Improving the performance of canola in retained wheat stubble

2006 ◽  
Vol 57 (11) ◽  
pp. 1203 ◽  
Author(s):  
S. E. Bruce ◽  
M. H. Ryan ◽  
J. A. Kirkegaard ◽  
J. Pratley

Four field experiments investigated strategies to reduce the negative effects of surface-retained wheat stubble on the emergence, growth, and yield of canola. All experiments compared 3 stubble treatments: (1) no stubble (stubble removed or burnt); (2) stubble-spread (6 t/ha wheat stubble evenly distributed on the surface); and (3) stubble-inter-row (6 t/ha stubble distributed on the inter-rows only). Seedling emergence was reduced in the presence of evenly spread stubble compared with no stubble, and the emerged seedlings had longer hypocotyls, reduced leaf number, and reduced biomass. Reduced shoot growth was not associated with lower shoot N concentration. These early effects on shoot growth persisted at 3 of the 4 sites, resulting in average yield reductions of 26% (range 0–59%) in the stubble-spread treatments compared with no stubble. Restricting stubble to the inter-rows resulted in an initial reduction in seedling growth compared with no stubble, but this difference had diminished by flowering. The yield for the stubble inter-row treatment was similar to no stubble at 2 sites and intermediate between no stubble and stubble-spread at the other 2 sites, with an overall yield reduction of 5.3% compared with no stubble. The results indicate that the negative effects on canola performance of surface-retained wheat stubble can be largely eliminated by adopting sowing techniques that push wheat stubble away from the seeding row and onto the inter-row. This provides a viable option to stubble burning and maintains the benefits of stubble retention.

2002 ◽  
Vol 29 (7) ◽  
pp. 797 ◽  
Author(s):  
Jorge Alberto Zavala ◽  
Javier Francisco Botto

We report the impact of present-day solar UV-B radiation on seedling emergence, its association with the accumulation of UV-absorbing compounds, and the growth and yield of radish (Raphanus sativus L.). Two field experiments were conducted at intermediate latitudes in South America (Buenos Aires, Argentina) using two cultivars of radish (`Scarlet Globe' and `Sparkler National'). Solar UV-B reduced the emergence of seedlings by nearly 20% for the Scarlet radish cultivar, and delayed emergence for both cultivars by least one day. Using a chlorophyll fluorescence method to estimate the degree of UV penetration into photosynthetic tissue, we found significant differences in the levels of UV-B-absorbing compounds between seedlings grown under contrasting levels of solar UV-B. The increase of specific UV-absorbing compounds in the cotyledons required an initial lag period of 4 d after the emergence of seedlings. We could not detect any relationship between the accumulation of UV-B-screening compounds in cotyledons and leaves of the same plant, suggesting that solar UV-B induced a localized response in green tissues. Ambient UV-B affected the biomass partitioned to tubers, resulting in an increase of at least 17% in tuber diameter and 26% in tuber fresh weight at the end of the life cycle. Our results indicate that the early effects of UV-B on seedling development involve a cost for young plants, but it appears to be advantageous to increase the carbon partitioning to the tubers at harvest. These findings suggest ways to improve the yield of radish crops.


1994 ◽  
Vol 45 (3) ◽  
pp. 511 ◽  
Author(s):  
JA Kirkegaard ◽  
JF Angus ◽  
PA Gardner ◽  
W Muller

An experiment was conducted on a red earth at Harden, N.S.W., to investigate the effects of tillage and stubble management on the growth and yield of wheat in the first year of conservation cropping. Treatments involved stubble-management systems of incorporation, burning or retention combined with tillage systems of either direct drilling or minimum tillage. The experiment was conducted on an oat stubble of 3.9 t ha-1. Direct drilling and stubble retention both reduced seedling growth by 15%, compared to cultivated and stubble burnt treatments, but had no effect on plant density or tillering. The effects on shoot growth were additive and persisted until maturity, leading to grain yields which varied from 2.16 t ha-1 for the stubble-mulched, direct-drilled treatment to 3.20 t ha-1 for the burned-stubble, minimum-till treatment. Direct drilling reduced the total root length in the profile (0-160 cm) at anthesis by 40%, but there was no effect of stubble retention. Reduced shoot growth and rooting depth on direct-drilled and stubble-retained treatments reduced the recovery of water and mineral N by the crop and increased the leaching of mineral N below the root zone. Early shoot growth reductions on direct-drilled plots were not related to levels of soil water, mineral nitrogen (N) or soil temperature. Reduced shoot growth was associated with increased severity of Rhizoctonia in some direct drilled plots, but growth reductions often occurred in the absence of obvious symptoms. High soil strength (>2 MPa) in the top 10 cm of soil may have contributed to reduced growth, although the exact mechanism remains unclear. Reduced growth associated with the presence of stubble was not caused by immobilization of N or increased leaf disease, although reduced soil temperatures may have been partly responsible.


