RESEARCHES ON THE EFFECT OF PHYTOSANITARY TREATMENTS TO GRAIN SORGHUM IN SANDY SOIL CONDITIONS

The pest and pathogens control is an essential requirement for sorghum, especially in the early stages of vegetation and at grain formation to waxi stage grain. Our results highlights the existence closely between the degree of pathogen attack and plant resistance to drought conditions. Thus, through the loss a quantity of water higher than 2.8 mmol H2O/m2 /s, was registered increasing the attack produced by Hadrotrichum sorghi and Fusarium moniliforme Sheld. Significant (r = 0.595 *) and distinctly significant (r = 0.811 **) correlations between plant transpiration and the pathogens degree of attack were established. Two treatments at 4-5 leaves and 6-8 leaves with Topsin 500 SC (0.07%), had determined the lowest degree of attack produced by Hadrotrichum sorghi (17.11% ) and Fusarium moniliforme Shedd (3.72%). Treatment with Calypso 480 EC, at a dose of 80 ml / ha has reduced with 81.4% the frequency of grain aphid (Schizaphis graminum) compared to untreated control. The quality of sorghum grain, respectively protein content was influenced both by the phytosanitary treatment and the climatic conditions during the growing season (high temperatures during the summer - autumn and precipitation almost nonexistent).