Seed Moisture Content Research Articles

Mechanical and Solvent Extraction of Moringa Oleifera Seeds for Vegetable Oil

Moringa oleifera is a plant that is predicted to be a potential source of vegetable oil. Moringa seeds contain 35-40% oil which is used in the pharmaceutical, cosmetic, automotive and fuel industries. Moringa oil contains oleic, palmitic, and behenic acid which is good for health. Obtaining oil from Moringa seeds in this study used the mechanical pressing method and continued with extraction using a solvent. Mechanical extraction was carried out by pressing Moringa seeds with a moisture content of 8 and 16% w/w. The best result was obtained with a moisture content of 8% with the yield of oil produced from 20 to 31% w/w. The pressing temperature also varied at 80, 100, and 120°C and the best result was given by the temperature of 100°C with the yield of oil produced 27.3-28.8% w/w at 8% moisture content of seeds and 20.9-23.6% w/w at 16% moisture content of seeds. The pressed cake from the mechanical pressing was extracted by maceration method using n-hexane as the solvent. The ratio of the amount of solvent to the amount of pressed cake (mL/gram) was 6/1, 8/1, and 10/1. The best ratio given by 8/1 with the yield oil produced from 8.44-22.82% w/w. Moringa oil was characterized using the standard method. The oil density obtained 0.912-0.919 g/cm3, saponification value 195-202 mgKOH/g oil, acid value 1.62-2.77 mgKOH/g oil, and peroxide value 1.85-3.70 meqO2/kg.

Hand Warmer-Induced Hypoxia Accelerates Pest Control in Hermetic Storage.

Accelerating oxygen depletion during hermetic storage can minimize pest damage and preserve product quality. This study evaluated the effectiveness of hand warmers in accelerating hypoxia to control insect pests inside hermetic containers. We used one, two, or four hand warmers to deplete oxygen in a 4-gallon hermetic jar with 4 kg of cowpea and cowpea bruchids, alongside a non-hermetic control with cowpea bruchids and no hand warmers. Oxygen levels, insect mortality, egg counts, seed moisture content, and germination rates were monitored over 2, 5, or 8 days of storage. Only the four hand warmers treatment reduced oxygen levels below 1% within 12 h and maintained them for up to 168 h. The other treatments did not achieve this level. Insect mortality was higher with more hand warmers and extended storage duration, reaching 100% after 5 and 8 days with four and two hand warmers, respectively. Similarly, increased hand warmers and extended storage durations reduced egg counts and adult emergence. The treatments did not affect the moisture content or germination rates of the stored cowpea seeds. Hand warmers proved effective in accelerating hypoxia during hermetic storage, resulting in high insect mortality and reduced reproduction, without compromising grain quality.

INVESTIGATION OF CONVENTIONAL AND MICROWAVE COMBINED ROASTING EFFECT ON THE PHYSICOCHEMICAL, TEXTURAL AND SENSORY PROPERTIES OF SUNFLOWER SEED

In this study, conventional, microwave, and also a combination of these two methods were applied to compare the quality properties of sunflower seeds. Alternative to conventional roasting at 160°C, microwave roasting at two different powers (300W and 600W) and also microwave with conventional roasting treatment (300 W+160°C, 600 W+160°C) were applied to raw sunflower seeds during 5 and 10 min. for each group. The moisture content of roasted seeds was found to be lower than 6%. The results show that the highest protein and fat content were found in the group of combined methods as 21.09±6.64 and 40.55±0.345% respectively. Additionally, the color values were found to be higher, and hardness and sensory characteristics were protected better after roasting compared to the control (unroasted) group. Roasting of microwave at 600W power for 5 min at 160°C was found to be advantageous for the roasting process of sunflower seed via these properties.

