Determining granule size of Cyperus rotundus tuber-based bioherbicide for weed control in upland rice

The application of granular bioherbicides derived from purple nutsedge (Cyperus rotundus L.) tubers offers an environmentally friendly alternative for managing weed competition in upland rice cultivation. This study evaluated the efficacy of various granular bioherbicide forms and sizes (67.5 kg ha-1) in suppressing weed growth and their impact on upland rice. A completely randomized design with twelve treatments was employed. Results showed that granular bioherbicides effectively controlled broadleaf weeds for up to four weeks without causing phytotoxicity to upland rice. Very small granular bioherbicides (spherical and cylindrical) were the most effective form to suppress weed growth of Alternanthera sessilis (L.) R.Br. ex DC., and Mimosa pudica L., and enhance upland rice growth and yield. Keywords: allelopathy; biological control; efficacy; pre-emergence; sustainable agricultur

Silicon priming enhances growth and photosynthetic pigments in rice plants under drought stress

Rice (Oryza sativa L.) variety \u27Inpari 24 Gabusan\u27 offers high nutritional value and a short growth cycle that is ideal for further development. This study aimed to assess the effect of silicon priming on the growth and photosynthetic pigments of rice \u27Inpari 24 Gabusan\u27 during the vegetative stage under drought conditions. A completely randomized design (CRD) was used with two factors: sodium metasilicate (Na₂SiO₃) concentrations (0 mM, 20 mM, 40 mM, and 60 mM) and field water capacity (100, 75, and 50%). Germination parameters (percentage and rate of germination, and seed vigor index) and vegetative parameters (plant height, leaf number, root length, biomass) were measured. Leaf chlorophyll and carotenoid content were also assessed. Results showed that silicon priming increased the germination rate from 57.17% at 0 mM to 63.83% at 60 mM. Seed vigor index significantly improved at 60 mM. However, sodium metasilicate concentration had no significant effect on the percentage of germination. Priming at 40 mM and 60 mM significantly enhanced growth and chlorophyll content, particularly at 100% and 75% field capacity. Under 50% field capacity, growth improvements were more limited due to water deficit. Higher sodium metasilicate concentrations also enhanced chlorophyll content, improved photosynthetic efficiency and drought tolerance. Keywords: carotenoid; chlorophyll; field capacity; germination; sodium metasilicat

Humic acid and chicken manure improve growth and productivity of organic edamame

Edamame (Glycine max L.), a soybean harvested for young pods, has high nutritional content and is promising as an export commodity. Here, organic edamame was produced by incorporating chicken manure and humic acid. This study aimed to evaluate the effects of chicken manure, humic acid, and their interaction on the growth and productivity of edamame. The study used a factorial randomized complete block design with two factors and three replications, and it was carried out at the IPB Experimental Station, Cikarawang A, Dramaga, Bogor, from May to September 2024. The first factor was chicken manure: 0, 8, 16, and 24 tons ha-1, and the second factor was humic acid: 0, 30, 60, and 90 kg ha-1. Vegetative variables were observed at 5 weeks after planting (WAP). The relative growth rate (RGR) and net assimilation rate (NAR) were determined from the period between 3 and 5 WAP. Yield components included the number, length, and weight of pods and pod yield. The results showed that the interaction of chicken manure and humic acid significantly increased root length, RGR, number of flowers, number of productive nodes, plant fresh weight, plant dry weight, pod weight per plant, and pod yield. Chicken manure at 9.5 tons ha-1 and humic acid at 90 kg ha-1 were the optimum doses to significantly increase pod yield. This study highlights the potential use of humic acid to reduce the amount of chicken manure demand in organic farming systems. Keywords: leaf greenness; net assimilation rate; nutrient levels; organic fertilizer; relative growth rat

Mycorrhiza application improves rice morpho-physiological traits in different soil water content

