Romanian Biotechnological Letters Vol. 22, No. 2, 2017 Copyright © 2017 University of Bucharest Printed in Romania. All rights reserved ORIGINAL PAPER Romanian Biotechnological Letters, Vol. 22, No. 2, 2017 12448 Influence of Pesticides on the Micro-Mycelia Present upon the Grape' Surface Received for publication, December,12, 2014 Accepted, October, 10, 2015 FELICIA TUTULESCU 1 , ANGELA POPA 2 , SINA NICULINA COSMULESCU 1 1 Department of Horticulture and Food Science, Horticulture Faculty, University of Craiova, Romania 2 Laboratory of Pesticides and Contaminants Residuum, DSVSA Dolj, Romania *Address for correspondence to: felixdragomir@yahoo.com Abstract The influence exerted by pesticides upon the microorganisms which are present within the vineyard' soil or upon the grape bacca' surface is a theme which has been approached by a lot of scientists. Our researches too come to join this line of investigation, focusing upon the effects exerted by some organically chloride pesticides on the micro-mycelia which are usually to be found upon the surface of the grapes' bacca. As a pesticide, we have made use of a product which relies on folpet as its active substance. Our experiment was carried on within a viticultural plantation and its aims were to study both the remanent effectiveness of the applied pesticide and the micro-organisms' subsistence after the concerned pesticide was applied. The stages of our experiment were: immediately after the applying of the pesticide (that is to say 24 hours since it was applied), respectively 7, 14 and 21 days consecutive to this moment. Thereby we have ascertained the fact that the applied product does act mostly upon the mildews but less upon the yeast' strains. We have also remarked that the concerned product does function at its greatest effectiveness immediately after being applied. Keywords: grapes, folpet, mildews, pesticides 1. Introduction The continuous development of the consumers’ expectations in regard to the respective amounts and qualities of the horticultural productions (fruits, vegetables, grapes and their respective consequently derived from products) has brought an increase for the number of existing horticultural exploitations of the intensive type; the implicit result of this fact is the use made of pesticides at a constantly increasing extent (this phenomenon goes for both fungicides and insecticides). Due to these circumstances, the individuals who do form the macro-fauna and the microflora of the concerned horticultural biological systems have come to develop some intrinsic mechanisms which do enable them to resist. Therefore it has become imperative to select the pesticides which could have, simultaneously:the quickest occurring effect; the longest lasting effect; the most precise pin-point effect. In the current practice of agriculture and of horticulture, a large amount of the applied pesticides do reach to the soil and remain within it; thus, most of the researches dedicated to the effect exerted by pesticides upon the microorganisms were orientated towards the soil’s microflora [4, 5, 7, 8, 9]. A relatively recent publication (2011) has brought to our attention the results of some researches carried on in Slovakia and concerning the consequences created by the action of adding pesticides upon the leaves and fruits' colonization with yeast' strains [10]. However, we are able to ascertain the fact that to the influence exerted by pesticides upon the useful micro flora (that is to say yeast' strains owning a high fermentation capacity), little attention has been granted yet at the worldwide level [1, 2, 6]. On the surfaces of grape baccas, the distribution