Opportunities to Narrow Potato Yield Gaps and Increase Resource Use Efficiency in West Java, Indonesia

Abstract

Consumer demand for potato in Indonesia increases while production stagnates. Government policy recognised this discrepancy and prioritised efforts to increase potato yields through farmer support programs with moderate effects to date. This study aimed to decompose potato yield gaps and identify agronomic yield constraints in West Java. Actual yield and management practices of 178 farm registrations over five consecutive growing seasons were analysed with stochastic frontier analysis. The potential yield (Yp) for each registration was simulated with the LINTUL-POTATO-DSS crop model. The overall yield gap was decomposed into its efficiency, resource and technology components. The potato yield gap was 21.5 t ha−1, corresponding to 54% of Yp. The efficiency and technology yield gaps were both ca. 10 t ha−1, corresponding to 26% of Yp, and the resource yield gap was negligible. All fields received sufficient inputs for potential production, but most inputs were used inefficiently. An early first fungicide spray after emergence and frequently spraying to control late blight increased yields significantly. The seed generation planted was critical to potato yield gaps as yield decreased significantly with older generations. Some high-yielding fields, however, were also planted with older seed generations, so other production factors contributed to the yield gap as well. Improving potato yield and reducing current yield gaps in West Java will require well-performed late blight control, the use of high-quality seed and improved management practices, which include reduced input rates.