Search Results (76)

This study presents an integrated spatiotemporal assessment of drought conditions in the Thung Kula Ronghai region of Northeastern Thailand from 2001 to 2023. Multiple satellite-derived drought indices, including SPI, SPEI, RDI, and AI, together with NDVI anomalies, were used to detect seasonal and long-term drought dynamics affecting rainfed Hom Mali rice production. The results show that dry season droughts now affect up to 17 percent of the region’s agricultural land in some years, while severe drought zones persist across more than 2.5 million hectares over the 20-year period. In the most recent 5 years, approximately 50 percent of cultivated areas experienced moderate to severe drought conditions. The RDI showed the strongest correlation with NDVI anomalies (r = 0.22), indicating its relative value for assessing vegetation response to moisture deficits. The combined index approach delineated high-risk sub-regions, particularly in central Thung Kula Ronghai and lower Surin, where drought frequency and severity have intensified. These findings underscore the region’s increasing exposure to dry-season water stress and highlight the need for site-specific irrigation development and adaptive cropping strategies. The methodological framework demonstrated here provides a practical basis for improving drought monitoring and early warning systems to support the resilience of Thailand’s high-value rice production under changing climate conditions. Full article

Sulfur (S) fertilizer is routinely applied together with other macronutrients by farmers across all regions to improve grain yield and quality, but its distinct effects on grain yield and aroma intensity in fragrant rice remain inadequately studied, especially when applied under varying existing soil S levels. This study aimed to determine the effects of S fertilizer application on grain yield and aroma intensity (2-Acetyl-1-Pyrroline, 2AP) in fragrant rice grown under varying soil S levels (very low, low, and medium). The premium Thai fragrant rice cultivar KDML105 was grown under field conditions during two cropping seasons in 2021 and 2022 in Surin province, northeastern Thailand. Sulfur fertilizer in the form of (NH4)₂SO₄ was applied at 0, 30, 60, 90, and 120 kg S ha⁻¹ at one time with the basal fertilizers phosphorus (P) and potassium (K) under varying soil S levels, using the same protocol in both cropping seasons. Plant growth parameters were evaluated at the tillering stage, and grain samples were harvested at maturity to evaluate grain yield and aroma intensity. The results showed that applying S at rates between 60 and 90 kg ha⁻¹ to soils with very low and low S increased grain yield from 4 to 20% compared to no S application, while no effect of S application was observed for the medium soil S level. The results were primarily attributed to the number of tillers and panicles per hill and the 1000-grain weight in both cropping seasons. Dissimilar effects of S application rates and soil S level were found for grain 2AP content. There was a higher grain 2AP content in the low and medium soil S levels compared to very low S, but the pattern varied according to the S application rate. Applying the appropriate rate of S fertilizer can significantly improve rice productivity, especially when cultivated under S-deficient soil, and higher soil S levels can promote the grain 2AP content of fragrant rice. Full article

Zinc (Zn) fertilization is widely used in maize (Zea mays L.) production to alleviate Zn deficiency and improve biomass and grain yield. However, limited research exists on Zn management in maize cultivated in high-pH paddy soils following rice-based systems, where altered soil chemistry may affect Zn availability and plant uptake. This study aimed to evaluate the effects of Zn application rates on growth, yield, and Zn uptake in two hybrid maize varieties under such conditions. Field experiments were conducted during the 2019 and 2020 dry seasons in Phetchabun Province, Thailand, using a randomized complete block design with a 4 × 2 factorial arrangement and four replications. Treatments included four Zn rates (0, 5, 10, and 20.6 kg of Zn/ha), applied as Zn sulfate monohydrate (ZnSO₄·H₂O, 36% Zn) by soil banding at the V6 stage, and two hybrid varieties, Suwan 5731 (SW5731) and Suwan 5819 (SW5819). In 2019, significant Zn × variety interactions were observed for biomass, crop growth rate (CGR), and grain yield. SW5819 at 10 kg of Zn/ha produced the highest biomass (31.6 t/ha) and CGR (25.6 g/m²/day), increasing by 15.3% and 39.1%, respectively, compared to its own no Zn treatment. In contrast, 20.6 kg of Zn/ha reduced SW5819 biomass by 6.6% and 13.1% relative to SW5731 and its own no-Zn treatment, respectively. Grain yield in SW5819 peaked at 14.7 t/ha under 5 and 10 kg of Zn/ha, significantly higher than SW5731 under 0 and 5 kg of Zn/ha by 16.7%, while SW5731 showed no significant response. In SW5819, shoot and grain Zn uptake significantly increased under 5 and 10 kg of Zn/ha by up to 36.8% and 33.3%, respectively, compared to no Zn treatment. The lowest shoot Zn uptake was found in SW5819 under 20.6 kg of Zn/ha (264.1 ± 43.9 g/ha), which was lower than all its Zn treatments and all SW5731 treatments, showing a reduction of 19.4–43.6%. Zn application improved soil Zn availability, and Zn partitioning among plant organs varied with Zn rate and season. A moderate Zn rate (10 kg of Zn/ha) optimized maize performance under high-pH, rice-based conditions, emphasizing the need for variety-specific Zn management. Full article

