Influence of single and combined mixtures of metal oxide nanoparticles on eggplant growth, yield, and Verticillium wilt severity

Plant Disease ◽  
2020 ◽  
Author(s):  
Wade H. Elmer ◽  
Roberto DeLaTorre Roche ◽  
Nubia Zuverza-Mena ◽  
Ishaq H Adisa ◽  
Christian Dimkpa ◽  
...  

Verticillium wilt, caused by Verticillium dahliae, is one of the major diseases of eggplants. Nanoparticles (NP) of CuO, Mn2O3, and/or ZnO were sprayed alone onto leaves young eggplants and in different combinations and rates and then seedlings were transplanted into soil infested with V. dahliae in the greenhouse and field during 2015-2018. All combinations of NP were consistently less effective than CuO NP applied alone at 500 µg/ml at enhancing disease suppression, biomass, and fruit yield. CuO NP were associated with an increase in fruit yield (17% and 33% increase) and disease suppression (28% and 22% reduction) in 2016 and 2017, respectively, when compared to untreated controls. However, this effect was negated in the greenhouse and field experiments when CuO NP was combined with Mn2O3. Combining NP of CuO with ZnO resulted in variable effects; amendments increased growth and suppressed disease in greenhouse experiments, but results were mixed in the field. Leaf tissue analyses from the greenhouse experiments showed that Cu concentration in leaves was reduced when CuO NP was combined with other NPs even when application rates were the same amount. A simple competition for entry sites may explain why combinations of CuO NP and Mn2O3NP reduced efficacy but does not explain the lack of inhibition between Cu and Zn. NPs of CuO performed better than their larger bulk equivalent and studies on application rate found 500 µg/ml was optimal. No phytotoxicity, as determined, by leaf burning, necrotic spots or dead apical buds was noted even at the highest combined rates of 1,500 µg/ml.

1998 ◽  
Vol 49 (8) ◽  
pp. 1297 ◽  
Author(s):  
L. P. D. Choo ◽  
G. H. Baker ◽  
L. P. D. Choo ◽  
G. H. Baker

The effects of 4 commonly used pesticides, endosulfan (insecticide), fenamiphos (nematicide), methiocarb (molluscicide), and ridomil (fungicide) on the survival, growth, and reproduction of the earthworm Aporrectodea trapezoides (Lumbricidae) were measured in laboratory and field experiments. When the earthworms were exposed to the pesticides on moist filter paper for 48 h, fenamiphos and, to a lesser extent, endosulfan caused significant mortality. In contrast, the survival of A. trapezoides was rarely affected by the pesticides during exposure for 5 weeks in pots and cages containing soil (only noted under 10 × normal application rate of endosulfan against adult worms). However, endosulfan did significantly reduce the weight of juvenile A. trapezoides within 5 weeks when applied to soil at normal application rate in both the field and laboratory. Fenamiphos did so at normal application rate in the field only. Fenamiphos and methiocarb reduced earthworm weight in the laboratory when applied at 10 × normal rate. The clitella of adult earthworms regressed with exposure to endosulfan at normal rate and also exposure to fenamiphos at 10 × normal rate. Cocoon production was inhibited by endosulfan and fenamiphos at normal application rates and methiocarb at 10 × normal rate. The use of some pesticides, in particular endosulfan, could significantly reduce the establishment of abundant and beneficial populations of earthworms in Australian pastures.


2017 ◽  
Vol 44 (1) ◽  
pp. 13-18 ◽  
Author(s):  
J.A. Arnold III ◽  
J.P. Beasley ◽  
G.H. Harris ◽  
T.L. Grey ◽  
M. Cabrera

