Chitosan and plant probiotics application enhance growth and yield of strawberry

Strawberry is a newly introduced fruit crop in Bangladesh, which gained considerable interests from both growers and consumers. Resource poor growers of the country will need alternate production technology to keep the cost under control as well as minimize health hazard by reducing use of synthetic pesticides. This study evaluated and compared the performance of plant probiotic bacteria, chitosan and fungicides on growth and fruit yield of strawberry. Application of two plant probiotic bacteria, Bph-4 and BTLK6a to strawberry plants significantly increased vegetative growth and fruit yield compared to non-treated control. Further investigation on these bacteria revealed that they possessed indole acetic acid production and/or antagonistic properties to phytopathogenic microbes. The Bph-4 and BTLK6a were identified as Stenotrophomonas sp. and Ochrobacterum sp., respectively through 16S rRNA gene sequencing. Chitosan @ 250–500 ppm and BTLK6a application on tissue-cultured plants of cv. Strawberry Festival produced 56% and 43% higher fruit yield, respectively, compared to non-treated control. Out of two different plant types tested, tissue-cultured plants responded to chitosan and probiotics better than runner grown plants for percentage of yield increase. Fungicide treatment did not provide any yield advantage likely due to the absence of targeted diseases. These results suggest that chitosan and plant probiotic bacteria could be used as natural bioregulators for safe production of strawberry fruits in Bangladesh.