tall wheats at 15°C (95 mm and 135 mm) and 31°C (46 mm and 70 mm). A 12-parent diallel indicated large additive and small non-maternal genetic effects for coleoptile length at 15°C and 27°C. Large genotype rank changes for coleoptile length across temperatures (rs = 0.37, P < 0.05) contributed to smaller entry-mean heritabilities (0.41–0.67) to reduce confidence in selection for long-coleoptile genotypes across contrasting temperatures. General combining ability effects were strongly correlated across temperatures (rp = 0.81, P < 0.01), indicating the potential of some donors in identification of progeny with consistently longer coleoptiles. Warmer soils in future will contribute to poor establishment and crop failure, particularly with deep-sown semidwarf wheat. Breeding long-coleoptile genotypes with improved performance will require targeted selection at warmer temperatures in populations incorporating novel sources of reduced height and greater coleoptile length.


2006 ◽  
Vol 20 (1) ◽  
pp. 242-248 ◽  
Author(s):  
Robert G. Wilson ◽  
Alex R. Martin ◽  
Stephen D. Kachman

Roots of Canada thistle were excavated from the soil monthly from 1999 to 2001 near Scottsbluff, NE, to quantify the influence of changing soil temperature on free sugars and fructans in roots. Sucrose concentrations were low from May through August then increased in the fall and remained at high levels during winter and then declined in April as plants initiated spring growth. Changes in sucrose, 1-kestose (DP 3) and 1-nystose (DP 4) were shown to be closely associated with changes in soil temperature. During the second year of the study, average soil temperatures during the winter were colder than the first year and resulted in an increase of sucrose in Canada thistle roots. Experiments were conducted from 2001 to 2004 to determine whether there was a correlation between herbicide efficacy, time of herbicide application, and the resulting herbicide effect on root carbohydrate and Canada thistle control. Clopyralid applied in the fall reduced Canada thistle density 92% 8 months after treatment (MAT) whereas treatment made in the spring reduced plant density 33% 11 MAT. Fall application of clopyralid increased the activity of fructan 1-exohydrolase (1-FEH) in roots and was associated with a decline in sucrose, DP 4, and 1-fructofuranosyl-nystose (DP 5) 35 d after treatment (DAT). Spring application of clopyralid also resulted in a decrease of the same carbohydrates 35 DAT, but by 98 DAT, or early October, sucrose level in roots had recovered and was similar to nontreated plants. Fall application of 2,4-D or clopyralid reduced Canada thistle density 39 and 92% respectively, 8 MAT, but only clopyralid resulted in a reduction of sucrose, DP 4, DP 5, and total sugar and an increase of 1-FEH compared with nontreated plants.


1980 ◽  
Vol 60 (1) ◽  
pp. 61-68 ◽  
Author(s):  
J. M. DESCHENES ◽  
C. A. ST-PIERRE

On a St-André sandy loam and on a Kamouraska clay, the effect of soil temperature on oats (Avena sativa L.) was measured in the greenhouse using a system described by Deschênes et al. in 1974 and in the field, using two dates of seeding. The effect of weeds was measured by using un weeded and hand-weeded treatments. In the greenhouse, cool soil temperatures have delayed maturity and decreased straw and grain yields as well as total phytomass of oats on the two soil types. The dry weight of weeds in un weeded pots increased slightly. The effect of hand-weeding on oats was especially noticeable on the St-André sandy loam where three times as many weeds were observed. The straw yield and the total phytomass of oats were higher in the field experiment following an early seeding of oats on both soil types. On the other hand, grain yield was lower on plots seeded early and located on St-André sandy loam while the opposite was true on Kamouraska clay. The dry weight of weeds was lower on unweeded plots seeded early. The weeds reduced straw and grain yields on the St-André sandy loam but had no effect on Kamouraska clay because of the low weed infestation on the latter. The greenhouse and field experiments suggest that soil temperature is not the main factor in explaining the increase in grain yield observed with early-seeded cereals.


1980 ◽  
Vol 60 (3) ◽  
pp. 929-938 ◽  
Author(s):  
A. L. DARWENT

Experiments were conducted in the field and in controlled environment chambers at Beaverlodge, Alberta to determine the influence of soil temperature on the phytotoxicity of trifluralin (α,α,α-trifluoro-2,6-dinitro-N, N-dipropyl-p-toluidine) to wild oats (Avena fatua L.). In the field trifluralin reduced wild oat emergence the most in early May when soil temperatures were lowest. As soil temperatures increased in May, the effectiveness of trifluralin in reducing wild oat emergence declined. In controlled environment studies, the effectiveness of trifluralin in reducing wild oat shoot growth was greatest at 4 °C. At 7.5 °C, the effectiveness of trifluralin in reducing wild oat shoot growth declined. However, at both 10 and 20 °C, small increases in trifluralin phytotoxicity occurred. Exposure of wild oat shoots to trifluralin vapors at 7.5 and 20 °C indicated decreased shoot growth of wild oats at 7.5 °C but increased volatilization of trifluralin at 20 °C. Thus, the lack of any major differences in the effectiveness of trifluralin in reducing wild oat shoot growth at temperatures from 7.5 to 20 °C may be due to the counteraction of these two phenomena.


