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We evaluated the effects of neodymium (0.000, 2.885, 5.770 and 8.655 mg · L−1) and zinc (0.1, 0.2 and 0.3 mg · L−1), as well as their interaction on lettuce plants in hydroponics. Applications of 2.885 mg Nd · L−1 and 5.770 mg Nd · L−1 increased plant height, number of leaves and leaf area, as well as fresh and dry stem, root and total biomasses. Root volume was greater in plants treated with 2.885 mg Nd · L−1. With 0.1 mg Zn · L−1, plant height, leaf area and fresh stem, root and total biomass were greater, while applying 0.3 mg Zn · L−1 increased the ratio of dry biomass of stems and roots. Plants exposed to 5.770 mg Nd · L−1 + 0.3 mg Zn · L−1 exhibited greater leaf length. The ratios of fresh and dry biomass of stems and roots increased in plants treated with 8.655 mg · L−1 Nd + 0.3 mg Zn · L−1. Dry biomass weights of stems, roots and total were the highest in plants treated with 20 mg Nd · L−1 + 0.1 mg Zn · L−1. Nd significantly increased foliar concentration of N, P and K. Hence, Nd and Zn improve growth and nutrition.

Terrestrial plants are constantly exposed to multiple environmental signals that influence their metabolism. Among these signals, nitrogen (N) nutrition and light affect importantly diverse metabolic and physiological processes. Herewith the effects of N nutrition (8.47, 12.71 and 16.94 mg · L−1 N) and shading percentages (0 and 70%) on plant morphology and chemical composition of the essential oil of marigold (Tagetes erecta L.) ‘Inca’ were assessed. Increasing N levels enhanced the number of secondary branches and the flower diameter, while shading reduced height of side branches, number of primary branches and opened flower buds. In leaves, flowers and stems, 15 different compounds were identified. In leaves, low and medium N levels and high light level increased the synthesis of ocimene, limonene and piperitone. As well, medium and high N doses, independently of the light level, stimulated the synthesis of caryophyllene and β-phellandrene in leaves. Nevertheless, increasing N doses and shading level decreased the synthesis of β-myrcene and α-pinene in leaves. In flowers, medium N level and high light intensity increased the synthesis of trans-pinene. Piperitone and verbenone were identified only in flowers of plants with high N doses and lower light intensity. In the stems, caryophyllene, piperitone and β-farnesene were more abundant with medium and high N levels. The interaction of study factors differentially affected both morphological variables and the composition of essential oil among organs studied. Therefore, N nutrition and light intensity are key factors that modify the morphology and composition of the essential oil in T. erecta.

Objective: To evaluate the effects of lithium (Li) supplied as lithium chloride (LiCl) on the emergence of seeds and initial growth of chili (Capsicum annuum L.) var. Guajillo seedlings. Design/methodology/approach: Guajillo variety chili seeds were treated with five doses of Li chloride (0, 20, 50, 75, and 100 μm) during the germination phase. The treatments lasted 20 days. In this period, parameters related to seed germination and initial growth of seedlings were evaluated. With the data obtained, analysis of variance and comparison of means test (Duncan) were carried out with the SAS software. Results: The doses of LiCl evaluated did not affect the percentages of germination and relative germination, the coefficient of velocity of germination, the average velocity of germination, and the weights of fresh and dry seedling biomass. Doses of 25 and 50 μm LiCl favored the germination index and the seed vigor index. Likewise, they significantly increased the height of the stem. On the contrary, the 100 μm Li dose significantly reduced the relative radicle growth, the germination index and the stem height. Limitations on study/implications: This study used only a single Li source, so the effects that accompanying anions have, are unknown. Findings/conclusions: Low doses of LiCl have positive effects on shoot growth in the initial phase of seedling growth, without affecting germination parameters. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the leaf application of silicon (Si) and titanium (Ti) in three doses (0, 75, and 150 mg L-1), independently, on tomato plants cv. Río Supremo, subjected to saline stress (0, 50, and 100 mM NaCl), on the percentage of juice and color attributes of the fruit. Design/methodology/approach: Two independent essays were carried out under a completely randomized experimental design in a 3² factorial arrangement, where the first study factor was the NaCl concentration in the nutrient solution and the second factor was the leaf application of Si or Ti. The percentage of juice and color attributes in fruits were determined. An analysis of variance and the comparison of means by Tukey (p≤0.05) with the SAS software were performed. Results: Salinity was found to reduce the percentage of juice, the color index, and the ratio of "a/b" indexes. Regarding the interactive effects, NaCl with both Ti and Si increases the "b" index. Leaf applications of Si increased the "b" index and reduced the percentage of juice, the color index, and the ratio of "a/b" indexes. Also, Ti improved the color index and the "b" index. Limitations of the study/implications: The results were obtained in the Río Supremo tomato variety under greenhouse conditions. Other varieties should be tested too. Findings/conclusions: Si and Ti applied to the leaves have positive effects on the color of the fruits of tomato plants under saline stress. [ABSTRACT FROM AUTHOR]

