Ismail Sahid’s research while affiliated with National University of Malaysia and other places

Weedy rice or locally known as ‘padi angin’ has been infesting rice granary areas in Malaysia for the last 20 years. The outbreak of weedy rice in the country started during the late 1980s in Projek Barat Laut Selangor (PBLS) due to the adoption of direct-seeding practices. Weedy rice can be characterized by its early maturing and easy-shattering traits. The objective of this study was to determine the morphological variations of weedy rice in selected granary areas located in Peninsular Malaysia. A total of 110 weedy rice accessions were collected from nine locations in three granary areas in Peninsular Malaysia (the Western, Eastern, & Northern regions). The collected weedy rice accessions were planted under greenhouse conditions to study their morphological features. Results of the present study indicated that 73.6% of weedy rice accessions were awnless while the remaining 26.4% produced awn. Selected traits such as plant height, flag leaf length, culm length, number of tillers, number of panicles, and panicle length were included in the Principal Component Analysis (PCA). The weedy rice accessions were grouped into three different clusters mainly Cluster 1: cultivated rice and awnless populations, Cluster 2: brown and red pericarp awnless populations, and Cluster 3: awned populations. The findings of this study may be used as guidance for farmers and researchers for designing sustainable weedy rice management in the future.

The content of heavy metals was appraised at paddy fields, from a total of 54 soil samples gathered from two locations in Ranau, Sabah and one from the UKM experimental paddy plot in Peninsular Malaysia, during2014 and 2015. Through an appraisal evaluate of contamination using the Index of Geo-accumulation (I geo) it was noted that Chromium and Nickel levels in Ranau field 1 came under grade 6 (I-geo > 5 is considered to be very contaminated), showing that the soil was heavily tainted with Cr and Ni, whilst Cobalt was discovered to be at the grade 3 level (medium to strong contamination). On the other hand, Ranau field 2's I-geo for other metals came under grade 1(which means medium to no contamination), highlighting the fact that the soils in these areas were tainted with the examined metals, while the control field was found to be grade 0 (no contamination). Ranau field 1 showed strong levels of the contamination factor (CF) for Co, Cr, and Ni, and its Pollution Load Index was(PLI) was> 1, denoting a steady degradation in the area, with high levels of pollution compared to those in the other tested areas. The average monomial ecological risk for Ni was found to be between (40 – 80), highlighting that Ni contamination was considered to be of medium danger to the surrounding environment. Through the Potential Ecological Risk Index, it was seen that Ni was a likely hazard and presented a substantial danger. The RI values for the test sites were as follows: season 2015 (2.89) < control for season 2014 (3.18).

The combination of mulch and herbicide is a promising method for weed control which could reduce the frequency of hand weeding. This study was conducted to evaluate the phytotoxic effects of Elaeis guneensis var. tenera (oil palm) frond (OPF) mulch in combination with several pre emergence herbicides on the inhibition of goosegrass (Eleusine indica (L.) Gaertn), slender cyperus (Cyperus distans L.f.) and coat buttons (Tridax procumbens (L.)) under greenhouse conditions. Three rates of dinoterb, oxyfluorfen, and isoxaflutole were respectively, applied with or without OPF mulch at 3.5 t ha−1. The results showed that the weed inhibition provided by the dinoterb-treated OPF mulch (60 to 100%) was greater than dinoterb (0 to 50%) or OPF mulch (0 to 60%) applied alone across all the application rates and bioassay species. The oxyfluorfen-treated OPF mulch also gave greater inhibition (70 to 90%) of T. procumbens than those provided by oxyfluorfen (20 to 40%) or the OPF mulch alone (55 to 60%). However, an increase in inhibition of C. distans and E. indica was only evident at a low rate of oxyfluorfen when combined the OPF mulch. Weed inhibition was noted with increasing rates of isoxaflutole alone but the isoxaflutole-treated OPF mulch did not lead to further inhibition of weeds except for T. procumbens. These results suggest that the phytotoxicity of OPF mulch in combination with herbicides are dependent on weed species, herbicides, and application rates, with dinoterb being the most compatible with OPF mulch when combined.

Water quality in Sungai Bertam declining because of clearing land for settlement, logging, agriculture and development. Therefore, a study to determine the current status of water quality and both nutrient and heavy metal content in the water and sediment was conducted on November 2017 in Cameron Highlands. Six sampling stations along the river were selected by considering the anthropogenic activities nearby to represent the entire river. In-situ parameters determined in this study were pH and dissolve oxygen (DO). Laboratory analysis have determined the parameters of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS) and ammonia nitrogen (NH3-N) according to standard methods. The results showed that Bertam River is classified as class II based on WQI. Those determined nutrients content comprised flouride (F-), chloride (Cl-), nitrate (NO3-), sulphate (SO42-), phosphate (PO3-) dan bromide (Br-). The concentration of (F-) in water was in the range of 0.035 to 0.058 mg/L, 1.488 to 4.157 mg/L for (Cl-), 0.056 to 1.273 mg/L for (Br-), 3.425 to 9.688 mg/L for (NO3-), 2.902 to 7.444 mg/L for (SO42-), and 0.112 to 0.242 mg/L for (PO3-). Meanwhile, the concentration of (F-) in sediment was in the range of 0.34 to 0.66 μg/g, 11.29 to 16.37 μg/g for (Cl-), 0.12to 0.25 μg/g for (Br-), 10.04 to 17.07 μg/g for (NO3-), 26.33 to 51.87 μg/g for (SO42-),and 1.03 to 2.85 μg/g for (PO3-). The composition of heavy metals in the organic oxidation fraction (OO) and resistant fraction (RR) were determined with inductively coupled plasma mass spectrometry (ICP-MS). Those determined heavy metals content comprised of Fe, Mn, Zn, Cu, Cd, Cr and Pb. The results showed that the total amount of heavy metals extracted from sediment sequentially was in the order Fe>Mn>Zn>Cr>Pb>Cu>Cd. Amount of heavy metals extracted sequentially in OO was in the order of Mn>Fe>Zn>Pb>Cr>Cu>Cd and in the order of Fe>Mn>Zn>Cr>Pb>Cu>Cd for RR. Meanwhile, the composition of heavy metals in water samples were in the order Fe>Zn>Cu>Cr>Pb>Mn>Cd. Sandy and sandy loam were the dominant texture of sediment in the sampling areas. This study overall contributes to identify the sources and level of pollution on Bertam River in Cameron Highlands.