1974 ◽  
Vol 83 (1) ◽  
pp. 125-133 ◽  
Author(s):  
P. C. Longden ◽  
R. K. Scott ◽  
D. W. Wood

SUMMARYFrom monogerm sugar-beet seed as harvested non-viable fruits have to be eliminated, multigerm ones rejected and the size made sufficiently uniform for use in precision drills. Seed which had been gently rubbed to remove some of the cortex was graded for diameter, thickness and by aspiration, either singly or in combination. Effects of grading were determined by laboratory germination tests, radiography and field sowings in which seedling emergence and crop growth and yield were recorded.Grading by thickness was effective in removing multigerm fruits. Grading by aspiration and diameter rejected non-viable seed and reduced the variation in size. By combining all three grading methods, samples of seed of 80% germination and 90% monogermity were produced, provided the seed lot as threshed gave at least 50% germination. True seed weight increased with fruit diameter but only the first aspiration was effective in removing light true seeds. Radiography showed that both aspiration and, to a less extent, grading by diameter were effective in removing most empty fruits but neither eliminated those with shrivelled seed. The field experiments confirmed that increase in fruit diameter or aspiration gave more seedlings. Even at uniform, high plant density, sugar yields were less from the smallest (less than 3 mm diameter) than from the other grades of seed. The initial aspiration also improved sugar yield but further aspiration decreased yield.


HortScience ◽  
2010 ◽  
Vol 45 (11) ◽  
pp. 1639-1642 ◽  
Author(s):  
Ricardo Goenaga ◽  
A. Graves Gillaspie ◽  
Adolfo Quiles

Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable, and for consumption of its dry beans, which provide 22% to 25% protein. The crop is very sensitive to alkaline soil conditions. When grown at soil pH of 7.5 or higher, cowpea develops severe leaf chlorosis caused by deficiencies of iron (Fe), zinc (Zn), and manganese (Mn) resulting in stunted plant growth and yield reduction. We evaluated in replicated field experiments at St. Croix, U.S. Virgin Islands, and Juana Díaz, Puerto Rico, 24 PIs and two commercial cultivars, some of which have shown some tolerance to alkaline soils in unreplicated, seed regeneration plots of the U.S. cowpea collection. Alkaline soil conditions at St. Croix were too severe resulting in average yield of genotypes at this location being significantly lower and 77% less than that at Juana Díaz. Nevertheless, some genotypes performed well at both locations. For example, PIs 222756, 214354, 163142, 582605, 582840, 255766, 582610, 582614, 582576, 582809, and 349674 yielded in the upper half of the group at both locations. Accession PI 163142 ranked third in grain yield production at both locations and outyielded the iron-chlorosis-resistant controls at St. Croix. These genotypes deserve further attention as potential sources of alkaline soil tolerance.


2003 ◽  
Vol 51 (4) ◽  
pp. 445-453 ◽  
Author(s):  
S. Kant ◽  
P. Verma ◽  
S. S. Pahuja

In the sub-tropical regions of India, the 1st to 3rd week of November is the optimum time for sowing wheat. A delay in sowing due to various factors causes a substantial yield reduction. Seeds of four wheat varieties (Sonak, UP 2338, Raj 3765 and PBW 343) were subjected to seed priming treatments involving water, salts, growth regulator and the sowing of sprouted seed under late-sown conditions during the winter seasons of 1998-99 and 1999-2000. The sowing of sprouted seeds resulted in significantly more rapid emergence of seedlings, accompanied by higher grain and straw yields. Seeds primed with IAA, KCl, water, ZnSO4 and Na2SO4 followed in this order. The lowest seedling emergence and grain yield were obtained for unprimed seeds. Seedling emergence was higher in the variety Sonak, while Raj 3765 and UP 2338 had higher leaf water, osmotic and turgor potentials during the 1998-99 season. The variety PBW 343 produced significantly higher grain and straw yields in the 1999-2000 season.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Sonam Antil ◽  
Rakesh Kumar ◽  
D. V. Pathak ◽  
Anil Kumar ◽  
Anil Panwar ◽  
...  

