DYNAMICS OF APPEARANCE AND EVOLUTION OF THE ATTACK OF SOME VIROSIS TO THE YELLOW MELON (CANTALOUPES) IN 2002 AND 2003 - DROUGHTY YEARS, AND 2004 AND 2005 – RAINY YEARS AND TO THE WATERMELONS IN 2004 – RAINY YEAR, UNDER THE CONDITIONS OF BĂRĂGANULUI FIELD PUBLISHEDEugen Velichi None
In the draughty years as well as in the rainy years, the yellow melons (cantaloupes) can be attacked by a series of virosis caused especially by the Cucumber Mosaic Virus – C. M. V. In the present, the dynamic of the appearance and evolution of virosis attack to the crops of Cucurbitaceae, especially to the yellow melons (cantaloupe) and watermelons was less studied. The aim of this research was to establish the moments of appearance of the attack, its evolution, the degrees of damages that the virosis can produce, as well as the possibilities of prevention and control. In this respect, the following values have been determined in the experimental field: the attack frequency (F%), the attack intensity (I%) and the attack degree (A.D.% = Fx I/100). As the Cerosypha gosypii to the cucumbers is a vector of some serious virosis to the cucurbitaceous plants (including C.M.V.) , it has also been noticed the dynamics of appearance and evolution of this pest attack, under field conditions, to the yellow melons (cantaloupes) and watermelons. During the four years of research (2002 - 2005), it was also noticed the behaviour of some species and hybrids of yellow melons (cantaloupes) and watermelons to the attack of the virosis. During these four years of research there were obtained interesting results regarding the attack of the virosis, the damages that this would produce beside other pathogens proper to the yellow melons (cantaloupes) and watermelons. It has been stated that the attack of the vector aphids is present every year. Though, between the intensity of the vector aphids attack and the intensity of the virosis attack there is no direct correlation. Also, each year, between the first attacks of the aphides and the first symptoms of the virosis, it passes approximately 30 days. During the four (4) years of research, during the draughty years as well as during the rainy years, the attack degree of the virosis was quite diminished at the species that have been researched. It has been stated that the older species (Hungary Treasure, Turkestan) proved to be very sensitive in some years. The hybrids created in the last years (“Galia” and “Cantaloupe”) proved to be resistant to virosis. We emphasize that the virosis to plants are diseases for which there are only preventive methods of control, and the avoidance of the damages occurred by them constitute an extremely complex problem for the entire vegetal kingdom.
virosis; Cerosypha gosypii; evolution