Identify what potassic (potash-based) fertilisers generally do NOT promote in crops, compared with nitrogenous fertilisers that primarily drive vegetative growth.

Introduction / Context:Nutrient roles differ: nitrogen encourages lush vegetative growth; phosphorus aids rooting and energy transfer; potassium enhances water regulation, enzyme activation, disease resistance, and improves starch and sugar formation. Distinguishing these roles helps avoid imbalanced fertilisation strategies.

Given Data / Assumptions:

• Focus on potassic fertilisers (e.g., muriate of potash, sulphate of potash).
• Trait comparisons include vegetative growth vs. quality attributes such as starch and sugar accumulation.

Concept / Approach:Potassium is most associated with improved tuber filling, starch/sugar content, lodging resistance, and stress tolerance. Rapid early vegetative growth of stems and leaves is typically nitrogen-driven. Therefore, potassic fertilisers do not primarily promote early stems-and-leaves expansion; instead, they elevate quality and resilience characteristics.

Step-by-Step Solution:

Verification / Alternative check:Agronomy guides cite K’s positive effect on tuber/grain filling and sugar content; N is cited for canopy expansion and leaf chlorophyll.

Why Other Options Are Wrong:

• Starches of potatoes & grains, sugar of fruits & vegetables, fibrous materials: all align with potassium’s roles.
• Tuber quality and disease resistance: also K-related benefits.

Common Pitfalls:Overapplying nitrogen expecting quality improvements that are actually K-dependent, leading to soft tissue and disease susceptibility.

Final Answer:stems & leaves during early stage of plant growth