Nano-enabled Zn fertilization against conventional Zn analogues in strawberry (Fragaria × ananassa Duch.)

Abstract

The comparative performance of nano-enabled Zn fertilization against conventional Zn analogues was carried out in strawberry (Fragaria × ananassa Duch.) cv. Sweet Charlie between late September to mid-October until June for two consecutive years of 2019 and 2020. Four foliar Zn fertilizer sources viz., nano-ZnO, Zn-EDTA, ZnO and ZnSO4 were included in the trial procedure. The treatments were laid out in Randomized Block Design and replicated thrice. The treatments were comprised of T1: nano-ZnO at 200 μg g−1, nano-Zn (200), T2: nano-ZnO at 400 μg g−1, nano-Zn (400), T3: nano-ZnO at 600 μg g−1, nano-Zn (600), T4: ZnSO4 at 200 μg g−1, ZnSO4 (200), T5: ZnSO4 at 400 μg g−1, ZnSO4 (400), T6: Zn-EDTA at 100 μg g−1, Zn-EDTA (100), T7: Zn-EDTA at 200 μg g−1, Zn-EDTA (200), T8: ZnO at 200 μg g−1, ZnO (200), T9: ZnO at 400 μg g−1, ZnO (400) and T10: ZnO at 600 μg g−1, ZnO (600). Observations on vegetative growth traits, flowering, fruit yield, quality attributes and rhizosphere stoichiometry flexibility were recorded. The results indicated that foliar application of nano-Zn at 200 μg g−1 improved vegetative growth traits and earliest flowering (within 41.5 days after transplanting) in strawberry plantlets. This superior treatment also registered significant increase in fruit set (16.9%), yield (48.3%) and metabolic content of strawberry fruits compared to other Zn nutrient analogues. Microbial biomass in terms of total bacterial population, soil fungi and actinobacterial count was increased by 2.17, 1.57 and 1.54 times, respectively. Maximum leaf N (3.97%), leaf P (0.36%), leaf K (1.97%) and fruit N (3.49%), fruit P (0.28%) and fruit K (1.67%) content were also recorded through nano-Zn application compared to other Zn analogues. Both in leaf and fruit samples, Zn content was directly correlated to nano-Zn fertilization. Principal component analysis induced the differences at nano-Zn and conventional Zn sources has identified maximum of the total variance based on the Eigen value (>1), which explained 92.51% (PC1), 97.23% (PC2), 99.04% (PC3) and 99.56% (PC4) of the cumulative variance. PC4 accounted for highest total cumulative variances for vegetative growth, flowering, yield related traits, soil properties, leaf and fruit nutrient content of strawberry. In our study, foliar application of nano-Zn has shown promising effects to improve the cropping behavior of strawberry which can be used as an alternative to traditional Zn fertilizer sources. The study also inferred that use of nano-Zn have shown promising effects to improve cropping behavior of strawberry which could be an alternative to conventional Zn nutrient sources.