Many studies have demonstrated ineffectiveness of finely ground phosphate rock (PR) use due to the low solubility of its P contents. This study was conducted to develop a simple, effective, and environmentally sound process to improve P availability of PR to crops by using a phosphate‐solubilizing fungus (PSF), Aspergillus niger BCC F.194, isolated from tropical acid soils. The optimum incubation period and the optimum level of PR were determined. The P‐solubilizing effect of the supernatant of 9‐d‐old liquid culture supernatant (LCS) of the fungus was also determined by reacting it at various concentrations with Morrocan phosphate rock (MPR). The inoculation of the growth media with the PSF A. niger resulted in the highest P solubility of the rock after 9 d of culturing at 2.5 g L−1 MPR. Up to a certain degree, direct inoculation of fungal biomass and its LCS onto MPR caused a remarkable increase in 2% citric acid–soluble P, but not in water‐soluble P content. The possibilities of using the LCS instead of H2SO4 in superphosphate (SP) production and using both with lower H3PO4 concentrations were investigated with MPR as raw materials. Replacement of H2SO4 by the LCS in the SP production process yielded a comparable 2% citric acid–soluble P content. Combining the LCS and H2SO4 reduced the consumption of H3PO4 that occurs in standard SP production. This LCS technique provides a practical means for an effective bioactivation of PR intended for both as a P fertilizer and a raw material of the SP.

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The role of Elaeidobius kamerunicus in oil palm plantations in recent times is questioned related to the decline in oil palm productivity. The research aim is to study the E. kamerunicus beetle population and the factors that influence it. The study was carried out in the oil palm plantation PTP Nusantara VIII Cisalak Baru, Rangkasbitung-Banten. The beetle population were calculated on 3 spikelets at the base, middle, and end of an anthesis flower bunch of oil palm plant samples aged 13 and 5 years using purposive sampling method. Observation were carried out 3 times in May, September and November 2015. Morphological observation of beetle E.Kamerunicus was carried out in Balittro laboratory. The results showed that the population of E. kamerunicus in the study area was quite abundant and fluctuated. The average population of E. kamerunicus in oil palm plantation in May, September and November, are 15.168, 6.139, and 37.575 insect/ha in plantations aged 13 years, and 11.205, 7.534, and 49.209 insect / ha in oil palm plantation aged 5 years with the higest population occur in November. The fluctuation seem influenced by environmental factors such as rainfall, the present of rats as natural enemy, and the number of spikelet.

Wilt and anthracnose are diseases on chili that cause substantial losses and even crop failure. Control of the diseases is generally carried out using chemical pesticides which are environmentally harmful. Therefore, the development of nanoparticles, such as nanochitosan-Cu, can be an environmentally friendly solution in controlling chili disease. The current technology in developing nanochitosan-Cu is green synthesis, which uses an effective reducing agent but non-toxic for plants and the environment. However, the process requires sonication, which is difficult to be adapted for scale-up production. This research aimed to synthesize and determine the formulation of nanochitosan –Cuusing magnetic stirrer method without sonication, and also to evaluate the antifungal ability of nanochitosan-Cu againstFusarium oxysporum and Colletotrichum capcisi causing wilt and anthracnose disease, respectively. Synthesis of nanochitosan-Cu was carried out at 50°C and 400 rpm of speed. Characterizations of nanochitosan-Cu were analyzed using SEM-EDX and PSA. In vitro antifungal activity test was carried out by food poisoning method.The results showed that the synthesis of nanochitosan-Cu using ionic gelation method can be carried out without sonication process, and produce round shape nanoparticles with 183.7 nm of diameter. The nanochitosan-Cu was effective against F. oxysporum and C. capsici, at a concentration of 100 ppm. It inhibited the growth of F. oxysporum and C. capsici by 100% and 92.38%, respectively.Layu dan antraknosa merupakan penyakit pada tanaman cabai yang menimbulkan kerugian besar bahkan gagal panen. Pengendalian penyakit tersebut umumnya dilakukan menggunakan pestisida kimia yang tidak ramah lingkungan. Untuk itu perlu dikembangkan biofungisida yang ramah lingkungan, salah satunya adalah nanopartikel kitosan-Cu. Teknologi pengembangan nanopartikel yang saat ini sedang berkembang adalah green synthesis, yaitu menggunakan reduktor yang efektif namun tidak toksik terhadap tanaman dan lingkungan. Proses sintesis ini membutuhkan sonikasi yang cukup sulit untuk diadaptasi pada skala produksi masal. Penelitian ini bertujuan untuk melakukan sintesis nanopartikel kitosan-Cu dengan metode magnetic stirrer tanpa sonikasi, serta mengevaluasi kemampuan antifungi terhadap Fusarium oxysporum dan Colletotrichum capcisi penyebab layu dan antraknosa. Sintesis nanokitosan-Cu dilakukan pada suhu 50°C dengan kecepatan 400 rpm. Karakterisasi nanokitosan-Cu dilakukan menggunakan SEM-EDX dan PSA. Uji aktivitas antifungi secara in vitro dilakukan menggunakan metode peracunan makanan. Hasil penelitian menunjukkan bahwa sintesis nanokitosan-Cu dengan metode gelasi ionik dapat dilakukan tanpa proses sonikasi dan menghasilkan nanopartikel berdiameter 183,7 nm dan berbentuk bulat. Nanokitosan-Cu yang dihasilkan efektif sebagai antifungi terhadap F. oxysporum dan C. capsici. Pada konsentrasi 100 ppm, nanokitosan-Cu mampu menghambat pertumbuhan F. oxysporum dan C. capsici masing-masing sebesar 100% dan 92,38%.

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The consortium biostimulant combines several types of biostimulant applied holistically, such as phytohormones to induce physiological processes, humic acid to improve nutrition intake and land fertility, and biofertilizer arbuscular mycorrhizal fungi to improve abiotic stress tolerance. The objectives of this research were to analyze the effect of application consortium biostimulant on the growth and productivity of Bululawang sugarcane variety planted in three land typologies, i.e. irrigated heavy soil with good drainage (BPL), irrigated heavy soil with poor drainage (BPJ), and rainfed light soil with good drainage (RHL). The research was conducted on plant cane (PC) sugarcane areal in Lumajang Regency, East Java, from July 2019 to September 2020. The treatment plot area was 1 ha for each land typologies, and the observation were conducted on 10 m plant row with ten times replications. Each treatment was replicated ten times. The results showed that the application of consortium biostimulant could induce faster growth of sugarcane shoots and better roots at one month after planting (MAP). Stalk height and diameter showed significantly different values between treatment and control at the plant age 6 to 12 MAP. In addition, the sugarcane stalk weight per meter row also increases by 13.72 – 28.57%. The growth performance of sugarcane on a commercial scale increased, also sugarcane productivity increased by 11.08 – 20.36%. The potential sugar yield increased by 15.05% in BPL land typology, 4.9% in BPJ land typology, and 9.7% in RHL land typology. The difference in land typologies affected the effectiveness of the consortium biostimulant application in increasing sugarcane productivity.

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