Rice root nematodes (Hirschmanniella spp.) cause serious damage to rice in various rice-producing countries in Asia. Nonetheless, there is limited information about the genetic diversity and structure of these nematodes, including in Thailand, where the current study explored the diversity and structure of Hirschmanniella spp. from 57 paddy fields in major rice-growing areas across the country. Using morphological characteristics and internal transcribed spacer rDNA sequencing, we identified all samples as Hirschmanniella mucronata. The use of the Inter-Simple-Sequence-Repeats-based delta K statistical test and principal coordinate analysis revealed two different genetic groups from three distinct geographical regions including the north and the northeast (Group 1) and the central (Group 2) regions. While the unbiased expected heterozygosity indicated low genetic diversity of H. mucronata in Thailand (0.149), the Shannon information index indicated there was higher diversity in Group 2 (0.259) than Group 1 (0.228). The AMOVA confirmed high genetic variation within such groups (76%), but low genetic variation between the two groups (24%). There was no clear correlation between genetic diversity and geographic distance. Given the presence of H. mucronata in almost all rice-growing countries, this first study of H. mucronata populations has provided fundamental knowledge that should help to combat this pest in the rice production system. Full article

Rice–fish culture, an ancient agronomic practice, integrates aquaculture with rice farming, a sustainable solution for enhancing food security and agricultural productivity. The recent advancements and historical perspectives on rice–fish culture have increased its ecological, economic, and social impacts. The practice spans over 2000 years and has seen significant technological improvements, especially in regions like China, Thailand, and Bangladesh. Implementations of modernized rice–fish systems demonstrate increased rice yields, reduced pest and weed prevalence, improvements in soil quality, and higher profits for farmers. For example, in China, it was reported that a rice–fishing system produced 6000–7000 kg of rice and 1500–7500 kg of fish per hectare per year. Furthermore, the fish reduce herbivore insect abundance and weed abundance, effectively eliminating the need for pesticides. Despite its advantages, challenges such as water management, the availability of quality fish seed, and socio-economic barriers remain. By synthesizing findings from various studies, we will highlight the potential of rice–fish culture to contribute to sustainable agriculture and rural development, recommending strategies for optimizing its adoption and addressing existing constraints. Full article

This study investigates the environmental issue of air pollution (PM 2.5) from agricultural waste in Thailand and promotes the utilization of agricultural wastes by using their chemical compositions, especially cellulose content. The fourth readily available varieties of agricultural waste, such as rice straw, corn husk, hemp shive, and durian rind, were selected to evaluate their fiber morphology and chemical properties. Subsequently, dialdehyde carboxymethyl cellulose (DCMC) was produced from four kinds of agricultural wastes under synthesis conditions involving a pH value of 3.0, a reaction temperature of 35 °C, a mass ratio of NaIO₄ and carboxymethyl cellulose (CMC) of 1:3, and a reaction time of 4 h. The formation of aldehyde substitution was confirmed by the degree of oxidation (DO) and aldehyde content. To characterize the DCMC properties determined, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), gel permeation chromatography (GPC), and scanning electron microscopy (SEM) were used. The results revealed that rice straw, corn husk, hemp shives, and durian rinds presented high DO and aldehyde content; the aldehyde contents were more significant than 30% and 50%, respectively. The highest DO and aldehyde contents were 38.63 and 77.23%, respectively, for the hemp shives. The characterized data in recent research illustrated that the added value of agricultural wastes could be increased by DCMC production, which can be applied as a crosslinking reagent for future novel biopolymer film applications. Full article

