Perbedaan pertumbuhan dan produktivitas varietas bayam hijau dan bayam merah

Bayam termasuk salah satu sayuran terpenting di Indonesia karena paling banyak dikonsumsi setelah kangkung. Bayam hijau dan bayam merah merupakan jenis bayam paling banyak ditanam dan dikonsumsi. Penelitian ini bertujuan untuk mengetahui perbedaan pertumbuhan dan produktivitas varietas bayam hijau dan bayam merah. Penelitian dilakukan pada Februari – April 2021 di Kebun Percobaan Leuwikopo, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, IPB University. Sebanyak 9 varietas bayam hijau (Maryland, Richie, Maestro, Benua, Doly, Khanafiah, Manila, Pacific, White Leaf) dan 4 varietas bayam merah (Mira, Baret Merah, Clara, Aurora) ditanam menggunakan rancangan kelompok lengkap teracak dengan tiga ulangan. Hasil penelitian memperlihatkan bahwa varietas bayam hijau memiliki kandungan persentase warna hijau daun lebih banyak namun memiliki persentase warna biru dan merah yang lebih rendah dibandingkan varietas bayam merah. Hasil penelitian juga memperlihatkan bahwa varietas bayam hijau menghasilkan tinggi tanaman dan produktivitas yang lebih baik dibandingkan varietas bayam merah, namun varietas bayam merah menghasilkan luas daun dan jumlah daun per tanaman saat panen yang lebih baik besar dibandingkan varietas bayam hijau. Varietas White Leaf merupakan varietas bayam yang sangat baik karena memiliki persentase warna hijau daun yang tinggi, luas daun yang besar dan produktivitas yang tinggi. Spinach is one of the most important vegetables in Indonesia because it was the second most consumed after kangkung. Green spinach and red spinach are the most widely grown and consumed types of spinach. This study aimed to determine differences in growth and productivity between varieties of green spinach and red spinach. The research was conducted in February – April 2021 at the Leuwikopo Experimental Field, Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University. A total of nine varieties of green spinach and four varieties of red spinach were planted using a completely randomized block design with three replications. The results showed that the green spinach variety contained a higher percentage of green leaf color but had a lower percentage of blue and red leaf color than the red spinach varieties. The results also showed that the green spinach varieties produced better plant height and productivity than the red spinach varieties, but the red spinach produced better leaf area and a number of leaves per plant at harvest than the green spinach. The White Leaf variety is the excellent spinach variety because it has a high percentage of green leaf color, large leaf area, and high productivity.

Green Leaf Volatiles in the Atmosphere—Properties, Transformation, and Significance

This review thoroughly covers the research on green leaf volatiles (GLV) in the context of atmospheric chemistry. It briefly takes on the GLV sources, in-plant synthesis, and emission inventory data. The discussion of properties includes GLV solubility in aqueous systems, Henry’s constants, partition coefficients, and UV spectra. The mechanisms of gas-phase reactions of GLV with OH, NO3, and Cl radicals, and O3 are explained and accompanied by a catalog of products identified experimentally. The rate constants of gas-phase reactions are collected in tables with brief descriptions of corresponding experiments. A similar presentation covers the aqueous-phase reactions of GLV. The review of multiphase and heterogeneous transformations of GLV covers the smog-chamber experiments, products identified therein, along with their yields and the yields of secondary organic aerosols (SOA) formed, if any. The components of ambient SOA linked to GLV are briefly presented. This review recognized GLV as atmospheric trace compounds that reside primarily in the gas phase but did not exclude their transformation in atmospheric waters. GLV have a proven potential to be a source of SOA with a global burden of 0.6 to 1 Tg yr−1 (estimated jointly for (Z)-hexen-1-ol, (Z)-3-hexenal, and 2-methyl-3-buten-2-ol), 0.03 Tg yr−1 from switch grass cultivation for biofuels, and 0.05 Tg yr−1 from grass mowing.

Accumulation of cations in lettuce cultivars under low-cost hydroponic system with brackish waters

ABSTRACT The use of brackish water to cultivate lettuce can cause nutritional imbalances, impairing production. In this context, the objective of the present study was to evaluate the effect of salinity on the accumulation of dry matter of the aerial part and macronutrients K, Ca and Mg and their relations with Na in lettuce cultivars grown in a low-cost hydroponic system. The experiment was conducted in a randomized block design, in a 6 × 2 factorial scheme, with four replicates. The treatments consisted of six electrical conductivities of the nutrient solution (1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 dS m-1) and two lettuce cultivars, Betty [iceberg] and Mimosa [green-leaf]. Regardless of the evaluated cultivar, the increase in the electrical conductivity of the nutrient solution reduced the accumulation of dry matter in the aerial part. In both cultivars, the increase in the electrical conductivity of the nutrient solution reduced the accumulations of K and Mg and increased Na/K, Na/Ca and Na/Mg ratios. The green-leaf cv. Mimosa showed Ca and Mg accumulations higher than that in the iceberg cv. Betty, regardless of electrical conductivity. The increase in electrical conductivity reduced the accumulation of K, in both cultivars evaluated. The decreasing order in the accumulation of macronutrients and sodium in both cultivars was: K > Na > Ca > Mg.