Abstract Background Nematodes (Meloidogyne spp.) are a major reason behind the global crop yield reduction. The bacterial strain KMT-4 was isolated from nematode-affected tomato (Solanum lycopersicum) rhizosphere at research farms, Hisar, India, and screened for its biocontrol potential against root-knot nematode Meloidogyne javanica as well as checked for its effect on plant growth and yield. Results The bacterium KMT-4 was identified as Bacillus aryabhattai based on phenotypic characters and 16S rRNA sequence analysis. During in vitro studies, hatching and mortality of M. javanica were significantly affected due to the antagonistic behavior exhibited by the bacterium. In addition to this, KMT-4 also displayed various direct as well as indirect plant growth-promoting attributes like siderophore production, growth hormone (IAA) production, ammonia excretion, hydrogen cyanide production, and chitinase activity. A pot house experiment conducted on brinjal resulted in nearly 73% reduction in eggs, while 80% reduction in galls in the plant root compared to the untreated and chemically treated plants. The final nematode population also reduced significantly in KMT-4 treatment. It was 1141.6 J2/200cc soil in control and reduced to 108 J2/200 cc soil inoculated with KMT-4. Similar results were obtained in field experiments on brinjal and cucumber conducted in years 2018 and 2019, respectively. Also, a notable enhancement in the plant growth was observed in both pot house experiment and field trials. Conclusion The possession of nematicidal activity along with plant growth-promoting properties in B. aryabhattai KMT-4 warrants its employment as a potent biological control agent against M. javanica and a promising substitute of chemical nematicides.


2020 ◽  
Vol 34 (6) ◽  
pp. 849-856
Author(s):  
Thierry E. Besançon ◽  
Maggie H. Wasacz ◽  
Baylee L. Carr

AbstractResidual herbicides remain the primary tool for efficient weed control in cucurbit crops because of the lack of crop tolerance to many POST herbicide options. Field experiments were conducted in New Jersey in 2018 and 2019 to determine weed control efficacy and tolerance of direct-seeded cucumber ‘Python’ and summer squash ‘Gold Prize’ to S-metolachlor applied at 0.7 or 1.4 kg ai ha−1 at planting (PRE) or when crops reached the second- to third-leaf stage (EPOST). Regardless of applied rate, S-metolachlor PRE or EPOST provided 96% to 100% control 3 wk after planting (WAP) of smooth pigweed, large crabgrass, and giant foxtail. S-metolachlor PRE significantly improved American black nightshade and carpetweed control 3 WAP with respect to bensulide, and smooth pigweed with respect to clomazone + ethalfluralin. Summer squash showed excellent tolerance, regardless of S-metolachlor rate or timing of application, with stunting not exceeding 17% 4 WAP and 3% 7 WAP at the 1.4 kg ha−1 rate. Marketable yield decreased by 15% with S-metolachlor PRE or POST at 1.4 kg ha−1 with respect to clomazone + ethalfluralin, a reduction not noted when comparing with bensulide or the handweeded control. Marketable fruit number plant−1 and individual fruit weight were not affected by S-metolachlor applications. Conversely, cucumber was more sensitive to S-metolachlor than summer squash was with 30% seedling emergence reduction and 36% to 43% stunting 4 WAP when S-metolachlor was applied PRE at 1.4 kg ha−1. EPOST application resulted in 15% to 26% cucumber injury 1 wk after treatment. Marketable yield declined by 21% and 39% with the 0.7 and 1.4 kg ha−1 rates of S-metolachlor, respectively, compared with clomazone + ethalfluralin. Therefore, S-metolachlor may be a novel alternative to already labeled residual herbicides for summer squash, but unacceptable injury and yield reduction do not support its registration on cucumber.


2020 ◽  
pp. 1-8
Author(s):  
Thomas M Batts ◽  
Donnie K. Miller ◽  
James L. Griffin ◽  
Arthur O. Villordon ◽  
Daniel O Stephenson ◽  
...  

