PNABD246.pdf

PCNB (1.5 micromolar) followed by benomyl (2 micromolar), chloroneb (4
micromolar) and thiophanate-methyl (65 micromolar). Four fungitoxicants were
found to be fungistatic. Formation of dome-shaped infection cushions on cotton
threads soaked in variable concentration of four fungitoxicants was inhibited
best by benomyl (2.5 micromolar) while higher concentrations were required of
thiophanate-methyl (100 micromolar), chloroneb (10 micromolar) and PCNB (10
micromolar) for the same. On the other hand, when the roots of 5-day-old Vigna
radiata seedlings were dipped in graded concentration of these fungitoxicants
for variable lengths of time and subjected to invasion by R. solani, it was
found that benomyl and thiophanate-methyl prevented the development of
infection structures (cushions) on the hypocotyls of treated seedlings when
these had received dip treatment at 250 micromolar for 30 min. Similar
inhibition of cushion formation was obtained in case of chloroneb at 250
micromolar for 120 min or 500 micromolar for 60 min and PCNB at 500 micromolar
for 240 min. Studies on inhibition of cushion formation on fungitoxicant
treated seedlings could be correlated with the level of control of R. solani
root rot and damping-off in pot culture tests when these fungitoxicants were
used as seed treatment. [ASj
*0515 Purkayastha, R.P. 1975. Influence of colchicine on the disease
susceptibility of gram seedlings to Fusarium orthoceras. SCIENCE AND CULTURE,
v.41(11):546-547. [En] (REP.MB-2459)
Seed treatments with 0.25% colchicine increased the susceptibility of
chickpea and blackgram to Fusarium orthoceras. [THHJ
*0516 Sharma, O.P. ; Tiwari, A. ; Kulkarni, S.N. 1975. Effect of seed
treatment with systemic and non-systemlic fungicides on the control of seedling
blight of mung (Phaseolus aureus) caused by (Rhizoctonia solani). INDIAN
PHYTOPATHOLOGY, v.28(I):114-115. [En] (REP.MB-0678)
Seedling blight symptoms caused by Rhizoctonia solani in mungbean are
described. Out of seven fungicides used as seed treatment for control of the
disease, benomyl was the best. [EMS]
*0517 Dublish, P.K. ; Pande, P.C. 1976. Effect of culture filtrates of
certain rhizosphere fungi on seed germination and seedling growth of Phaseolus
mungo Linn., Luffa cyclindrica H. Roem. and Cucumis sativus Linn. BANGLADESH
JOURNAL OF BOTANY, v.5(1/2):39-42. [EnJ [En Abst] (REP.MB-1723)
Bioassay tests of the culture filtrates of common rhizosphere fungi were
performed to study their phytotoxic or promoting effects on germination
percentage, speed of germination index and length of seedlings of Vigna mungo,
Luffa cylindrica and Cucumis sativus. The culture filtrates of Cladosporium
herbarum and Trichoderma lignorum had a marked adverse effect on percentage
germination of test seeds while Aspergillus niger and Fusarium oxysporum
reduced the root and shoot growth of some of the crops. Percentage germination
and speed of germination index was definitely promoted by some of the fungi.
[AS]
*0518 Huang, C.S. ; Mew, I.P. ; Yang, C.Y. 1976. Screening for varietal
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