Agroforestry is often seen as a sustainable land-use system for agricultural production providing ecosystem services. Intercropping with food crops leads to equal or higher productivity than monoculture and results in food production for industry and subsistence. Low rubber price and low labor productivity in smallholdings have led to a dramatic conversion of rubber plantations to more profitable crops. The literature analysis performed in this paper aimed at better understanding the ins and outs that could make rubber-based agroforestry more attractive for farmers. A comprehensive search of references was conducted in March 2023 using several international databases and search engines. A Zotero library was set up consisting of 415 scientific references. Each reference was carefully read and tagged in several categories: cropping system, country, main tree species, intercrop type, intercrop product, level of product use, discipline of the study, research topic, and intercrop species. Of the 232 journal articles, 141 studies were carried out on rubber agroforestry. Since 2011, the number of studies per year has increased. Studies on rubber-based agroforestry systems are performed in most rubber-producing countries, in particular in Indonesia, Thailand, China, and Brazil. These studies focus more or less equally on perennials (forest species and fruit trees), annual intercrops, and mixed plantations. Of the 47 annual crops associated with rubber in the literature, 20 studies dealt with rice, maize, banana, and cassava. Agronomy is the main discipline in the literature followed by socio-economy and then ecology. Only four papers are devoted to plant physiology and breeding. The Discussion Section has attempted to analyze the evolution of rubber agroforestry research, progress in the selection of food crop varieties adapted to agroforestry systems, and to draw some recommendations for rubber-based agroforestry systems associated with food crops. Full article

Prolonged exposure to environmental oxidative stress can result in visible signs of skin aging such as wrinkles, hyperpigmentation, and thinning of the skin. Oryza sativa variety Sang 5 CMU, an inbred rice cultivar from northern Thailand, contains phenolic and flavonoid compounds in its bran and husk portions that are known for their natural antioxidant properties. In this study, we evaluated the cosmetic properties of crude extracts from rice bran and husk of Sang 5 CMU, focusing on antioxidant, anti-inflammatory, anti-melanogenesis, and collagen-regulating properties. Our findings suggest that both extracts possess antioxidant potential against DPPH, ABTS radicals, and metal ions. Additionally, they could downregulate TBARS levels from 125% to 100% of the control, approximately, while increasing the expression of genes related to the NRF2-mediated antioxidant pathway, such as NRF2 and HO-1, in H₂O₂-induced human fibroblast cells. Notably, rice bran and husk extracts could increase mRNA levels of HO-1 more greatly than the standard L-ascorbic acid, by about 1.29 and 1.07 times, respectively. Furthermore, the crude extracts exhibited anti-inflammatory activity by suppressing nitric oxide production in both mouse macrophage and human fibroblast cells. Specifically, the bran and husk extracts inhibited the gene expression of the inflammatory cytokine IL-6 in LPS-induced inflammation in fibroblasts. Moreover, both extracts demonstrated potential for inhibiting melanin production and intracellular tyrosinase activity in human melanoma cells by decreasing the expression of the transcription factor MITF and the pigmentary genes TYR, TRP-1, and DCT. They also exhibit collagen-stimulating effects by reducing MMP-2 expression in H₂O₂-induced fibroblasts from 135% to 80% of the control, approximately, and increasing the gene associated with type I collagen production, COL1A1. Overall, the rice bran and husk extracts of Sang 5 CMU showed promise as effective natural ingredients for cosmetic applications. Full article

