Effect of Irradiance and Temperature on Composition of Spinach

Gent, Martin P.N.

doi:10.21273/hortsci.51.2.133

Cited by 14 publications

(23 citation statements)

References 31 publications

(55 reference statements)

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“…This may be due to the effect of temperature on metabolism of sugars in spinach. Sugars in petioles tended to decrease with temperatures up to 20°C (Gent, 2016). We saw no effect on RGR of EC, which only varied between 1.0 and 1.4 dS · m -1 in the spinach experiments.…”

Section: Discussioncontrasting

confidence: 52%

“…Leaf area index and NDLI were two parameters that were related to the size of the plants. As shown in studies of the effect of irradiance on composition of lettuce and spinach, NDLI accounted for a large part of the effect of size on plant growth (Gent, 2014(Gent, ,2016 The correlation between RGR and these variables varied from -0.18 for leaf area index to 0.55 for NDLI ( Table 2). The highest covariation among the variables used to predict RGR was between solution and air temperature.…”

Section: Resultsmentioning

confidence: 88%

“…Except for nitrate, metabolite concentrations on a fresh weight basis increased with irradiance, and the changes in sugars due to irradiance were greater when plants were harvested in the afternoon rather than in the morning. The NDLI also explained much of the variation in composition of spinach (Gent, 2016). However, unlike in lettuce, sugars in spinach decreased more with an increase in temperature than expected from NDLI.…”

mentioning

confidence: 79%

“…Previously, I studied the effects of environment on composition of metabolites in lettuce and spinach (Gent, 2014(Gent, , 2016. In lettuce, much of the variation in tissue composition on a fresh weight basis was related to NDLI (Gent, 2014).…”

mentioning

confidence: 99%

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Factors Affecting Relative Growth Rate of Lettuce and Spinach in Hydroponics in a Greenhouse

Gent¹

2017

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Relative growth rate (RGR), the relative increase in weight per day, can analyze the effect of environment and nutrition on growth. I examined which of the parameters responding to plant growth scaled according to RGR for lettuce and spinach grown in heated greenhouses in hydroponics with control of the nutrient solution. The experiments for lettuce in 2006–08 included all times of year, high vs. low temperature, and effect of withdrawal of nitrogen. There were four parameters that were significant in multiple linear regression vs. RGR; irradiance divided by leaf area index if it was greater than one, or normalized daily light integral (NDLI), solution temperature, electrical conductivity (EC), and logarithm solution nitrate when it was between 3 and 55 mg·L−1 N. NDLI had the most significant coefficient, but the other parameters had regression coefficients more than three times se. For experiments on spinach in 2009–10, all the parameters mentioned previously were significant in multiple linear regression vs. RGR, except EC. The coefficient for NDLI in spinach was about half the value in lettuce. The coefficients for solution temperature and low nitrate were two and three times that in lettuce. In a third set of experiments on lettuce in 1996–98, solution temperature was the only significant parameter among those mentioned previously. The coefficient for solution temperature was similar to that for regression of lettuce in 2006–08.

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Section: Discussioncontrasting

confidence: 52%

Section: Resultsmentioning

confidence: 88%

mentioning

confidence: 79%

mentioning

confidence: 99%

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Factors Affecting Relative Growth Rate of Lettuce and Spinach in Hydroponics in a Greenhouse

Gent¹

2017

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“…Arugula, spinach, lettuce, and escarole are vegetables that are eaten raw, are species with a tendency to accumulate high concentrations in the leaves and ribs, and have no restrictions on daily intake (Cometti et al, 2011;Gent, 2016). Beetroot and radish are also considered root vegetable sources of nitrates (European Food Safety Authority, 2008).…”

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confidence: 99%

Effect of the Intensity and Spectral Quality of LED Light on Yield and Nitrate Accumulation in Vegetables

