Effect of Potting Media on the Growth Performance of Cherry Tomato (Solanum lycopersicum)

Tomato (Solanum lycopersicum) is a fruit vegetable, and its fruits contain excellent source of vitamins and antioxidants. Soil has been the only potting medium for tomato cultivation until the soilless culture was introduced, coupled with the decline in availability of quality soil. Peat moss and perlite are among the popular soilless media, but they are costly in Malaysia, and the exploitation of peat moss might contribute to greenhouse gas effect. Coco peat and rice husk are more easily available in Malaysia. This study compared the effect of four potting media, peat moss and perlite (3:1), coco peat (1), topsoil (1), and topsoil and rice husk (1:1) on growth performance of cherry tomato. The treatments were arranged in a completely randomised design with seven replicates per treatment. pH, water holding capacity, electrical conductivity and nitrogen content of the potting media were analysed before the experiment. Plant height, leaf number, root shoot ratio, flower number, total number of fruits and fruit sweetness of the plants in peat moss and perlite, topsoil, and topsoil and rice husk were not significantly different from each other. The plants in coco peat did not perform well, and few plants died toward the end of the experiment. Topsoil and rice husk medium could be a good choice as potting medium for tomato in containers in terms of cost and environmental concern

Plant Based Plastic and Leather-Like Material

Synthetic plastic and animal leather: we love both. Plastic is convenient, and leather is durable and elegant. However, have we ever thought about their downsides? United Nations Environmental Programme has warned us that we are drowning in plastic pollution. Leather and its production process, on the other hand, pose damaging effects on environment and on human health. Probably, it is the time for us to change. But would it be possible? The answer is yes

Effect of Trichoderma sp. on anthracnose disease of stored chilli

Chilli is commonly used as spice in Malaysian culinary, principal ingredients in paste (sambal) and as the raw material in sauce industry. Anthracnose disease caused by Colletotrichum capsici is one of the major causes of economic loss to chilli production especially in Asia. Even a small lesion on chilli might affect the quality, thus the market value of the chilli. Disease symptoms caused by C. capsici include brown, circular and sunken lesion with concentric rings of black acervuli. Chemicals have been used to treat the chilli but they might cause environmental pollution, affect human health and lead to pathogen resistance to the chemicals. Therefore, an alternative method to chemical control is required. In this study, C. capsici was isolated from a naturally infected chilli fruit (Capsicum frutescens), and a species of Trichoderma was isolated from the rhizosphere of grasses. Pure cultures of both fungi were established then used in antagonism studies in in vitro and in vivo. Dual culture of pathogens and Trichoderma sp. indicated that Trichoderma sp. competed with C. capsici for space and nutrients, caused the loss of turgidity of the fungal hyphae, and reduced the fungal growth by producing volatile metabolites. Trichoderma sp. decreased disease severity on chilli artificially inoculated fruits up to 64% when Trichoderma mycelial plug was used and 55% when culture filtrate was applied. Field trials are recommended to examine the antagonism of Trichoderma sp. in real production conditions

Effect of thiabendazole and hydrogen peroxide on the pathogen of dry rot of potato

Potato is an important food crop produced all around the world but its susceptibility to a number of post-harvest and storage diseases, including dry rot caused by Fusarium species, has caused a noticeable yield loss. This study was conducted to examine the effect of two chemicals, thiabendazole and hydrogen peroxide on a Fusarium sp., isolated from diseased potato tubers and proved to be pathogenic. The effectiveness of the chemicals was first evaluated in vitro on potato dextrose agar plates amended with the chemicals, and then in vivo on artificially inoculated potato tubers by dipping method. Colony diameters of the pathogen on chemicals amended plates were measured and compared with those on chemicals-free PDA plates (Control) while disease incidence and disease severity were assessed for the chemicals-treated tubers in comparison with non-treated ones. The results showed successful inhibition of the pathogen growth by both chemicals in vitro at concentrations of 7.5 mg L-1 of thiabendazole in potato dextrose agar and 1:111 v/v or 9 ml of hydrogen peroxide in 1 L of medium. However, the two chemicals did not prove to successfully suppress the growth of the pathogenic Fusarium and the development of dry rot on the potato over 21 days of incubation. Further studies on method to apply the chemicals are warranted to prove the efficacy of the two chemicals in controlling the pathogen growth and development on potato tubers

Morphological and molecular characterization of Fusarium spp. associated with Fusarium wilt disease of Piper nigrum L. in Northwestern region of Sarawak

Aims: Piper nigrum L. (black pepper) is an economically important commodity plant in Malaysia, which generated RM200.95 million from pepper export in the year of 2018. However, the increase in pepper production is restricted by diseases. Fusarium wilt is one of the major diseases of P. nigrum L. The objectives for this study were to isolate Fusarium spp. associated with Fusarium wilt of P. nigrum L. from selected pepper farms in the northwestern region of Sarawak and to characterize the Fusarium spp. isolated morphologically and molecularly. Methodology and results: Fusarium spp. were isolated from diseased root samples. The pathogen was grown on potato dextrose agar (PDA) under dark condition at circa (ca.) 25 °C for morphological characterisation. Molecular characterisation was done by using internal transcribed spacer (ITS). Phylogenetic tree was constructed to study the genetic relationship of the isolates. Fusarium solani, F. oxysporum, F. proliferatum were the three Fusarium species identified. There were variations in morphological characters observed between and among the species, including the colony form, margin, elevation, surface appearance and pigmentation. No distinctive morphological characteristic was specific to a location. In addition, growth rate, macroconidia sporulation rate, and microconidia sporulation rate of the isolates were not correlated. In molecular phylogeny, the three Fusarium species were separated into three distinct clades representing the three identified species. The genetic relatedness between isolates within each species was depicted in the tree. Conclusion, significance and impact of study: Variations were observed among isolates in this study based on morphological and molecular characterization. This study would contribute information on the variations of Fusarium spp. associated with Fusarium wilt of P. nigrum L. from the northwestern region of Sarawak

