Judul: Development of Water Stress Treatment System for Long-term High Brix Tomato Production in Hydroponic Culture
Abstrak: Nowadays, the demand of high brix tomato as known as fruit tomato is increased. Many studies found that water stress treatment can be used for the production of high brix tomato, however, these are obtained for short-term experiment in water content around 50%-80% (Nuruddin et al. 2003; Patane and Consentino, 2010). The effect of water stress treatment on plant growth is well known, but how to operate the water stress treatment to increase the quality of tomato fruits is not known very well. It is not easy to grow health plant in water stress condition. This research introduces visual monitoring system to control severe water stress condition. The objectives of the present study are to develop a water stress treatment system for long-term high brix tomato production in hydroponic culture and evaluate the performance of water stress treatment system in long-term severe water condition with seasonal change on the quantity and quality of tomato fruits. Furthermore, the effect of water stress on plants growth was examined. All data that from this research could be used for database of development of water stress treatment system on tomato plants. Tomato (Solanum lycoperscium L., Momotaro Sakura) plants were grown hydroponically on rock wool slabs in a greenhouse in Faculty of Agriculture, Ehime University. Water stress treatment was applied at 14 weeks after transplanting. Leaf area was monitored by digital camera that pictures were captured every 15 minutes. The water content of the slabs was measured by Water Content Meter once a day at noon. There are two treatments in this research, water stress treatment and control. The water content of slab was maintained around 20%-30% for water stress treatment and 60%-70% for control, which was controlled base on the projected leaf area and water content of slabs. When the projected leaf area was decreased fewer or less than 95% of the maximum projected leaf area which was measured after the last irrigation and the water content of the slab was fewer than 20%, the nutrient solution was supplied to the plant until recovering to 20%. For the growth rate measurement, stem diameter and elongation were measured once a week by caliper and measuring tape, respectively. Fruit diameter, sweetness, and sourness were measured by ISEKI grading machine. The calibrations for sweetness were conducted by destructive method with Refractometer, while the sourness was calibrated by KUBOTA Fruits Selector machine. The results indicated that it took 1.5 hours from full unfuried condition to full recover. Some irregular situations were observed when solar radiation was high and relative humidity was low, water content was around 11% that was lower than the expectation. On the other hand, when solar radiation was low and relative humidity was high, water content was around 40% that was not expected. Low solar radiation and high relative humidity can be contributed to maintain the water content at high level. Stem diameter was 4.4 mm-7.78 mm for water stress and 8.45 mm-11.68 mm for control. Stem elongation rate was 0.08 m week-1-0.18 m week-1 for water stress and 0.17 m week-1-0.25 m week-1 for control. Both
Keyword: high technology greenhouse, irrigation control, high brix tomato, water stress

Judul: Physiological and Production Responses of Microtome Tomatoes to High Temperature and Artificial Light with Light Emitting Diodes
Abstrak: Tomat adalah produk hortikultura semusim yang populer. Tomat merupakan komoditas sayuran buah dari keluarga Solanaceae yang banyak diproduksi dan dikonsumsi di seluruh dunia, tomat kaya akan mineral, vitamin, asam amino esensial, gula dan serat. Mikrotom (Solanum lycopersicum cv. Micro-Tom) adalah tanaman model berukuran kecil dengan siklus hidup yang pendek dan buah yang kecil. Perubahan iklim global mengakibatkan peningkatan suhu, sehingga diperlukan percobaan budidaya di kondisi suhu tinggi. Penggunaan cahaya buatan dalam teknik budidaya diketahui dapat memperpendek siklus tanaman dan mempercepat fase juvenil. Penelitian ini bertujuan untuk mempelajari respons pertumbuhan, fisiologi, dan produksi tomat Mikrotom dan beberapa varietas lainnya terhadap perlakuan suhu tinggi dan pencahayaan buatan dengan LED. Penelitian ini dilakukan di Kebun Percobaan Leuwikopo IPB Bogor, dari Maret hingga November 2023. Rancangan acak kelompok lengkap (RAKL) digunakan pada perobaan suhu tinggi dan rancangan acak lengkap (RAL) pada percobaan LED. Identifikasi full length transcript menghasilkan data raw reads dan clean reads yang merepresentasikan kualitas dan kuantitas dari RNA-sequencing, selain itu diperoleh diagram venn kelompok gen hasil dari pemetaan clean reads terhadap referensi genom tomat dan diperoleh juga data kelimpahan gen hasil dari analisis kluster menggunakan heatmap. Hasil penelitian pada percobaan suhu tinggi menunjukkan bahwa perlakuan suhu normal (NT) masih lebih unggul dibandingkan suhu tinggi (HT) dalam hal parameter pertumbuhan seperti tinggi tanaman, jumlah daun, dan jumlah bunga, parameter fisiologis seperti kandungan klorofil dan kandungan glukosa-fruktosa, serta komponen produksi seperti jumlah buah. Respons yang berbeda-beda dapat dilihat dari 4 varietas tomat yang digunakan yaitu Bareto F1, Gustavi F1, Tymoti F1 dan Mikrotom, varietas Bareto secara umum lebih unggul dibandingkan varietas lainnya. Respons tomat Mikrotom terhadap cahaya buatan menggunakan LED Ungu dan LED Putih tidak menunjukkan perbedaan signifikan dalam parameter pertumbuhan dan produksi, perbedaan signifikan diamati pada genotipe tomat yang digunakan, yaitu WildType dan iaa9-3. Pada parameter fisiologi seperti klorofil dan glukosa-fruktosa, tidak ada perbedaan signifikan dalam perlakuan LED atau genotipe tomat mikrotom. Dalam hal parameter kualitas buah, nilai PTT (brix) – TAT (acidity), glukosa-fruktosa, dan asam malat juga tidak menunjukkan perbedaan signifikan. Penggunaan kombinasi LED polikromatrik dan monokromatik dapat memberikan respons yang beragam. Analisis LC-MS/MS pada daun LED Ungu menghasilkan profil metabolit sekunder yang didominaasi dari kelompok senyawa asam lemak., Tomatoes are a popular seasonal horticultural product. As a fruit vegetable commodity from the Solanaceae family, tomatoes are widely produced and consumed worldwide, rich in minerals, vitamins, essential amino acids, sugars, and fiber. Micro-Tom (Solanum lycopersicum cv. Micro-Tom) is a small-sized model plant with a short life cycle and small fruits. Global climate change has resulted in increased temperatures, necessitating cultivation experiments under high-temperature conditions. The use of artificial light in cultivation techniques is known to shorten the plant cycle and accelerate the juvenile phase. This research aimed to study the growth, physiological, and production responses of Micro-Tom tomatoes and several other varieties to high-temperature treatment and artificial LED lighting. The study was conducted at the Leuwikopo Experimental Field of IPB Bogor from March to November 2023. A complete randomized block design (CRBD) was used for the high-temperature experiment, and a completely randomized design (CRD) was used for the LED experiment. The identification of
Keyword: LED, production, secondary metabolites, high temperatures, lights

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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