Effect of Culture Period and Stocking Density on Input Demand and Scale Economies of Milkfish (Chanos chanos) Polycultures with White Shrimp (Penaeus indicus)

Milkfish, Chanos chanos, is one of the major inland cultured fish species in Taiwan. Variations land resources and climate have led to application two distinct culture practices milkfish polycultures with white shrimp, Penaeus indicus. This study applies a translog cost function model analyze production scale economy input demand price elasticity four polyculture systems different periods (OWC NOWC) shrimp–milkfish fry stocking ratios (low SMR: 10–55 fry/ha; high 56–100 fry/ha). The findings show that require operational adjustments increase while reducing average cost. More specifically, overwinter cultures (OWC) economies scale. Farmers may reduce by expanding Non-overwinter (NOWC) SMR are at stage decreasing return scale, meaning gains output cannot In terms factor use, farmers OWC sensitive fluctuations since constitutes exhibiting highest own-price elasticity. Moreover, feed households levels substitutability, whereas other exhibit substitutability low SMR. NOWC farming SMR, capital substitutability. It thus recommended modify use according mode density ratio. found NOWCs considerably higher than OWCs, which lead deterioration water quality fishponds lower survival rates. 31:1 achieve rate shrimp.