Fruit Science (Pomology)

• Correct Answer: Stage I & Stage II.
• In fruit ontogeny (especially drupes and pome fruits exhibiting sigmoid or double-sigmoid growth curves):

  - Stage I (Cell division phase): High levels of free gibberellins are synthesized by developing seeds/endosperm to stimulate cell division and early fruit set.
  - Stage II (Cell enlargement / embryo development phase): High concentrations of conjugated and active gibberellins are again synthesized in the embryo and cotyledons to drive active cell elongation and pit hardening.

• Marcottage (also called Chinese layering or gootee) is known as Air Layering (I).
• Stooling is synonymously termed Mound Layering (II), commonly used in apple and guava rootstock propagation.
• Serpentine layering is known as Compound Layering (III), where a flexible branch is bent into the soil at multiple points.
• Inarching is known as Attached Grafting (or approach grafting) (IV), where the scion remains attached to its own root system until the union heals.

• Tristeza matches Kagzi lime (I): Acid lime (Citrus aurantifolia) produces characteristic vein clearing and stem pitting when infected with Citrus tristeza virus (CTV).
• Exocortis matches Rangpur lime (II): Rangpur lime or Trifoliate orange displays yellow blotching and bark shelling when infected with Citrus exocortis viroid (CEVd).
• Psorosis matches Sweet orange var. Pineapple (III): Produces oak-leaf patterns and shock reactions on young leaves.
• Greening matches Sweet orange var. Valencia (IV): Displays chlorotic mottle and zinc-deficiency-like symptoms on Valencia sweet orange indicator seedlings.