ABSTRACT Calcium (Ca) availability in the 0 to 8 cm soil depth often limits peanut yield and influences grade in the southeastern United States. Field experiments were conducted in 2012 and 2013 at the University of Georgia's Coastal Plain Experiment Station, Tifton, GA (CPES) and the Southwest Georgia Research and Education Center, Plains, GA (SWREC) to determine large-seeded (Georgia-06G) and medium-seed sized (Georgia Greener) runner-type cultivar response to gypsum application rates of 0, 560, 1120, 1650 kg/ha. Peanut pod yield and grade (TSMK) were significantly different between locations with 7610 and 6540 kg/ha at CPES and SWREC, respectively. However, there were no differences between peanut cultivars or gypsum rates. Standard germination, seed vigor (cold germination), and seed Ca content analysis were also conducted on subsamples from each plot. Average peanut seed germination was 97% across all samples. No differences were observed for standard germination or vigor testing. Differences in locations were observed for yield, TSMK, percent jumbo, percent medium kernels, and seed Ca content. Peanut cultivar and gypsum application rate had effects on seed Ca concentration. Seed Ca concentration levels were 825 and 787 mg/kg for Georgia Greener and Georgia-06G, respectively. Seed Ca content increased as field gypsum application rate increased at both locations.


1984 ◽  
Vol 64 (4) ◽  
pp. 571-576 ◽  
Author(s):  
UMESH C. GUPTA ◽  
J. A. CUTCLIFFE

Field experiments were conducted at four locations in Prince Edward Island to determine the effect of applied B on leaf tissue B and yields of beans (Phaseolus vulgaris L.) and cabbage (Brassica oleracea var. capitata L.) in the year of application of B and again the following year. Application rates of 8.8 kg B∙ha−1 reduced bean seed yields at all locations and the 4.4-kg B∙ha−1 rate reduced yields at two locations in the first year. Leaf tissue B levels > 109 μg∙g−1 are clearly toxic for beans and seriously reduced bean yields. Furthermore, the yield and visual symptom data strongly suggest that tissue B levels even as low as 60 μg∙g−1 are toxic for this crop. No significant reductions in bean yields were noted in the second year crop, even at the 8.8 kg B∙ha−1 rate. Rates of up to 8.8 kg B∙ha−1 did not cause any reduction in cabbage yield even during the year of application. Leaf tissue B concentrations as high as 71–132 μg∙g−1 were not related to any B toxicity in cabbge. Added B did not increase yield of either beans or cabbage. Even though leaf tissue B levels as low as 16 μg∙g−1 in cabbage and 26 μg∙g−1 in beans occurred, no B deficiency was found. After the first and second years of beans the hot-water-soluble B in the soil ranged from 1.4 to 1.9 and from 0.8 to 1.2 μg∙g−1, respectively, where B had been applied at 8.8 kg∙ha−1. Key words: Cabbage, beans, boron toxicity, tissue boron, yields


2015 ◽  
Vol 29 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Patrick E. McCullough ◽  
Christopher R. Johnston ◽  
Thomas V. Reed ◽  
Jialin Yu

Buckhorn plantain is a perennial weed in turfgrass and efficacy of POST herbicides is often inconsistent for control in spring. Indaziflam is a cellulose biosynthesis inhibitor used for PRE control of annual weeds in turf and applications have shown to be injurious to established buckhorn plantain. The objectives of this research were to evaluate (1) effects of indaziflam application rate and placement on buckhorn plantain injury; (2) effects of tank-mixing indaziflam with POST herbicides for buckhorn plantain control; and (3) physiological effects of indaziflam on absorption and translocation of14C-2,4-D in buckhorn plantain. In greenhouse experiments, indaziflam reduced buckhorn plantain shoot mass 61 to 75% from the nontreated at 4 wk after treatment (WAT) and hierarchical rank of application placements were: foliar + soil ≥ soil ≥ foliar. Differences in biomass reduction from application rates (27.5 and 55 g ai ha−1) were not detected. In field experiments, indaziflam at 55 g ha−1controlled buckhorn plantain 34% at 9 WAT but enhanced the speed of control from all herbicides tested in tank mixtures. Exclusive applications of 2,4-D or 2,4-D + dicamba + MCPP provided poor control (< 70%) of buckhorn plantain at 9 WAT, but tank mixtures with indaziflam provided 81 and 98% control, respectively. Fluroxypyr and simazine alone controlled buckhorn plantain < 38% but tank mixtures with indaziflam enhanced control more than twice as much from exclusive applications. Tank-mixing indaziflam with metsulfuron did not improve control from metsulfuron alone after 9 wk. Bermudagrass injury was not detected from any treatment. In laboratory experiments,14C-2,4-D absorption and translocation in buckhorn plantain was similar with or without indaziflam tank mixtures at 72 and 168 h after treatment. Overall, indaziflam may improve buckhorn plantain control from POST herbicides by providing additive phytotoxicity in tank mixtures in spring.


