Journal of Tropical Crop Science
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Response of Growth and Yield of "IPB 9G" Rice to The Application of NPK and Biofertilizers
Full text linkRice is a staple food crop that is challenging to replace with alternative crops. Strategies that balance high yields with environmental sustainability are crucial to enhance rice production. One such approach is integrating organic, biological, and chemical fertilizers. This study aimed to evaluate the effects of combining these fertilizers on the growth and yield of "IPB 9G" rice. The experiment was conducted at the IPB experimental farm in Cikabayan, Bogor, Indonesia, from March to June 2024, using a randomized complete block design with two factors and three replications. Treatments included two doses of NPK fertilizer (100% and 50% of the recommended dose) and five combinations of organic and biofertilizers: Azotobacter sp., Azotobacter sp. + Pseudomonas sp., humic acid, PGPR (Plant Growth-Promoting Rhizobacteria), and a combination of Azotobacter sp. + Pseudomonas sp. + humic acid + PGPR. Parameters observed included leaf area, root volume, shoot dry weight, and yield components such as the number of panicles, 1000-grain weight, and the number of grains per panicle. The results demonstrated a significant interaction between NPK dosage and organic-biofertilizer combinations on plant growth and yield. Notably, applying 50% of the recommended NPK dose combined with Azotobacter sp. + Pseudomonas sp. produced comparable or superior yields to the full NPK dose. These findings highlight the potential of reducing chemical fertilizer usage by incorporating biofertilizers, offering an environmentally sustainable strategy for rice cultivation
Protocol Development for Assessing Seed Moisture Content and Germination Testing in Amorphophallus muelleri Blume
Full text linkSeed quality testing involves the evaluation of germination capacity under a standardized moisture content. However, limited reports have been found for seed testing methodology, especially for Amorphophallus muelleri. Standardizing the seed testing method for A. muelleri is essential to ensure repeatability, reproducibility, and reliable seed germination results. This study aimed to develop procedures for assessing seed moisture content and germination tests. Three seed lots were used for seed moisture content determination. The necessity for seed cutting and efficacy of high-temperature oven methods (133°C for 4, 5, and 6 h) were compared to low-temperature oven methods (103°C for 17 h). Five lots of seeds of different ages were used for the seed germination test using the between-paper method in a constant temperature germinator of 25 and 30 °C. There was no significant difference in the moisture content between the uncut/whole and the seeds cut. The high temperature of 133°C for four hours is an alternative to the low temperature. Germination rates at 25 and 30°C had no significant difference, i.e., 84 to 97% and 83 to 99%, respectively. However, at 30°C, it was shorter to 50% germination (T50) and germination period. Preheating the seeds for four weeks using the dry heat method shortened the seed germination time from 57 to 37 days. Seed lot exposed to dry heat had half the time required to reach T50, or 16.4 to 31.9 days after treatment, with a germination period of 37 to 52 days. The first count of germination at 25°C without preheating was 47 days after planting, and the final count was 73 days after planting, whereas at 30OC, it was 37 and 57 days after planting. The first and final count for germination with preheating treatment at both temperatures was 20 DAP and 37 DAP
The Patterns of N/P/K Stoichiometry of Indonesian Soybean Varieties in the Dryland Environment
Full text linkSoybeans are among the best plant-based sources of protein. However, a high intake of rich potassium legumes such as soybean could have negative impacts on people who are sensitive to high potassium. A study on NPK stoichiometry of the most popular Indonesian soybean varieties was conducted as a preliminary evaluation to develop low-potassium soybeans. The experiment was conducted at Cikabayan Experimental Station, IPB University, from January to April 2024. The field experiment was arranged in randomized block design using 12 soybean varieties: “Anjasmoro”, “Deja 2”, “Dena 1”, “Dering 1”, “Denasa 1”, “Denasa 2”, “Dering 3”, “Devon 1”, “Devon 2”, “Grobogan”, “Mallika”, and “Slamet”. Results showed that “Slamet” produced the highest stover while “Anjasmoro” was the lowest. “Slamet”, “Dering 1”, and “Mallika” produced the highest bean production per hectare (3.75-4.73 t ha- 1). N uptake was higher than P, and K. Seed of “Dena 1” had the lowest K content, while the highest was “Denasa 1”. The stoichiometric ratios of N/P, N/K, P/K showed different values according to varieties. Thus, decreasing the K level in seed could be done by selecting a low K variety
Cytological Deterioration of Bitter Gourd (Momordica charantia L.) Pollen During Storage and Its Impact on Effectiveness for Seed Production
Full text linkPollen storage plays an important role in the hybrid seed production of bitter gourd, but a primary challenge is the rapid decline in pollen viability. This research aimed to investigate the mechanisms of bitter gourd pollen deterioration during storage and to assess the effectiveness of stored pollen for hybrid seed production. The study was conducted at the Leuwikopo Research Station, IPB University, from September 2018 to June 2021. Bitter gourd pollen was collected at anthesis and stored in a deep freezer at -21±3ºC. Pollen viability was observed at 0, 2, 4, 6, 8, 10, and 12 weeks after storage (WAS), while pollen ultrastructure was examined at 0, 4, 8, and 12 WAS using a transmission electron microscope. The stored pollen was then used for pollination, observations were made on fruit set, seed set, and seed quality. The viability of bitter gourd pollen declined rapidly following dehydration before storage. The declining pollen viability during storage was due to the degeneration of the intine, followed by mitochondrial deterioration. The cristae became disorganised, leading to the dissolution of the cristae and outer membrane of mitochondria. Storing the pollen in a deep freezer (-21±3ºC) after dehydration did not prevent a further decline in pollen viability. Bitter gourd pollen stored for more than 2 weeks at -21±3ºC is ineffective for seed production. Cucurbit pollen remains viable for only two weeks; thus, fresh pollen is more practical for hybrid seed production. Development of more effective pollen storage methods is necessary to prolong pollen viability and enhance breeding efficiency.
