Compost Research Articles

Prevalence of Varroa destructor and first report of Nosema sp. in Apis mellifera drone congregation areas

Varroosis and nosemosis are diseases that affect honey bees (Apis mellifera) and therefore have a great impact on beekeeping worldwide. These parasites can be dispersed by drones and, in the case of Varroa destructor (etiological agent of varroasis), its presence has been reported in areas of natural fertilization of A. mellifera, known as Drone Congregation Areas (DCA). Previously, several DCAs were identified in Argentina and progress was made in their topographic and genetic characterization, and sanitary studies were also initiated. In this study, three DCA and one apiary located in the province of Tucumán were monitored for four years, and the presence of V. destructor and Nosema sp. was evaluated. The results indicated the presence of V. destructor in the drone samples of the DCA throughout the study. Although a trend of decreasing parasitization over time was observed, no statistically significant differences were found between years or among the considered DCAs. The presence of Nosema sp. was detected for the first time in the DCA, with samples exhibiting high spore load. The results support the role of drones in the dynamics and dispersal of diseases and allow us to conclude that the analysis of DCAs represents a key tool for monitoring the health of bee populations, complementary to the analyses carried out in apiaries.

Optimizing Straw-Rotting Cultivation for Sustainable Edible Mushroom Production: Composting Spent Mushroom Substrate with Straw Additions.

In recent years, the optimization of straw-rotting formulations for cultivating edible mushrooms and the management of the resulting spent mushroom substrate have emerged as new challenges. This study aimed to investigate the composting of spent mushroom substrate produced from mushroom cultivation with various straw additions, under conditions where chicken manure was also used. Parameters measured during the composting process included temperature, pH, electrical conductivity (EC), germination index (GI), moisture, and total nitrogen content. Additionally, changes in nutrient content within the compost piles before and after composting were determined, and the variations in bacterial and fungal communities across different treatments before and after composting were analyzed using 16S rRNA and ITS sequencing. The results indicated that the spent mushroom substrate produced by adding 20% straw during mushroom cultivation was more suitable for composting treatment. The findings suggest that incorporating an appropriate amount of straw in mushroom cultivation can facilitate subsequent composting of spent mushroom substrate, providing an effective strategy for both environmental protection and cost reduction.

RENURE – PROCESSED NATURAL FERTILIZERS. SELECTED ENVIRONMENTAL, PRODUCTION-ECONOMIC ISSUES

The aim of the paper is to present the essence of natural fertilizers in the form of RENURE, taking into account environmental and production-economic issues. For several decades, international programs and strategies for sustainable development have been implemented. The need to achieve various objectives in business activity is also underlined by the European Green Deal strategy, introduced at the end of 2019. An important element of it is the correct management of natural fertilizers, both for environmental and production and economic reasons. The case of the Netherlands was presented, where pilot studies on the conversion of manure into RENURE were introduced. The study used literature sources and selected, recent statistics from Eurostat resources (2019, 2020). Agriculture in EU countries in the context of production and possibilities of using natural fertilizers is illustrated. Analysis of statistical data has shown that agriculture in the EU is highly diversified in terms of manure management. The case of the Netherlands, which has implemented the RENURE pilot program, results from the specificity of their agriculture – a small area of the country, a very high population and a high stocking density of livestock. Countries that face similar agricultural challenges as the Netherlands can seek similar solutions. In the case of Polish, which differs significantly in terms of the organisation of agriculture and its natural management conditions, the economic and environmental justification for the introduction of RENURE is not justified on a sector-wide scale.

Characterization of Parageobacillus Bacteriophage vB_PtoS_NIIg3.2-A Representative of a New Genus within Thermophilic Siphoviruses.