Effect of microwave energy combined with hot air on the functional properties and antioxidant activity and pasting properties of Samh (Mesembryanthemum forsskalei Hochst) seeds

The study aimed to investigate the effect of microwave heating combined with hot air (70 °C) at different application times (0, 90 &180 s,) on the colour, digestible a soluble protein, functional and pasting properties, antioxidant capacity of Samh seeds (8, 12 & 16 % moisture content). The results indicated that microwave heating caused a significant change in Samh seed's colour and enhanced the protein solubility of the seeds, and the functional properties and viscosities of the Samh seeds. Moreover, the results showed that the moisture content of the Samh seeds and application time significantly impact the seeds' quality parameters. However, the partial least square (PLS) model validated that the microwave treatments of the samh seed with (16 %, 180 s) were treated with microwave energy combined with hot air circulation Accordingly, microwaves may offer the potential of being an effective emerging technology for improving the quality and functional characteristics of Samh seeds.

Detection of moisture and size of winter melon seeds based on hyperspectral imaging and convex polygon size measurement

The level of moisture content and size of winter melon seeds affect their storage, germination and growth processes. Moderate moisture and size are essential for seed germination and growth. Therefore, detecting the moisture and size of winter melon seeds is beneficial to improve their germination rate. Traditional seed moisture testing methods are complex to operate and require destructive sample preparation or chemical treatment. Common dimensional measurement methods are also time-consuming and laborious. Hyperspectral imaging technology can acquire information about the surface and internal structure of the target separately, it can be used to quickly and non-destructively detect the moisture and size of winter melon seeds. In this study, partial least squares regression (PLSR) and partial least squares support vector machine (LSSVM) models were established to predict the moisture content of winter melon seeds by using reflection and transmittance spectral data. The models were optimized using five variable selection methods. The optimal performance of the LSSVM model based on the CARS algorithm was achieved in both single reflection and transmission spectra. The RP2 and RMSEP of the model based on the reflection spectra were 0.9667 % and 0.0215 %, respectively. The RP2 and RMSEP of the model based on the transmission spectra were 0.9644 % and 0.0223 %, respectively. In low-level data fusion, the LSSVM model based on the CARS algorithm also achieved optimal performance, but with only a little improvement compared to a single model (reflection spectra or transmission spectra), with RP2 and RMSEP of 0.9679 % and 0.0212 %, respectively. In the mid-level data fusion, the LSSVM model also based on the CARS algorithm achieved the optimal performance, and the performance of the model was further improved. The RP2 and RMSEP of the model were 0.9738 % and 0.0191 %, respectively. Finally, the image processing algorithm and the convex polygon size measurement method was proposed to measure the size of winter melon seeds. The absolute error between the calibrated winter melon seed length and width and the true length and width was less than 0.22 mm, and the relative error was less than 2 %. The results show that hyperspectral imaging technology can accurately detect the water content of winter melon seeds. Data fusion method and LSSVM model based on CARS algorithm can detect the water content of winter melon seeds more accurately. The image processing algorithm combined with the convex polygon size measurement method can be effectively used to detect the size of winter melon seeds with high precision.

Interannual Variability in Seed Germination Response to Heat Shock in Cistus ladanifer

Mediterranean climates, characterised by hot and dry summers, have predictable fire regimes, and many species with physical seed dormancy (PY) thrive after wildfires. While it is well known that PY is released after heat shock in these species, intraspecific variation in seed response to heat is less understood. This research explores, for the first time, the variability in the traits of Cistus ladanifer seeds from the same central Spain population over eight years. It examines seed germination and viability under different heat shocks and the relationships among seed traits and climatic variables. While the response to heat shock remained constant over the years studied, achieving the highest germination percentages after heat shock at 100 °C, seed germination varied between years, and environmental conditions affected seed traits. Seed moisture content was negatively correlated with the maximum summer temperatures, and seed viability was positively related to annual precipitation. Germination at 100 °C was lower in warmer years as more seeds did not break their PY. In conclusion, despite the fact that PY appears to be genetically determined, it also depends on the environmental conditions experienced by the mother plant. This interannual phenotypic variability may help Cistus ladanifer to cope with the increasingly unpredictable conditions imposed by climate change.

