Biofilmed biofertilizers for improved quality and quantity of strawberry (Fragaria ananassa) under field conditions

Abstract

In order to reduce high doses of chemical fertilizers (CFs) used in strawberry, scientists have tested monoculture-based biofertilizers without much success. In recent years, biofilmed biofertilizers (BFBFs) have been used in cash crops successfully while reducing the recommended dosage of CFs up to 50%. A field trial was carried out to evaluate the effects of BFBF, developed using microbial isolates from strawberry rhizosphere (Aspergillus sp. and Enterobacter sp.), on the quantity and quality of strawberry harvest. Strawberry plants were subjected to BFBF only, BFBF + 50% CFs, 50% CFs and 100% CFs with nine replicates for each treatment arranged in Randomized Complete Block Design. The control was maintained without BFBF or CFs. BFBF diluted 20 times in water was sprayed on to raised planting beds a week prior to introducing strawberry plants followed by repeated application in two-month intervals. Yield was recorded up to the 30th week. The quality of fruits was analyzed using Total Soluble Solids (TSS), titratable acid and ascorbic acid contents. Diameter of the plant spread (crown) and plant dry weight were measured. Flowering was first observed in plants treated with BFBF + 50% CFs. The highest cumulative fruit yield (109 g), mean fruit count (14.77 ± 4.62) and fruit size (6.39 cm3 ± 0.86) per plant were also observed in the same treatment. The plant spread was found to be a good predictor of the yield. The TSS levels and TSS/acid ratios were significantly higher in all treatments over 100% CFs (p < 0.05). The BFBF + 50% CFs practice were ca. 30% more profitable than the 100% CFs alone. The results confirmed that the BFBF coupled with 50% CFs can be recommended over the full dosage of CFs alone for more profitable and highquality strawberry production under field conditions tested. Thus, further studies are needed to introduce BFBF for strawberry under variable soil and climatic conditions.