Studies on the effect of foliar application of chemicals for improving flowering, yield and quality of dragon fruit

The present study evaluated the effects of foliar application of potassium nitrate (KNO 3 ), mono-potassium phosphate (KH 2 PO 4 ), and thiourea (CH 4 N 2 S) at 1% and 2% concentrations on flowering, yield, and fruit quality of dragon fruit or pitaya, Selenicereus costaricensis (F.A.C. Weber) S. Arias & N. Korotkova ex Hammel during 2020–2022. Seven treatments, including an untreated control, were assessed during the six flowering flushes in a year. The application of KH 2 PO 4 at 2% exhibited significant improvement in reproductive performance, producing the highest number of blooms per pillar (23.65–23.84), fruit number (21.51–23.36 per pillar), and yield (5.40–5.80 kg per pillar) across the successive flushes. In contrast, foliar application of KNO 3 at 2% enhanced fruit quality attributes, recording the highest total soluble solids content (16.98°Brix) and non-reducing sugar concentration (2.53%). Thiourea treatments showed comparatively lower responses for most reproductive and quality parameters. The results indicate that KH 2 PO 4 at 2% is effective for enhancing flowering, fruit set, and yield, whereas KNO 3 at 2% improves fruit quality. These findings suggest that targeted foliar nutrition can be an effective strategy for improving productivity and fruit quality in dragon fruit cultivation.