Effect of Packaging Material and Storage Period on Popping Behaviour of Roasted Makhana Seeds

The effect of storage period and type of packaging material on the popping behaviour of roasted makhana seeds was studied. Raw makhana seeds with a diameter of 9-10 mm were roasted using a batch-type primary roasting machine and tempered for 48 hours to bring the roasted seed moisture content to about 16% dry basis (d.b.). The roasted seeds were stored in 15, 25, and 80 µm Low-Density Polyethylene (LDPE), 110 µm Polypropylene (PP), 140 µm Biaxially Oriented Polypropylene (BOPP), and 60 μm Silver Laminate (SL) packets for six months. Popping of the stored seeds was conducted at 15-day intervals, and observations were made on popped makhana recovery, popping efficiency, colour of popped makhana, and expansion characteristics. The expansion ratio, expansion index, popped makhana recovery and popping efficiencies prior to storage were 2.37±0.22, 13.64±4.04, 48.53±0.50, and 82.89±0.78%, respectively. Duncan’s multiple range tests showed that the seeds packed in 15 µm LDPE packages maintained the quality and recovery up to 60 days only. The 80 μm LDPE packets, BOPP, PP, and SL packets were found effective in maintaining popping efficiency, recovery of popped makhana, and expansion ratio more than 81.44±0.70%, 47.95±0.43%, and 2.14±0.14, respectively with no significant colour change up to 135 days storage of the roasted seeds. Significant changes in colour values of popped makhana were observed after 135 days of storage and a* value increased whereas L* and b* values decreased. This study showed that makhana seeds may be popped effectively with >47% popped makhana recovery, >16 mm average diameter and acceptable colour values up to 120 days when the roasted seeds are stored at 15.53±0.49% (d.b.) in airtight packaging material, which was not possible until now.

Metabolomic and Physiological Analyses Reveal the Effects of Different Storage Conditions on Sinojackia xylocarpa Hu Seeds.

Sinojackia xylocarpa Hu is a deciduous tree in the Styracaceae family, and it is classified as a Class II endangered plant in China. Seed storage technology is an effective means of conserving germplasm resources, but the effects of different storage conditions on the quality and associated metabolism of S. xylocarpa seeds remain unclear. This study analyzed the physiological and metabolic characteristics of S. xylocarpa seeds under four storage conditions. Our findings demonstrate that reducing seed moisture content and storage temperature effectively prolongs storage life. Seeds stored under that condition exhibited higher internal nutrient levels, lower endogenous abscisic acid (ABA) hormone levels, and elevated gibberellic acid (GA3) levels. Additionally, 335 metabolites were identified under four different storage conditions. The analysis indicates that S. xylocarpa seeds extend seed longevity and maintain cellular structural stability mainly by regulating the changes in metabolites related to lipid, amino acid, carbohydrate, and carotenoid metabolic pathways under the storage conditions of a low temperature and low seed moisture. These findings provide new insights at the physiological and metabolic levels into how these storage conditions extend seed longevity while also offering effective storage strategies for preserving the germplasm resources of S. xylocarpa.

Chemical Solutions for Seed Dormancy: A Comprehensive Review on Strategy to Combat Pre-harvest Sprouting in Mung Bean

The mung bean, or Vigna radiata (L.) Wilczek, is a significant grain legume with enormous global economic value. Kharif is the most significant of the three seasons and during this time pre-harvest sprouting (PHS) is a major issue that results in significant production losses. Due to PHS, yield losses in green gram have been estimated to be between 60 and 70 per cent. Chemical treatments that induce seed dormancy may prevent premature germination and enable a timely harvest. This study covers the effectiveness of inducing dormancy in mung bean plants with various chemicals at critical developmental stages before harvest. Treatment with various chemicals like maleic hydrazide, sodium azide and plant growth regulators (abscisic acid, ethylene, gibberellins) following chemical administration at pre-arranged intervals, physiological parameters such as seed moisture content, germination rates and antioxidant enzyme activities can be considered to prevent PHS. Mitigating pre-harvest sprouting losses and increasing mung bean output can be achieved by optimising dormancy induction by prudent chemical use. To increase mung bean output, PHS-tolerant cultivars must be developed due to the significant losses incurred by PHS. This review discusses various aspects, including how different traits affect pre-harvest sprouting.