A high temperature-adapted bacteriophage, vB_PtoS_NIIg3.2 (NIIg3.2), was isolated in Lithuania from compost heaps using Parageobacillus toebii strain NIIg-3 as a host for phage propagation. Furthermore, NIIg3.2 was active against four strains of Geobacillus thermodenitrificans, and it infected the host cells from 50 to 80 °C. Transmission electron microscopy analysis revealed siphovirus morphology characterized by an isometric head (~59 nm in diameter) and a noncontractile tail (~226 nm in length). The double-stranded DNA genome of NIIg3.2 (38,970 bp) contained 71 probable protein-encoding genes and no genes for tRNA. In total, 29 NIIg3.2 ORFs were given a putative functional annotation, including those coding for the proteins responsible for DNA packaging, virion structure/morphogenesis, phage-host interactions, lysis/lysogeny, replication/regulation, and nucleotide metabolism. Based on comparative phylogenetic and bioinformatic analysis, NIIg3.2 cannot be assigned to any genus currently recognized by ICTV and potentially represents a new one within siphoviruses. The results of this study not only extend our knowledge about poorly explored thermophilic bacteriophages but also provide new insights for further investigation and understanding the evolution of Bacilllus-group bacteria-infecting viruses.

THE STUDY OF SOIL EROSION UNDER A SYSTEMIC CONCEPTION

This article aimed to understand how erosion processes can be analyzed from a systemic point of view. Soil erosion is considered here a naturally occurring phenomenon, which can be (and usually is) influenced by human activities, constituting one of the main environmental problems of the planet, in addition to being the main modeling agent of the terrestrial surface. The consequences of the accelerated action of erosion processes are numerous, such as: reduction of natural fertility and productive capacity of soils; silting and pollution of water bodies; impoverishment of rural communities; rural exodus; among many others. Understanding the dynamics of this phenomenon becomes fundamental because a comprehension of a spatio-temporal scope, coupled with the knowledge of the possible problems that may occur with its accelerated performance, provides support for the development of sustainable management. Given that soils are the 'foundation' of the fauna, flora, and mainly of human subsistence, it is a valuable resource. The analytical procedures of this manuscript followed the construction of a system based on a case study, exemplifying how the systemic approach can be developed in the studies of erosive processes. By analyzing soil erosion from a systemic approach, it was possible to observe how the different flows of matter and energy occurred between the variables, explain the importance of understanding erosion processes in an integrated way, and avoid fragmented and reductionist interpretations.

Investigation of 29 Antimicrobial Compounds in Soil Using Newly Developed UHPLC-MS/MS Method.

While the prudent and reasonable use of veterinary antimicrobial agents in food-producing animals is necessary, researchers over the decades have shown that these antimicrobial agents can spread into the environment through livestock manure and wastewater. The analysis of the occurrence of antimicrobial compounds in soil samples is of a great importance to determine potential impacts on human and animal health and the environment. In this study, an affordable, rugged and simple analytical method has been developed for the determination of twenty-nine antimicrobial compounds from five different classes (tetracyclines, fluoro(quinolones), macrolides, sulfonamides and diaminopirimidines). Liquid-liquid extraction (LLE) with extract filtration combined with ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was the best strategy for the simultaneous determination of all analytes. The developed method was validated according to the Commission Implementing Regulation (EU) 2021/808. The limit of detections (LODs) ranged from 0.5 to 2.0 µg/kg, while the limit of quantitation (LOQ) was established at 1.0 to 20.0 µg/kg. The developed method was successfully applied for the determination of antimicrobial residues in one hundred and eighteen soil samples obtained from four European countries (Austria, Czech Republic, Estonia and Portugal). Doxycycline in the concentration levels of 9.07 µg/kg-20.6 µg/kg was detected in eight of the analysed samples. Samples were collected from areas where natural fertilizers (swine or cow manure) were applied. Our method can be efficiently used to monitor anti-microbial compounds in soil samples.

