scholarly journals Analysis of Salt Tolerance in Nine Leafy Vegetables Irrigated with Saline Drainage Water

2000 ◽  
Vol 125 (5) ◽  
pp. 658-664 ◽  
Author(s):  
Michael C. Shannon ◽  
Catherine M. Grieve ◽  
Scott M. Lesch ◽  
John H. Draper
Keyword(s):  
Salt Tolerance ◽  
Brassica Rapa ◽  
Spinacia Oleracea ◽  
Drainage Water ◽  
Leafy Vegetables ◽  
Sand Culture ◽  
Yield Reduction ◽  
Chemical Compositions ◽  
Swiss Chard ◽  
Pac Choi

Saline agricultural drainage water may be used as a resource to grow high value horticultural crops and reduce the volume of drainage for eventual disposal. To explore reuse options the effects of salinity and timing of application were tested on selected leafy vegetables grown in 24 sand culture plots in Riverside, Calif. The leafy winter vegetables included `Ruby Red Chard' Swiss chard [Beta vulgaris L. var. flavescens (Lam.) Lam.], `Space' spinach (Spinacia oleracea L.), `Vitamin Green' salad greens [Brassica rapa L. (Narinosa Group)], `Red Giant' mustard greens [Brassica juncea L. (Czerniak)], pac choi [Brassica rapa L. (Chinensis Group)], `Winterbor' kale [Brassica oleracea L. (Acephala Group)], tatsoi [Brassica rapa L. (Narinosa Group)], `Salad King' curly endive (Cichorium endivia L.), and `Red Preco No. 1' radicchio (Cichorium intybus L.). All vegetables were planted at the same time and irrigated initially with tap water and nutrients. At 3 and 7 weeks after seeding (application times), six salinity treatments were initiated by adding salts to the irrigation water to represent the chemical compositions of drainage waters found typically in the San Joaquin Valley, Calif. The six salinity treatments had electrical conductivities of 3 (control), 7, 11, 15, 19, or 23 dS·m-1. A randomized complete block design was used with (6 salinities × 2 application times × 2 replications). Within each plot a 1.5-m row of each of the nine vegetables was grown as split plots. Salinity reduced fresh weight (FW) yields of all species. Salt stress applied at 3 weeks after seeding reduced FWs for seven of the nine vegetables compared to salination at 7 weeks. Analyses of salt tolerance curves, maximum yields, and the point of 50% yield reduction (C50) were conducted. Greens produced the highest biomass at 874 g/plant, but was the most affected by application time. Swiss chard and radicchio were not significantly affected by timing of salinity application, and Swiss chard was the most salt tolerant overall. Greens, kale, pac choi, and to a lesser extent, tatsoi, have potential as winter-grown, leafy vegetables in drainage water reuse systems.

scholarly journals Hydroponic Production of Reduced-Potassium Swiss Chard and Spinach: A Feasible Agronomic Approach to Tailoring Vegetables for Chronic Kidney Disease Patients

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 627 ◽  
Author(s):  
Massimiliano D’Imperio ◽  
Francesco F. Montesano ◽  
Massimiliano Renna ◽  
Angelo Parente ◽  
Antonio F. Logrieco ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Spinacia Oleracea ◽  
Vegetable Consumption ◽  
Leafy Vegetables ◽  
Positive Effects ◽  
Tissue Content ◽  
Swiss Chard ◽  
Crop Performance ◽  
Leaf Vegetables

Tailored foods are specifically suitable for target groups of people with particular nutritional needs. Although most research on tailored foods has been focused on increasing the nutrient content in plant tissues (biofortification), in populations with specific physiological conditions, it is recommended to reduce the uptake of specific nutrients in order to improve their health. People affected by chronic kidney disease (CKD) must limit their consumption of vegetables because of the generally high potassium (K) content in the edible parts. This study aimed to define an appropriate production technique for two baby leaf vegetables, spinach (Spinacia oleracea L.) and Swiss chard (Beta vulgaris L. ssp. vulgaris), with reduced K tissue content, minimizing the negative effects on their crop performance and overall nutritional quality. Plants were grown in a hydroponic floating system. The K concentration in the nutrient solution (NS) was reduced from 200 mg/L (K200, the concentration usually used for growing baby leaf vegetables in hydroponic conditions) to 50 mg/L over the entire growing cycle (K50) or only during the seven days before harvest (K50-7d). The reduction of K in the NS resulted in a significant decrease of K tissue content in both species (32% for K50 and 10% for K50-7d, on average), while it did not, in general, compromise the crop performance and quality traits or the bioaccessibility of K, magnesium, and calcium. The production of reduced-potassium leafy vegetables is a feasible tailored nutrition approach for CKD patients in order to take advantage of the positive effects of vegetable consumption on health without excessively increasing potassium intake.