Nájera¹,

Urrestarazu²

2019

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At present, trends exist in the production of food for the benefit of human health. The negative effect of an excessive intake of nitrates accumulated in vegetables is well known, causing worldwide concern. Light plays an important role in the accumulation of this ion. The objective of this work was to evaluate the effect of light-emitting diode (LED) spectra used in artificial lighting for horticulture on the accumulation of nitrates in leafy and root vegetables compared with the effects with white LED lights. Two independent experiments were carried out in the culture chamber. In Expt. 1, six species of nitrate accumulators were used: arugula, spinach, lettuce, endive, radish, and beetroot. In Expt. 2, four lettuce cultivars were used. In both experiments, the treatments were two spectra—T1 = AP67 Valoya® and the control (T0) = white Roblan®—at two illumination intensities [high (H) and low (L)] with a 16/8-hour (day/night) photoperiod. The fresh biomass and the concentration of nitrates were measured at 35 days of treatment posttransplantation. An important and significant increase of 50% of the mean fresh weight was obtained in all the species when the light intensity increased. Except for spinach in the low-intensity treatment, all nitrate content values were less than the maximum limits of European regulation. The nitrate content generally decreased with increasing intensity, and this benefit was greater in the T1 treatment. T0 showed a reduction in the nitrate content compared with T1 in only one case, which was the H in beetroot. A large and significant reduction was observed in the nitrate content in T1. For L in Expt. 1, the nitrate decrease was 18%, whereas for H, it was 35%. In Expt. 2, the decrease in the nitrate content was 10% for L and 21% for H. A greater benefit was derived when using the photosynthetic spectrum in the growing chambers under low light intensity.

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Nitrogen fertilization strategies to reduce the risk of nitrate leaching in open field cultivation of spinach (Spinacia oleracea L.)^#

Frerichs

Key

Broll

et al. 2022

J. Plant Nutr. Soil Sci.

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Background Spinach is a nitrogen (N) demanding crop with a weekly N uptake of up to 60 kg ha–1. Consequently, a high N supply is required, which can temporarily lead to high quantities of nitrate (NO3–) being at risk of leaching. Aims The objective of this study was to develop a N fertilization approach to reduce the risk of NO3– leaching in field‐grown spinach production without adversely affecting crop yield and quality at an early and late harvest stage. Methods Ten fertilization trials were conducted to compare different base fertilization rates and splits of top dressings. For top dressings, granulated fertilizers or foliar sprays were used. In a further treatment, N supply was reduced by withholding the second top dressing of 50–70 kg ha−1. Results Nitrate concentration at risk of leaching was considerably reduced by decreasing the base fertilizer rate as well as by splitting the top dressing. However, at an early harvest stage, total aboveground dry mass was reduced by, on average, 6% by these measures across all seasons. In contrast, at a later harvest stage, spinach was less affected by the fertilizer schedule. Urea foliar sprays proved to be insufficient in promoting plant growth and caused leaf necrosis. A reduced N supply led to impaired plant growth and yellowish leaves in both spring and winter. Conclusions Base N fertilization of spinach is only required in spring, but not in other seasons. Despite slight yield reduction, the top dressing should be split to reduce the risk of NO3− leaching after an early harvest.

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Effect of Irradiance and Temperature on Composition of Spinach

Cited by 14 publications

References 31 publications

Factors Affecting Relative Growth Rate of Lettuce and Spinach in Hydroponics in a Greenhouse

Factors Affecting Relative Growth Rate of Lettuce and Spinach in Hydroponics in a Greenhouse

Effect of the Intensity and Spectral Quality of LED Light on Yield and Nitrate Accumulation in Vegetables

Nitrogen fertilization strategies to reduce the risk of nitrate leaching in open field cultivation of spinach (Spinacia oleracea L.)^#

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Effect of Irradiance and Temperature on Composition of Spinach

Cited by 14 publications

References 31 publications

Factors Affecting Relative Growth Rate of Lettuce and Spinach in Hydroponics in a Greenhouse

Factors Affecting Relative Growth Rate of Lettuce and Spinach in Hydroponics in a Greenhouse

Effect of the Intensity and Spectral Quality of LED Light on Yield and Nitrate Accumulation in Vegetables

Nitrogen fertilization strategies to reduce the risk of nitrate leaching in open field cultivation of spinach (Spinacia oleracea L.)#

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Product

Resources

About

Nitrogen fertilization strategies to reduce the risk of nitrate leaching in open field cultivation of spinach (Spinacia oleracea L.)^#