Sugarcane (Saccharum spp. hybrids) Response to Simulated Fallow Field Residues of Metribuzin and Sulfometuron

1998 ◽  
Vol 12 (3) ◽  
pp. 454-457 ◽  
Author(s):  
Donnie K. Miller ◽  
Edward P. Richard ◽  
James L. Griffin

Sulfometuron at 17 g ai/ha in the planting furrow (13% of the anticipated fallow-field application rate) inhibited sugarcane emergence and development and ultimately reduced sugar yields in the initial production year by 13% when compared to a weed-free control that contained no herbicide in the planting furrow. Residual levels of metribuzin in the planting furrow representing 100% of the standard fallow-field application rate of 1,680 g ai/ha had no adverse effect on sugarcane development or sugar yield. When applied only to the soil surface immediately after planting, sulfometuron did not injure sugarcane, and sugar yields were equivalent to standard, at-planting, preemergence (PRE) applications of either metribuzin at 2,020 g/ha or a mixture of pendimethalin plus atrazine each at 2,240 g ai/ha. To minimize sugarcane injury, sulfometuron should be kept out of the germinating zone of lateral buds along planted sugarcane stalks.

2005 ◽  
Vol 83 (12) ◽  
pp. 1622-1629 ◽  
Author(s):  
J.K. Rowntree ◽  
E. Sheffield

The systemic herbicide asulam is used extensively to control the weedy fern bracken ( Pteridium aquilinum (L.) Kuhn). Other ferns were thought to be highly sensitive to asulam exposure, but there has been a dearth of experimental evidence. Eight fern species were exposed to asulam spray at three different application rates or a control of water. Asulam was applied at the recommended field application rate for bracken clearance, and at two further rates corresponding to 10 and 50 m downwind of an aerial spray event. Damage was assessed over two seasons. All ferns tested were severely damaged by exposure to the highest application rate, but sensitivity varied between species. Maximum damage occurred 1 year after spraying, and limited signs of recovery could be seen by the second season. The effects of adding the adjuvant Agral® to applications of asulam were tested on the threatened pteridophyte Pilularia globulifera L. No damage additional to that caused by exposure to asulam was observed. This work supports the view that 50 m buffer zones are sufficient to protect sensitive ferns from the effects of aerial spraying with asulam, provided that drift-reducing nozzles are used and the manufacturer’s application guidelines are observed.


2002 ◽  
Vol 82 (3) ◽  
pp. 599-610 ◽  
Author(s):  
L. M. Dosdall ◽  
R. -C. Yang ◽  
P. M. Conway

While the importance of sulfur nutrition for the development of healthy stands of canola is well documented, the role of sulfur in the management of insect pest infestations has not previously been investigated in this crop. Field experiments were conducted at three sites in central Alberta in 1997 and 1998 to determine the influence of sulfur and sulfate applications on infestations of root maggots (Delia spp.) (Diptera: Anthomyiidae) in canola (Brassica rapa L.). Different formulations (granules, powder, prills, and sprays), application methods (either drilled in with the seed or top-dressed on the soil surface), and application rates were evaluated. To assess the degree of root maggot infestation, oviposition throughout the season and damage to taproots at the end of the season were monitored. Sulfur contents were analyzed from leaf samples collected mid-season and seed yields were measured from all treatment plots. Root maggot responses to the different sulfur treatments and application methods varied among years and sites, indicating that environmental factors have great importance in determining infestation levels by these pests, and the oxidation rate of elemental sulfur in soil. Sulfur formulation and application rate had significant effects on root maggot egg deposition and root damage for some sites and years, but even at high rates of application (112 kg ha-1) reductions in infestation levels were not substantial relative to the controls. While sulfur additions alone will not greatly reduce root maggot infestation levels in canola, growers should employ adequate sulfur nutrition for optimum crop health to enable plants to better compensate for damage by these pests. Key words: Brassica rapa, Delia radicum, Delia floralis, elemental sulfur, sulfate, canola


Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 683-687 ◽  
Author(s):  
Richard W. Jones ◽  
W. Thomas Lanini ◽  
Joseph G. Hancock

Gliocladium virens, when grown on peat moss amended with sucrose and ammonium nitrate and then applied to soil, resulted in root necrosis. Herbicidal activity was correlated with fungal production of the phytotoxin viridiol. Viridiol had a wide spectrum of activity; it was particularly effective against annual composite species but was less effective in monocot control. Emergence of most weeds was reduced >90% at application rates of 8.7% (of total volume) or less. Treated seedling dry weights were drastically reduced. Applications of 4.5% reduced root and shoot weight of redroot pigweed by 93 and 98%, respectively. Crops were affected at higher treatment levels; however, the toxicity was readily avoided by applying the mycoherbicide out of the root zone of the crop, instead applying it between the seed and the soil surface. Viridiol production, which confers herbicidal activity, was detected 3 days after incorporation of the fungus-peat mixture. Viridiol production peaked on days 5 and 6 at approximately 25 μg viridiol/100 ml soil, based upon an application rate of 11%, then declined to undetectable levels by the end of 2 weeks.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tianbao Ren ◽  
Huanhuan Wang ◽  
Ye Yuan ◽  
Huilin Feng ◽  
Bo Wang ◽  
...  