scholarly journals Damping-off of Swiss Chard, Caused by Rhizoctonia solani, in California

Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 695-695 ◽  
Author(s):  
S. T. Koike ◽  
K. V. Subbarao
Keyword(s):  
Rhizoctonia Solani ◽  
Brassica Campestris ◽  
Plant Density ◽  
Spinacia Oleracea ◽  
Disease Incidence ◽  
Leafy Vegetables ◽  
Damping Off ◽  
Leaf Stage ◽  
High Plant Density ◽  
Swiss Chard

In California, various leafy vegetables are planted at extremely high seeding rates (up to three million seed per acre), grown to the four- to eight-leaf stage, then mechanically clipped and bagged for market as “spring mix” or “baby leaf” salad products. The crops are planted in separate strips, usually four to 16 beds of each, and include Japanese mustard (Brassica campestris subsp. nipposinica), red mustard (Brassica juncea subsp. rugosa), tah tsai (Brassica campestris subsp. narinosa), multiple lettuce (Lactuca sativa) cultivars, spinach (Spinacia oleracea), arugula (Eruca sativa), and Swiss chard (Beta vulgaris subsp. cicla). In 1997 and 1998, severe damping-off disease of Swiss chard was observed in the Salinas Valley (Monterey County). Symptoms on emergent plants consisted of wilting, brown necrosis of crown tissue, and eventual death of seedlings. Because of the high plant density, disease incidence increased rapidly, affecting large numbers of plants. Rhizoctonia solani was isolated consistently from symptomatic plants. Pathogenicity was tested by placing agar plugs of representative isolates adjacent to crowns of potted Swiss chard at the two- to four-leaf stage. Brown stem necrosis and plant collapse occurred within 5 days after inoculation, and R. solani was reisolated. Control plants, inoculated with sterile agar plugs, did not develop disease. Tests were repeated and results were similar. Anastomosis group testing revealed that all five isolates belonged to AG3 (1). For California, this appears to be the first documentation of damping-off of Swiss chard caused by R. solani. Reference: (1) B. Sneh et al. Identification of Rhizoctonia Species. American Phytopathological Society, St. Paul, MN, 1991.

scholarly journals Nutrient Solution Deprivation as a Tool to Improve Hydroponics Sustainability: Yield, Physiological, and Qualitative Response of Lettuce

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1469
Author(s):  
Michele Ciriello ◽  
Luigi Formisano ◽  
Antonio Pannico ◽  
Christophe El-Nakhel ◽  
Giancarlo Fascella ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Potential Effect ◽  
Quality Parameters ◽  
Leafy Vegetables ◽  
Nitrate Content ◽  
Yield Reduction ◽  
Quality Performance ◽  
Floating Raft ◽  
Amino Acids Profile ◽  
Excessive Nutrients

Hydroponics growing systems often contain excessive nutrients (especially nitrates), which could lead to a quality loss in ready-to-eat leafy vegetables and posing a health risk to consumers, if managed inadequately. A floating raft system was adopted to assay the production and quality performance of lettuce (Lactuca sativa L. cv ‘Maravilla De Verano Canasta’) deprived of the nutrient solution by replacement with only water, three and six days before harvest. Yield and quality parameters, mineral composition, pigments, organic acids, amino acids profile, soluble proteins, and carbohydrate content were determined. Nutrient solution deprivation six days before harvest resulted in a significant reduction in leaf nitrate (−53.3%) concomitant with 13.8% of yield loss, while plants deprived of nutrient solution three days before harvest increased total phenols content (32.5%) and total ascorbic acid (102.1%), antioxidant activity (82.7%), anthocyanins (7.9%), sucrose (38.9%), starch (19.5%), and γ-aminobutyric acid (GABA; 28.2%), with a yield reduction of 4.7%, compared to the control. Our results suggest that nutrient solution deprivation three days before harvest is a successful strategy to reduce nitrate content and increase the nutritional quality of lettuce grown in floating raft systems with negligible impact on yield. These promising results warrant further investigation of the potential effect of nutrient solution deprivation on the quality attributes of other leafy vegetables cultivated in floating raft systems and in a “cascade” growing system.