The Clearfield® rice production system is an effective management tool for weedy rice and other weeds in the direct-seeded rice culture. However, if farmers cultivating the Clearfield® rice disregard stewardship recommendations, the industry could face a problem of herbicide-resistant weedy rice which would occur through the selection of outcrosses. This study aimed to confirm imidazolinoneresistant weedy rice in Malaysia. The resistant weedy rice (R-WR) was found to be 67 fold more resistant to OnDuty® (premix of imazapic and imazapyr) than the susceptible weedy rice (S-WR) based on the GR50 values (rate that causes 50% inhibition of shoot growth). The Clearfield® rice cultivar was 32-fold more tolerant to OnDuty® than the S-WR. Furthermore, the R-WR was 54 and 89 fold more resistant to imazapic and imazapyr applied separately than the S-WR, respectively. The Clearfield® rice was 140- and 40-fold more tolerant to imazapic and imazapyr, respectively than the S-WR. The R-WR biotype was susceptible to non-selective herbicides glyphosate and glufosinate, as well as the selective graminicide quizalofop. Oxadiazon controlled the R-WR biotype, but pretilachlor was ineffective. The present study documented the first case of weedy rice that was cross-resistant to imazapic and imazapyr in Malaysian Clearfield® rice field. © 2018, Sociedade Brasileira da Ciencia das Plantas Daninha. All rights reserved.

Life Cycle Assessment (LCA) has been applied in the Malaysian oil palm industry since 2010. It is important to ensure that this main industry is ready to meet the demands and expectations of European market on the environmental performance of the oil palm industry. In addition, oil palm biomass, especially oil palm trunk (OPT) are abundantly available after replanting every year. In order to maximize the usage of OPT as a green product, it can be converted to palm lumber as a value-added product. Palm lumber act as a basis product from OPT before it is converted to panel product such as plywood, sandwich board and so on. However, the LCA study on palm lumber production is still scarce in Malaysia. Hence, this paper aims to perform and collect the inventory data for palm lumber production, which is known as Life Cycle Inventory (LCI). A gate-to-gate system boundary and the functional unit of 1 m³ of palm lumber produced have been used in this study. This inventory data was collected from three batches of the production cycle. The inputs are mainly the raw materials which are the OPT and the energy from diesel and electricity from the grid. Generally, each consumption of input such as energy and fossil fuel were different at each stage of palm lumber production. Kiln-drying represents a prominent stage in terms of energy consumption, which electrical use in the dryer represents 94% of total electrical grid consumption as compared to another stage of palm lumber production. By adding the inventory information especially in the downstream sector of biomass industry, hopefully it can improve the sustainability of oil palm industry in Malaysia.

2,4-Di-tert-butylphenol (2,4-DTBP) has herbicidal properties that cause lipid peroxidation on plant tissues. The present study aimed at examining the phytotoxic effects of 2,4-DTBP compared to that of selected herbicides which induced lipid peroxidation based on quantum yield (φ) and membrane integrity of two bioassay weed species namely Oldenlandia verticillata and Leptochloa chinensis under light and dark conditions. Laboratory assays showed reduced φ of 2,4-DTBP-and dinoterb-treated leaf discs within the first 3 h of the dark incubation period, with further decrease during the subsequent 15 h dark period and 6 h light period. Diuron drastically reduced the φ of the bioassay species throughout the incubation period. The φ of glufosinate-treated O. verticillata leaf discs was marginally reduced and decreased further upon light exposure; it had no effect on the φ of L. chinensis. Fluridone, isoxaflutole, clomazone and oxyfluorfen also had negligible effect on φ, whereas paraquat caused a rapid reduction in φ upon light exposure for both bioassay species. 2,4-DTBP, paraquat and dinoterb induced electrolyte leakage during the dark incubation period; this was further increased in the presence of light for O. verticillata and L. chinensis. For both bioassay species, glufosinate caused a marked amount of electrolyte leakage, whereas diuron, fluridone, isoxaflutole, clomazone and oxyfluorfen had negligible effect on ion leakage. These results suggested that 2,4-DTBP has herbicidal activity comparable to that of dinoterb without dependence on light. © 2018 Penerbit Universiti Kebangsaan Malaysia. All rights reserved.