Unit 4

• Latin Square Design (LSD) Degrees of Freedom: For an $m \times m$ Latin Square with $m$ treatments:

$$\text{Total df} = m^2 - 1$$ $$\text{Row df} = m - 1, \quad \text{Column df} = m - 1, \quad \text{Treatment df} = m - 1$$ $$\text{Error df} = (m - 1)(m - 2)$$

• Calculation for $m = 6$:

$$\text{Error df} = (6 - 1) \times (6 - 2) = 5 \times 4 = 20$$

Correct option: (4) 20

• Completely Randomized Design (CRD): The simplest experimental design where treatments are assigned entirely at random to homogeneous experimental units without blocking.
• Suitability for Laboratories: Ideal for laboratory, growth chamber, and greenhouse experiments where environmental factors (light, temperature, humidity) are strictly uniform and homogenous across all units.

Correct option: (2) CRD (Completely Randomized Design)