No abstract

The stages of flower and fruit development of Macaranga gigantea, its seed germination behavior in nature and from fruit harvesting, as well as the process of raising its seedlings in the laboratory were studied to determine the potential for production of M. gigantea seedlings. Five reproductive trees of M. gigantea were chosen as sources of seed. To estimate natural germination rates, four sample plots of 1 x 1 m 2 in four cardinal directions below the crown of every tree were set up. In addition, dry and wet extraction processes were carried out to determine, which the more effective method for germination of M. gigantea seeds. The results showed that the time required from flower development to fruit ripening in M. gigantea flowers was 5-6 months. The flower buds initiated in the dry season (August 2011) and the fruits ripened in the rainy season (December 2011-January 2012). The seeds that fell under the parent tree germinated in approximately 24 days with an average seedling density of 75-267 per m 2. The germination in laboratory showed that the percentage and the rate of germination of the seeds extracted through the wet extraction process were higher than those extracted through the dry extraction process. The highest rate of germination (65%) is by the combination of seeds extracted through wet extraction process and grown on compost media. The relative growth rate of seedlings planted on mushroom spawn waste media was the highest rate (0.36 0.42%), followed by those planted on compost media (0.150.09%), top soil media (0.100.04%) and sand media (0.100.07%).

Susanto D, Mulyati S, Purnomo H, Ruhiyat D, Amirta R. 2017. Growth, biomass production and nutrient accumulation of Macaranga gigantea in response to NPK fertilizer application. Nusantara Bioscience 9: 330-337. Research described in this paper investigated the effect of fertilizer application on the growth, biomass production and nutrient accumulation of mahang (Macaranga gigantea) plant components. The experiment was carried out in a research area of the Faculty of Forestry, Mulawarman University, Samarinda, East Kalimantan. The effects of five dose levels of an NPK (16-16-16) fertilizer on the growth rate of mahang seedlings planted in field conditions were compared. The treatments consisted of a control group (with no fertilizer), and dosages of 40 g, 80 g, 120 g and 160 g per plant. Fertilization at those levels was applied twice: the first application at four weeks after the planting and the second application at 6 months after the first. Growth rates between treatments were compared over a twelve month period. The research findings revealed that as the dosages of fertilizer increased, so the growth, biomass production and nutrient accumulation in components of the plants also increased. The best growth was found in the treatment in which fertilizer was applied (twice) at a dosage of 120 g per plant; at this dose level, by twelve months of age, the stem basal diameter had reached 45.24.9 cm, stem height 219.239.1 cm, number of leaves per plant 17.31.2, and canopy diameter 246.725.0 cm. The highest production of above-ground biomass was also found in the fertilizer treatment of 120 g per plant; the largest proportion of the biomass was in the leaves, followed by the wood, and then bark. The nutrient element that had accumulated most in plants at 1 year of age was potassium, followed by phosphorus and then nitrogen. The highest nitrogen uptake of stands was found in the NPK fertilization with a dosage of 160 g per tree, while the highest phosphorus and potassium uptake was found at a fertilizer dosage of 120 g per tree. The amount of nutrients accumulated in producing one tonne of above-ground biomass increased in response to different fertilization treatments. The fertilizer treatment of 120 g per plant (applied twice; the first soon after planting and the next after 6 months) resulted in the accumulation within the 1 year old plants of 2.38 kg of nitrogen, 6.36 kg of phosporus and 17.83 kg of potassium, with an N:P:K ratio of 13.3 : 35.6 : 100. The availability of the element potassium needs special attention when this species is cultivated.

Macaranga gigantea is an important pioneer plant species in the tropical secondary forest of Kalimantan and as far the attractive wood species was not commercially cultivated. This study aims to determine the soil and nutrient status on growth of M. gigantea in the secondary forest particularly after shifting cultivation activity. For this purposes, the observation plots with 50m x 50m sizes were made and measured to collect the data of diameter, height, soil conditions and leaf nutrient concentrations (N, P and K) of M. gigantea in different ages of natural growth. A simple linear correlation analysis was used to determine the relationship of plant growth with the leaf and soil nutrient concentrations as well. The results showed that the soil condition on growth of M. gigantea has the average at pH 4.7, CEC 5.57 meq/100g, base saturation 30.22%, and the concentration of soil nutrients were 0.062±0.015% (N), 12.65±4.9 ppm (P), and 57.76±33 ppm (K). We also found that the leaf nutrient concentration was 1.94±0.13% (N), 0.22±0.08% (P) and 0.66±0.27% (K), respectively. Moreover, the highest growth of diameter was found from the 6 years old of plant (27.88 m). The annual yield of diameter and high were 4.65 cm year-1 and 2.96 year-1 and it was gradually decreased until the 10 years old of plant. The negative correlations was observed from the soil nutrient K and growth of diameter and high of M. gigantea (r=0.95, p< 0.05). The positive correlation was observed from the P and K content in the leaf of plant and growth of M. gigantea (diameter, height and volume increment, p<0.1). We suggested that phosphorus and kalium content was play an important roles on the growth of M. gigantea and this nutrient factor should be considered well when this species will be cultivated for the commercial purposes in the future.

Petiken is one of the villages in Gresik Regency that still preserves religious traditions. In its implementation, this tradition is an annual routine. Religious traditions are still carried out by the community even during the COVID-19 pandemic. This study aims to (1) find out the religious traditions in Petiken, Driyorejo, Gresik Villages before the COVID-19 and (2) know the religious traditions in Petiken Village, Driyorejo, Gresik as a form of cultural preservation of the community during the COVID-19 pandemic. This research uses qualitative methods with data collection through interviews and observations. The results of this study were (1) religious traditions in Petiken Village, Driyorejo, Gresik before the COVID-19 were carried out normally, both annual traditions and weekly routines and (2) religious traditions in Petiken Village,the early days of the arrival of COVID-19 which made all traditions temporarily abolished, the PSBB period with the implementation of some traditions underwent a change, and a new normal period by re-implementing all traditions by complying with health protocols.