Several strains of Trichoderma are applied in the field to control plant diseases due to their capacity to suppress fungal pathogens and control plant diseases. Some Trichoderma strains also are able to promote plant growth through the production of indole-3-acetic acid (IAA). In southern Thailand, the local rice variety “Chor Khing” is mainly cultivated in the Songkhla province; it is characterized by slow growth and is susceptible to sheath blight caused by Rhizoctonia solani. Therefore, this research aimed to screen Trichoderma species with the ability to promote plant growth in this rice variety and enact biological control against R. solani. A total of 21 Trichoderma isolates were screened for indole compound production using the Salkowski reagent. The Z2-03 isolate reacted positively to the Salkowski reagent, indicating the production of the indole compound. High-performance liquid chromatography (HPCL) confirmed that Z2-03 produced IAA at 35.58 ± 7.60 μg/mL. The cell-free culture filtrate of the potato dextrose broth (CF) of Z2-03 induced rice germination in rice seeds, yielding root and shoot lengths in cell-free CF-treated rice that were significantly higher than those of the control (distilled water and culture broth alone). Furthermore, inoculation with Trichoderma conidia promoted rice growth and induced a defense response against R. solani during the seedling stage. Trichoderma Z2-03 displayed an antifungal capacity against R. solani, achieving 74.17% inhibition (as measured through dual culture assay) and the production of siderophores on the CAS medium. The pot experiment revealed that inoculation with the Trichoderma sp. Z2-03 conidial suspension increased the number of tillers and the plant height in the “Chor Khing” rice variety, and suppressed the percentage of disease incidence (PDI). The Trichoderma isolate Z2-03 was identified, based on the morphology and molecular properties of ITS, translation elongation factor 1-alpha (tef1-α), and RNA polymerase 2 (rpb2), as Trichoderma breve Z2-03. Our results reveal the ability of T. breve Z2-03 to act as a plant growth promoter, enhancing growth and development in the “Chor Khing” rice variety, as well as a biological control agent through its competition and defense induction mechanism in this rice variety. Full article

Rice is a crucial crop for many people worldwide, especially in regions like Asia, Latin America, and parts of Africa. Thailand is one of the largest exporters of rice. Nowadays, farmers use chemicals to control rice disease, which can have negative effects on humans and the environment. Therefore, the objective of this study was to examine the plant-promoting capabilities of the endophytic fungal strains DMKU-R3G3 in greenhouse settings. The endophytic fungi strain DMKU-R3G3, which was isolated from organic rice root, was identified as Aspergillus cejpii based on morphological characteristics and phylogenetic analysis. The production of IAA was detected using Salkowski’s reagent. After 7 days of incubation, the finding revealed that the strain cultivated in PDB supplemented with tryptophan yielded a greater concentration of IAA (25.45 μg/mL). The inoculation with A. cejpii DMKU-R3G3 significantly enhanced rice growth, as evidenced by notable increases in shoot height, root length, and fresh weight. Moreover, the chlorophyll content of the rice plants also increased by 1.78 times more than the control group. In addition, proteomic analysis revealed that rice responded toward the colonization of endophytic fungi by producing auxin-responsive proteins to regulate the IAA content in plant tissue and inducing total chlorophyll production due to the up-regulation of proteins in the chlorophyll biosynthesis pathway. The results obtained from this study lead to the conclusion that the A. cejpii strain DMKU-R3G3 possesses the capability to enhance plant growth through the production of phytohormones in greenhouse conditions. Therefore, endophytic A. cejpii DMKU-R3G3 has the potential to be a promising eco-friendly plant growth promoter for sustainable rice cultivation. Full article

This study aimed to determine aluminum (Al) contents in commonly consumed noodles and estimate the risk of Al exposure through the consumption of noodles in the Thai population. A total of 80 samples, 20 samples each of rice stick noodles, egg noodles, wide rice noodles, and Thai rice noodles was purchased from markets in Bangkok Metropolitan and other four provinces in each region of Thailand. Wet digestion and graphite furnace atomic absorption spectrometry (GFAAS) were used to determine Al contents. Exposure assessment of Al was conducted by applying the consumption amounts of noodles from the national consumption survey and the Al contents of the noodle samples. The hazard quotient (HQ) was calculated to estimate the risk of exposure to Al. Aluminum contents in the noodles ranged from not detected to 630 mg/kg. Exposure to Al from consumption of each noodle product in all age groups was lower than the provisional tolerable weekly intake (PTWI). However, Al exposures in children calculated from the high consumer models and Al exposures in all age groups from the worst-case scenarios were higher than the PTWI, indicating potential adverse health effects. Consumers who regularly consume large amounts of noodle products containing Al may be at risk of having adverse health effects. Full article

