scholarly journals Evaluation of Residue Levels of Imidacloprid and Thiamethoxam After Foliar Application to the Citrus Varieties Lane Late, Valencia Late, Rohde Summer, and Nules

2019 ◽  
Vol 112 (6) ◽  
pp. 2676-2685
Author(s):  
María Teresa Martínez-Ferrer ◽  
José Miguel Campos-Rivela ◽  
María Dolores Hernando-Guil ◽  
Ana Isabel García-Valcárcel
Keyword(s):  
Exposure Assessment ◽  
Foliar Application ◽  
Field Studies ◽  
Flowering Period ◽  
Potential Exposure ◽  
Residue Levels ◽  
Citrus Varieties ◽  
Citrus Variety ◽  
Citrus Trees

Abstract Neonicotinoids are used to protect citrus trees against pests. Dissipation and persistence of neonicotinoids in pollen and nectar of citrus trees after foliar applications and their potential exposure to pollinators have not been well characterized. Field studies were conducted using three orange and one mandarin varieties to compare the imidacloprid and thiamethoxam residue levels and their decline in pollen and nectar after treatments in pre-bloom close to flowering period and their persistence 1 yr after treatment. The possible risk to honeybees was assessed. In nectar, thiamethoxam and imidacloprid residues were between 61 and 99% lower than in pollen, depending on the citrus variety or/and the days after treatment when applied close to blooming. At the end of the flowering period, imidacloprid in pollen and nectar was not detected in the mandarin variety after treatment in pre-bloom, whereas for thiamethoxam, no residues were detected in nectar but 10 ng/g was detected in pollen. There were no quantifiable levels of residues for either neonicotinoids in pollen or nectar during the flowering period of the following year. Neonicotinoid residue levels and their decline in nectar and pollen in citrus depended on the timing of applications relative to flowering and on the citrus variety. The absence of neonicotinoid residues 1 yr out after foliar applications in all varieties assayed demonstrated that none of the neonicotinoids tested were persistent. The results could be different in other citrus varieties, and therefore, also the exposure assessment for managed pollinators.

Effect of foliar application of chelated copper and manganese on yield components and fibre properties of Egyptian cotton (Gossypium barbadense)

1993 ◽  
Vol 121 (2) ◽  
pp. 193-198 ◽  
Author(s):  
Z. M. Sawan ◽  
M. H. Mahmoud ◽  
B. R. Gregg
Keyword(s):  
Yield Components ◽  
Agricultural Research ◽  
Foliar Application ◽  
Field Studies ◽  
Gossypium Barbadense ◽  
Research Centre ◽  
Fibre Properties ◽  
Foliar Sprays ◽  
Egyptian Cotton ◽  
Cotton Cultivar

SUMMARYA decline in supplies of organic manures and the increased use of chemical fertilizers has led to a decrease in the micronutrient content of the soil, with attendant effects on yield.Field studies were conducted in 1986 and 1987 at the Giza Agricultural Research Centre, Egypt, to determine the effect of Cu-EDTA and Mn-EDTA foliar sprays on growth, mineral content, yield components and fibre properties of the Egyptian cotton cultivar Giza 75 (Gossypium barbadense L.).All combinations used significantly increased the uptake of Cu and Mn and the dry matter yield. The earliness of harvest and the value of yield components were all increased by the application of Cu or Mn; 25 mg/1 of both Cu and Mn gave the highest values. Lint percentage and fibre properties were not significantly affected.This study indicated that the yield of cotton, grown under otherwise standard conditions, may be increased by foliar sprays of Cu-EDTA and Mn-EDTA combined.

