Natural Resources and Agricultural Sciences Journal

Editor's Note

2025-06-23T11:00:15+07:00

2025-06-23T11:24:46+07:00

Efficacy of Various Trichoderma spp. in Controlling Anthracnose Disease in White Chaiburi Pepper (Capsicum frutescens)

2025-04-17T12:42:12+07:00

Abstract

This study aimed to evaluate the efficacy of three Trichoderma strains (TSU, TSUZ2-03, and PT3.5) in controlling anthracnose disease caused by Colletotrichum spp. in White Chaiburi pepper, through laboratory. Chili fruits showing disease symptoms were collected and subjected to a pathogenicity test. Three isolates of the pathogen were obtained, designated as Chi-1, Chi-2, and Chi-3. Among them, isolate Chi-2 showed the highest disease severity (lesion width of 0.9 cm.) Results demonstrated that Trichoderma TSU exhibited the highest inhibitory activity, reduced lesion size on pepper fruits to an average of 0.33 – 0.4 cm, and achieved a 67.26% inhibition rate, while PT3.5 and TSUZ2-03 showed lower efficacy (38.56% and 13.56%, respectively). Field trials confirmed that Trichoderma TSU significantly reduced disease severity (p<0.01) compared to the control group. These findings highlight Trichoderma TSU as a promising biocontrol agent for sustainable anthracnose management in White Chaiburi pepper, offering an alternative to synthetic chemical pesticides.

Selection of Native Entomopathogenic Nematode from Southern Thailand for Developing EPN-based Bioproduct

2025-04-21T09:45:56+07:00

Entomopathogenic nematode (EPN) is one of the important biological control agents for controlling key agricultural insect pests, ensuring safety for non-target organisms and the environment. This study was conducted to screen the effective local EPNs from soil samples collected from four provinces in southern Thailand. The results found that EPN from Pattani province ultimately killed 100% of the tested larvae, wax moth (Galleria mellonella), within 2 days. From the visible symptoms of infected wax moth and the morphological characteristics of selected EPN under a microscope and morphometric study, it could be identified that the selected EPN was Heterorhabditis sp. Subsequently, Heterorhabditis sp. was developed into an EPN-based bioproduct. Regarding the Plackett−Burman design, evaluating the solubility of the product, viability of EPN, and host infection ability resulted in selecting high-affected formulation components, including kaolin, Tween 20, CMC, formalin, and sodium polyacrylate.

Genetic Diversity Analysis and Identification of Plai-Dum (Zingiber ottensii Valeton) in Thailand with Molecular Markers

2025-04-18T09:18:06+07:00

Plai-Dum (Zingiber ottensii Valeton) is a local medicinal herb primarily found in southern Thailand belonging to the Zingiberaceae family. The plant is characterized by zerumbone as a major component in its essential oils, which exhibits antimicrobial, anticancer, and anti-inflammatory properties. This study investigated the genetic diversity and classification of Plai-Dum using molecular markers. A total of 34 accessions of Z. ottensii from Thailand and 19 accessions of other Zingiber species were collected and analyzed. Fifty-eight simple sequence repeat (SSR) primer pairs were screened, and 33 pairs successfully amplified DNA through PCR. Among these, 14 pairs of SSR primers showed polymorphism in Z. ottensii and related species The analysis detected a total of 150 alleles with an average of 10.71 alleles per primer. Cluster analysis based on genetic relationships using UPGMA classified all accessions into three distinct clusters. Cluster 1 consisted exclusively of Z. ottensii accessions. Cluster 2 included Z. zerumbet, Z. flavomaculosum, Z. montanum, and Z. parishii, while cluster 3 comprised Z. officinale accessions. The genetic similarity coefficient ranged from 0.57 to 1.00, with an average of 0.83. Notably, all Z. ottensii accessions showed the highest genetic similarity coefficient (1.00), indicating a common origin and identical clones with the same genetic information within Thailand. This genetic uniformity likely results from the common practice of asexual propagation through rhizomes, which produces genetically identical offspring. The study identified ZOSSR25 as an effective marker for distinguishing Z. ottensii from other Zingiber species, demonstrating the utility of SSR markers as rapid and reliable tools for identifying seedlings in plantation establishment.

Antioxidant Activity, Total Phenolic and Total Flavonoid Content of Etlingera maingayi (Baker) R.M.Sm.

2025-04-22T11:13:02+07:00

Etlingera maingayi (Baker) R.M.Sm. is a rare plant species native to southern Thailand. It is infrequently utilized, with its primary use being for edible flowers. This study aimed to investigate and evaluate the antioxidant properties of the aerial parts of E. maingayi. Dried plant materials were extracted using ethanol, followed by solvent removal via rotary evaporation. Antioxidant activities were assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, and the ferric reducing antioxidant power (FRAP) assay. The chemical constituents of the extract were quantified using the Folin–Ciocalteu method for total phenolic content and the aluminum chloride colorimetric method for total flavonoid content. The E. maingayi extract exhibited antioxidant activity with an IC_₅₀ value of 0.56 ± 0.01 mg/mL in the DPPH assay, compared with Trolox as a positive control (IC₅₀= 0.036 ± 0.003 mg/mL). In the ABTS assay, the extract showed an IC₅₀value of 4.53 ± 0.59 mg/mL, compared with Trolox (IC₅₀= 0.28 ± 0.06 mg/mL). Furthermore, the extract demonstrated ferric reducing antioxidant power (FRAP) at 150.54 ± 1.79 mg FeSO₄/g extract. The total phenolic and flavonoid contents were 83.76 ± 3.36 mg gallic acid equivalents (GAE)/g extract and 65.11 ± 6.84 mg catechin equivalents (CE)/g extract, respectively. These results indicate that the ethanolic extract of the aerial parts of E. maingayi possesses significant antioxidant activity and is rich in polyphenolic compounds. Therefore, this species may serve as a potential natural source of antioxidants for future applications.

Chemical Profiling of Essential Oils of Zingiber ottensii Valeton Collected from Yala Province, Southern Thailand

2025-04-18T14:01:10+07:00

Zingiber ottensii Valeton is a medicinal plant that belongs to the Zingiberaceae family. It has been used as traditional medicine to relieve pain and inflammation in many local communities, especially in the lower southern region of Thailand. Three accessions of Z. ottensii, including Yala-1, Yala-2, and Yala-3, were collected from three different sub-districts of Than To District, Yala Province. The rhizome oils of three accessions were extracted using the hydrodistillation method before being analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). Twenty-four chemical compounds representing 88.77–94.89% of essential oils were identified, which consisted of zerumbone, terpinene-4-ol, α-humulene, and sabinene as major constituents. Zerumbone is a monocyclic sesquiterpene that was found in the highest percentages of rhizome oils of Yala-1 (51.26%), Yala-2 (46.32%), and Yala-3 (36.71%). In addition, the soil of three cultivation areas was analyzed for plant nutrients, which included organic carbon (OC), organic matter (OM), nitrogen (N), phosphorus (P), and potassium (K). Soil samples from the Yala-1 cultivation area exhibited the highest percentages of OC, OM, N, and K. These results may indicate that soil fertility has a positive effect on the rate of zerumbone in Z. ottensii’s rhizome oil, which would provide the benefits of soil-improving management for maximizing the yields of Z. ottensii cultivation and zerumbone contents.