Rice is not only central to Thailand’s economy and dietary consumption but also plays a significant role in global food security. Northeast Thailand, in particular, is a principal region for rice cultivation. However, with the mounting concerns of climate change, it becomes paramount to understand the interplay between regional weather patterns and rice yields, aiming to develop effective adaptive agricultural strategies. The current study aimed to fill the research gap by investigating an optimal copula for the spatial dependence of rice production and related meteorological variables in this area. The objective of this study is to understand how rice production in different areas relates to each other in order to improve farming practices and address challenges such as suitable weather. To achieve this goal, we apply three families of copulas—elliptical, Archimedean, and extreme—to analyze crop and meteorological variables across the watershed in the northeastern region of Thailand. With a data foundation extending from 1981 to 2021 from the Regional Office of Agricultural Economics Sector 4, Thailand, this study offers a comprehensive analysis of the spatial dynamics driving rice production across twenty provinces in Northeast Thailand. Using a piecewise linear model, we dissected rice yield trends, revealing distinct slopes in production and yield across various periods. The analysis leaned on elliptical, Archimedean, and extreme copula families, using the maximum likelihood estimation to discern marginal distribution residuals. Through rigorous bootstrap goodness-of-fit tests and cross-validation, the most appropriate copula for each province was identified. Key findings demonstrate pronounced spatial interdependencies in rice yields, with the Frank copula prominently capturing the product relationship between provinces such as Maha Sarakham and Roi-Et. Conversely, the Clayton copula better characterized regions such as Srisaket and Ubon Ratchathani. Moreover, the results underscore the considerable influence of meteorological factors, notably rainfall and temperature, on rice production, especially in regions like Ubon Ratchathani. In distilling these multifaceted relationships, the study charts a pathway for crafting sustainable, localized agricultural strategies. As the world grapples with climate change’s ramifications, the insights from this research stand crucial, offering direction for fostering resilience, adaptation, and optimizing rice productivity across Thailand’s diverse agrarian landscapes. Full article

In recent years, climate change has greatly affected agricultural activity, sustainability and production, making it difficult to conduct crop management and food security assessment. As a consequence, significant changes in agricultural land and land cover (LC) have occurred, mostly due to the introduction of new agricultural practices, techniques and crops. Earth Observation (EO) data, cloud-computing platforms and powerful machine learning methods can certainly support analysis within the agricultural context. Therefore, accurate and updated agricultural land and LC maps can be useful to derive valuable information for land change monitoring, trend planning, decision-making and sustainable land management. In this context, this study aims at monitoring temporal and spatial changes between 2001 and 2021 (with a four 5-year periods) within the Chi River Basin (NE–Thailand). Specifically, all available Landsat archives and the random forest (RF) classifier were jointly involved within the Google Earth Engine (GEE) platform in order to: (i) generate five different crop type maps (focusing on rice, cassava, para rubber and sugarcane classes), and (ii) monitoring the agricultural land transitions over time. For each crop map, a confusion matrix and the correspondent accuracy were computed and tested according to a validation dataset. In particular, an overall accuracy > 88% was found in all of the resulting five crop maps (for the years 2001, 2006, 2011, 2016 and 2021). Subsequently the agricultural land transitions were analyzed, and a total of 18,957 km² were found as changed (54.5% of the area) within the 20 years (2001–2021). In particular, an increase in cassava and para rubber areas were found at the disadvantage of rice fields, probably due to two different key drivers taken over time: the agricultural policy and staple price. Finally, it is worth highlighting that such results turn out to be decisive in a challenging agricultural environment such as the Thai one. In particular, the high accuracy of the five derived crop type maps can be useful to provide spatial consistency and reliable information to support local sustainable agriculture land management, decisions of policymakers and many stakeholders. Full article