Mycorrhizal fungi are beneficial soil microorganisms that establish mutualistic associations with plant roots, significantly enhancing nutrient and water uptake under abiotic stress conditions. In West Kalimantan, limited soil water content frequently constrains rice cultivation, negatively impacting plant growth and yield. This study aimed to evaluate the effects of mycorrhizal inoculation on the morphophysiological traits of rice under varying levels of soil water content. The experiment was conducted from February to June 2022 in Mempawah Regency, West Kalimantan, using a split-split-plot randomized complete block design. The main plot factor was mycorrhizal inoculation (inoculated and uninoculated), the subplot factor was soil water content (100%, 80%, and 60%), and the sub-subplot factor was rice variety (Inpari 32 and Inpari 42). The results demonstrated that mycorrhizal inoculation significantly improved rice tolerance to moderate drought stress through adaptive morphophysiological mechanisms. This was indicated by increased phosphorus uptake efficiency and enhanced net assimilation rate, even at 60% soil water content. These physiological improvements contributed to better plant morphological development, including greater plant height (84.73 cm), dry biomass (8.36 g), number of panicles (15.83 panicles), panicle length (22.21 cm), number of grains per panicle (189.96 grains), and grain weight per clump (72.31 g). Keywords: mutualistic associations; mycorrhizal inoculation; physiological improvements; rice tolerance

Shallot distribution model under hydroclimatic extremes and soil physical properties in Sleman, Yogyakarta

Global climate change significantly affects the agriculture sector, including reducing crop productivity and potential distribution through the frequency of hydrometeorological disasters. Despite its economic importance, limited research has explored the effects of such hydroclimatic extremes on shallot (Allium cepa var. aggregatum) cultivation. This study aims to identify the soil-climate conditions, extreme events, variable contributions, and potential distribution areas of shallot in Sleman regency. The MaxEnt model was used herein to predict the suitable distribution area of shallot under hydroclimatic extremes and soil physical properties. The results show that shallot potential distribution in Sleman regency is governed by the synergistic action of climatic extremes and soil physical structure based on MaxEnt analysis. The dominance of Consecutive Dry Days (CDD) and soil moisture underscores the necessity of maintaining a stable soil–water equilibrium under intensifying hydroclimatic variability. These insights support the use of high-resolution soil and climate mapping to inform adaptive irrigation scheduling, precision tillage, and organic amendment strategies. Keywords: Climate change; extreme events, maximum entropy, soil properties, species distribution

Understanding gene interactions controlling resistance to pepper yellow leaf curl disease through phenotype-based analysis

Pepper yellow leaf curl disease (PYLCD) is the primary disease that affects chili plants, resulting in a loss of quality and quantity. The identification of chili plants resistant to PYLCD is a solution to support optimal chili cultivation. The purpose of this study was to estimate genetic parameters to obtain information on the genetic control of chili resistance to PYLCD. The genotypes used in this study consisted of four parental, four hybrid genotypes, and 180 individuals of the F2 population. The results showed that the genotypes "F6074" and "IPBC12" were categorized as resistant, while the genotypes “IPBC5” and “YUNI” were categorized as susceptible. The distribution of resistance level in chili peppers to yellow curly leaf disease tends to follow a ratio of 13:3, with a dominance of susceptible traits. The assumption for this phenomenon is that resistance to PYLCD is controlled by at least two genes. Both genes have dominant and recessive epistatic interactions. Keywords: Begomovirus; chi-square; epistasis; resilienc

Effect of row orientation and cowpea row numbers on sweet corn-cowpea intercropping

Intercropping between sweet corn (Zea mays L. var. saccharata Sturt) and cowpea (Vigna unguiculata L. Walp) can improve land productivity, but requires optimization of row orientation and cowpea row number. This study evaluated the effects of row orientation and cowpea row number on the growth, yield, and economic performance of sweet corn–cowpea intercropping. The experiment was conducted from June to September 2024 at the IPB experimental field in Sawah Baru, Bogor, Indonesia. A split-plot design with four replications was employed. The main plots consisted of two row orientations (North–South and East–West), while the sub-plots included maize monoculture, intercropping with one row, and two rows of cowpea. A significant interaction between row orientation and cowpea row number was observed on maize height, leaf number, and stem diameter at two weeks after planting. Although row orientation did not significantly affect maize and cowpea performance, the East–West orientation increased cowpea yield by 14.6% and reduced maize yield by 5.3% compared to the North–South orientation. The East–West orientation combined with one cowpea row produced the highest land equivalent ratio (LER = 1.93) and benefit–cost ratio (R/C = 1.45). Keywords: LER, R/C ratio, aggressivity, competitive rati