1978 ◽  
Vol 58 (4) ◽  
pp. 917-921 ◽  
Author(s):  
S. FREYMAN

Two winter wheat (Triticum aestivum L.) cultivars, Kharkov 22 MC and Winalta, were grown for 14 or 28 days under controlled environment from large or small seed or from seed with about half the endosperm removed. The kernels were seeded either 1 or 5 cm deep. After a 14-day cold hardening period followed by a freezing test, plants that had grown actively for 28 days were hardier than those that had grown actively for only 14 days. Plants from large kernels were hardier than those from small kernels, which in turn were slightly hardier than those from kernels with half the endosperm removed. Deep seeding reduced cold hardiness. The treatments had a marked effect on the dry weight of crowns and a smaller effect on crown total available carbohydrate content, both of which were positively correlated with cold hardiness, whereas water content was negatively correlated with cold hardiness.


1976 ◽  
Vol 12 (3) ◽  
pp. 279-288 ◽  
Author(s):  
F.R. Minchin ◽  
P.A. Huxley ◽  
R.J. Summerfield

The effects of different soil temperature regimes on vegetative growth, symbiotic nitrogen fixation and seed yield of two cowpea cultivars (K 2809 and Prima) were investigated in experiments carried out in plastic houses during the UK summer. Mean maximum soil temperatures above 32°C significantly reduced vegetative growth of both cultivars, through their effects on branch, peduncle and root dry weight per plant and, to a lesser extent, leaf production. The warmest temperature regime (35.4°C) also reduced nodule activity, especially in cv. Prima. Seed yields were adversely affected, due largely to changes in the number of peduncles per plant, as mean maximum soil temperature increased from 25.8 to 35.4°C.


1986 ◽  
Vol 66 (3) ◽  
pp. 385-395 ◽  
Author(s):  
M. C. J. GREVERS ◽  
A. A. BOMKE

Crop production in northern regions is mainly affected by a short growing season, and can also be further limited on heavy-textured soils by cool, wet spring conditions. Selected sod breaking practices were carried out resulting in maximum differences with respect to sod burial and soil physical properties. Soil physical properties measured included bulk density, air-filled porosity, aggregate size distribution, surface roughness and soil temperature. The main effects of the different tillage systems were: (1) differences in soil structure in terms of density and air-filled porosity, and (2) differences in the degree of residue incorporation. Moldboard plowing resulted in more favorable aeration porosity and soil temperature in spring than chisel plowing or discing. Rotovating prior to either moldboard plowing or chisel plowing had only a minor effect on soil physical conditions. In general the more effective the tillage was in incorporating crop residue and thatch, the higher was the subsequent soil temperature during the first 5 wk of the growing season. The differences in crop production followed the same trend as did differences in soil structure. This effect persisted through the third cropping season. Increasing levels of fertilizer N increased barley yields in all tillage treatments but did not offset the effect of physical differences caused by the tillage implements. Key words: Northern soils, tillage, soil temperature, soil structure, fertilizer nitrogen, barley


1973 ◽  
Vol 3 (2) ◽  
pp. 185-195 ◽  
Author(s):  
F. Endean ◽  
D. Hocking

Four types of container-grown lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) seedlings differing in age and rearing regime were transplanted into a controlled laboratory environment and into the field. After 12 weeks, seedlings were excavated and stem length and dry weight of shoot and roots were measured, these and derived parameters were compared with values obtained at the time of planting. Survival was uniformly high, the largest seedlings prior to planting performed best under all conditions. In the controlled environment experiment, initial shoot weight, total weight, and ratio of shoot weight/shoot length were significantly correlated with final root weight, an important factor in initial establishment; in addition shoot and total weight increment were significantly and positively correlated with initial shoot/root ratio. In the field no overall significant correlations were obtained. Shoot/root ratio decreased slightly in the controlled environment and significantly in the field after outplanting. Results suggest that the largest plant which can be grown and planted economically shows largest increment and achieves largest final total dry weight and root dry weight in the first growing season after outplanting. The need for a physiological rather than morphological grading of seedlings is stressed.


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