AbstractIn order to explore the effects of biochar on root system and growth characteristics of flue-tobacco, three years of field experiments were conducted to study the influence of different biochar application levels [600 (T1), 1200 (T2), 1800(T3), 2400 (T4), 3000 (T5) kg/ha] and no fertilizer (CK) on the root physiological indexes and growth index of tobacco. Compared with local conventional fertilization, the application rate of N fertilizer in each treatment (except for control) was reduced by 40% to analyze the effects of different amount of biochar on the physiological indexes of tobacco roots and leaf photosynthesis during flourishing. The results showed that tobacco plants' root development status in the flourishing period was consistent with the photosynthetic physiological indexes, chlorophyll content, and leaf-area coefficient. Compared with the control, the application of biochar could increase the root vigor by 177.8%. Biochar improved the roots, increasing the total root area by 91.35% and the number of root tips by 100.9%. Meanwhile, biochar increased the net photosynthetic rate of tobacco leaves by 77.3% and the total tobacco biomass by 72.5%. Studies have shown that biochar can promote the development of tobacco roots, and then enhance the photosynthesis of leaves, so that tobacco plants can grow healthily, which is conducive to the tobacco production and the cultivation of soil.


Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 640-644 ◽  
Author(s):  
Nagabhushana G. Gubbiga ◽  
A. Douglas Worsham ◽  
Frederick T. Corbin

Greenhouse and growth chamber experiments were conducted to determine the reasons for stunted growth and yield suppression of corn noticed sometimes in nicosulfuron-treated corn fields infested with heavy population of johnsongrass. Results indicated that in the absence of johnsongrass, nicosulfuron applied broadcast POST at 35 g ai ha−1had no effect on corn. However, growth reduction of corn occurred when nicosulfuron-treated johnsongrass and corn were allowed to share the same rooting medium with their root systems intermingled. The reduction in growth was even greater when corn foliage or the soil surface were also treated with johnsongrass. The extent of growth reduction of corn growing with nicosulfuron-killed johnsongrass depended on weed density and herbicide application rate. Greater growth reductions occurred at four johnsongrass plants per pot compared to two and at a higher application rate of 100 μg nicosulfuron per plant. In general, johnsongrass killed by nicosulfuron appeared to be more phytotoxic to corn than plants killed by paraquat. Nicosulfuron provided excellent control of johnsongrass and improved corn growth by two to three times that of not controlling johnsongrass, but it could not elevate corn growth to the level obtained when johnsongrass was controlled by paraquat or in the absence of interference from johnsongrass.


Author(s):  
Blake E Wilson

Abstract The sugarcane borer, Diatraea saccharalis (F.), is the primary pest of sugarcane, Saccharum spp., in Louisiana. Recent evidence suggests an integrated pest management (IPM) program has reduced the pest’s impact, but the success of this program has not been assessed across the industry. The level of D. saccharalis injury present at harvest was recorded from 388 billet samples from five sugar mills from 2017 to 2019. These results were used to estimate direct and indirect revenue losses from D. saccharalis on the Louisiana sugarcane industry. Insecticide use records were used to estimate control costs and determine total economic impact. The mean percentage of bored internodes was 1.1, 0.3, and 1.7% for 2017, 2018, and 2019, respectively. Direct losses from reduced sugar yield averaged US$4.6 million across years. Indirect losses across years accounted for US$3.0 million and $463,000 for insecticidal control costs and reduced milling efficiency, respectively. The total economic impact of D. saccharalis averaged $8.0 million annually during the three-year study period. This study demonstrates the efficacy of pest management implementation in reducing D. saccharalis injury and highlights the value of IPM. Our findings provide new support for the emergence of D. saccharalis management in the Louisiana sugarcane industry as a modern IPM success story.