Abstract A major concern of sweetpotato producers is the potential negative effects from herbicide drift or sprayer contamination events when dicamba is applied to nearby dicamba-resistant crops. A field study was initiated in 2014 and repeated in 2015 to assess the effects of reduced rates of N,N-Bis-(3-aminopropyl)methylamine (BAPMA) or diglycloamine (DGA) salt of dicamba, glyphosate, or a combination of these individually in separate trials with glyphosate on sweetpotato. Reduced rates of 1/10, 1/100, 1/250, 1/500, 1/750, and 1/1,000 of the 1× use rate of each dicamba formulation at 0.56 kg ha−1, glyphosate at 1.12 kg ha−1, and a combination of the two at aforementioned rates were applied to ‘Beauregard’ sweetpotato at storage root formation (10 d after transplanting) in one trial and storage root development (30 d after transplanting) in a separate trial. Injury with each salt of dicamba (BAPMA or DGA) applied alone or with glyphosate was generally equal to or greater than glyphosate applied alone at equivalent rates, indicating that injury is most attributable to the dicamba in the combination. There was a quadratic increase in crop injury and a quadratic decrease in crop yield (with respect to most yield grades) observed with an increased herbicide rate of dicamba applied alone or in combination with glyphosate applied at storage root development. However, with a few exceptions, neither this relationship nor the significance of herbicide rate was observed on crop injury or sweetpotato yield when herbicide application occurred at the storage root formation stage. In general, crop injury and yield reduction were greatest at the highest rate (1/10×) of either salt of dicamba applied alone or in combination with glyphosate, although injury observed at lower rates would be cause for concern after initial observation by sweetpotato producers. However, in some cases yield reduction of No.1 and marketable grades was observed following 1/250×, 1/100×, or 1/10× application rates of dicamba alone or with glyphosate when applied at storage root development.


2013 ◽  
Vol 23 (2) ◽  
pp. 247-251 ◽  
Author(s):  
Ricardo Goenaga ◽  
Tomas Ayala ◽  
Adolfo Quiles

Cowpea or southernpea (Vigna unguiculata) is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans, which provide 22% to 25% protein. The crop is very sensitive to alkaline soil conditions. When grown at a soil pH of 7.5 or higher, cowpea develops severe leaf chlorosis caused by deficiencies of iron, zinc, and manganese resulting in stunted plant growth and yield reduction. We evaluated in replicated field experiments at St. Croix, U.S. Virgin Islands, and Miami, FL, four PIs and one commercial cultivar, some of which have shown some tolerance to alkaline soils in unreplicated, seed regeneration plots of the U.S. cowpea collection. At both locations, PI 582702 had significantly higher seed protein concentration than the other PIs, averaging 28%. Alkaline soil conditions at St. Croix were severe resulting in average yield of PIs at this location being significantly lower and 69% less than that in Florida. Nevertheless, some PIs performed well at both locations. For example, PI 582605 had significantly higher yield in Florida, whereas in St. Croix, PIs 582605, 582674, and 582702 were the highest yielders. These PIs may serve as an alternative to growers or home gardeners wishing to establish a legume crop in areas where agricultural production is severely restricted by high soil alkalinity.


Agriculture ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 15
Author(s):  
Spyridon D. Koutroubas ◽  
Christos A. Damalas

The use of plant growth regulator mepiquat chloride (MPC) has been a widespread practice for the control of vegetative growth in cotton production for several decades. As a growth retardant, MPC could potentially provide a means of controlling plant height in field sunflower (Helianthus annuus L.), but this possibility has not been studied. Field experiments over two years were conducted in northern Greece to study the influence of MPC at rates of 37.5 plus 37.5 g ha−1 (named double application) and 37.5 plus 37.5 plus 37.5 g ha−1 (named triple application) on sunflower growth and yield. MPC provided a height reduction of 9.5% (25 cm) with the double application and a height reduction of 14.4% (49.2 cm) with the triple application at maturity. The number of nodes was also reduced, indicating shorter plants, whereas stem width did not show a consistent response. Moreover, MPC resulted in increased crop growth rate with the triple application scheme. MPC reduced nitrogen utilization efficiency in both growing seasons. However, a reduction in achene yield per plant by 19.9% was observed with the triple application scheme. The achene yield reduction resulted by the reduction in the 100-achene weight (22.3%), given that the number of filled achenes was similar to control. None of the application schemes reduced seed nitrogen and oil content. The results from testing application schemes could be a basis for further research on the use of MPC in this crop, e.g., different timing of applications could be tested for benefits to height reduction.


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