Metolachlor and Alachlor Persistence in Rice (Oryza sativa) Following Soybean (Glycine max)

1989 ◽  
Vol 3 (1) ◽  
pp. 82-85 ◽  
Author(s):  
James L. Griffin ◽  
John F. Robinson
Keyword(s):  
Oryza Sativa ◽  
Glycine Max ◽  
Residual Effect ◽  
Field Studies ◽  
Silt Loam ◽  
Herbicide Application ◽  
Rice Yields ◽  
Residue Levels ◽  
Soil Residue

Field studies were conducted for 3 yr to evaluate the persistence of metolachlor and alachlor applied to ‘Centennial’ soybean and to determine their residual effect on ‘Mars' rice. At labeled use rates of metolachlor at 2.8 kg ai/ha and alachlor at 3.9 kg ai/ha, soil residue levels in the fall 5 months after application on Crowley and Midland silt loam soils averaged 0.04 and 0.05 ppmw, respectively. Metolachlor fall soil residues averaged 3.5 times higher when applied at 5.6 and 11.2 kg/ha compared to 2.8 kg/ha, but residues for labeled and double rates of alachlor were similar. In the spring 9 months after herbicide application, soil residues averaged over years did not exceed 0.06 ppmw. The 3-yr rice yields were not affected by residual metolachlor or alachlor.

Potential exposure assessment errors associated with body-worn RF dosimeters

2007 ◽  
Vol 28 (7) ◽  
pp. 573-576 ◽  
Author(s):  
Juan Blas ◽  
Francisco Angel Lago ◽  
Patricia Fernández ◽  
Rubén Mateo Lorenzo ◽  
Evaristo José Abril
Keyword(s):  
Exposure Assessment ◽  
Potential Exposure

scholarly journals Reducing Sprinkler Irrigation Volumes for Strawberry Transplant Establishment in Florida

2012 ◽  
Vol 22 (2) ◽  
pp. 224-227 ◽  
Author(s):  
Bielinski M. Santos ◽  
Teresa P. Salame-Donoso ◽  
Alicia J. Whidden
Keyword(s):  
Foliar Application ◽  
Sprinkler Irrigation ◽  
Field Studies ◽  
Early Morning ◽  
Fruit Weight ◽  
Control Treatment ◽  
Water Volume ◽  
Kaolin Clay ◽  
Irrigation Control ◽  
Water Volumes

Two field studies were conducted to determine whether foliar kaolin clay applications would reduce water volumes during the establishment of bare-root strawberry (Fragaria ×ananassa) transplants. Transplant establishment treatments resulted from combinations of duration of sprinkler irrigation and foliar application of kaolin clay were: a) 4 days of sprinkler irrigation, b) 4 days of sprinkler irrigation plus kaolin clay on day 5, c) 6 days of sprinkler irrigation, d) 6 days of sprinkler irrigation plus kaolin clay on day 7, e) 8 days of sprinkler irrigation, f) 8 days of sprinkler irrigation plus kaolin clay on day 9, and g) 10 days of sprinkler irrigation (control). One day of sprinkler irrigation was defined as the application of 8 hours per day of irrigation to ensure plant establishment, using ≈6000 gal/acre per hour of water. Kaolin clay treatments were applied using a rate of 25 lb/acre and on the early morning of the following day after sprinkler irrigation was suspended. Treatments influenced the number of established plants and diameter at 4 and 8 weeks after transplanting (WAT), leaf greenness at 8 WAT, and early and total fruit weight. There were no differences in the number of established plants among treatments that received 10 days of sprinkler irrigation (control), 8 days of sprinkler irrigation followed by kaolin clay on day 9, and 6 days of sprinkler irrigation followed by kaolin clay on day 7, ranged between 97% and 98% plant survival. The highest strawberry early and total fruit weights (3.6 and 15.7 tons/acre, respectively) occurred in plots transplanted with either 6 days of sprinkler irrigation plus kaolin clay on day 7, 8 days of sprinkler irrigation plus kaolin clay on day 9, or 10 days of sprinkler irrigation. These data indicated that the addition to kaolin clay after 6 or 8 days of sprinkler irrigation improved strawberry establishment, growth, and yields to the same levels as the control treatment, while saving at least 20% of the water volume needed for establishment.

scholarly journals A Current Overview of Two Viroids Prevailing in Citrus Orchards: Citrus Exocortis Viroid and Hop Stunt Viroid

2021 ◽  
Author(s):  
Zineb Belabess ◽  
Nabil Radouane ◽  
Tourya Sagouti ◽  
Abdessalem Tahiri ◽  
Rachid Lahlali
Keyword(s):  
Control Strategies ◽  
Seed Transmission ◽  
Detection Methods ◽  
Stunt Viroid ◽  
Citrus Exocortis Viroid ◽  
Certification Programs ◽  
Hop Stunt Viroid ◽  
Citrus Orchards ◽  
Citrus Varieties ◽  
Citrus Trees

