The potency of mulch and paclobutrazol treatments to increase potato (Solanum tuberosum L.) tuber production in a high-temperature area

Abstract

Climate change, in this case, global warming causing a direct effect on the future production of potatoes in Indonesia by reducing the suitable area in high altitude land. The optimum temperature for potato crop growth is 10-25°C. Temperature above 30°C causing the delay of tuber initiation, increase shoot growth and decrease potato tuber production. The research aims to enhance potato tuber production under the above-optimum temperature was conducted in July – September 2017. The experiment took place in the field at 600m asl. The experiment design used was factorial with a split-split plot design. The three factors tests were with and without paclobutrazol application (67.5 ml/plant), straw mulch (SM) and plastic mulch (PM), and cultivars. The cultivars tested were fresh-potato cultivars (Olympus) and processed-potato cultivars (Andina and Amabile). The result showed that the temperature range during the experiment was 18 - 35°C. Soil temperature under SM showed 1.17°C lower than that under PM. No significant effect of a paclobutrazol application for growth and tuber production. In average, Olympus produced 712 g fresh tuber that was significantly higher than Andina and Amabile, which were 516 g and 461 g respectively. The percentage of small size tuber per plant (< 80 gram) of all cultivar was more than 60%, which showed that the assimilates translocation to tuber still not maximal. This experiment suggested increasing paclobutrazol dosage to enhance the assimilate translocation from the source to the tuber sink and increase the fresh tuber weight per plant.