Tobacco stems contain 56.10% cellulose content, 15.11% lignin, 22.44% hemicellulose, and 44.61% total organic carbon, which can be used as a source of energy or fuel. This study aimed to utilize tobacco stems in a briquette form as alternative energy. The materials used in this study were tobacco stem waste, rice husk, wood charcoal, and coconut shell. The treatments used in this study consisted of T1 (100% of tobacco stems), T2 (80% of tobacco stem + 20% of coconut shell), T3 (80% of tobacco stem + 20% rice husk), and T4 (33.33% of tobacco stems + 33.33% of rice husk + 33.33% coconut shell). The fastest combustion rate was found at T3, 0.12 gram/sec, while T1 and T2 had the same combustion rate. T4, a mixture of various materials, had no significant difference compared to T1, T2, and T3. The highest calorific value of tobacco stem briquettes was in T4 (4127 Kcal/kg), and the lowest was in T1 (2343 Kcal/kg). The combustion rate of these tobacco stem briquettes was longer than that of charcoal briquettes, whose average burning rate is 0.234 grams/second. Overall, this study provides an overview of the best combination to create briquettes from agricultural waste.

Tobacco variety H382 was a cigar type tobacco that has a high economic value and potential as export trade commodity in Indonesia. The development stage of tobacco was very sensitive to water stress, like the water excess. Silicon was one of the most abundant elements in earth crust and has a role in water stress reduction to the plant. The objective of this study was to determine the response of tobacco crop variety H382 with the application of silicon fertilizer to adapt in waterlogging stress condition. This study used a factorial randomized block design with first factor was silicon fertilizer (0, 0.15, 0.30 and 0.45 ml) and second factor was excess water stress treatments (50% to 70%, 70% to 90%, 90% to 110% and 110% to 130% of field capacity). All treatments were replicated three times. The results showed that the addition of 0.45 ml silicon fertilizer to waterlogged tobacco crop could escalate the adaptive response of plant to cope with stress; seen from the increasing of the opened stomata, aerenchyma formation and the chlorophyll content of tobacco crop under excess water stress compared to control. Silicon supplementation improves the water availability in root surroundings and repairs the root architecture; thus, lead to a better hydraulic conductivity of the root for water and nutrient intake. Furthermore, authors found that the application of silicon fertilizer helped tobacco crop variety H382 improve plant adaptability to deal with excess water stress.