DETERMINING THE ASSOCIATIONS BETWEEN CROP PHENOLOGY, GROWTH, YIELD, AND YIELD-RELATED PARAMETERS OF MALT BARLEY (HORDEUM VULGARE)

The study was conducted at two locations, namely Holeta and Kulumsa Agricultural research centers of Ethiopia, for 2 consecutive years from 2019 to 2021 main cropping seasons. The objective of the experiment was to determine the association between crop phenology, growth, yield, and yield-related parameters. One variety of newly harvested pre-basic seed class of malt barley variety, namely IBON 174/03, was used for the experiment. Total number of treatment combinations was eighteen. The treatments were laid out in a randomized complete block design in two factorial arrangements with three replications. The factors are five deterioration/aging days 0 (control/un-aged), 2, 4, 6, 8, and 10 days and three seeding rates (75, 100, and 125 kg/ha). Before artificial deterioration, the seed moisture content for all treatments was 12.5%. Seeds were subjected to artificial deterioration treatments and placed in an incubator at 42°C for 0 (control), 2, 4, 6, 8, and 10 days at approximately 100% relative humidity. The result revealed that above-ground dry biomass (AGDBM) and grain yield (GYLD) per hectare were significantly affected both by deterioration days and seed rate. As deterioration day increased the mean value for AGDBM and GYLD per hectare was significantly reduced and as the seeding rate increased from 75 to 125 kg/ha AGDBM and GYLD per hectare increased by 30.53% and 21.01%, respectively. The main effect of deterioration days showed a significant difference (p<0.05) for spike length (SL) as deterioration days increased from 2 to 10 days SL was reduced by 7.7–22.62% as compared to un-aged treatment but, the percentage reduction for barley seed deteriorated for 6 and 10 days recorded similar value which is 22.62% as compared to un-aged treatment. Seed per spike and thousand kernels weight were influenced by the main effect of seed rate but, not by deterioration days. As the seeding rate increased from 75 to 125 kg/ha, number of seeds per spike reduced by 4.75% whereas, seeds sown at a low seeding rate (75 kg/ha) recorded a higher thousand kernel weight (TKW) as compared to the seed sown at higher seed rate 100 and 125 kg/ha. Interaction effect of deterioration days and seed rate were only significant for TKW and it was non-significant for the rest of the evaluated crop phenology, growth, yield, and yield-related parameters. This study was only a field experiment result based on further conclusions on how aging can affect the genetic potential such as germination and viability; laboratory inclusive test will be required.

Derivation of seed viability constants (KE and CW) and prediction of longevity of Solanum aethiopicum seeds

The seed viability equation uses species viability constants to predict seed longevity under different storage conditions. There are already established universal values of constants that account for the effect of temperature on seed longevity (CH and CQ) which can be applied to different crop species. However, constants accounting for the effect of seed moisture (CW) and genotype (KE) are species-specific. This study aimed to derive viability constants and predict seed longevity for African eggplant (Solanum aethiopicum) under genebank conditions. The seeds were subjected to experimental storage at 40°C and different seed moisture contents (6, 8, 10 and 12%) for 120 days to derive survival curves and hence, CW and KE. CW and KE values for S. aethiopicum were 3.32 and 7.4978, respectively. The validation of the derived constants show that they can be used to predict seed longevity of other seed lots within the same species. The genebank curators and other commercial seed technologists may be able to accurately predict longevity of African eggplant seeds under cold dry storage conditions using the improved viability equation and the constants established in this research.

