Greenhouse tomato production is shifting to meet emerging consumer needs. Increasing environmental concerns have pressured growers to supply high-quality vegetables using sustainable production methods. The utilization of adapting fertigation to production conditions and/or nutrient solutions of moderately high conductivity seems promising in providing high yields of superior quality while limiting the emission of nutrients to the environment in greenhouse tomato crops. A tomato crop was grown in soilless culture with various levels of electrical conductivity (EC), 2.2, 3.5, and 4.5 dS·m−1, adjusting the final nutrient concentration and maintaining nutritional balance. The effect of nutrient solutions with moderately high EC on fertigation parameters and the emission of nutrients to the environment, total crop productivity, distribution of fruit sizes, and dietary and organoleptic qualities were measured. Nutrient solutions of moderately high EC decreased total and commercial yield, with an average reduction from 5% to 19% and 3% to 22%, respectively. A considerable decrease in extra large and large fruits, with an average reduction from 69% to 42%, was also observed. Nonetheless, dietary-related metabolites were significantly increased at the highest EC values: lycopene (6.3%), ascorbic acid (8.8%), total phenolics content (8.3%), and total antioxidant activity (11.1%). EC values of 3.5 and 4.5 dS·m−1 are not widely used in commercial production but are frequently measured in drainage solutions in open hydroponic systems and discarded solutions in closed systems, mainly because of the use of poor-quality water and the accumulation of excess nutrients.

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The phylogenetic relationships of subtribe Chloraeinae, a group of terrestrial orchids endemic to southern South America, have not been satisfactorily investigated. A previous molecular phylogenetic analysis based on plastid DNA supported the monophyly of Chloraeinae and Gavilea, but showed that Chloraea is non-monophyletic and that the sole species of Bipinnula analysed is sister to Geoblasta. However, that analysis included only 18 of the 73 species belonging to this subtribe. Here, the phylogenetic relationships of Chloraeinae were assessed by analysing aproximately 7500 bp of nucleotide sequences from nuclear ribosomal internal transcribed spacer (ITS) and plastid DNA (rbcL, matK, trnL-trnF, rpoB-trnC) for 42 species representing all four currently accepted genera of Chloraeinae and appropriate outgroups. Nuclear and plastid data were analysed separately and in combination using two different methods, namely parsimony and Bayesian inference. Our analyses support the monophyly of Chloraeinae and their inclusion in an expanded concept of Cranichideae, but none of the genera of Chloraeinae that includes more than one species is monophyletic. Gavilea and Bipinnula are paraphyletic, with Chloraea chica nested in Gavilea and Geoblasta penicillata in Bipinnula. As currently delimited, Chloraea is polyphyletic. The taxonomic changes proposed recently are for the most part not justifiable on phylogenetic grounds, except for recognition of the monotypic genus Correorchis. The lack of resolution for the relationships among species of 'core' Chloraea suggests a relatively recent diversification of this group. The current generic classification is in need or revision, but additional study is advisable before carrying out further taxonomic changes.

Coastal/lowland quinoa ecotype is an important source of germplasm due to its cultivation in cold-temperate and high latitude areas. However, the interaction of its morphological traits and yields to define breeding criteria is unknown. The present study was designed to characterize the phenotypic diversity of twelve coastal/lowland quinoas using sixteen standardized morphological descriptors under rainfed conditions in central Chile. Complementary analysis of uni-and multivariate tools allowed a fuller understanding of interrelationships within quinoa germplasm. Through the analysis of frequency distribution, it was possible to determine that genotypes were characterized by plants having low height and medium grain yield. Cluster analysis revealed that plant morphological variables were independently grouped from grain yield components. Additionally, principal component analysis (PCA, 74.8% of total variation data), revealed the existence of three outstanding genotypes (QC01, QC02 and QC05) that were distantly located from the average dispersion of entire germplasm collection. These genotypes were associated with grain yield components, allowing the identification of two groups of high yield (VI and VII), which yielded 3337.7 and 3052.0 kg ha -1 , respectively. The data set presented in this study is the first report of coastal/lowland quinoas assessed in central Chile and could assist the development of breeding programmes in cold-temperate areas having similar agro-climatic conditions.

Use of avoidance tests is a quick and cost-effective method of assessing contaminants in soils. One option for assessing earthworm avoidance behavior is a two-section test, which consists of earthworms being given the choice to move between a test soil and a control substrate. For ecological relevance, tested soils should be field-contaminated soils. For practical reasons, artificial soils are commonly used as the control substrate. Interpretation of the test results compromised when the test soil and the artificial substrate differ in their physico-chemical properties other than just contaminants. In this study we identified the physico-chemical properties that influence avoidance response and evaluated the usefulness of adjusting these in the control substrate in order to isolate metal-driven avoidance of field soils by earthworms. A standardized two-section avoidance test with Eisenia fetida was performed on 52 uncontaminated and contaminated (Cu >155mgkg, As >19mgkg) agricultural soils from the Aconcagua River basin and the Puchuncaví Valley in Chile. Regression analysis indicated that the avoidance response was determined by soil organic matter (OM), electrical conductivity (EC) and total soil Cu. Organic matter content of the artificial substrate was altered by peat additions and EC by NaCl so that these properties matched those of the field soils. The resultant EC for avoidance (indicative of soils of "limited habitat") was 433mg Cu kg (339 - 528mgkg 95% confidence intervals). The earthworm avoidance test can be used to assess metal toxicity in field-contaminated soils by adjusting physico-chemical properties (OM and EC) of the artificial control substrate in order to mimic those of the field-collected soil.