Growth Response, Physiology, Metabolomic, and Production of Micro-Tom Tomatoes to Additional Lighting with White and Purple Light-Emitting Diode
Full text linkTomatoes are a widely produced and consumed fruit-vegetable belonging to the Solanaceae family. It contains minerals, vitamins, essential amino acids, sugars, and fiber. Micro-Tom is a wild-type cultivar from a cross between the Florida Basket and Ohio 4013-3 cultivars. Micro-Tom has two mutant types, the iaa9-3 and iaa9-5 mutants, which exhibit strong parthenocarpic properties. It is classified as a mutant tomato due to a mutation in the IAA9 gene, which belongs to the Auxin/IAA (Indole-3-Acetic-Acid) gene family and plays a role in suppressing the endogenous auxin signal transcription pathway. Using artificial light in cultivation techniques shortens the plant cycle and accelerates the juvenile phase. This study aimed to investigate the morphological, physiological, and production responses of Micro-Tom tomatoes to supplemental LED lighting. The research was conducted at the Leuwikopo experimental field of IPB University from March to November 2023. A completely randomized design was employed, with two factors (LED spectrum and Micro-Tom genotyping) and nine replicates. The study also examined the potential benefits of combining polychromatic and monochromatic light-emitting diodes (LEDs). The response of Micro-Tom tomatoes to artificial lighting with purple and white LEDs did not show significant differences in growth and production parameters. However, significant differences were observed between the tomato types, specifically between the Wild-type and the iaa9-3 mutant. No significant differences were found in LED treatment or Micro-Tom genotype for physiological parameters such as chlorophyll content and glucose-fructose levels. Regarding fruit quality, no significant differences were observed for parameters such as total soluble solids (TSS, Brix) to total titratable acidity (TTA, acidity), glucose and fructose, and malic acid. The LC-MS/MS analysis of leaves exposed to purple LED light revealed a profile dominated by secondary metabolites from the fatty acid compound group, suggesting the potential benefits of this lighting combination. In conclusion, using LED lights can accelerate the plant life cycle and shorten the juvenile phase, as evidenced by the first flower emergence, which occurred 20 days after transplanting (DAT) in the wild-type genotype and 16 DAT in the mutant genotype
Application of Arbuscular Mycorrhizal Fungi (AMF) to Enhance Biomass of Uncaria gambir (Gambier) in Ex Coal Mining Soil
Full text linkGambier cultivation faces limitations due to decreasing land availability; however, utilizing ex-coal mining land presents a promising alternative for sustainable expansion. Ex-coal mining land has the problem of low available nutrients because of bonded nutrients. Arbuscular Mycorrhiza Fungi (AMF) can help release bound nutrients into available nutrients, so that on ex-coal mining land, there is an increase in the amount of available nutrients that can be absorbed by plants for their growth. The study aimed to determine the effect of different types of arbuscular mycorrhizal fungi (AMF) and their doses on the biomass of gambier seedlings planted in ex-coal mining soil. An experimental design was employed using a randomized block design with two treatments: the types of arbuscular mycorrhizal fungi (AMF) (Acaulospora sp., Glomus sp., and Gigaspora sp.) and the AMF dosages (0, 5, 10, 15, and 20 g per seedling). All treatments were replicated three times. The parameters observed were soil chemical analysis, root colonization by arbuscular mycorrhizal fungi (AMF), shoot and root fresh and dry weights, net assimilation rate, and relative growth rate. The results obtained showed that AMF type and dose treatment had a significant effect on all parameters, except for the relative growth rate, and there was no interaction between the two treatments. Glomus sp. at a dose of 20 g per seedling provided the best influence in increasing gambier seedlings' biomass under the ex-coal mine soil
The Effect of Shade and Harvest Age on Biomass and Patchouli Oil Production in the Lowlands