The Value of Tea Culture from the Perspective of Integration of Tea and Tourism Industry: A case study of Jingmai Mountain, Yunnan

Under the influence of large modern machinery industry, pesticides which invented artificially are commonly used in modern tea production in order to increase labor productivity greatly. The most important thing is to increase product output in exchange for profits. While modern industry has brought fast development to the tea industry, it has also brought many new problems, such as the excessive application of artificial products such as fertilizers and pesticides, which have polluted the soil and near-body waters. In fact, it has also affected the natural reproduction of tea plants. Jingmai Mountain, located in Yunnan province, the ancient tea garden is a sacred mountain in the heart of local people. If the local tea farmers used the famous strategy of "prisoner's dilemma" for their personal benefit, the ancient tea forest would have long disappeared in history. Here, one can see that ancient tea trees and towering trees are intertwined. Mountains and villages, ancient tea houses, forests and tea farmers are integrated into a harmonious and unified world. People of all ethnic groups here grow tea trees, and every family goes hand in hand to protect natural environment. The ancient tea growing in the jungle of Jingmai Mountain grows on natural fertility, without any pollution, and has excellent quality, which has become a model of sustainable development for human and the society.

Evaluation of Natural Fertilizer Potential of Neem Leaves Aqueous Extract for Irrigation Practices

Evaluation of Natural Fertilizer Potential of Neem Leaves Aqueous Extract for Irrigation Practices

Study of rice varieties, fertilizer application, and planting system on rice production in irrigated rice

In Indonesia, increasing rice production to achieve food security is a top priority. To maximize rice production, researchers are still looking for the best and most efficient technology. The goal of this study was to see how different rice varieties, fertilizer applications, and row planting systems affected rice production. The activities took place in Pulau Gambar village, Serba Jadi district, Serdang Bedagai regency, from April 2021 to January 2022 for two planting times (PT). PT.I used varieties of Inpari 30, 32, and Mekongga, legowo row planting system (2:1), (4:1), and Tegel, application of granulate organic fertilizer (GOF) at 400 kg ha-1, natural organic fertilizer (guano) at 100 kg ha-1, NPK fertilizer (15-15-15) at 300 kg ha-1, and Urea at 200 kg ha-1, and PT.II used varieties of Inpari 16, 32, 43, and Mekon The results showed that using Inpari 32 varieties with a combination of organic and inorganic fertilizer and a legowo 2:1 raw planting system was the best treatment for irrigated rice in North Sumatra.

AREVIEW ON THE RECYCLING OF HOUSEHOLD WASTE AND ITS USE AS FERTILIZER OF PLANTS

Human activity may cause damage to the natural environment, and most people witness environmental pollution in different places, so a picture of an exposed waste place or picture of invisible black smoke are all pollutants to the environment, but what matters to our research is household waste and may be the most visible form of pollution. in the past, people throw millions of tons of solid household waste. the problem of pollution with house hold waste is one of the problems that threaten the existence and health of man . it receives intense attention these daye by most of the governments of the rich and deveioping countries of the world, as it represents a painful environmental headache and a great burden that falls on the shoulders of officials in these countries because the huge increase and great diversity in consumption is accompanied by asteady increase in the volume of waste that must be disposed of daily. Hence the idea of recycling came to ride the environment of this waste,as well as the sever shortage of the countries of the world for some basic materials such as rubber,and others which prompted them to recycle these wastes .including the possibility of benefitng from waste its energy value and in agriculture as the production of natural fertilizers and pestisides . In order to reach ahealthy and healthy environment for us and our childernthe project of managing household wasteand environmentally disposing of it and recycling household crumbs represents the ideal solution to reach sustainable development and constitutes asafe gateway to any economic development,hence the objective of the study

Age-dependent relationships among diet, body condition, and Echinococcus multilocularis infection in urban coyotes.

