When antagonists were applied on normal host plant surfaces, the resulting
disease incidence and severity would indicate their ability to control sheath blight in the
presence of other phyllosphere epiphytes (indigenous microorganisms). Conversely, when
antagonists were introduced onto a rice sheath from which indigenous microflora had been
removed, the resulting incidence and severity of the disease would indicate the efficiency
of the antagonist in controlling the disease without any interactive effect from indigenous
microflora. Therefore, a set of rice plants was used in an open-field pot experiment to
determine the efficiency of five selected antagonists in controlling sheath blight in the
presence and absence of indigenous microflora. The five antagonists which showed the
highest in vitro antagonism were selected for the investigation. The rice plants were
established similarly to the open-field pot experiment that was employed to determine the
effect of 14 antagonists. Microorganisms dwelling on the sheath area of rice plants were
removed by spraying 0.5% Clorox for 3 min and rinsing subsequently with sterile distilled
water for 15 min. A previous study determined this method to be a successful and safe way
of surface sterilization of rice sheath (6). Sheath areas of plants which were subjected to the
removal of epiphytic microflora were sprayed separately with 60 ml of broth cultures of five
different antagonists at a concentration of 108 cfu m1-1 at 43 DAT. These plants were then
inoculated at 45 DAT with five rice seeds containing R. solani after which the rice sheaths
were sprayed again with broth cultures (60 ml) of antagonists with the same concentration
at 47 DAT. Rice plants from which epiphytic microflora were not removed, but inoculated
with R. solani at 45 DAT, were also treated similarly with five antagonists at 43 and 47
DAT. Control treatments were maintained by spraying the rice sheaths with broth having
no antagonists, similarly to the open-field pot experiment that was conducted to determine
the effect of 14 antagonists. Each treatment was replicated three times according to a
completely randomized design
When antagonists were applied on normal host plant surfaces, the resulting disease incidence and severity would indicate their ability to control sheath blight in the presence of other phyllosphere epiphytes (indigenous microorganisms). Conversely, when antagonists were introduced onto a rice sheath from which indigenous microflora had been removed, the resulting incidence and severity of the disease would indicate the efficiency of the antagonist in controlling the disease without any interactive effect from indigenous microflora. Therefore, a set of rice plants was used in an open-field pot experiment to determine the efficiency of five selected antagonists in controlling sheath blight in the presence and absence of indigenous microflora. The five antagonists which showed the highest in vitro antagonism were selected for the investigation. The rice plants were established similarly to the open-field pot experiment that was employed to determine the effect of 14 antagonists. Microorganisms dwelling on the sheath area of rice plants were removed by spraying 0.5% Clorox for 3 min and rinsing subsequently with sterile distilled water for 15 min. A previous study determined this method to be a successful and safe way of surface sterilization of rice sheath (6). Sheath areas of plants which were subjected to the removal of epiphytic microflora were sprayed separately with 60 ml of broth cultures of five different antagonists at a concentration of 108 cfu m1-1 at 43 DAT. These plants were then inoculated at 45 DAT with five rice seeds containing R. solani after which the rice sheaths were sprayed again with broth cultures (60 ml) of antagonists with the same concentration at 47 DAT. Rice plants from which epiphytic microflora were not removed, but inoculated with R. solani at 45 DAT, were also treated similarly with five antagonists at 43 and 47 DAT. Control treatments were maintained by spraying the rice sheaths with broth having no antagonists, similarly to the open-field pot experiment that was conducted to determine the effect of 14 antagonists. Each treatment was replicated three times according to a completely randomized design
การแปล กรุณารอสักครู่..