Application of fern Davallia denticuluta L. extract using different solvents as biostimulants for Kopay chili (Capsicum annuum L.) production

Ferns are a potential source of biostimulant compounds due to their rich content of bioactive secondary metabolites. This study aimed to evaluate different solvents for extracting bioactive compounds from Davallia denticulata and to identify the optimal extract formulation for enhancing the growth and yield of Kopay chili. This research was conducted from February to May 2024 at the Plant Physiology Research Laboratory and Greenhouse, Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Andalas, Padang. A completely randomized design with 16 treatment combinations involving four solvents (A1 = aquadest, A2 = methanol, A3 = ethanol, A4 = butanol) and four extract concentrations (B0 = 0 mg L-1, B1 = 25 mg L-1, B2 = 50 mg L-1, and B3 = 100 mg L-1) was employed. Plant growth parameters responded differently to various combinations of extract concentration and solvent type. Methanol extract at 100 mg L-1 significantly increased plant height, ethanol at 50 mg L-1 improved shoot dry weight and root biomass, butanol at 100 mg L-1 increased chlorophyll b and total chlorophyll, and methanol at 25 mg L-1 resulted in higher fruit weight. These results indicate that Davallia denticulata extract, when properly formulated, holds strong potential as a natural biostimulant to improve growth and productivity in chili cultivation. Keywords: active compouns; chili growth; plant extract; secondary metabolites; solvents extractio

In vitro growth of Coelogyne hybrid (Coelogyne pandurata x Coelogyne rumphii) on medium 2.4D and BAP

Coelogyne is a genus of ornamental orchids renowned for its distinctive floral characteristics and high conservation and economic value, particularly Coelogyne pandurata, which is commonly referred to as a black orchid. Efforts in cultivating black orchids in vitro require media modification with the addition of growth regulators to optimize plant development. Growth regulators that can be used include auxins and cytokinins. This study evaluates the effects of 2.4D (2,4-Dichlorophenoxyacetic Acid ) and BAP on the in vitro growth and shoot proliferation of Coelogyne pandurata X Coelogyne rumphii hybrid seedlings. The experiment used a completely randomized design with two factors: 2,4-D and BAP, each with four concentration levels (0, 0.5, 1, and 1.5 ppm), resulting in 16 treatment combinations. The variables observed were the percentage of callus formation, callus color, shoot number, root number, leaf number, and plant length. The results showed that the optimal callus growth was achieved with a combination of 2,4-D at 0.5 ppm and BAP at 0.5 ppm, resulting in 100% callus formation. The 2,4-D treatment yields the optimum results in terms of leaf numbers (23.56) and plant height (2.15 cm), while the 1.5 ppm BAP treatment achieves the optimum results in terms of leaf numbers (31) and shoot numbers (22.39). Keywords: auxin; black orchid; callus; cytokinin; plant growth regulato

Improving edamame yield on peat soil via Rhizobium and soil amendment applications

Soil amendment is a key factor in improving peat soil suitability for agriculture from the perspective of its fertility and quality. Red mud is potentially used as a peat soil ameliorant. The study aimed to evaluate red mud application as an ameliorant and application of Rhizobium on peat soil for growing edamame. The research was conducted at Tanjungpura University, Pontianak, from February to October 2024. A completely randomized design factorial was used to compile field experiments. The ameliorant factor consisted of 4 levels: control (dolomite 8 tons ha-1) and Red Mud of 10 tons ha-1, 15 tons ha-1, and 20 tons ha-1. The second factor was without and with Rhizobium. The application of Red Mud as an ameliorant increased pH, Na, and P2O5 levels and increased base saturation in peat soil. The Red Mud increased Na absorption in edamame tissues and increased pod yield. The highest edamame yield was reached with 20 tons ha-1 of red mud which was similar to with 8 tons ha-1 dolomite. Rhizobium has a role in supporting the formation of better root nodules. Keywords: crop yield; microorganisms; red mud; soil chemistry; soybea