Phenolic compounds, such as chlorogenic acid, caffeine, sugars, vitamins, minerals and volatile substances are major compounds of coffee (Coffea ssp.). They perform distinctive biological functions and are classified as nutraceuticals and insecticides. In at least one phenological stage, coffee leaves are more likely to be used for commercial purposes. The objective of this study was to analyze leaf area, content of chlorophyll a, b and total, caffeine, chlorogenic acid (5-CQA), sugars and macro and micronutrients in arabica coffee leaves (Coffea arabica) var. Caturra rojo grafted on robusta coffee (Coffea canephora) var. Romex during an annual cycle. The quantification of chlorogenic acids, caffeine and reducing sugars was analyzed by chromatography (HPLC). Nutrients were quantified by atomic absorption spectrophotometry and we performed one-way factorial designed ANDEVA and Tukey means comparison test. Sampling of 10 trees was done completely at random, and the samples in chromatographic analyses were run in triplicate. The largest values occurred as follows: leaf area in the blooming and fruiting stage; chlorophyll a, b and total during the vegetative stage; caffeine in the blooming stage; 5-CQA was obtained during the vegetative stage, in which we observed the highest concentrations of glucose and fructose. The concentration of macronutrients, except Mg, was higher during the fruiting stage, while Fe and Zn were higher during blooming and Mn and B in fruiting. Macro and micronutrients accumulated during the fruiting stage. Coffee leaves may be both functional and nutraceutical during the vegetative and fruiting stages. [ABSTRACT FROM AUTHOR]

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agrociencia is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fruits of chayote [Sechium edule (Jacq.) Swartz] are a non-traditional vegetable widely consumed in Latin America, with the state of Veracruz, México being the world's main producer, but little is known about the nutraceutical potential. This study aimed to determine the chemical compositions and antioxidant activities from the juice fruits from two commercial varieties of chayote cultivated in Mexico, as well as a proposal for the elaboration of chayote juices with stevia leaves and pineapple juice. The physicochemical properties of juice from virens levis (VL) and nigrum spinosum (NS) varieties were determined using standard methods. The juice of the two varieties differ significantly regarding the concentrations of total soluble solids and total sugars, but not vitamin C. The total concentration of phenolics in NS extracts was slightly higher than in VL (1005 and 856 mg 100 g-1 dry-weight, respectively), but the total flavonoid contents were similar (27 and 26 mg 100 g-1 dry-weight, respectively). Cucurbitacin D was predominant in both varieties. The radical scavenging capacities of VL and NS extracts varied slightly (IC50 = 0.45 to 0.65 mg mL-1), while the antioxidant activities were similar (~80%). The NS variety is particularly promising regarding nutraceutical application. The chayote juice combined with stevia and pineapple maintained the original nutraceutical characteristics of the fruit, but enhanced the organoleptic characteristics like density and sugar/acidity balance. [ABSTRACT FROM AUTHOR]