Second-generation lactic acid production requires the development of sustainable and economically feasible processes and renewable lignocellulose biomass as a starting raw material. Weizmannia coagulans MA42 was isolated from a soil sample in Chiang Mai province, Thailand and showed the highest production of L-lactic acid and lignocellulolytic enzymes (cellulase, β-mannanase, xylanase, β-glucosidase, β-mannosidase, and β-xylosidase) compared to other isolates. Weizmannia coagulans MA42 was able to grow, secrete lignocellulolytic enzymes, and directly produce L-lactic acid in the medium containing various lignocellulosic feedstocks as the sole carbon source. Moreover, L-lactic acid production efficiency was improved after the substrates were pretreated with diluted sulfuric acid and diluted sodium hydroxide. The highest L-lactic acid production efficiency of 553.4 ± 2.9, 325.4 ± 4.1, 326.6 ± 4.4, 528.0 ± 7.2, and 547.0 ± 2.2 mg/g total available carbohydrate was obtained from respective pretreated substrates including sugarcane bagasse, sugarcane trash, corn stover, rice straw, and water hyacinth. It is suggested that structural complexity of the lignocellulosic materials and properties of lignocellulolytic enzymes are the key factors of consolidated bioprocessing (CBP) of lignocellulosic feedstocks to lactic acid. In addition, the results of this study indicated that W. coagulans MA42 is a potent bacterial candidate for CBP of a variety of lignocellulosic feedstocks to L-lactic acid production; however, further bioprocess development and genetic engineering technique would provide higher lactic acid production efficiency, and this would lead to sustainable lactic acid production from lignocellulosic feedstocks. Full article

Fragrant rice has various flavor types, mainly the popcorn flavor, corn flavor and lotus root flavor. Chinese fragrant rice from China and Thai fragrant rice from Thailand were analyzed. GC-MS was used to determine the volatile compounds of fragrant rice. It was found that there were 28 identical volatile compounds between Chinese and Thai fragrant rice. The key compounds of different flavor types of fragrant rice were obtained by comparing the common volatile compounds. The key compounds of the popcorn flavor were 2-butyl-2-octenal, 4-methylbenzaldehyde, ethyl 4-(ethyloxy)-2-oxobut-3-enoate and methoxy-phenyl-oxime. The key compounds of the corn flavor were 2,2′,5,5′-tetramethyl-1,1′-biphenyl, 1-hexadecanol, 5-ethylcyclopent-1-enecarboxaldehyde and cis-muurola-4(14), 5-diene. By using a combination of GC-MS and GC-O, the flavor spectrogram of fragrant rice was constructed, and the characteristic flavor compounds of each flavor type were identified. It was found that the characteristic flavor compounds of the popcorn flavor were 2-butyl-2-octenal, 2-pentadecanone, 2-acetyl-1-pyrroline, 4-methylbenzaldehyde, 6,10,14-trimethyl-2-pentadecanone, phenol and methoxy-phenyl-oxime. The characteristic flavor compounds of the corn flavor were 1-octen-3-ol, 2-acetyl-1-pyrroline, 3-methylbutyl 2-ethylhexanoate, methylcarbamate, phenol, nonanal and cis-muurola-4(14), 5-diene. The characteristic flavor compounds of the lotus root flavor were 2-acetyl-1-pyrroline, 10-undecenal, 1-nonanol, 1-undecanol, phytol and 6,10,14-trimethyl-2-pentadecanone. The resistant starch content of lotus root flavor rice was relatively high (0.8%). The correlation between flavor volatiles and functional components was analyzed. It was found that the fat acidity of fragrant rice was highly correlated (R = 0.86) with the characteristic flavor compounds, such as 1-octen-3-ol, 2-butyl-2-octenal and 3-methylbutyl-2-ethylhexanoate. The characteristic flavor compounds had an interactive contribution to the production of the different flavor types of fragrant rice. Full article