Fungicides selectivity

Verloop, A., Tipker, J. Use of Linear Free Energy Related and Other Parameters in the Study of Fungicidal Selectivity. Pest. Sci. 1976, 7, 379-390. 

Phenylamide fungicides selectively inhibit ribosomal RNA synthesis of sensitive Oomycete fungi by interference with the activity of the RNA polymerase I-template complex. 

The relative fitness of resistant and sensitive biotypes in the absence of fungicide selective pressure (untreated fruit) is a... 

Several factors that Influence the rate of buildup of resistant biotypes can be manipulated 1n strategies (Figure 2) to manage the problem (1) The Initial level of the resistant biotypes in the environment (2) Intensity of fungicide selection pressure (3) Rate of multiplication of the resistant biotypes (4) Dispersal of spores of resistant biotypes (5) Availability of injuries on the fruit surfaces that are susceptible to Infection. 

Minimize Fungicide Selection Pressure. Treatment of harvested fruit with a selective fungicide should be limited to situations which require unique action by the treatment (e.g., curative action, spoliation control, etc.). Non-selective treatments such as heat, active chlorine, sodium carbonate, and low temperature should be emphasized whenever possible to discourage the buildup of fungicide-resistant biotypes of Penici Hi urn. 

The rarer that resistant mutants are in the initial population, the longer that resistance will take to develop. Poor fitness may prevent the development of resistance, but fungicide selection pressures are sometimes extremely strong, especially in enclosed environments such as packing-sheds and glass-houses, so that relative unfitness of resistant forms will only slow down the evolution of resistance substantially if the fungicide is not used continuously. 

Modification of natural polysaccharides through various graft copolymerization techniques is discussed in this chapter. Characterization of graft copolymers using different techniques like FT-IR, C-NMR, SEM, XRD, TGA, DTA and DTG along with their physical, chemical and mechanical properties are discussed as a function of different reaction conditions of their synthesis. Applications for modified polysaccharides include drug delivery devices, controlled release of fungicides, selective water absorption from oil-water emulsions and purification of water. 

H. Lyr, in H. Lyr, ed.. Modem Selective Fungicides—Properties, Application and Mechanism of Action, Gustav Fischer Vedag, Jena, Germany, 1987, p. 75. 

In general, triazines are pre- and post-emergence selective herbicides particularly effective on annual and perennial broadleaf and grassy weeds in corn, sorghum, cotton, soybeans, sugar cane, and a host of other fruit and cereal crops. Some have anti-fungicidal properties (e.g., anilazine), and some (e.g., simazine) can be used for... 

Curalan DF is a fungicide produced by BASF Corp. for the purpose of treating such diseases as brown patch and fusarium patch on turf. Curalan DF was applied to turf in California, Florida, and Pennsylvania at a rate of 5.6 lb of active ingredient in 80 gallons of finished spray solution per acre using a tractor-mounted boom sprayer. Four applications were made 14 days apart. These conditions were selected to reflect the maximum level of dislodgeable residue when the product is typically used in agricultural practice. 

Further insight on the frequency of multiple residues is evident in Table 14.4, which shows the number of residues found per sample for selected foods tested in 2004 by the PDP. Conventional apples were found to contain, on average, 3.6 residues, while the one positive organic sample had a very minute level of the post-harvest fungicide thiabendazole. The level of residue found in the one positive organic apple sample was 0.0002 parts per million, while the mean thiabendazole residue found in 641 positive conventional samples was 0.43 ppm, over 2100 times higher than the level found in the organic sample. 

Krishnayya PV, Grewal PS. Effect of neem and selected fungicides on viability and virulence of the entomopathogenic nematode Steinemema feltiae. Biocont Sci Tech. 2002 12 259-266. 

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