2018 ASHS Annual Conference

Sweet pepper (Capsicum annuum) is one of the most important vegetable crops with high demand for consumption in Puerto Rico and the United States. This crop ranks among the top five vegetables produced on over 700 small farms located mainly in the southern region of Puerto Rico. Over the past decades many factors have contributed to the decline in production of sweet pepper on the island, including changes in rain and drought patterns, lack of improved varieties, inadequate crop management practices, and emergence of new pests that limit production. Therefore, growers have become heavily dependent on consecutive applications of synthetic agrochemicals to maintain higher yields, making their business unsustainable. The objective of this study was to develop a sustainable management system for sweet pepper that integrates a mix of cover crops as a soil amendment and the application of microbial inoculants on varieties of Cubanelle-type sweet pepper that could improve fruit yield while maintaining a healthy soil. During the growing seasons of 2016 and 2017 we studied the single and combined effects of a cover crop mix of Canavalia ensiformis L., Mucuna pruriens L., and Crotalaria juncea L. as a soil amendment and rhizobacteria Bacillus subtilis QST713 and Bacillus amyloliquefaciens D747 applied as soil or foliar treatment, respectively, on sweet pepper varieties ‘Key West’ (F1), ‘Grenada’ (F1) and SPP9301. In 2016 the mix of cover crops incorporated as green manure significantly increased sweet pepper fruit weight by 18% compared to plots without cover crops. There were no significant differences among varieties or microbial inoculant treatments during this year. However, at the end of the 2016 growing season bacterial leaf blight, caused by Xanthomonas campestris pv. vesicatoria, was identified in sweet pepper varieties and disease was suppressed by 6% in plants that were treated with B. amyloliquefaciens strain D747 compared to the control, but this was not statistically significant. During the 2017 growing season the variety SPP9301 had a 20% greater fruit weight than ‘Grenada’ and 18% greater than ‘Key West’. No significant differences were observed due to cover crop or microbial inoculant treatments on sweet pepper yield in 2017. The strategies evaluated give an alternative to small scale farmers to implement a low-input crop management practice that best suits their specific farming system.