Season and Species: Two Possible Hurdles for Reducing the Food Safety Risk of Escherichia coli O157 Contamination of Leafy Vegetables

2019 ◽  
Vol 82 (2) ◽  
pp. 247-255 ◽  
Author(s):  
KARIN SÖDERQVIST ◽  
ANNA KARIN ROSBERG ◽  
SOFIA BOQVIST ◽  
BEATRIX ALSANIUS ◽  
LARS MOGREN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Shelf Life ◽  
Spinacia Oleracea ◽  
Growing Season ◽  
Leafy Vegetables ◽  
Production Chain ◽  
Safety Risk ◽  
E Coli ◽  
Food Safety Risk

ABSTRACT The food safety risk of Shiga toxin–producing Escherichia coli (STEC) infection per serving of leafy vegetables was investigated using a quantitative microbial risk assessment (QMRA) approach. The estimated level of E. coli O157 contamination was based on observed numbers of Enterobacteriaceae and E. coli on leafy vegetables grown and processed in southern Sweden from 2014 to 2016. Samples were collected before harvest, after washing, and at the end of shelf life. The observed counts were combined with data on the ratio of E. coli to E. coli O157 taken from earlier studies to estimate the probability of illness. The risks of STEC infection associated with species, either spinach (Spinacia oleracea) or rocket (Diplotaxis tenuifolia), growing season (spring or autumn), and washing (washed or not washed) were then evaluated. The results indicated that leafy vegetable species and growing season could be possible hurdles for reducing the food safety risk of STEC infection. At harvest, the probability of infection was 87% lower when consuming rocket compared with spinach and 90% lower when consuming leafy vegetables grown in spring compared with autumn. These relative risk reductions remained consistent even with other serving sizes and dose-response models. The lowest risk of STEC infection was associated with leafy vegetables early in the production chain, i.e., before harvest, while the risk increased during storage and processing. Consequently, the highest risk was observed when leafy vegetables were consumed at the end of shelf life. Washing had no effect on the food safety risk of STEC infection in this study. To improve the quality of QMRA, there is a need for additional data on the relationship between indicator organisms that can be easily enumerated (e.g., E. coli and Enterobacteriaceae) and E. coli strains that can cause STEC infection (e.g., E. coli O157) but are difficult to identify in food samples such as leafy vegetables.

The possible role of embryo sac degeneration in yield reduction of summer turnip rape cultivar Candle

1995 ◽  
Vol 75 (3) ◽  
pp. 595-598
Author(s):  
Xiuying Tian ◽  
L. Van Caeseele ◽  
M. J. Sumner
Keyword(s):  
Brassica Rapa ◽  
Seed Set ◽  
Embryo Sac ◽  
Pollen Tubes ◽  
Yield Reduction ◽  
Turnip Rape ◽  
Key Words:Brassica

When pollination occurred within 24 h after anthesis, 69.2% of the pods of Brassica rapa cultivar Candle contained at least 50% fertilized ovules. If pollination occurred later than 4 d after anthesis, an occasional ovule near the base of the pistil was fertilized; however, no significant seed set was observed. Pollen tubes were observed entering the locules of the ovary from pollinations carried out as late as 5 d after anthesis. At 3 d after anthesis, in unpollinated flowers, a general deterioration of the embryo-sac contents began and gradually increased to include integumentary cells by 6 d after anthesis. Some ovules swelled as though they were fertilized, but no embryos were present. The results suggest that yield reductions in this species may occur because of the reduction of fertilization potential through rapid degeneration of embryo sacs following anthesis. Key words:Brassica rapa, embryo sac, yield

Functions of Cotton Yield Response to Soil Salinity in Akesu River Irrigation District

2012 ◽  
Vol 535-537 ◽  
pp. 486-494
Author(s):  
Yu Zhang ◽  
Pei Tong Cong ◽  
Shun Jun Hu ◽  
Li Hong Wang ◽  
Feng Qing Guo ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Salt Content ◽  
Soil Layer ◽  
Relative Yield ◽  
Irrigation District ◽  
Yield Response ◽  
Yield Reduction ◽  
Soil Salt Content ◽  
Soil Salt ◽  
Salinized Soil

Based on experimental data from the five observation points during the three years, the linear subsected functions and the nonlinear s-shaped functions between the cotton relative yield and soil salt content on the salinized soil about the 0-20cm soil layer and the 0-40cm soil layer in Akesu River Irrigation District were constructed by linear regression and nonlinear least square approximation. Their applicabilities were analyzed and compared and it was found the nonlinear s-shaped function of the 0-20cm soil layer to fit better with the response relationship between the cotton relative yield and the soil salt content on the salinity soil than others in Akesu River Irrigation District.which and the indexes of cotton salt tolerance were definited, and then the indexes of cotton salt tolerance were drawn on with the function with better applicability. From the function, some indexes of salt tolerance，which contained the cotton critical soil salt content, the cotton threshold soil salt content, the soil salt content at the fastest rate of cotton relative yield reduction, and the soil salt content at the 50% cotton relative yield reduction, and so on, were determined, which can be provide as the important references for the agricultural planting, improvement of salinized soil and irrigation with saline water in Akesu River Irrigation District.

scholarly journals Determination of Pesticide Residues in Most Commonly Consumed Leafy Vegetables in Riyadh Region (Al-Kharej Province)