1971 ◽  
Vol 77 (2) ◽  
pp. 243-246
Author(s):  
Maurice Eddowes

SummaryIn a series of field experiments from 1966 to 1969, on light sandy loam soils in the West Midlands, comparisons were made between two levels of application of herbicides based on urea, triazine and bipyridil compounds for weed control in early potatoes.Under conditions of adequate nutrient and water supply, the high application rate controlled about 94%, and the low application rate about 88% of the annual weeds. At equivalent application rates, urea compounds and herbicide mixtures containing ureas, gave superior weed control to triazine compounds and herbicide mixtures containing triazines, but the ureas were apparently more phytotoxic to the potatoes.In 1970, comparisons were made between three levels of application of ametryne and monolinuron, high, medium and low and an unsprayed control treatment.The highest yields of potatoes were associated with the low application rates of herbicides from 1966 to 1970.It was concluded that, on these light sandy loam soils, when irrigation is available, relatively low application rates of either monolinuron or ametryne, or mixtures of ureas or of triazines, or mixtures of bipyridils and ureas or triazines could give adequate control of annual weeds in early potatoes at low cost.


Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Tracy E. Klingaman ◽  
Charles A. King ◽  
Lawrence R. Oliver

Field experiments were conducted in 1986, 1987, and 1988 to evaluate imazethapyr rate and time of application on postemergence control of 24 weed species. Contour graphs were developed that predicted imazethapyr rates required for various levels of weed control based upon weed leaf number at application. Rates below the labeled rate (70 g ha−1) provided 90% or greater control of common cocklebur, smallflower morningglory, and smooth pigweed if applied to 3 true-leaf or smaller weeds and of barnyardgrass, seedling johnsongrass, and Palmer amaranth if applied while weeds were in the cotyledon or 1 true-leaf stage. A rate of 70 g ha−1provided 90% control of large crabgrass in the 1 true-leaf stage. Entireleaf morningglory, red rice, pitted morningglory, and velvetleaf are not susceptible enough to imazethapyr for 90% or greater control to be obtained with rates lower than 70 g ha−1at the 1 true-leaf growth stage. These data demonstrate how control data can be used for developing effective reduced-rate herbicide recommendations based on weed leaf number.


1982 ◽  
Vol 22 (119) ◽  
pp. 420 ◽  
Author(s):  
K Spencer

To assess the feasibility of adding selenium to pastures likely to be associated with White Muscle Disease and related disorders in stock, plants of subterranean clover (Trifolium subterraneum L.) were raised in pots and supplied with rates of selenium (as selenate) and sulfur (as sulfate) in factorial combinations. On the soil used, increasing rates of selenium progressively depressed growth of clover and increased its selenium concentration; sulfur stimulated growth up to an addition of about 16 yg S/g and depressed the selenium concentration only when selenium was added. More sulfur was required to depress the selenium concentration to a threshold level, which was characteristic of a particular selenium application rate, at high initial selenium levels than at low. Clover growth was reduced when the sulfur to selenium ratio in the tops was less than 50: 1. Application rates greater than 0.025 �g Se/g soil (= 40 g/ha) produced young clover plants with excessive levels of selenium for consumption by stock. The safe rate for application to a mixed pasture is likely to be considerably less than that value. Field experiments confirmed that appreciable diminution of the selenium concentration in pasture as a result of sulfur addition occurred only when selenium was in plentiful supply. Grasses were much more affected than clovers. It is concluded that the negative interaction demonstrated between selenium and sulfur is of no practical significance when each is added at rates appropriate to the treatment of low sulfur-low selenium pastures.


