Influence of Fertilizers and Plant Growth Regulators Application on Physicochemical Attributes of ‘Kinnow’ Mandarin Fruit

ABSTRACT

Plant growth regulators (Kinetin, GA₃ and Wokozim) and fertilizers (nitrogen, phosphorus, potassiumand calcium) alone and in various combinations were applied to young ‘Kinnow’ mandarin trees to improve their quality. Fruit harvested at commercial maturity was analyzed at harvest and seven days after storage at ambient conditions. Results revealed that higher seed number (20) was recorded with Kinetin at 60 mg l⁻¹ and minimum seed number (10) with Kinetin at 30 mg l⁻¹+ GA₃ at 10 mg l⁻¹. More healthy and less aborted seeds were recorded with Wokozim (1500 g tree⁻¹)+2 ml l⁻¹ foliar spray. High juice mass (%) and low rag mass (%) were observed with control and 250 g tree⁻¹ phosphorous (P) application as single super phosphate. The TSS were higher with 150 g tree⁻¹ calcium (Ca) applied as calcium ammonium nitrate and lower with P application at 500 g tree⁻¹. Titratable acidity was higher in fruit treated with Kinetin at 60 mg l⁻¹ and lower in fruit treated with NPK (230 + 250 + 250 g tree⁻¹)+Ca (150 g tree⁻¹)+Kinetin at 30 mg l⁻¹. The TSS:TA ratio was higher in fruit treated with NPK (230 + 250 + 250 g tree⁻¹)+ Ca (150 g tree⁻¹)+Kinetin at 30 mg l⁻¹ and lower in fruit treated with P (250 g tree⁻¹)+ Kinetin at 30 mg l⁻¹. Ascorbic acid was higher in fruit treated with Ca (150 g tree⁻¹)+P (250 g tree⁻¹)+Kinetin at 30 mg l⁻¹ and lower with Wokozim (1500 g tree⁻¹)+2 ml l⁻¹ foliar applications.

KEYWORDS:

• Fruit quality
• fertilizers
• ‘Kinnow’ mandarin
• plant growth regulators
• tree age

Acknowledgments

The authors acknowledge the Higher Education Commission (HEC) of Pakistan for providing financial provision in the form of indigenous PhD scholarship scheme. The authors are also grateful to Mr. Tariq Mehmood Cheema, a citrus grower in Sargodha district for permitting work at his orchards.

Disclosure Statement

The authors announce that they have no conflict of interest.