Sengon (Falcataria moluccana) prevention from gall rust through seed irradiation: field test in endemic location

The gall rust disease is the diseases of sengon plant (Falcataria moluccana), that it caused by Uromycladium spp. which can cause the decreased productivity. However, at this time not yet retrieved the right techniques to reduce attacks of gall rust disease on sengon plant. Efforts to control gall rust disease at the level of seeds can be through by seed irradiation technique. Irradiation techniques on seeds can be used to increase productivity through increased vigour and seed quality. The aim of the study was to determine the effectiveness of gamma rays irradiation techniques on sengon seeds its shown by the growth and percentage of damage caused gall rust at sengon plantation at Pandantoyo Sub Forest District (RPH), Pare Forest District (BKPH), Kediri Forest Management Unit (KPH), East Java. The research design used a randomized block design consisting of 3 blocks. Each block consists of 10 treatments based on irradiated doses (0, 5, 10, 15, 30, 45, 60, 75, 90 and 105 Gy) and each treatment consist of 20 plants. The parameters observed were percentage of attacked plants that divided into four level of damage: healthy (0%); low (≤ 10%), moderate (≥ 11%-45%) and severe (≥ 46%) and growth of diameter and height. Generally, the health conditions of sengon plantation were affected by gall rust. At 18-months-old, the gamma rays irradiation at 75 Gy was the largest percentage of healthy plants (42.5%) and better than control (24 %). At 25-months-old, the plants derived from seeds that were not irradiated (control) was the largest percentage of plants with severe damage. Gamma rays irradiation does not affect the growth of diameter and height. The highest percentage of healthy plants were at 1^st block but the fastest growth of plant diameter was 2^nd block.