Weed Science ◽  
1976 ◽  
Vol 24 (5) ◽  
pp. 461-466 ◽  
Author(s):  
R. G. Wilson ◽  
H. H. Cheng

The fate of 2,4-D [(2,4-dichlorophenoxy)acetic acid] in the soil under winter wheat (Triticum aestivumL. ‘Nugaines’) and fallow cropping schemes was studied under the field conditions of eastern Washington in 1973 and 1974 using formulated dimethylamine salt and isooctyl ester of 2,4-D. Soil samples taken 1 hour after herbicide application showed that amine-treated plots retained considerably more applied 2,4-D than ester-treated plots. The rapidity of 2,4-D breakdown decreased gradually with time, and at the end of 6 months, an average of 0.04 ppm of 2,4-D remained in the sampled soil profile regardless of formulation, application rate, or cropping scheme. Loss of 2,4-D from the soil surface in runoff occurred when the plots were irrigated heavily one day after the herbicide application. The herbicide was also leached into the soil profile by both irrigation and natural precipitation. Herbicide concentrations in the sampled portion of the upper soil profile decreased during the summer and then increased slightly in the fall.


Plant Disease ◽  
2012 ◽  
Vol 96 (8) ◽  
pp. 1104-1110 ◽  
Author(s):  
Deborah A. Samac ◽  
Dawn Foster-Hartnett

Glyphosate, the active ingredient in Roundup herbicide, inhibits 5-enol-pyruvyl shikimate 3-phophate synthase (EPSPS), an enzyme found in plants, fungi, and bacteria. Plants engineered for glyphosate tolerance with a glyphosate-insensitive EPSPS take up and translocate the herbicide throughout the plant. In greenhouse experiments, we found that application of glyphosate at the recommended field application rate completely controlled alfalfa rust (Uromyces striatus) on 4-week-old plants inoculated with the fungus 3 days after glyphosate treatment. Control was effective in all seven cultivars tested. The level of protection declined with time after application, indicating that control transitory and protection declined with time after inoculation, suggesting that protective treatments have fungistatic activity. Complete control of rust was obtained when glyphosate was applied up to 10 days after inoculation with rust spores, indicating that the herbicide also has curative activity. Treatment increased protection from anthracnose, caused by Colletotrichum trifolii, a hemibiotrophic pathogen, and reduced symptom severity for spring black stem and leaf spot, caused by Phoma medicaginis, a necrotrophic pathogen. These results indicate that glyphosate could be used to help manage foliar diseases in glyphosate-tolerant alfalfa.


2017 ◽  
Vol 11 (4) ◽  
pp. 1-9
Author(s):  
Gulzar Sanghera ◽  
Harmandeep Singh ◽  
Vikrant Tyagi ◽  
Rupinder Singh ◽  
Lenika Kashyap

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 572 ◽  
Author(s):  
Weijin Wang ◽  
Glen Park ◽  
Steven Reeves ◽  
Megan Zahmel ◽  
Marijke Heenan ◽  
...  

Nitrous oxide (N2O) emissions from sugarcane cropped soils are usually high compared with those from other arable lands. Nitrogen-efficient management strategies are needed to mitigate N2O emissions from sugarcane farming whilst maintaining productivity and profitability. A year-long field experiment was conducted in wet tropical Australia to assess the efficacy of polymer-coated urea (PCU) and nitrification inhibitor (3,4-dimethylpyrazole phosphate)-coated urea (NICU). Emissions of N2O were measured using manual and automatic gas sampling chambers in combination. The nitrogen (N) release from PCU continued for >5–6 months, and lower soil NO3– contents were recorded for≥3 months in the NICU treatments compared with the conventional urea treatments. The annual cumulative N2O emissions were high, amounting to 11.4–18.2kg N2O-Nha–1. In contrast to findings in most other cropping systems, there were no significant differences in annual N2O emissions between treatments with different urea formulations and application rates (0, 100 and 140kgNha–1). Daily variation in N2O emissions at this site was driven predominantly by rainfall. Urea formulations did not significantly affect sugarcane or sugar yield at the same N application rate. Decreasing fertiliser application rate from the recommended 140kgNha–1 to 100kgNha–1 led to a decrease in sugar yield by 1.3tha–1 and 2.2tha–1 for the conventional urea and PCU treatments, respectively, but no yield loss occurred for the NICU treatment. Crop N uptake also declined at the reduced N application rate with conventional urea, but not with the PCU and NICU. These results demonstrated that substituting NICU for conventional urea may substantially decrease fertiliser N application from the normal recommended rates whilst causing no yield loss or N deficiency to the crop. Further studies are required to investigate the optimal integrated fertiliser management strategies for sugarcane production, particularly choice of products and application time and rates, in relation to site and seasonal conditions.


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