Monday, March 30, 2020

Apple Tree Diseases: Objective questions on apple

Yesterday I posted some objective questions on apple in the form of fill in the blanks. Today again I am going to post some more fill in the blanks with reasoning questions. This will complete important questions from apple fruit crop.

Fill in the blanks:
  1. Unlike apple scab fungus, the spores of powdery mildew do not require _____________ for germination.
  2. Black rot disease of apple is caused by                               and is also known as                         .
  3. Phytophthora cactorum  survives in the soil as                                      that are resistant to drought and relatively resistant to chemical treatment.
  4. Characteristic feature of white root rot is                                                that can be seen on roots during monsoon months and can be seen on soil level.
  5. Young trees if infested with                                                   may die quickly with necrotic leaves still on the dead plant is a characteristic symptom.
  6. Soil pH                 , soil moisture                 and Temperature                  play an important role in incidence and survival of Dematophora necatrix.
  7. Crown gall of apple is caused by                                 and hairy root is caused by                       can be managed by bio-control agent                                                   strain

Descriptive questions

  1. How excess nitrogen makes the plants more susceptible? What is the role of balanced nutrition in disease management?
  2. Why overhead irrigation be avoided during fire blight outbreak?
  3. Why control of insects with sucking type of mouth parts is important in management of fire blight of pome fruits?
You may answer the fill in the blanks in comment section. I shall be posting the answers in comment section tomorrow.

1 comment:

  1. 1. a film of water
    2. Botryospaeria obtusa, frog eye leaf spot
    3. thick-walled spores (oospores)
    4. white fluffy growth of mycelium
    5. Dematophora necatrix
    6. 6-6.5, >70% 17oC
    7. Agrobacterium tumefaciens, A. rhizogenes, Agrobacterium radiobacter K84