Security–reliability analysis of AF full-duplex relay networks using self-energy recycling and deep neural networks

This paper investigates the security-reliability of simultaneous wireless information and power transfer (SWIPT)-assisted amplify-and-forward (AF) full-duplex (FD) relay networks. In practice, an AF-FD relay harvests energy from the source (S) using the power-splitting (PS) protocol. We propose an analysis of the related reliability and security by deriving closed-form formulas for outage probability (OP) and intercept probability (IP). The next contribution of this research is an asymptotic analysis of OP and IP, which was generated to obtain more insight into important system parameters. We validate the analytical formulas and analyze the impact on the key system parameters using Monte Carlo simulations. Finally, we propose a deep learning network (DNN) with minimal computation complexity and great accuracy for OP and IP predictions. The effects of the system’s primary parameters on OP and IP are examined and described, along with the numerical data.Web of Science2317art. no. 761

Inequalities between peri-urban and urban areas in urbanization process of Ho Chi Minh city: an urban political-ecology perspective

Thanks to the implementation of Vietnam’s economic renovation or ‘Doi Moi’ policy since 1986, Ho Chi Minh City (HCMC) urban has grown quickly. However, this also leads to an increase in inequality. Its peri-urban area, which undergoes higher level of urbanization than urban area, faces more problems such as land use change, inadequate development process, unequal allocation of services and investment, and ignorance of environmental protection and cultural preservation. These impacts show inequality in standards of living between residents of the two areas. Using the framework of the Peri-Urban Political-Ecology, this paper aims to depict a general picture of the situation and analyse the causes of social inequalities between these two areas in terms of economy, public services, and environment through “everyday practices” (i.e. events, problems, stories, etc.). The paper uses HCMC’s statistical data in 2015-2017 periods and research findings from previous studies. The results shows that the main causes in inequalities between these two areas are the inevitability of urban metabolism and the unequal power interaction among the state, society and market

Morphological and Physiological Development of Pyricularia oryzae Isolates from North-western Region of Sarawak on Different Media under Laboratory Conditions Laboratory Conditions

Rice blast (causal agent: Pyricularia oryzae) is an important disease of rice in Sarawak. Understanding the pathogen’s morphological characteristics, genetic diversity and pathogenicity is important. Having a suitable medium for culturing and maintaining P. oryzae is important to ensure the availability of inoculum or materials under laboratory conditions. Oatmeal agar (OMA) and potato dextrose agar (PDA) are common media used for growing P. oryzae. OMA allows better mycelial growth and better sporulation as compared to PDA. There are also other alternatives such as fresh rice leaf agar and rice straw agar. Although OMA seems to be the best medium, unfortunately the opaqueness of the medium causes difficulty in observing the morphology and growth of mycelia. In addition, it is known that different isolates of P. oryzae will respond differently to different media. This study aims to identify the best media for culturing and maintaining P. oryzae isolates from Sarawak. A total of 14 P. oryzae isolates were characterised for their morphological characteristics, growth rate and sporulation rate using seven growing media. These 14 isolates included seven newly identified isolates in this study and seven isolates from a previous study, which were verified using internal transcribed spacer DNA sequence. The colony surface of the 14 P. oryzae isolates varied on different growing media. The pigmentation of colony surface varied from different shades of grey, translucent light brown, white and colourless. Pyricularia oryzae isolates grew better on OMA and PDA, while OMA was the best for sporulation. These two media can be recommended for culturing and maintaining different P. oryzae isolates under laboratory conditions

Isolation and characterization of Pyricularia oryzae isolated from lowland rice in Sarawak, Malaysian Borneo

Aims: Rice blast disease caused by Pyricularia oryzae is one of the major biotic diseases of rice in Sarawak, Malaysian Borneo. This study aims to isolate and characterize rice blast fungus obtained from infected leaf collected from four different divisions in Sarawak, viz, Miri, Serian, Sri Aman, and Kuching. Methodology and results: Twelve succeeded isolates were pre-identified as P. oryzae by morphological characteristics of spores, followed by verification through (internal transcribed spacer) ITS sequencing. The isolates were evaluated for morphological characteristics, growth rate and sporulation rate, which were grown on two types of media, (filtered oatmeal agar) FOMA and (potato dextrose agar) PDA. Morphological characterization showed that the colony surface of the different isolates varied from smooth and fluffy to rough and flattened mycelia; some were with the present of concentric rings, and some with aerial mycelia. The growth rate and sporulation rate of each isolate varied based on types of media used. Most of the isolates grew faster on PDA than on FOMA but produced higher number of spores on FOMA as compared to PDA. Conclusion, significance and impact of study: This preliminary study showed that there were variations observed based on morphological and physiological characterization for the different isolates collected in Sarawak, Malaysian Borneo. This study is the first step towards understanding variation in the population of P. oryzae from Sarawak