Canker Control in Apples Quiz Quiz

Explore best practices for identifying and managing canker diseases in apple orchards with this horticulture-focused quiz. Improve your understanding of effective prevention, diagnosis, and treatment strategies.

1. Canker Identification

   When inspecting apple trees, which symptom most reliably indicates the presence of canker disease on the bark?

   1. Unusually large, uniform fruit size
   2. Wilting of leaves throughout the tree
   3. Sticky honeydew accumulation on branches
   4. Sunken, dead areas with cracked bark

   Explanation: Cankers typically appear as sunken, dead regions of bark, often with cracks or oozing sap. Wilting leaves can be due to various stresses, not specific to canker. Sticky honeydew is more characteristic of insect pests like aphids. Larger, uniform fruit is unrelated to canker diseases.

2. Environmental Influence

   Which orchard condition increases the risk of canker development in apple trees?

   1. Sandy soils with poor water retention
   2. Frequent wounds from pruning or hail
   3. High levels of pollinator activity
   4. Consistently low soil pH

   Explanation: Wounds create entry points for canker pathogens, making frequent injuries a significant risk factor. Low soil pH and sandy soils generally affect nutrient uptake, but are less directly linked to canker incidence. Pollinator activity does not increase canker risk.

3. Management Practice

   What is the most recommended management action after identifying a canker on a limb of an apple tree?

   1. Paint the canker with tree sealant
   2. Apply fertilizer to the soil around the base
   3. Spray the leaves with insecticide
   4. Prune the affected limb during dry weather

   Explanation: Pruning out infected limbs during dry periods helps prevent spread of canker pathogens. Fertilizers and insecticides do not directly treat fungal cankers. Tree sealants have not shown consistent effectiveness against canker pathogens.

4. Chemical Control

   Which type of chemical is typically recommended for managing canker diseases in apple orchards?

   1. Insecticides
   2. Fungicides
   3. Herbicides
   4. Nematicides

   Explanation: Fungal pathogens cause most apple cankers, so fungicides are used to help control them. Herbicides target weeds, insecticides target insects, and nematicides target soil nematodes; none of these directly address canker fungi.

5. Resistant Varieties

   Why do growers often choose apple varieties with canker resistance for new orchards?

   1. They reduce the need for frequent chemical applications.
   2. They deter pollinating insects.
   3. They guarantee larger fruit yield every season.
   4. They require no irrigation whatsoever.

   Explanation: Resistant varieties are less likely to develop canker, which can decrease reliance on fungicides. While resistance helps disease management, it does not eliminate irrigation needs, guarantee larger yields, or deter pollinators.