Urban coyotes (Canis latrans) in North America increasingly exhibit a high prevalence of Echinococcus multilocularis, a cestode of recent and rising public health concern that uses rodents as intermediate hosts and canids as definitive hosts. However, little is known about the factors that drive the high urban prevalence of this parasite. We hypothesized that the diet of urban coyotes may contribute to their higher E. multilocularis infection prevalence via either (a) greater exposure to the parasite from increased rodent consumption or (b) increased susceptibility to infection due to the negative health effects of consuming anthropogenic food. We tested these hypotheses by comparing the presence and intensity of E. multilocularis infection to physiological data (age, sex, body condition, and spleen mass), short-term diet (stomach contents), and long-term diet (δ13C and δ15N stable isotopes) in 112 coyote carcasses collected for reasons other than this study from Edmonton, Alberta and the surrounding area. Overall, the best predictor of infection status in this population was young age, where the likelihood of infection decreased with age in rural coyotes but not urban ones. Neither short- nor long-term measures of diet could predict infection across our entire sample, but we found support for our initial hypotheses in young, urban coyotes: both rodent and anthropogenic food consumption effectively predicted E. multilocularis infection in this population. The effects of these predictors were more variable in rural coyotes and older coyotes. We suggest that limiting coyote access to areas in which anthropogenic food and rodent habitat overlap (e.g., compost piles or garbage sites) may effectively reduce the risk of infection, deposition, and transmission of this emerging zoonotic parasite in urban areas.

Diagnosis and management of isthmocele (Cesarean scar defect): a SWOT analysis.

The purpose of this State-of-the-Art Review was to provide a strategic analysis, in terms of strengths, weaknesses, opportunities and threats (SWOT analysis), of the current evidence regarding the management of uterine isthmocele (Cesarean scar defect). Strengths include the fact that isthmocele can be diagnosed on two-dimensional transvaginal ultrasound, and that surgical repair may restore natural fertility potential and prevent secondary infertility, as well as reduce the risk of miscarriage and other obstetric complications. However, there is a lack of high-quality evidence regarding the best diagnostic method and criteria, as well as the potential benefits of surgical repair with respect to fertility. There is a need for experienced surgeons skilled in the various isthmocele repair techniques. Isthmocele repair does not prevent the need for Cesarean delivery in subsequent pregnancies. There is increasing awareness regarding the accuracy of transvaginal ultrasound in diagnosing isthmocele. This may lead to surgical correction and prevention of obstetric and perinatal complications in subsequent pregnancies, including Cesarean scar pregnancy. Regarding threats, the existence of different surgical techniques means that there is a risk of selecting an inadequate approach if the type of isthmocele and the patient's characteristics are not considered. There is a risk of overtreatment when asymptomatic defects are repaired surgically. Finally, there is an absence of cost-effectiveness analyses to justify routine repair. Thus, while there are many data suggesting that isthmocele has an adverse effect on both natural fertility and the outcome of assisted reproduction techniques, high-quality evidence to support surgical isthmocele repair in all asymptomatic patients desiring future fertility are lacking. There is increasing agreement to recommend hysteroscopic repair of isthmocele as a first-line approach as long as the residual myometrial thickness is at least 2.5-3.0 mm. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Sosialisasi Pemanfaatan Eco Enzyme untuk Mengurangi Sampah Organik di Dawis Anggrek Desa Blederan, Wonosobo, Jawa Tengah

Indonesia has a serious waste problem and needs attention from all parties. Waste management can be carried out based on the 4R principle, namely reduce, reuse, recycle and replace. Garbage itself consists of organic and inorganic waste. Organic waste that is over capacity and not managed properly can cause hazards such as odors, affecting water quality, reducing soil quality, and producing methane gas as a contributor to greenhouse gases which can cause environmental damage. One of the efforts to reduce organic waste is through the manufacture of eco enzymes as a natural fertilizer for plants while reducing the greenhouse effect. Activities are carried out through socialization methods and training in making eco enzymes. The results of the activity show that there is an increase in public understanding about the benefits of eco enzyme for the environment as well as how to make eco enzyme by utilizing kitchen waste that is found every day..