Phytochemistry and antioxidant activity of Amaranthus viridis L (Green leaf)

Phytochemistry and antioxidant activity of Amaranthus viridis L (Green leaf) were undertaken with standard methods. The leaf sample after being screening for phytochemicals, contained tannins, saponins, flavonoids, alkaloids, steroids, phenolic compounds, proteins and anthraquinones at different concentrations. A further study using Gas Chromatography-Mass Spectrophotometry (GC-MS) analytic method on the leaf sample revealed a total of twenty-two detailed compounds among which are 3-Hydroxy-N-methylphenethylamine, Erucic acid, n-Hexadecanoic acid, 1,2-Propanediol,3-chloro-, and Cystamine. 3-Hydroxy-N-methylphenethy lamine had the highest retention time; Erucic acid had the highest molecular weight while n-Hexadecanoic acid had the highest peal area. Most of the compounds have important applications in body care products and cosmetics, pharmaceutical or food industries. A. viridis leaf extract exhibited a better antioxidant activity against the ascorbic acid used as control in the present study. The phytochemicals present in the leaf sample could be behind its antioxidant activity. The study has shown the phytochemistry and antioxidant activity of A. viridis leaf sample.

Spectral Blocking of Solar Radiation in High Tunnels by Poly Covers: Its Impact on Nutritional Quality Regarding Essential Nutrients and Health-Promoting Phytochemicals in Lettuce and Tomato

Spectral characteristics of solar radiation have a major role in plant growth and development and the overall metabolism, including secondary metabolism, which is important for the accumulation of health-promoting phytochemicals in plants. The primary focus of this study was to determine the effect of spectral characteristics of solar radiation on the nutritional quality of lettuce (Lactuca sativa L., cv. red leaf ‘New Red Fire’ and green leaf ‘Two Star’ and tomato (Solanum lycopersicum L., cv. BHN-589) grown in high tunnels in relation to the accumulation of essential nutrients and phytochemicals. Solar spectrum received by crops was modified using photo-selective poly covers. Treatments included commonly used standard poly, luminescence poly (diffuse poly), clear poly, UV blocking poly, exposure of crops grown under the standard poly to full sun 2 weeks prior to harvest (akin to movable tunnel), and 55% shade cloth on the standard poly. All the poly covers and shade cloth reduced the PAR levels in the high tunnels, and the largest reduction was by the shade cloth, which reduced the solar PAR by approximately 48%. Clear poly allowed the maximum UV-A and UV-B radiation, while standard poly allowed only a small fraction of the solar UV-A and UV-B (between 15.8% and 16.2%). Clear poly, which allowed a higher percentage of solar UV-A (60.5%) and UV-B (65%) than other poly covers, increased the total phenolic concentration and the antioxidant capacity in red leaf lettuce. It also increased the accumulation of flavonoids, including quercetin-3-glucoside, luteolin-7-glucoside, and apigenin-3-glucoside in red leaf lettuce, compared to the standard poly. Brief exposure of crops grown in high tunnels to full sun prior to harvest produced the largest increase in the accumulation of quercetin-3-glucoside, and it also resulted in an increase in luteolin-7-glucoside and apigenin-3-glucoside in red leaf lettuce. Thus, clear poly and brief exposure of red leaf lettuce to the full sun, which can increase UV exposure to the plants, produced a positive impact on its nutritional quality. In contrast, shade cloth which allowed the lowest levels of solar PAR, UV-A and UV-B relative to the other poly covers had a negative impact on the accumulation of the phenolic compounds in red leaf lettuce. However, in green leaf lettuce, luminesce poly, clear poly, UV-block poly, and shade treatments increased the accumulation of many essential nutrients, including protein, magnesium, and sulfur in green leaf lettuce compared to the standard poly. Poly cover treatments including shade treatment did not affect the accumulation of either carotenoids (lutein, β-carotene, and lycopene) or essential nutrients in mature tomato fruits. The results show that clear poly cover can enhance the accumulation of many phenolic compounds in red leaf lettuce, as does the brief exposure of the crop to the full sun prior to harvest. Thus, UV radiation plays an important role in the accumulation of phenolic compounds in red leaf lettuce while the overall spectral quality of solar radiation has a significant influence on the accumulation of essential nutrients in green leaf lettuce.