Responses of Soledad Chile Pepper (<i>Capsicum annuum </i>L.) to Combined Application of Chitosan and <i>Bacillus subtilis</i>: A Study on Growth and Yield

The cultivation of Soledad pepper (Capsicum annuum L.) is essential in Oaxaca and Veracruz, but it faces issues with pests and diseases, which affect yield and cause economic losses. To mitigate these impacts, farmers have started using biostimulants such as chitosan and plant growth-promoting bacteria instead of agrochemicals due to their environmental and health benefits. This study evaluated the effect of Bacillus subtilis and chitosan, both individually and combined, on the growth, yield, and fruit quality of Soledad pepper under greenhouse conditions. Four treatments were applied at different stages of the crop cycle: Q (Chitosan), BS (Bacillus subtilis), Q+BS (Chitosan + Bacillus subtilis), and T (Control). The results showed that the combination of chitosan and Bacillus subtilis significantly improved plant growth, especially in height and stem diameter. The chitosan treatment produced the highest number of fruits and plant weight, while the combination of chitosan and Bacillus subtilis enhanced fruit quality, increasing characteristics such as size, weight, pericarp thickness, and physicochemical parameters, notably in brix degrees, citric acid percentage, and pH, outperforming the individual treatments and the control.