Faecal nutrient deposition of domestic and wild herbivores in an alpine grassland

The contribution of herbivores to ecosystem nutrient fluxes through dung deposition has the potential to, directly and indirectly, influence ecosystem functioning. This process can be particularly important in nutrient-limited ecosystems such as alpine systems. However, herbivore dung content (carbon, C; nitrogen, N; phosphorus, P; potassium, K) and stoichiometry (C/N) may differ among species due to differences in diet, seasonality, body type, feeding strategy, and/or digestive system with consequences for soil biogeochemistry. Here we explore how species, body size, and seasonality may result in differences in dung stoichiometry for four alpine herbivores (chamois, sheep, horse, and cattle). We found that herbivore dung nutrient content often varies among species as well as with body size, with the dung of small herbivores having larger C, N, and P faecal content. Seasonality also showed marked effects on faecal nutrient content, with a general pattern of decreasing levels of faecal P, N and an increase of C/N as the summer progresses following the loss of nutrient value of the vegetation. Moreover, we showed how herbivores play an important role as natural fertilizers of C, N, and P in our study area, especially cattle. Our study highlights the importance of considering the relative contribution of different herbivores to ecosystem nutrient fluxes in management practices, especially with ongoing changes in wild and domestic herbivore populations in alpine ecosystems.

SIMULATION OF THE PROCESS OF FORMING THE EDGE AND MIXING THE COMPONENTS OF THE COMPOST MIXTURE WITH A SINGLE-DRAMED AERATOR

The most widespread approach for implementing the technological process of organic compost production involves using mobile aerator-mixers of the rotary-drum type. Based on the analysis of various designs of mechanized composting equipment from previous theoretical and experimental studies conducted by renowned scientists, as well as our own research, it has been established that mechanized compost production requires further investigation. The analysis revealed that rotary drum-blade working elements are efficient. However, there is insufficient research on the dependencies of changes in the height of the pile during formation, indicators of homogeneity and structure of the mixture, energy consumption during the operation of drum-blade working elements in relation to the rotation frequency, working element's linear velocity, and geometric parameters of the blades. Additionally, changes in the bulk density, mixture structure, and temperature distribution within the pile under the influence of the working elements have not been investigated. This highlights the relevance of conducting research in the chosen direction. The analysis of developed models for the interaction of the working element with the compost mixture has shown that they cannot be used to assess the quality of mixing and pile formation, as it is necessary to consider the movement of discrete particles that make up the compost mixture. The mathematical description of the movement of discrete elements is achievable using modern CAE (Computer-Aided Engineering) systems, and one such system is Simcenter Star-CCM+. Through numerical simulation of the technological process of pile formation and mixture mixing, an argumentation of the constructive and technological parameters of the working element of a single-drum aerator was conducted. To construct the physical-mathematical model of the compost mixing and pile formation processes, the following mesh and physical models were utilized: meshless DEM (Discrete Element Method), solution interpolation, Lagrangian multiphase, unsteady implicit, DEM, multiphase interaction, gravity force, and boundary forces of DEM. As a result of simulating the compost mixture mixing process using a single-drum blade working element, dependencies of the height (H') and width (L') of the formed pile on the rotation frequency (n), linear velocity of the working element (V), and the blade's inclination angle (ξ) were established. A mathematical expression in the form of second-order regression equations was derived, linking the coefficient of variation of mixing quality (δ) with the research factors. Solving the compromise problem using the Wolfram Cloud software package allowed us to determine the rational parameters for the working element: rotation frequency (n) of 237 rpm, linear velocity (V) of 0.15 m/s, and blade inclination angle (ξ) of 15.8°. Consequently, the coefficient of variation of mixing quality (δ) was found to be 0.51, and the width (L') and height (H') of the formed pile were 1.23 m and 1.54 m, respectively.

A Possible Synergistic Approach: Case Study of Saccharina latissima Extract and Nitrifying Bacteria in Lettuce

