Nano-Biochar Suspension Mediated Alterations in Yield and Juice Quality of Kinnow (Citrus reticulata L.)

Nutrient deficiency negatively affects the yield and quality of citrus fruit. The present experiment was carried out to investigate the improvement in fruit yield and juice quality of Kinnow (Citrus reticulata L.) by foliar application of nano-biochar suspension (NBS). The experiment was carried out in a citrus farmer’s orchard with a history of low fruit yield, using a randomized complete block design. Four NBS treatments, i.e., 0% (control), 1, 3, and 5%, were applied through foliar application at the flowering stage. Foliar application of NBS at 5% and 3% significantly (p < 0.05) improved flowering, fruit retention, fruit set, fruit size, length, weight, diameter, juice volume levels, and minimized fruit dropping. The electrical conductivity of the juice was significantly decreased by increases in NBS concentration. Total dissolved solids increased slightly with treatments as compared to control. However, NBS foliar application did not show significant effects on nitrogen (N), potassium (K), and sodium (Na) leaf contents, but had some effect on phosphorus (P) content. Principal component analysis and a correlation matrix revealed significant (p < 0.05) positive and negative associations among the studied traits. The results of the current experiment showed that all parameters were significantly improved with the application of NBS at 3 and 5%, except that N, K, and Na levels were unaffected. The most encouraging results were achieved at a concentration of 5% NBS. In conclusions, the foliar application of NBS had a significant positive impact on fruit yield and juice quality.