Predictive model for moisture content of Coffea liberica seeds subjected to ambient air drying

Predictive model for moisture content of Coffea liberica seeds subjected to ambient air drying

Rapid prediction and visualization of safe moisture content in alfalfa seeds based on multispectral imaging technology

Moisture significantly impacts seed sales, storage, and processing. Traditional moisture testing methods are often slow, labor-intensive, and inadequate for the rapid detection demands of modern agriculture, particularly for non-destructive testing of individual seeds. This study applied multispectral imaging to obtain morphological and spectral data from alfalfa seeds at six moisture levels (4 %, 8 %, 12 %, 16 %, 25 %, and 41 %). By integrating algorithms such as Support Vector Machines (SVM), Random Forests (RF), Linear Discriminant Analysis (LDA), Back Propagation Neural Network (BPNN), and normalized typical discriminant analysis (nCDA) algorithms, classification models were developed to distinguish between safe and unsafe moisture levels. The Results indicated that spectral data alone significantly improved model accuracy and prediction. nCDA visualizations effectively illustrated spatial moisture distribution, highlighting stark color differences between seeds in the safe moisture range (4 %, 8 %, 12 %) and those in the unsafe range (16 %, 25 %, 41 %). BPNN exhibited high model precision, achieving a recognition accuracy rate of 90.1 % for safe and unsafe moisture content. Key wavelengths identified by the Permutation method included 970, 880, 570, and 490 nm. Pearson correlation analysis showed a significant positive correlation between germination indicators and spectral data, which strengthened with longer seed storage. These findings confirm the potential of multispectral imaging for assessing the safe moisture content of alfalfa seeds, supporting the development of detection systems for evaluating moisture content in individual seeds. This advancement enables the rapid removal of high-moisture seeds, preventing deterioration during storage.

Biologically Effective Dose of Diflufenican for the Control of Multiple Herbicide-Resistant Waterhemp in Soybean

Waterhemp biotypes have evolved resistance to Weed Science Society of America (WSSA) Herbicide Groups 2, 5, 9, 14, and 27 in Ontario Canada, are present in 15 counties, spanning a distance of 800 km across southern Ontario, and cause an average soybean yield loss of 42%. Five field experiments were established in growers’ fields in southwestern Ontario to determine the biologically effective doses of diflufenican (Group 12) applied preemergence (PRE) to control multiple herbicide-resistant waterhemp in soybean. The calculated diflufenican doses to elicit 50, 80, and 95% control of MHR waterhemp were 71, 164, and 304 g ai ha-1 at 2 weeks after herbicide application (WAA); 50, 115, and 214 g ai ha-1 at 4 WAA; and 69, 158, and 294 g ai ha-1 at 8 WAA, respectively. The calculated diflufenican doses that caused a 50, 80, and 95% reduction in MHR waterhemp density were 28, 70, and Non-est. g ai ha-1 and the doses that caused a 50, 80, and 95% reduction in MHR waterhemp biomass were 44, 109, and Non-est. g ai ha-1, respectively. The calculated diflufenican doses that resulted in 50, 80, and 95% of the soybean yield of the industry standard herbicide (flumioxazin/pyroxasulfone) were 3, 12, and 57 g ai ha-1, respectively. Diflufenican (180 g ai ha-1) PRE controlled MHR waterhemp 89, 92, and 85%; metribuzin (300 g ai ha-1) PRE controlled MHR waterhemp 94, 84, and 69%; and flumioxazin/pyroxasulfone (105/134 g ai ha-1) PRE controlled MHR waterhemp 100, 99, and 98% at 2, 4, and 8 WAA, respectively. Diflufenican, metribuzin, and flumioxazin/pyroxasulfone applied PRE reduced MHR waterhemp density 96, 84, and 100% and biomass 93, 67, and 99%, respectively at 8 WAA. Diflufenican, metribuzin, and flumioxazin/pyroxasulfone applied PRE caused 9, 0, and 4% visible soybean injury, respectively but the injury was transient and caused no adverse effect on seed moisture content or seed yield of soybean. This study concludes that diflufenican and metribuzin applied PRE provide comparable MHR waterhemp control; however, control was lower than flumioxazin/pyroxasulfone.

