تعیین خسارت بیماری سیاهک ساقه نیشکر در استان خوزستان

Sugarcane is attacked by many pathogenic agents that caused lost in yield. Identification and evaluation of the damage of these causal agents and preventation of their incidence in the area should be done to decrease damage. This study was implemented to evaluate the damage of caused by smut disease in 10 cultivars, in the form of a randomized complete blocks design by two treatments and three replications in experimental field located at sugarcane research and training institute of Khuzestan in 2021-2023. So about 300 single-bud setts from each cultivar were prepared and treated with 50oC hot water, then 150 single-bud setts from each cultivar were selected as control treatment and incubated about 48 hours at 28-30oC. About 150 single-bud setts from each cultivar were dipped in smut spore suspension for 15 minutes to inoculate. The setts were planted according to design after incubating. In order to evaluate the qualitive and quantitive traits of treatments, 20 samples were selected of each treatment randomely and stem height, length and number of internodes, dimension of middle internode, stem weight and complete analyzes of syrup were measured. Statistical analyzes of data were run with SAS software. Evaluation of qualitive and quantitive traits during two years indicate that in the case of stem height, length of middle internode, weight of 20 stalks, yield per hectar, %Q.R., percent of sugar to sugarcane, % R.S., there are significant difference at level one percent among cultivars. In addition, a significant difference is observed at level one percent between control and inoculated treatment. At the first year, the interaction effect of cultivar on inoculated with spore was significant at level one percent at the internode dimension trait. The results of first year in the case of effect of smut disease on yield loss as the results of second year, show the significant difference between inoculated treatment and control. Analyzes of data during two years show that most yield lost is belong to cultivar NCo310 by 52.6% and 49.8% and the least yield lost is belong to cultivar SP70-1143 by 11% and 13.46% respectively. The results emphasize that according to rate of damage, planting the high quality and susceptible cultivars should be stopped. Also, the resistant and moderately resistant with low quantity and quality damage could be applied in selection program as parental source. So, the high resistant cultivars will be produced with more efficiency of product and decrease of damage.