Coffee Plants' Endomycorrhizae Potential to increase the growth and nutrient uptake of Arabica Coffee (Coffea arabica L.) under Field Condition

Inorganic fertilizers utilization is the most common way to increase plant productivity. However, the intensive use of organic fertilizer can harm the environment. Therefore, alternative fertilization by utilizing soil microorganisms to provide plant nutrients is needed. Endomycorrhizae is known as a microorganism that can increase the availability of nutrients and plant growth. This study aimed to determine the potential of endomycorrhizae to increase the growth of arabica coffee seedlings under field conditions. A Randomized Complete Block Design (RCBD) with 5 replications was used with four treatments, i.e., (P0) control: without endomycorrhizae and fertilizer, (P1) inorganic fertilizer: NPK recommended dose for seedlings nine months after sowing (N 184 kg/ha, P2O5 72 kg/ha, and K2O 120 kg/ha from 400kg/ha urea, 200 kg/ha SP-36, and 200 kg/ha KCl, respectively), (P2) endomycorrhizae: 1:1 (w/w basis) endomycorrhizal inoculum-planting medium, and (P3) endomycorrhizae + organic fertilizer: 1:1 (w/w basis) endomycorrhizal inoculum-planting medium with the addition of chicken manure at a dose of 10 tons/ha. The results showed that endomycorrhizae could increase the growth of arabica coffee seedlings by increasing plant height, plant dry weight, and plant N, P, and K uptake by 15.4%, 23.3%, 52.5%, 90.8%, and 75.6%, respectively compared to the control with 67,5% of root colonization at 16 weeks after transplanting (WAT). In conclusion, endomycorrhizae can potentially increase the growth of arabica coffee seedlings under field conditions

Metode Penyimpanan Bakteri Xanthomonas Oryzae pv. oryzae Penyebab Penyakit Hawar Daun Bakteri Pada Tanaman Padi Menggunakan Glycerol

The existence of Xanthomonas oryzae pv. oryzae, the bacteria which causes Bacterial Leaf Blight of rice, is really necessary for the laboratory to support the research activities of the phytopathology experts. Long-term preservation by using glycerol under -20°C can be conducted to preserve the culture’s availability to stay viable in the laboratory. This research aimed to determine the glycerol concentration that is able to preserve the viability and pathogenicity of Xanthomonas oryzae pv. oryzae bacteria after being preserved for 3 and 6 months. This experiments were performed using Completely Randomized Design which comprised of six treatments and four replications, they were: glycerol 50%, 40%, 30%, 20%, 10%, and control (without glycerol). The results of this study showed that viability of Xanthomonas oryzae pv. oryzae that was preserved within 20% glycerol solution for 6 months was different compared to control group. The number of Xanthomonas oryzae pv. oryzae bacteria on 20% glycerol was 4,49 x 109 CFU/ml, while on control group was 1,76 x 109 CFU/ml. 20% glycerol concentration had significant effect on the Bacterial Leaf Blight symptoms’ length after 6-months preservation that observed on the 7th day after incubation. The Bacterial Leaf Blight symptoms’ length on 20% glycerol treatment group was 46,2 mm and 22,7 mm on control group. Meanwhile for the 3 months preservation, the administration of glycerol did not show any significant effect on the Xanthomonas oryzae pv. oryzae’s viability and the Bacterial Leaf Blight symptoms’ length.