Full text linkThis study investigated the effects of different shade levels and harvest ages on the growth, biomass yield, and essential oil production of the patchouli (Pogostemon cablin Benth.) cultivar Sidikalang, cultivated in a lowland environment. The experiment was conducted in Bogor from August 2023 to February 2024, using a nested design with three shade treatments (no shade, 55%, and 75%) and three harvest ages (4, 5, and 6 months). The results indicated that 75% shade significantly enhanced vegetative growth, including plant height, number of secondary branches, and leaf production, suggesting that this level of shading is beneficial for patchouli cultivation in lowland areas. However, these effects were not significantly different from those observed under 55% shade. The highest essential oil yields were obtained from patchouli plants grown under 75% shade and harvested at 4 months, as well as from those grown under full sunlight and harvested at 6 months
Growth and Yield Response of Superior Rice Varieties under Different Biofertilizer Rates in Lowland Rice Fields
Full text linkEfforts to increase rice productivity through a sustainable and environmentally friendly approach are using biofertilizers. The biofertilizer contains beneficial microorganisms that play an essential role in promoting plant growth and increasing rice yield. This study aimed to investigate the potential of biofertilizers and evaluate the performance of superior rice varieties by applying several rates of biofertilizers in lowland rice fields for enhancing growth and yield. A split-plot design was laid out using a randomized complete block design with three replications. The main plot consisted of superior rice varieties, including “Inpari 30”, “Inpari 32”, “Inpari 36”, and “Inpari 42”, while the subplot involved biofertilizer rates of 0, 400, and 800 g.ha-1. The utilization of biofertilizer contributed to the improvement of seedling height and root length. Applying biofertilizer increased plant height, panicle length, the number of grains per panicle, the number of filled grains per panicle, and the percentage of f illed grains, while decreasing the number of unfilled grains per panicle. The application of biofertilizer at a rate of 400 g.ha-1 significantly improved grain yields for “Inpari 30”, “Inpari 32”, and “Inpari 36”. However, “Inpari 42” required a higher biofertilizer rate of 800 g.ha-1 to produce high grain yields. The grain yield of superior rice varieties increased by 10%-21.6% with the application of biofertilizer. The findings of this study may provide recommendations for applying biofertilizers to enhance grain yields of several superior rice varieties in specific lowland rice field agroecosystems
Growth Dynamics of Young Avocado (Persea americana Mill) Plants under Drought Stress in Potted Condition
Full text linkDrought stress significantly influences plant metabolic processes, including overall vegetative growth and the transition from the vegetative to the generative phase. Under changing environmental conditions, plants adapt through specific mechanisms to survive unfavorable circumstances, including a reduction in the juvenile phase. This study aimed to examine the effects of drought stress on the growth dynamics of young avocado plants. The experiment consisted of three treatment levels: routine watering as the control (P1), drought stress for 8 weeks (P2), and drought stress for 16 weeks (P3). The 8 week drought stress did not significantly reduce the number of leaves or increase the number of vegetative buds; however, one plant produced flowers at week 33. The drought stress for 16 weeks (P3) significantly reduced the number of leaves but did not affect branch length. Instead, it increased the number of vegetative buds per branch at 16 and 24 weeks after treatment (WAT). Drought stressed plants exhibited a compensatory growth mechanism following rewatering, as demonstrated by an increase in the number of leaves and vegetative buds at 24 WAT
Effect of Pullulan Derived from Micrococcus luteus on Preserving Selected Properties of Sunflower Oil
Full text linkThis study evaluates the efficacy of pullulan, a bacterial polysaccharide extracted from a local Micrococcus luteus isolate, in preserving the oxidative stability of unrefined sunflower oil. Using peroxide value (PV) and thiobarbituric acid value (TBA) as metrics. Five treatments were compared against a traditional antioxidant, butylated hydroxytoluene (BHT), and a control. Results demonstrated that the use of 800 ppm pullulan significantly inhibited oxidative degradation of the unrefined sunflower oil, particularly at 20°C storage. Peroxide values for 800 ppm pullulan (1.91 mEq.kg-1 at 20°C; 2.88 mEq.kg-1 at 50°C) were slightly higher than BHT (1.82 and 1.99 mEq.kg-1) but markedly lower than the control (4.49 and 3.59 mEq.kg-1). Thiobarbituric acid values for 800 ppm pullulan (0.38 mg MDA.kg-1 (malondialdehyde) at 2°C at day 40, and at 50°C at day 30, were marginally lower than BHT (0.43 and 0.47 mg MDA.kg-1) and significantly reduced versus the control (0.51 and 1.42 mg MDA.kg-1), respectively