Studies on Cultivation of Several Varieties of Onion (Allium ascalonicum L.) under Plastic Shade during Rainy Season in Jakarta

Onion (Allium ascalonicum L.) cultivation in Indonesia at the rainy season may affect the productivity which impacted on the price value fluctuation. Therefore, it was necessary to determine the best onion cultivation technology during the rainy season. This research was conducted to determine the effect of plastic shade on the growth and yield of several onion varieties during the rainy season in Jakarta. The study was conducted at Jakarta Assessment Institute for Agricultural Technology (Jakarta AIAT), from November 2018 to February 2019. The research arranged as a split plot design with two factors and four replications. The first factor was the plastic shade utilization, while the second factor was the onion varieties, namely Mentes, Bima and Trisula varieties. The results showed that the treatment without using a plastic shade provided the best effect on plant height parameters at 63 day after planting (42,57 cm). The number of tubers / plants with an average of 9.33 tubers. Wet weight / average plant 41.31g. Diameter / average tuber of 18.85 mm. The treatment of varieties showed that the best average height was obtained by Bima variety (40.55 cm) at 56 days. The mean number of leaves of Mentes and Bima varieties was 63 days after planting (26.75 and 25.37 pieces). The highest number of tubers / plants was found in the Mentes variety (9.87 tubers), the best compared to Bima and Trisula. Meanwhile, the mean wet weight of Bima variety (31.59 gr) was not significantly different from the wet weight of Mentes and Trisula varieties.