Potential productivity of hydroponically-grown tomatoes ill the Genting Highlands, Malaysia

Five trials were carried out to assess the potential productivity of tomatoes in a deep culture hydroponic system in Genting Highlands (1,200 m a.s.l.), Malaysia. The tomatoes were maintained as single-stemmed plants using the layering and vertical methods of plant training. Determinate and indeterminate varieties producing large, medium and small-sized fruits were investigated in these trials. Under the layering system, the indeterminate plants could last for nine months but if crops were kept for only six months, two crops per year could be produced with a potential yield of 252-288 ton/ha/year. The vertical system could produce three crops per year with a range of 21 0-248 tonnes/ha/year for the three sizes of fruits. The determinate varieties produced a wide range of yields and, with three crops per year, a yield range of 131-216 ton/hal could be expected. The yields obtained in the tested hydroponic system were at least five to ten times higher than those obtained from traditional soil cultivation under highland and lowland conditions in Malaysia

Disease Caused by Phytium Spp. on Selected Crops Grown Under Hydroponic Culture System and Their Control

Large scale hydroponic crop production is a recent entity in Malaysia with University of Agriculture Malaysia (UPM) playing a lead role in research and development. Since its inception in 1982, pre- and post-emergent damping-off in cucumber, muskmelon and tomato seedlings had been frequently observed. Pythium spp. were also isolated from roots of wilted mature cucumber, muskmelon and tomato plants at UPM hydroponic, at Malaysia Agricultural Research and Development Institute (MARDI) and at FIMA hydroponic in Fraser's Hill. The mature muskmelon plants exhibited drastic interveinal chlorosis and yellowing of young and old leaves at the onset of fruiting and was accompanied by general necrosis of the root system resulting in subsequent plant death. Isolation of Pythium implicate them to be the causal agent. Since little is known about their role and control in the hydroponic system in Malaysia, studies were undertaken to characterize and identify the Pythium spp., to establish their pathogenicity, to determine the sources of inoculum, as well as to investigate the in-vitro and in-vivo efficacy of some fungicides in their control. Through cultural and morphological studies, three Pythium spp. namely P. myriotylum, P. splendens and a non-sporulating Pythium Spa were identified from six isolates obtained

Kesan Paras N dan K dalam Larutan Nutrien terhadap Keupayaan Pertukaran Kation Akar Tanaman Selada (Lactuca sativa)

A study on the influence of nitrogen (N) (100, 200, 300 and 400 mgNL-l ) and potassium (K) (100, 200 and 400 mgKL-l) combinations in solution using the nutrient film technique, hydroponic system on the root cation exchange capacity (GE.G) of lettuce plant (Lactuca sativa var crispa cv. Poly) was undertaken. Roots were sampled on the 20th, 30th and 40th day after germination. Significant increase in roots GE. Cfrom 39.4 7 to 51.11 cmol(+)kgl due to the N level was only detected on the 40th day of sampling. However, increasing the k concentration in nutrient solution at the three sampling times significantly decreased the root GE.C values from 29.48-57.00 to 23.25-35.92 cmol(+)kgl . Root GE.C increased from 27.1 7 to 46.23 cmol(+)kg1 with plant growth stage

A metabolome genome-wide association study implicates histidine N-pi-methyltransferase as a key enzyme in N-methylhistidine biosynthesis in Arabidopsis thaliana

A genome-wide association study (GWAS), which uses information on single nucleotide polymorphisms (SNPs) from many accessions, has become a powerful approach to gene identification. A metabolome GWAS (mGWAS), which relies on phenotypic information based on metabolite accumulation, can identify genes that contribute to primary and secondary metabolite contents. In this study, we carried out a mGWAS using seed metabolomic data from Arabidopsis thaliana accessions obtained by liquid chromatography–mass spectrometry to identify SNPs highly associated with the contents of metabolites such as glucosinolates. These SNPs were present in genes known to be involved in glucosinolate biosynthesis, thus confirming the effectiveness of our analysis. We subsequently focused on SNPs detected in an unknown methyltransferase gene associated with N-methylhistidine content. Knockout and overexpression of A. thaliana lines of this gene had significantly decreased and increased N-methylhistidine contents, respectively. We confirmed that the overexpressing line exclusively accumulated histidine methylated at the pi position, not at the tau position. Our findings suggest that the identified methyltransferase gene encodes a key enzyme for N-methylhistidine biosynthesis in A. thaliana

Integrated metabolome and transcriptome analyses provide insight into the effect of red and blue LEDs on the quality of sweet potato leaves