The pivotal role of water potential in phenology and seed germination of Abies spectabilis in the western Himalayan treeline region

Abies spectabilis (East Himalayan Fir), a dominant timber-producing species in the Himalayas, plays a dynamic role in ecological balance and sustains various habitats across temperate to subalpine altitudes. Himalayan montane forests express signs of changes in the growth, regeneration, and population density of forest tree species due to ongoing climate change, including its upper distribution limit. The research was conducted at 30°11´02˝N and 79°39′36˝E, ranging from 3,100 to 3,500 m asl elevation in the treeline ecotone of western Himalaya. The study presents a comprehensive perspective on how water availability and its intricate interactions with climatic and ecological variables shape the dynamics of treeline ecosystems. The study’s phytosociological analysis of treeline sites revealed the complex interplay between species composition, adaptability, and regeneration potential. The eco-physiological aspects of water balance were thoroughly explored, underscoring how plants employ various strategies to cope with changing water availability. The soil moisture content ranged from 32.17 to 73.50%. The dynamic nature of water potential (pre-dawn (ΨPD) and mid-day (ΨMD)) across seasons and years reflects and varies between −0.13 and − 1.25 MPa, the species’ ability to adjust and manage water balance according to environmental shifts. Osmotic potential at full turgor varied from −0.72 to −1.77 MPa, these adjustments are crucial for key life cycle events of vegetative and reproductive phases of species. The strong correlation of water potential (Ψ) and phenophases emphasizes the importance of water status in regulating these vital processes. Furthermore, the study delved into the maturation and germination processes, highlighting the significance of Ψ and moisture content in seed development and germination success. The maximum germination of 46.33% was observed when the seed moisture content was 30.90 ± 3.11%. The observed correlations between cone characteristics and seed parameters indicate the existence of trade-offs that impact seed size, weight, and germination capacity, contributing to the overall fitness of the species.

Sorption Drying of Wheat Seeds Using Kieserite as a Solid Desiccant

The moisture content (MC) of wheat seeds must be reduced before storage using appropriate dehydration processes. Desiccant drying is a promising alternative to conventional drying methods because it improves seed quality while providing overall energy efficiency. This study explores the sorption drying of wheat seeds using granulated kieserite MgSO4·H2O as a solid desiccant, which has a high water capacity and is regenerated at low temperatures <100 °C. Desiccant characterization was conducted using SEM-EDS, XRD, DSC-TG, and particle size analysis. Wheat seeds mixed directly with kieserite in various mass ratios were dried under uniform stirring and controlled temperature conditions. A 240-min drying time was required to reduce the initial MC of wheat from 21.5% to 15.1% at a desiccant-to-grain ratio of 1:1. After 360 min, a final MC of 14.4% was achieved. The germination energy and seed capacity after sorption drying were 91 ± 1% and 97 ± 2%, respectively. Due to the available water capacity of kieserite, several batches of seeds can be dried without intermediate desiccant regeneration. This study is useful for developing low-cost, non-thermal, and sustainable drying technology for various agricultural products.

Relationship Between Seed Maturity and Seed Dormancy In Acer Buergerianum Miq.

Seeds are fundamental to plant survival and dispersal, yet their development and germination are influenced by various internal and external influences. There is little known about seed maturity and seed dormancy in Acer buergerianum. So, we investigated the relationship between seed maturity and seed dormancy through assessments of seed moisture content and various germination tests. The results showed that: 1. The water content in A. buergerianum seeds decreases as they mature. 2. Elevated seed maturity is linked to increased dormancy depth. 3. A. buergerianum seeds exhibit physiological dormancy. 4. Stratification can effectively release dormancy in A. buergerianum seeds. Understanding the dynamics between seed water content, maturity, and dormancy is pivotal for seed germination and seed propagation in Acer species. Bangladesh J. Bot. 53(2): 353-359, 2024 (June)