Nowadays, the exponential expansion in human population has resulted in the massification of intensive agricultural practices, with crop yield and sustainability being one of the most pressing challenges. Therefore, there was a need for new and natural fertilizers and pesticides, which has become a popular agricultural trend nowadays. Therefore, there was an increased interest to apply seaweed and bacterial extracts in agriculture to promote new means of sustainability and soil usage. This work aims to test seaweed inclusion in the agricultural field, as a simple or complex foliar biofertilizer solution applied together with a nitrifying bacteria, to verify if there is a potential synergistic effect of these two different types of biofertilizers on economically important vegetables. As a result, experiments were conducted in a greenhouse using an aqueous extract of the brown seaweed Saccharina latissima (1.2% v/v) and a biofertilizer based on BlueN bacteria (0.03% m/v), both simple or in combination, on lettuce (Lactuca sativa L. var. crispa) plants. The seaweed extract (simple or in combination), presented favorable effect on lettuce growth and nutritional properties. The aqueous algal extract, and it in combination with BlueN, produced heavier lettuce leaves (74.25 ± 6.86 and 74.13 ± 3.07 g, respectively) than the controls and enriched leaf micronutrient contents (zinc and manganese). Also, this study demonstrated that a combined seaweed-bacteria fertilizer did not show synergistic behavior, being a non-profitable solution when compared to a simple seaweed extract. In summary, this study demonstrated that simple (crude) seaweed extracts can be considered as an important key for natural plant biofertilizers and growth stimulators concerned with the blue circular economy.

Intraterritorial differences in reproductive losses

Introduction. Postponing motherhood correlates with a decrease in natural fertility, the accumulation of aggravated reproductive experience, somatic and other diseases, and, as a result, an increase in the risk of reproductive losses. The present study reflects the significance of intraterritorial differences in the structure and frequency of reproductive losses among female residents of the Tyumen region. Aim. To assess intraterritorial differences in reproductive losses on the example of the Tyumen region.Materials and methods. An analytical study has been carried out. The study period is 2016–2021. Reproductive losses in various autonomous districts of the Tyumen region were analyzed. Used data from medical records.Results and discussion. In Tyumen region, 94.33% of reproductive losses occur before 12 weeks of gestation. The proportion of primigravidas in the total number of reproductive losses is 6.78%, HIV-infected – 2.06%. Reproductive losses in the first pregnancy is associated with a gestational age of more than 12 weeks (OR 2.31, 95% CI 2.13–2.49), with HIV infection – less than 12 weeks (OR 3.59, 95% CI 2, 88–4.47). Tyumen region without AO is characterized by a greater association of reproductive losses in pregnancy up to 12 weeks with HIV infection in comparison with the Khanty-Mansiysk Autonomous Okrug – Yugra (KhMAO): OR 1.83, 95% CI 1.67–2.00; and Yamalo-Nenets Autonomous Okrug (YNAO): OR 7.68, 95% CI 6.01–9.81; from 12 to 22 weeks – with HIV infection compared with KhMAO (OR 1.93, 95% CI 1.20–3.09) and YNAO (OR 3.0, 95% CI 1.30–6, 95), with a first pregnancy compared with KhMAO (OR 1.26, 95% CI 1.07–1.48) and YNAO (OR 1.81, 95% CI 1.40–2.35). The greatest contrast was noted between Tyumen region and YNAO. More than 50% of reproductive losses in pregnancy before 12 weeks is due to medical abortion. In Tyumen region without autonomous regions, at more than 12 weeks of gestation, medical abortion competes in frequency with spontaneous abortion. Tyumen region without AO showed high achievements in the total overcoming of criminal abortion.Conclusion. On the example of Tyumen region, the non-universality of the intra-territorial structure of the Republic of Poland is shown. Artificial reproductive losses dominate over non-artificial ones. Intraterritorial differences in reproductive losses require taking into account, monitoring many risk factors, adapting measures for their prevention, preservation and restoration of reproductive health to them.

