Mango (Mangifera indica L.), the sixth most important fruit crop worldwide, is likely at risk under a climate change scenario of accelerated soil organic matter mineralization and constrained plant nutrient supplies such as zinc (Zn) and boron (B). We identified the optimum nutrient formulation and application method to possibly rectify nutrient deficits in mango plants grown in one of the warmest and driest regions—Multan, Pakistan. We evaluated the yield and physiological (quality) responses of 20-year-old mango trees to seven treatments of foliar and soil applications of Zn and B. Combined soil application of B and Zn resulted in optimum increases in leaf mineral B and Zn and fruit-set, retention, yield, pulp recovery and total soluble solids at ripening (p = 0.021), while reducing titratable acidity and early fruit shedding (p = 0.034). Additionally, this treatment improved fruit quality (taste, flavour, texture, aroma, acceptability; p ≤ 0.05). Yield was found to be correlated with retention percentage (P ≤ 0.001; R² = 0.91), which was in turn related to fruit-set number panicle⁻¹ (P = 0.039; R² = 0.61). Therefore, we suggest that combined soil application of B and Zn mitigates leaf mineral deficiencies and improves the yield and quality of mango more efficiently than other individual or combined foliar or soil treatments used in this study.

Poor uptake of nutrients not only deteriorates the quality but also the yield of horticultural crops. Among various macro and micronutrients, the role of K, Ca and B is very important. Therefore, balanced application and uptake of K and Ca and B can improve the quality and yield of mango trees. So, a field study was conducted with the hypothesis that combined application of K and Ca along with B would be effective to improve yield and quality of Mango cv. Summer Bahisht (SB) Chaunsa. There were two sources of Ca(CaCl2 and Ca(NO3)2) and three sources of K(KNO3, K2SO4 and K-Citrate) combined with boric acid (BA). All Ca and K sources were applied at the rate of 1% while BA was applied at 0.2%. As compared to control, a significant improvement in fruit set panicle-1 (35.7% and 50.0%), fruit retention (125% and 40%), shelf life (73.3% and 36.6%), total soluble solids (35.1% and 40.6%) and fruit yield (52.5% and 49.2%) in 2016 and 2017 respectively, confirmed the effectiveness of KNO3 (1.0%) + BA (0.2%). Between CaCl2 and Ca(NO3)2, application of Ca (NO3)2 was found more efficacious regarding improvement of quality and yield of SB Chaunsa. It is concluded that to improve the quality and yield of Mango cv. SB Chaunsa, KNO3 (1.0%) + BA (0.2%) is the best nutrients combination, and Ca(NO3)2 is a better option as compared to CaCl2.

Deficiency of nutrients resulted in low quality and yield of fruits. It is an established fact that foliar application of nutrients can mitigate nutritional stress to some extent. Keeping in mind the economic value of Sufaid Chaunsa, a field study was conducted, to find the effect of co-application of sucrose or potassium citrate with boric acid on yield and quality of Sufaid Chaunsa. The study was designed with hypothesis that co-application of boric acid (BA) with potassium citrate (PC) or sucrose (S) would have potential to improve quality and yield of Sufaid Chaunsa. It was observed that BA (0.2%) + S1 (10%) remained significantly best for improvement (13%) in fresh fruit weight as compared to control. In connection with results, maximum increase in plant yield (19%), total soluble solids (29%) and reduction in fruit acidity (37%), it is clear that BA (0.2%) + S1 (10%) is a better approach. However, a significant increase (69%) in shelf life of Chunsa as compared to control also validated the efficacious functioning of BA (0.2%) + PC2 (0.4%). It is concluded that application of BA (0.2%) + S1 (10%) is a better approach for improvement in the quality of Sufaid Chaunsa. Comparative for yield, both BA (0.2%) + S1 (10%) and BA (0.2%) + PC2 (0.4%) are equally effective. However, for shelf life, application of BA (0.2%) + PC2 (0.4%) is more efficacious.

The mango cultivar Summer Bahisht (SB) Chaunsa is the most sensitive and susceptible to dieback disease among other cultivars. Despite the environmental variables, low nutritional value contributes to the drastic prevalence of the disease. Therefore, it was hypothesized that providing balanced nutrition through an integrated nutrient approach could rehabilitate plants affected by dieback disease. Treatments were NPK at the recommended dose (control), NPK + farmyard manure, NPK + press mud, NPK + poultry litter, and NPK + city effluent, and NPK + sulfur. Sulfur was applied at 3 kg per plant, while the organic amendments were applied at 100 kg per plant NPK was applied at the recommended dose per square feet of tree canopy. Leaf samples were taken 5 months after treatment application. Results were analyzed through two-way ANOVA analysis using R statistical language software. Although the disease recovery rate was slow and we did not find any plant that recovered one year after treatment application, the reduction in disease was prominent in the treatment where poultry litter + NPK was applied. The poultry litter with the recommended NPK treatment showed 20% and 50% reductions in disease intensity in the 2nd and 3rd years of the experiment, respectively, as compared to NPK alone.