Battling Nematodes in Brinjal Quiz Quiz

Explore core principles and key management techniques for controlling nematode infestations in brinjal cultivation. Sharpen your understanding of symptoms, life cycles, and effective control strategies in horticulture.

1. Identifying Symptom Patterns

   Which of the following is a common above-ground symptom of root-knot nematode infestation in brinjal plants?

   1. Silvery leaf patches
   2. Excessive fruit drop
   3. Yellowing and stunting of plants
   4. Stem gall formation

   Explanation: Yellowing and stunting of plants are typical symptoms caused by nematodes disrupting nutrient and water uptake. Silvery leaf patches are more associated with thrips. Excessive fruit drop can result from various stresses but isn't specific to nematodes. Stem gall formation is more characteristic of certain bacterial infections, not nematodes.

2. Understanding Life Cycles

   In the context of brinjal, at which stage are root-knot nematodes (Meloidogyne spp.) most infective to the plant roots?

   1. Second-stage juvenile
   2. Adult female
   3. Egg mass
   4. First-stage larva

   Explanation: The second-stage juvenile is the infective stage that invades roots and initiates gall formation. Adult females and egg masses remain mostly inside root tissue. First-stage larvae do not leave the egg, making them less relevant for infection.

3. Cultural Management Techniques

   Which cultural practice helps reduce nematode populations before planting brinjal?

   1. Frequent overhead irrigation
   2. Crop rotation with non-hosts
   3. Continuous monocropping
   4. Applying excessive nitrogen fertilizer

   Explanation: Rotating with non-host crops disrupts nematode life cycles and lowers their populations. Overhead irrigation and excessive nitrogen do not directly control nematodes. Continuous monocropping increases nematode buildup over time.

4. Biological Control

   Which organism is commonly used as a biocontrol agent against brinjal nematodes?

   1. Bt kurstaki
   2. Paecilomyces lilacinus
   3. Spider mite
   4. Aphid midge

   Explanation: Paecilomyces lilacinus is a fungus known for its ability to parasitize nematode eggs, reducing infestations. Aphid midge targets aphids, Bt kurstaki is specific to caterpillar pests, and spider mite is itself a pest, not a biocontrol agent.

5. Chemical Nematicides in Practice

   What is a critical precaution when using chemical nematicides for brinjal nematode management?

   1. Mixing any two nematicides for faster control
   2. Spraying directly onto fruit during harvest
   3. Applying in high temperatures only
   4. Adhering strictly to recommended dosages and safety intervals

   Explanation: Correct application rates and pre-harvest intervals are essential for effectiveness and safety. High temperature application isn't always advised, and mixing chemicals can be unsafe. Direct spraying on fruit at harvest poses residue and safety risks.