Enhanced biodegradation of endocrine disruptor bisphenol A by food waste composting without bioaugmentation: Analysis of bacterial communities and their relative abundances

Composting with food waste was assessed for its efficacy in decontaminating Bisphenol A (BPA). In a BPA-treated compost pile, the initial concentration of BPA 847 mg kg-1 fell to 6.3 mg kg-1 (99% reduction) over a 45-day composting period. The biodegradation rate was at its highest when bacterial activity peaked in the mesophilic and thermophilic phases. The average rate of total biodegradation was 18.68 mg kg-1 day-1. Standard methods were used to assess physicochemical parameters of the compost matrix and gas chromatography combined with mass spectrometry (GC/MS) was used to identify BPA intermediates. Next-generation sequencing (NGS) was used to detect BPA degraders and the diverse bacterial communities involved in BPA decomposition. These communities were found consist of 12 phyla and 21 genera during the composting process and were most diversified during the maturation phase. Three dominant phyla, Firmicutes, Pseudomonadota, and Bacteroidetes, along with Lactobacillus, Proteus, Bacillus, and Pseudomonas were found to be the most responsible for BPA degradation. Different bacterial communities were found to be involved in the food waste compost biodegradation of BPA at different stages of the composting process. In conclusion, food waste composting can effectively remove BPA, resulting in a safe product. These findings might be used to expand bioremediation technologies to apply to a wide range of pollutants.

Effect of Seaweed Extract Application Rate and Method on Growth, Flowering and Yield of Pansy (Viola x wittrockiana)

Pansies, part of the Viola genus, are vibrant flowers with velvety petals and a distinct center blotch. They are popular as ornamental plants due to their colorful appearance. Seaweed extract, derived from various types of seaweed or marine algae, is utilized in agriculture, gardening, and skincare. Seaweed is nutrient-rich, containing essential macro and micronutrients, making seaweed extract a valuable natural fertilizer to enhance plant growth and health. Therefore, present investigation was carried during the Winter-2022-23 with a view to determine the effect of seaweed extract application on pansy variety Majestic Giant Mix for its growth, flowering, yield. The study was examined using completely randomized block design. From the present investigation, it is concluded that treatment T4 i.e., application of Sea weed extract @ 4ml/l as drench application found superior in terms of plant height (16.00 cm), plant spread (17.56), number of branches per plant (28.81), days taken for first flower opening (30.00), days taken for 50% flowering (58.33), stalk length (8.60 cm), flower diameter (7.83) number of leaves (43.33), number of flowers per plant (38.88) and seed yield per plant (3.00g).

Growth Performance of Photoperiod-Sensitive Rice (Oryza sativa L.) Varieties in Different Soil Types under Rainfed Condition in Cambodia

In Cambodia, rice is predominantly produced in areas with rainfed lowland conditions where photoperiod-sensitive varieties are cultivated. A number of varieties have been released for rainfed lowland areas, and the rice grain yield has reportedly increased by approximately 12% over the past ten years. Moreover, great fluctuations in yield performance have been observed across different soil types of the rainfed ecosystems of Cambodia. Therefore, the present study aimed to analyze the grain yield and stability among ten popular varieties that were released for rainfed lowland ecosystems across the four different soil types in Cambodia in two years. The grain yield varied 566 g m−2 as the highest in clay soil and about 220 g m−2 as the lowest in sandy soil. A combined ANOVA revealed significant differences for the main effect of genotype, environment, and genotype-by-environment interaction (GEI) for all yield-related traits and grain yield per square meter. The principal component test results showed that the heterogeneity of grain yield was mainly attributable to the effect of environment, followed by the effect of genotype. In fertile conditions, a higher percentage of filled grains was supported by higher leaf N until the late stage with a wider flag leaf. In conditions of moderate fertility, larger numbers of panicles were supported by a higher percentage of productive culms with higher leaf N until the late stage. In conditions of poor fertility, a higher percentage of filled grains was supported by higher leaf N until the late stage, which is considered to be important for higher grain yield. The variety Phka Rumduol showed these preferable traits and produced higher yields in fertile to poor natural soil fertility conditions with moderate variation. This variety is considered to be more desirable and ideal due to its stability and higher grain yield. The other varieties, namely, Phka Mealdei, Phka Rumdeng, and CAR4, were identified as above-average yielders. Therefore, those varieties potentially may be recommended for cultivation in rainfed lowland rice ecosystems in Cambodia due to their high yields. CAR4 showed moderate variation at the same level as Phka Rumduol. From the point of stability, Phka Rumduol and CAR4 can be expected to excel.