2019 ◽  
Vol 28 (2) ◽  
pp. 63-73
Author(s):  
Turki Kh. Faraj Turki Kh. Faraj
Keyword(s):  
Pesticide Residues ◽  
Spinacia Oleracea ◽  
Leafy Vegetables ◽  
Petroselinum Crispum ◽  
Anethum Graveolens ◽  
Kingdom Of Saudi Arabia ◽  
Liquid Liquid Extraction ◽  
Residue Levels ◽  
Higher Doses

A total of 81 samples of various leafy vegetables viz., Rocket (Eruca sativa), Lettuce (Lactuca sativa), Coriander (Coriandrum sativum), Corchorus (Corchorus olitorius), Parsley (Petroselinum crispum), Spinach (Spinacia oleracea), Radish (Raphanus sativus), Dill (Anethum graveolens), Mint (Mentha sachalinensis) and Green onions (Allium cepa) were collected from 20 different areas in Riyadh region of the Kingdom of Saudi Arabia. Liquid-Liquid Extraction of extraction partitioning method and confirmation by gas chromatograph-mass spectrometer for the presence of various pesticide residues was performed. Pesticide residues were detected in all the collected samples with varying concentrations. A variety of pesticides including organochlorines, organophosphates, pyrethroids, carbamates, herbicides, acaricides and insecticides have been identified in the samples. While the residue levels were low for most pesticides, higher levels of chlorpyrifos (0.123 mg/kg and resmethrin (0.1 mg/kg) were found in Rocket, carbaryl (0.92 mg/kg) in spinach and corchorus (0.116 mg/kg), permethrin (total cis + trans permethrin) inlettuce (0.103 mg/kg) and coriander (0.126 mg/kg), and cypermethrin in parsley (0.126 ppm). The highest maximum residue limit (MRL) values of pesticide residues on leafy vegetables of 0.10 mg/kg were observed for carbaryl in Spinach and Corchorus, whereas in Parsley an MRL of 0.5 mg/kg was found. The current research shows that in some leafy vegetables, higher doses of pesticides were found.

scholarly journals Size Matters: Biological and Food Safety Relevance of Leaf Damage for Colonization of Escherichia coli O157:H7 gfp+

2021 ◽  
Vol 11 ◽  
Author(s):  
Emina Mulaosmanovic ◽  
Sofia T. Windstam ◽  
Ivar Vågsholm ◽  
Beatrix W. Alsanius
Keyword(s):  
Food Safety ◽  
Leaf Area ◽  
Plant Tissue ◽  
Spinacia Oleracea ◽  
Leafy Vegetables ◽  
Leaf Damage ◽  
Post Inoculation ◽  
Depth Of Invasion ◽  
Damage Level ◽  
E Coli

This study examined the biological and food safety relevance of leaf lesions for potential invasion of food pathogens into the plant tissue (internalization). This was done by determining the role of artificial leaf damage in terms of damaged leaf area on proliferation of E. coli O157:H7 gfp+. In a two-factorial experiment, unwashed fresh baby leaf spinach (Spinacia oleracea L.) was subjected to four damage levels (undamaged, low, moderate, high damage; factor 1) and three incubation intervals (0, 1, 2 days post-inoculation; factor 2). Individual leaves were immersed for 15 s in a suspension loaded with E. coli O157:H7 gfp+ (106 CFU × mL–1). The leaves were analyzed individually using image analysis tools to quantify leaf area and number and size of lesions, and using confocal laser scanning and scanning electron microscopy to visualize leaf lesions and presence of the introduced E. coli strain on and within the leaf tissue. Prevalence of E. coli O157:H7 gfp+ was assessed using a culture-dependent technique. The results showed that size of individual lesions and damaged leaf area affected depth of invasion into plant tissue, dispersal to adjacent areas, and number of culturable E. coli O157:H7 gfp+ directly after inoculation. Differences in numbers of the inoculant retrieved from leaf macerate evened out from 2 days post-inoculation, indicating rapid proliferation during the first day post-inoculation. Leaf weight was a crucial factor, as lighter spinach leaves (most likely younger leaves) were more prone to harbor E. coli O157:H7 gfp+, irrespective of damage level. At the high inoculum density used, the risk of consumers’ infection was almost 100%, irrespective of incubation duration or damage level. Even macroscopically intact leaves showed a high risk for infection. These results suggest that the risk to consumers is correlated with how early in the food chain the leaves are contaminated, and the degree of leaf damage. These findings should be taken into account in different steps of leafy green processing. Further attention should be paid to the fate of viable, but non-culturable, shiga-toxigenic E. coli on and in ready-to-eat leafy vegetables.

Sign in / Sign up

Export Citation Format

Share Document