Integrated hormonal and nutrient management promote fruit retention and quality traits of Citrus reticulata

Abstract

Kinnow (Citrus reticulata), a type of citrus fruit grown in Pakistan, is world-famous due to its unique taste. However, deficiency of nutrients, environmental stresses, and pests and disease attacks are causing low fruit productivity, juice quality, and fruit dropping. In this study, integrated management of hormones and nutrients was performed in orchards with high premature fruit dropping from major citrus-producing areas of Pakistan to improve fruit yield and quality. Thirty trees (10 to 20 y old) were selected from each orchid. Salicylic acid (100 mg L⁻¹ SA), potassium (100 mg L⁻¹ K), zinc (100 mg L⁻¹ Zn), 2, 4-dichlorophenoxyacetic acid (2 mg L⁻¹ 2,4-D), indole acetic acid (10 mg L⁻¹ IAA), and their combinations (SA + K, SA + Zn, SA + 2,4-D, SA + IAA, and SA + K+Zn) were foliar applied at the initiation of flowering, fruit formation, and fruit color initiation stages. Each treatment was repeated thrice while water was sprayed for control. The pathological study and soil and leaf nutrient analysis showed that the yield, quality, and citrus fruit dropping were influenced by insect pests, microbial pathogen infestations, and nutrient deficiency. The results indicated that SA + 2,4-D proved most effective in closely enhancing fruits' weight and size, followed by SA + K+Zn. However, the SA + K+Zn showed the highest net photosynthesis and fruit drop control, followed by SA + 2,4-D.

Keywords:

• Growth regulators
• Auxin
• Mandarin orange
• Salicylic acid
• Nutrient deficiency

Disclosure statement

No conflict of interest was reported by the authors.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by PSF/NSLP/P-NIAB (658) project.