Step 1: Definitions of HDP and UHDP.
High Density Planting (HDP) entails reduced spacing to augment plant population.
Ultra High Density Planting (UHDP) in guava utilizes very close spacing to maximize yield per hectare.
Step 2: Spacing Standards.
Standard planting: 6 m × 6 m.
High density planting: 3 m × 3 m.
Ultra high density planting: 2 m × 1 m.
Step 3: Summary.
Therefore, the spacing employed in UHDP for guava is 2 m × 1 m.