Effects Of Captan Research Articles

PERFORMANCE OF McINTOSH APPLE TREES SPRAYED WITH CAPTAN, DODINE OR PRE-COVER AND COVER SPRAYS OF DICHLONE

A five-year study was conducted on the effect of captan, dodine and dichlone on the performance of mature McIntosh apple trees. There were no significant differences in yield, trunk cross-sectional area, amount of bloom, fruit size and fruit color. Dodine injured 0.5% of the fruit in one year of the test and pre-cover sprays of dichlone caused some fruit russeting. The results indicate that any harmful effect of dichlone on yield occurs from pre-cover applications, or pre-cover followed by cover sprays.

The Effect of Captan on Strawberry Pollen Germination1

Abstract Captan has been shown to inhibit pollen germination of the strawberry when included in or sprayed on agar germination media, or when sprayed on anthers after dehiscence. Toxic effects did not disappear during prolonged germination. Pollen germination was slightly affected by captan sprayed on the undehisced anthers.

Effects of captan on the non-parasitic microflora of apple leaves

The microflora of leaves from Worcester Pearmain apple trees sprayed with captan according to normal orchard practice, and from unsprayed trees, was examined by shaking, macerating and spore-fall techniques. Serial dilutions of macerates or wash liquids were incubated on selective media and the major groups of micro-organisms enumerated. Bacteria and yeasts were more numerous than moulds. Total numbers of yeasts and moulds were greatly reduced by captan but this effect was not long-lasting so that by the end of the season the numbers, and proportions of the major groups, on leaves from sprayed and unsprayed trees, were similar. The effect of captan sprayed in one season was not carried over to the next season. No conclusive data were obtained on the toxicity of captan to leaf bacteria. The implications of fungicide usage in relation to the balance of saprophytic and parasitic micro-organisms of the phylloplane are discussed.

Differential Response of Timothy Varieties to Captain1

AbstractSeedlings of seven cultivars of timothy, Phleum pratense L., were grown in soil to which captan, N−[(trichloromethyl) thio]−4−cyclohexene−l,2−dicarboximide, was applied as a drench immediately after the seeds were planted. Stunted plants occurred in all varieties, but the number differed significantly among varieties. ‘Climax’ had the fewest and ‘Heidemij’ had the most. Effect of captan was much greater when applied as a surface drench than when mixed with the soil before planting. Excessive watering resulted in more stunted plants than light watering.

Postharvent Preservatives, Effect of Captan, Isopropyl N-Phenylcarbamate, Isopropyl N-(3-Chlorophenyl)carbamate, and Malathion on Keeping Quality of Plant Commodities in Storage

Postharvent Preservatives, Effect of Captan, Isopropyl N-Phenylcarbamate, Isopropyl N-(3-Chlorophenyl)carbamate, and Malathion on Keeping Quality of Plant Commodities in Storage

STUDIES ON THE FUNGICIDAL ACTION OF N–(TRICHLOROMETHYLTHIO)–4–CYCLOHEXENE–1,2–DICARBOXIMIDE (CAPTAN)

N(trichloromethylthio) -4-cyclohexene-1, 2-dicarboximide (captan)3 is an important member of a class of organic fungicides which has been synthesized by the reaction of perchlorome-thyl mercaptan with certain imides, amides, and hydantoins (Kittleson, 1952). All the compounds of this class have in common the N-trichloromethylthio group to which their activity has been attributed (Kittleson, 1953). Captan is currently used extensively in the control of certain fungus diseases of plants. Studies of certain effects of captan on fungus metabolism reported in this paper were undertaken to elucidate the mode of action of this fungicide. MATERIALS AND METHODS.-Captan 4 was purified from a technical sample by precipitation from acetone with water and had an uncorrected melting point of 172?C. Inasmuch as captan is of limited solubility in water, a wetting agent 5 was used to prepare fine suspensions which could be pipetted accurately: The final concentration of wetting agent (0.00125 per cent) had no measurable effect on the biological materials used. The fungus, Fusarium roseum Lk., was used as a test organism and was grown on a medium containing: maltose, 10 g.; proteose peptone, 5 g.; KH2PO4, 0.5 g-; MgSO4. 7H20, 0.5 g.; FeSO4. 71120, 0.03 g-; agar, 20 g.; and distilled water, 1 1. Conidia were harvested by washing them from the surface of cultures which were 7 days old. The conidial suspensions were freed, of mycelial fragments by passage through several layers of cheese cloth, and the conidia were washed 3 times by alternate centrifugation and resuspension. For use in manometric experiments, the conidia were suspended in a basal solution containing: 0.002 M MgSO4 7H20 and 0.0001 M FeSO4 7H20 and potassium phosphate buffer (0.04 M