1996 ◽  
Vol 127 (4) ◽  
pp. 475-486 ◽  
Author(s):  
M. F. Allison ◽  
M. J. Armstrong ◽  
K. W. Jaggard ◽  
A. D. Todd ◽  
G. F. J. Milford

SUMMARYThe effects of different rates of N fertilizer (0–180 kg N/ha) were tested on the growth, yield and processing quality of sugarbeet in 34 field experiments in England between 1986 and 1988. The experiments were performed using soil types, locations and management systems that were representative of the commercial beet crop in the UK. The responses obtained showed that current recommendations for N fertilizer use are broadly correct, but large differences occurred on some soil types, in some years, between the recommended amounts and the experimentally determined optima for yield. The divergence was largest when organic manures had been applied in the autumn before the beet crop. Calculations using a simple nitrate-leaching model showed that much of the N in the manures was likely to be leached, the extent of leaching being much less if the manure application was delayed until spring. In these circumstances, spring measurement of inorganic mineral N in the soil could improve fertilizer recommendations. In situations where higher than optimum rates of fertilizer N were used, the extra N had little effect on yield. Increasing the rate from 0 to 180 kg N/ha increased the amount of nitrate left in the soil at harvest by only 8 kg N/ha. The amount of inorganic N released into the soil from crop residues at harvest increased by 50 kg N/ha with N application rate, and the fate of this N has not been established.


2020 ◽  
Vol 56 (No. 4) ◽  
pp. 305-316
Author(s):  
Ivana Doležalová ◽  
Irena Petrželová ◽  
Martin Duchoslav

Field experiments were conducted to evaluate the efficacy, selectivity and health harmlessness of four application rates of two pre-emergent herbicides (pethoxamid and dimethachlor) in the rocket [Eruca vesicaria (L.) Cavanilles)]. Pethoxamid was found to be less efficient on the total weed density (efficacy 86.0–93.3%) in comparison with the effect of dimethachlor (94.9–95.8%). Dimethachlor expressed an excellent efficacy on Echinochloa crus-galli (L.) P. Beauvois, Portulaca oleracea Linnaeus, Amaranthus retroflexus Linnaeus, Lamium purpureum Linnaeus, and Veronica persica Poiret from the lowest tested application rate (800 g/ha). Pethoxamid showed an excellent efficacy on E. crus-galli, Lamium purpureum, Lamium amplexicaule Linnaeus, V. persica, and P. oleracea. In higher application rates, pethoxamid controlled Chenopodium polyspermum Linnaeus and Chenopodium album Linnaeus. In contrast to mostly negative effects of dimethachlor, pethoxamid showed either no effects or positive ones on the rocket yield. Residues of both herbicides in the harvested product were always below a 'default limit', which is the baseline maximum residue level for food. The selectivity of pethoxamid at an application rate of 960 g/ha was good, herbicide residues in the rocket were not detected and the yield of the rocket increased.


2014 ◽  
Vol 28 (1) ◽  
pp. 213-224 ◽  
Author(s):  
Michael L. Flessner ◽  
J. Scott McElroy ◽  
Glenn R. Wehtje

‘Replay' and ‘JS501’ perennial ryegrass cultivars have been conventionally bred for reduced sensitivity to glyphosate, potentially allowing the herbicide to be used for selective weed control in overseeded bermudagrass. Field experiments were conducted to evaluate optimal glyphosate application rate, regime (single and sequential applications), and timing for annual bluegrass control in bermudagrass overseeded with these cultivars. Additionally, greenhouse experiments were conducted to compare the sensitivity to glyphosate of Replay and JS501 to susceptible cultivars ‘Caddy Shack' and ‘Top Gun II' through log-logistic rate-response analysis. In field experiments, only two treatments resulted in > 90% annual bluegrass control and < 25% perennial ryegrass injury. These two treatments were a single application of 280 g ae ha−1glyphosate in January and 140 g ha−1followed by an additional 140 g ha−1applied in January. Perennial ryegrass cultivars were compared using 50% inhibition (I50) values, i.e. 50% visible estimates of injury or 50% reduction in clipping weight.I50values obtained 6 wk after treatment from injury data were 2.56, 2.64, 0.81, and 0.84 g ha−1glyphosate for Replay, JS501, Caddy Shack, and Top Gun II, respectively. Replay and JS501 were similar in sensitivity to glyphosate and were up to four times more tolerant than Caddy Shack and Top Gun II across rating dates and data types.


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