QUESTIONS

QUESTIONS

Q.No. 1. Tick the correct answer
1. The basidial stage of Rhizoctonia solani is:
a) Glomerella cingulata b) Thanatephorus cucumeris c) Diaporthe vexans d) Diplocarpon rosae
2. Rhizoctonia solani overwinters in the soil in the form of :
a) Sclerotia b) Oospore c) Conidia d) Chlamydospore
3. Soil borne inoculums of Rhizoctonia solani spread to foliage through:
a) Moist wind b) Insects c) Rain splashes d) Irrigation water
4. Favourable conditions for web blight development are:
a) High rainfall coupled with high soil temperature
b) High rainfall and soil moisture coupled with moderate temperature
c) High rainfall and soil moisture coupled with 23 to 25o C temperature
d) High rainfall and soil moisture coupled with low temperature
5. Web blight of French bean is caused by :
a) Macrophomina phaseolina b) Rhizoctonia solani
c) Sclerotium rolfsii d) Sclerotinia sclerotiorum
6. Most striking symptoms of anthracnose appear on pod as:
a) Dark brown and smooth b) Mousy green and sunken
c) Light brown and smooth d) Brown and sunken
7. Brown to light chocolate coloured sunken cankers may develop on seed coat due to infection of:
a) Angular leaf spot b) Anthracnose c) Web blight
d) Common bacterial blight
8. Optimum temperature for anthracnose is :
a) 10-15o C b) 15-20o C c) 18-27o C d) 25-30o C
9. Columnar hyphae producing conidiophores are lately joined together in the form of :
a) Synnemata b) Sclerotia c) Paraphysis d) Setae
10. Optimum temperature for Phaeoisariopsis griseola sporulation is:
a) 5-10o C b) 10-15o C c) 18-24o C d) 25-30o C
11. Floury leaf spot fungus overwinters in:
a) Seed b) Plant debris as mycelium c)In embryo of seed d) Plant debris as conidia
12. Floury leaf spot is a common disease at an altitude of:
a) 300-500 masl b) 500-800 masl c) 1000-1400 masl d) 1500-2000 masl
13. Sclerotial stage of Macrophomina phaseolina is:
a) Rhizoctonia solani b) Rhizoctonia bataticola c) Rhizopus stolonifer c) Ramularia spp.
14. Spore stages of Uromyces phaseoli typica are not commonly encountered in nature:
a) Urediniospore b) Teliospore c) Pycnidia and Aecial d) Uredial
15. Bean common mosaic virus is transmitted by:
a) Aphid b) Whitefly c) Thrips d) Jassid

Answers
1.B 2 a 3 c 4 c 5 b 6 d 7 b 8 c 9 a 10 c 11 d 12 d 13 b 14 c 15 a

Q.No. 2. Fill in the blanks:
1. In case of Colletotichum lindemuthianum acervulus, setae produced are ------------------.
2. Anthracnose of French bean pathogen perpetuate in the form of----------------------- and in--------------------------------.
3. In field the spread of anthracnose can be limited by the sprays of ---------------------- or ------------------------.
4. Conidia of Phaeoisariopsis griseola disseminate either by---------------------- or wind blown---------------------------.
5. Optimum RH for sporulation, spore germination and symptom development of Phaeioisariopsis griseola is ----------------%.
6.Mycovellosiella phaseoli is an ------------------ parasite.
7. Overwintering conidia of Mycovellosiella phaseoli may be----------------------- by rain to ------------------ leaves.
8. The optimum temperature for Mycovellosiella phaseoli conidial germination and germtube elongation is----------------------------.
9. Soil temperature of ------------------o C or ----------------------------- favours disease development.
10. Bean rust is --------------------- in nature.
11. On leaves, bean rust may appear on both surfaces, but is more common on the -------------------- surface.
12. Due to infection of bean common mosaic, the seed may be ------------------, ------------------------ or----------------------.
13. The causal organism for the bean rust is -----------------------.
14. Common blight of beans is caused by ------------------------.
15. Floury leaf spot of bean is caused by ---------------------.
16. Bean angular leaf spot pathogen produce conidiophores which are laterally joined together to form ----------------- or ----------------------.
Answers:
1. Sparingly 2. Infected seed, plant debris 3. Mancozeb, carbendazim 4. Rain splashes, soil particles 5. > 90% 6. Obligate 7. Splashed, lower 8. 20o C 9. 28, more 10. Autoecious 11. Abaxial 12. Aborted, Smaller, Malformed. 13. Uromyces phaseoli typica 14. Xanthomonas axanopodis pv. phaseoli 15. Mycovellosiella phaseoli 16. synnemata or coremia

Subjective type questions:
1. Write down the causal organism and characteristic symptoms of following diseases:
a. Root rot and web blight of bean
b. Angular leaf spot of bean
c. Bean common mosaic
d. Common blight
2. Write down the management practices for the following diseases:
a. Anthracnose of bean
b. Common blight of bean
c. Bean common mosaic
3. Write down the disease cycle and epidemiology of following disease:
a) Angular leaf spot
b) Bean Anthracnose
c) Root rot and web blight
d) Common blight
Last modified: Thursday, 1 March 2012, 10:24 AM