The Hygroscopic Properties and Sorption Isosteric Heat of Coix Seeds

Coix seeds are one of the most difficult-to-store cereal foods, and in order to maintain their quality during storage, the present study was conducted to determine the moisture adsorption and desorption isotherms of five varieties of coix seeds in the ranges of 10-35 °C and 11.3%-96.0% equilibrium relative humidity (ERH) using a static gravimetric method. The isotherms showed sigmoidal curves, and there was a hysteresis between adsorption and desorption isotherms. Six equilibrium moisture equations were used to fit the isotherms, and the Modified Chung-Pfost (MCPE), Modified Guggenheim-Anderson-deBoer (MGAB), Modified Henderson (MHE), Modified Oswin (MOE) and our developed modified Caurie (MCaurie) equations were suitable for fitting the data, among which MCPE was the best fitting equation. The monolayer water content decreased with increasing temperature, and the content of monolayer water, the density and layer number of adsorbed water, and the content of bound water for desorption were significantly higher than those of adsorption. The absolutely (ERH 65%) and relatively (ERH 70%) safe moisture contents (MC, wet basis, w.b.) of coix seeds were respectively 12.45%-12.82% and 13.15%-13.69% at 25 ℃. At equilibrium moisture content (EMC) less than 14.9% w.b., the desorption isosteric heats of coix seed were greater than the adsorption isosteric heats, and both decreased sharply in a hyperbolic form, approaching the latent heat of pure water at 14.9% w.b. The sorption isosteric heat of large-grain coix seed was slightly less than that of small-grain seed due to more cracks in the kernel back surface and more micropores in starch granular surface and resultantly more moisture sorption capacity. These results suggest that the desorptive and adsorptive behaviors of coix seeds should be differentiated for cooldown aeration, demoisturizing and remoisturizing operation, and the average isotherm can be used for common storage management.

The evaluation of Indigofera seed production and quality in different environments

Abstract Seed production and quality are pivotal factors in the success of Indigofera cultivation as forage crop for livestock. This study aims to evaluate the seed production and quality of Indigofera in different environments of Seed Production Unit (SPU). Seven distinct SPU’s, namely BPPIB-TSP Bunikasih, BBIB Singosari, BPTU-HPT Denpasar, BPTU-HPT Pelaihari, BPTU-HPT Sembawa, BBPTU-HPT Baturraden, and CV Cahaya Baru Semarang selected as the observed locations. Environmental data pertaining to elevation (m a.s.l.), annual rainfall (mm/year), temperature (°C), humidity (%), and light intensity (Lumen-hour) were collected for each unit. Seed production parameters were seed yield (g) and seed weight (g per 1,000 seeds). Seed quality parameters encompassed water content (%), purity (%), and viability (%). The analysis in this study involved assessing the mean differences in these parameters through the application of analysis of variance (ANOVA). The result showed the seed production and quality were diverse across SPUs, with BPTU-HPT Sembawa and CV Cahaya Baru Semarang demonstrating outstanding seed production, while BPTU-HPT Pelaihari maintains high-quality standards. The highest positive correlation emerged between elevation and water content (r = 0.72), highlighting the influence of altitude on the moisture content of seeds. The strongest negative correlation was observed between temperature and water content (r = -0.76), emphasizing the role of temperature in drying seeds.

Seed germination ecology of endangered plant Horsfieldia hainanensis Merr. In China

BackgroundHorsfieldia hainanensis Merr., an indicator species of China’s humid tropical rainforests, is endangered due to difficulties with population regeneration. In this study, the biological characteristics and germination adaptability of the seeds were studied for the first time, in order to provide a basis for analyzing the causes of endangerment and strategies for the artificial cultivation of H. hainanensis. The effects of biological characteristics (population, arils, seed coat, seed weight, seed moisture content) and environmental factors (temperature, light, drought, substrate, burial depth) on seed germination and seedling growth of H. hainanensis were studied.Results and discussionThe fruits were found to be capsules containing seeds wrapped in a pericarp and fleshy aril, which provide protection and assist in seed dispersal, but also pose risks to the seeds, as the peel and fleshy aril can become moldy under high temperature and humidity conditions. There were significant differences in fruit morphology and germination characteristics among different populations, and the seed quality of populations in Niandian village, Daxin County, Chongzuo City, Guangxi Zhuang Autonomous Region was better. The arils significantly inhibited seed germination, the germination of large seeds was better, and seedling growth from medium seeds was superior. H. hainanensis seeds were sensitive to dehydration, and intolerant to drought and low temperature, which is typical of recalcitrant seeds. The seeds are suitable for germination on a moist substrate surface with good water retention and breathability at 30–35℃.