Consider a greenhouse experiment on Tobacco Mosaic Virus (TMV). Each experimental unit was a single leaf on a plant and the data consisted of the number of lesions produced on the leaf by rubbing the leaf with a solution which contained the TMV. Each row of the design was a single plant. The columns were the ‘position’ from top to bottom, of the four leaves, which were used in each plant. Accordingly, the following Youden square design was constructed rep he Ee ohh er he Prhee ke re hee be Consider the following statements:
- Properties of Youden Square Design:
- Youden Square is an incomplete Latin square design that eliminates two sources of positional variation (rows and columns).
- For the given TMV greenhouse experiment with 7 treatments and 4 leaf positions across 7 plants:
- Plants (rows) form blocks of size $k = 4 \lt v = 7$, thus forming a Balanced Incomplete Block Design (BIBD), not a complete RBD. (False, inverted in statement)
- The columns (positions) represent complete blocks containing all treatments, while rows form a symmetric BIBD with $v = b = 7, r = k = 4, \lambda = 2$. (False as worded)
- Every Youden square design is formed by selecting $k$ rows from a full $v \times v$ Latin square, making it an incomplete Latin square. (True)
- The leaf position effect (columns) is completely orthogonal to the treatment effect. (True)
- Conclusion: Statements (A), (C) and (D) only (Option 3).
Correct option: (3) (A), (C) and (D) only.