Red and blue light-emitting diodes (LEDs) affect the quality of sweet potato leaves and their nutritional profile. Vines cultivated under blue LEDs had higher soluble protein contents, total phenolic compounds, flavonoids, and total antioxidant activity. Conversely, chlorophyll, soluble sugar, protein, and vitamin C contents were higher in leaves grown under red LEDs. Red and blue light increased the accumulation of 77 and 18 metabolites, respectively. Alpha-linoleic and linolenic acid metabolism were the most significantly enriched pathways based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. A total of 615 genes were differentially expressed between sweet potato leaves exposed to red and blue LEDs. Among these, 510 differentially expressed genes were upregulated in leaves grown under blue light compared with those grown under red light, while the remaining 105 genes were expressed at higher levels in the latter than in the former. Among the KEGG enrichment pathways, blue light significantly induced anthocyanin and carotenoid biosynthesis structural genes. This study provides a scientific reference basis for using light to alter metabolites to improve the quality of edible sweet potato leaves

The Funambulist Papers, Volume 1

This book is a collection of thirty-five texts from the first series of guest writers’ essays, written specifically for The Funambulist weblog from June 2011 to November 2012. The idea of complementing Lambert’s own texts on his blog with those written by others originated from the idea that having friends communicate with each other about their work could help develop mutual interests and provide a platform to address an audience. Thirty-nine authors of twenty-three nationalities were given the opportunity to write essays about a part of their work that might fit with the blog’s editorial line. Overall, two ‘families’ of texts emerged, collected in two distinct parts in this volume. The first part, The Power of the Line, explores the legal, geographical and historical politics of various places of the world. The second part, Architectural Narratives, approaches architecture in a mix of things that were once called philosophy, literature and art. This dichotomy represents the blog’s editorial line and can be reconciled by the obsession of approaching architecture without care for the limits of a given discipline. This method, rather than adopting the contemporary architect’s syndrome that consists in talking about everything but being an expert in nothing, attempts to consider architecture as something embedded within (geo)political, cultural, social, historical, biological, and dromological mechanisms that widely exceed what is traditionally understood as the limits of its expertise

The use of daylighting in the design of a controlled environment for food reduction in the Caribbean and other equatorial climates.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1989.Title as it appeared in M.I.T. Graduate List, June 1989: The use of daylighting in the design of a controlled environment for food reduction in the Caribbean and other equatorial climates.Includes bibliographical references (leaves 219-224).This thesis addresses the use of daylight in the design of a controlled environment for food production in the Caribbean and other Equatorial climates. An expanding population has put a tremendous burden on the food production industry in these climates. The increasing population in these climates means that existing fertile land is being taken-over for housing and infrastructure. Furthermore, the fishing industry is also a victim of over-fishing due to a need for alternative foods. This design proposes a technological solution to this social problem. Presented is one answer to improve the fishing industry, through a controlled environment for intensive aquaculture production. To improve crop production due to depleting fertile land and flooding, this thesis proposes hydroponic cultures in multi-stories. In addition, the success of this farming complex is dependent on appropriate research by staffed scientists, seeking to continually improve the end products of this facility. Within this ecosystem, far greater yields will be attained than traditional forms of agriculture, and, aquaculture. The challenge here is to present the most economic solution. As a result, the design of this facility is based on a three-level hydroponic (crops growing in a nutrient solution) facility, a fish hatchery, indoor fish ponds, and, research laboratories within the aquaculture and hydroponic facilities. This thesis presents two design solutions :one on land, that addresses the issues of flooding and a depletion of available fertile land, and one at sea, that addresses a time in which the population has grown to such a degree that food production at sea becomes an economic reality. There are many ways to introduce natural daylight into this proposed farming complex. Intensive research has indicated that these methods can often range from the very simplistic to the very intricate, as displayed in new emerging technologies such as the Himawari system developed by La Foret Engineering, of Japan. However, the following are techniques that will be applied in this thesis to bring daylight into the buildings of this proposed farming complex : 1. Optical lighting Himawari system); 2. Perimeter lighting; 3. Reflective lighting; 4. Top/Core lighting. Research has indicated that even during the rainy season (July to December)- in some of these equatorial climates there is adequate available diffused sunlight to reach the crops and aquatic life within this proposed controlled environment. This thesis also addresses the energy and cooling load requirements that result from the use of daylighting. Once again the most economic design is presented in this case study. However, the resulting economic solution ( to meet the cooling loads ) that is presented for the proposed site in Trinidad, may not be the most desirable solution for other equatorial climates. Consequently, wind energy, solar energy, co-generation, and traditional electricity, are all analyzed.by Curtis B. Charles.M.S