Citrus exocortis viroid (CEVd) and hop stunt viroid (HSVd) are the main viroids circulating in all citrus-growing areas worldwide, and causing two well-known diseases on citrus trees; exocortis and cachexia, respectively. These viroids are small, covalently closed single-stranded RNA, allocated to the Pospiviroidae family. CEVd is the first viroid being described on citrus trees in 1948 in California. It is considered the largest citrus viroid at 371 nucleotides. It causes bark scaling disorder on the rootstock of citrus trees grafted on trifoliate orange and its hybrids and can cause dwarfing of trees grown on these rootstocks. HSVd was first observed in 1945 in Florida. It consists of 299 nucleotides. Stunting, chlorosis, bark gumming, stem pitting, decline, and depressions in the wood are the main symptoms of HSVd in mandarin and its hybrids. The introduction and propagation of infected budwoods are the main causes of viroids spread in citrus orchards. These agents are mechanically sap-transmissible and spread by contaminated tools. Neither seed transmission nor vectors have been reported for both viroids. Root transmission, though possible, would be overshadowed by mechanical transmission. Rapid and sensitive molecular-based detection methods specific to both viroids are available. Both diseases are controlled by using viroids-free budwoods for new plantations, launching budwood certification programs, and establishing a quarantine system for new citrus varieties introduction. The most important achievements in CEVd and HSVd researches are outlined in this chapter. This would help to provide a clearer understanding of the diseases they cause and contribute to the development of better control strategies.

scholarly journals Calcium Nutrition and Cultivar Influence Incidence of Tipburn of Collard

HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 544-546 ◽  
Author(s):  
Jon R. Johnson
Keyword(s):  
Brassica Oleracea ◽  
Nutrient Solution ◽  
Foliar Application ◽  
Normal Growth ◽  
Field Studies ◽  
Sand Culture ◽  
Culture Studies ◽  
Calcium Nutrition ◽  
Soil Application ◽  
Young Leaves

The collard (Brassica oleracea, Acephala group) cultivar Vates was more susceptible than `Blue Max' to tipburn in sand-culture and field studies. Calcium concentrations in young leaves were similar for both cultivars. `Blue Max' appears to require a lower Ca concentration in young leaves than `Vates' for normal growth. In sand-culture studies, increasing the Ca level in nutrient solution to 3 mm or higher decreased tipburn in `Vates'. `Blue Max' did not develop tipburn regardless of Ca level. Increasing the Ca level in nutrient solution increased Ca concentration in young and old leaves for both cultivars. Soil application of CaSO4 or foliar application of Ca(NO3)2 or CaCl2 did not decrease occurrence of tipburn in Yates', presumably because these treatments did not increase Ca concentrations in young leaves.

scholarly journals Glucosinolate Enhancement in Cabbage Induced by Jasmonic Acid Application

HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1188-1191 ◽  
Author(s):  
Vincent A. Fritz ◽  
Veronica L. Justen ◽  
Ann M. Bode ◽  
Todd Schuster ◽  
Min Wang
Keyword(s):  
Jasmonic Acid ◽  
Brassica Oleracea ◽  
Human Health ◽  
Foliar Application ◽  
Field Studies ◽  
Climatic Data ◽  
Split Application ◽  
Water Control ◽  
Application Rates ◽  
Glucosinolate Concentration

