Nitrogen

Abstract

A direct relationship was found between N‐deficiency and frost damage to avocado trees. Lack of N resulted in typical N‐deficiency symptoms expressed by restricted growth, pale small‐sized leaves, and early leaf shedding; in addition the total number of fruits and fruit size were significantly reduced.

Gradual increase in N level was followed by gradual decrease in frost damage. Reduced N fertilization resulted in reduced N levels in the leaves (below the critical levels) and fruits. The frost damaged fruit was not suitable for marketing.

Key words:

• Avocado
• frost resistance
• fruit size
• nitrogen
• yield

Notes

Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 1774‐E, 1986 series.