Glucosinolates (GSL) are bioactive compounds found in cruciferous vegetables that have been shown to have chemopreventive benefits for human health. The objective of this study was to determine whether foliar application of jasmonic acid (JA) increases glucosinolate accumulation and yield in cabbage (Brassica oleracea L. Capitata group). Field studies were conducted in 2004 and 2005 with a green (‘Quisto’) and red (‘Ruby Perfection’) cabbage cultivar. Foliar JA application rates were 0.1 mm, 0.2 mm, and split application of 0.2 mm JA with surfactant, surfactant control, and water control. Yield of both cabbage cultivars was not changed by JA application in both years of the study. In both years, ‘Ruby Perfection’ had significantly higher glucosinolate concentrations than ‘Quisto’ with sinigrin being the predominant glucosinolate in both varieties. JA application consistently increased sinigrin, gluconapin, and glucoiberin concentrations across cultivars and years of the study. JA application also increased progoitrin and total GSL concentrations, but the effect was inconsistent between years and cultivars. In most cases, a split application of 0.2mm JA resulted in the highest GSL accumulation. GSL accumulation was significantly higher in 2005 than 2004 for both cultivars. Climatic data suggest that annual differences in temperature may have influenced the variability in glucosinolate concentration in cabbage.

scholarly journals Manipulation of Barley Development and Flowering Time by Exogenous Application of Plant Growth Regulators

2022 ◽  
Vol 12 ◽  
Author(s):  
Brendan M. Kupke ◽  
Matthew R. Tucker ◽  
Jason A. Able ◽  
Kenton D. Porker
Keyword(s):  
Plant Growth ◽  
Flowering Time ◽  
Growth Regulators ◽  
Field Studies ◽  
Sowing Date ◽  
Flowering Period ◽  
Hordeum Vulgare L ◽  
Barley Cultivars ◽  
Controlled Conditions ◽  
Accelerate Development

Matching flowering time to the optimal flowering period in Mediterranean cropping zones is pivotal to maximize yield. Aside from variety selection and sowing date, growers have limited options to alter development in season. Plant hormones and growth regulators are used in perennial horticultural systems to manipulate development and floral initiation. In this study, a range of plant hormonal products were tested to analyze their effects on barley (Hordeum vulgare L) development by exogenous spray applications. Plants were grown in controlled conditions under long and short photoperiods with different vernalization treatments. The gibberellin (GA) products demonstrated the greatest potential for altering development. The GA inhibitor trinexapac-ethyl was able to delay the time to flowering in genetically divergent barley cultivars by up to 200 degree days under controlled conditions. A similar delay in flowering could be achieved via application at both early (GS13) and late (GS33) stages, with higher rates delaying flowering further. Notably, trinexapac-ethyl was able to extend the duration of pre-anthesis phases of development. By contrast, GA3 was unable to accelerate development under extreme short (8 h) or long (16 h) day lengths. There was also little evidence that GA3 could reproducibly accelerate development under intermediate 10–12 h day lengths. In addition, sprays of the cytokinin 6-benzyladenine (6-BA) were unable to reduce the vernalization requirement of the winter genotype Urambie. The present study provides baseline data for plant growth regulator treatments that delay cereal development. These treatments might be extended in field studies to align flowering of early sown crops to the optimal flowering period.

scholarly journals The effect of irrigation and foliar fertilization on the colonization of american ginseng (Panax quinquefolium l.) diseased parts by different micro-organisms

2012 ◽  
Vol 63 (1) ◽  
pp. 179-188
Author(s):  
Alina Pastucha ◽  
Barbara Kołodziej
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Sandy Soil ◽  
Foliar Application ◽  
Field Studies ◽  
American Ginseng ◽  
Qualitative Composition ◽  
Panax Quinquefolium ◽  
Pythium Irregulare ◽  
Foliar Fertilization ◽  
Micro Organisms

Field studies on the health of American ginseng cultivated in the Lublin district on poor sandy soil were conducted in the years 2004-2006. The studies involved treatment combinations with irrigation and without irrigation as well as foliar fertilization with Alkalin PK and Resistim of American ginseng plants. Mycological analysis was made of diseased ginseng parts with the aim of determining the quantitative and qualitative composition of fungi-like organisms and fungi threatening the cultivation of this plant. Fungi from the genera of <i>Cylindrocarpon</i>, <i>Fusarium</i> and the following species <i>Alternaria alternata</i>, <i>Rhizoctonia solani</i>, <i>Sclerotinia sclerotiorum</i>, as well as fungi-like organisms: <i>Pythium irregulare</i> and <i>Phytophthora</i> sp., were isolated from the infected parts of ginseng. The smallest number of fungi was isolated from the plants growing on the plots without irrigation and those where foliar application with Alkalin PK was applied.

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