Yield and Postharvest Quality of Lettuce in Response to Nitrogen, Phosphorus, and Potassium Fertilizers

Abstract

<jats:p>Commercial lettuce production requires adequate levels of nitrogen (N), phosphorus (P), and potassium (K) to provide high-quality postharvest attributes needed for longer shelf life. Factorial experiments were conducted in Salinas, CA, to evaluate yield and postharvest quality of both romaine and iceberg lettuce using fertilizers containing various levels of N, P, and K. Lettuce was evaluated for yield and postharvest quality parameters, including color, wilt, turgidity, glossiness, decay, brittleness, fringe burn, and salt burn. Uptake of N, P, K, calcium, and silicon by plants was also determined. Regardless of fertilizer treatment, shelf life and visual quality were better in the iceberg lettuce than romaine lettuce when cold-stored at 1 °C for 14 d. Yield increased with increased N application rate, but post-harvest quality fell at high levels of N (337 kg·ha<jats:sup>−1</jats:sup>) and P (225 kg·ha<jats:sup>−1</jats:sup>). The most economical treatment providing the highest yield and best post-harvest quality was the combination of 225 kg·ha<jats:sup>−1</jats:sup> N and 112 kg·ha<jats:sup>−1</jats:sup> P.</jats:p>

Lettuce Biomass Accumulation and Phytonutrient Concentrations Are Influenced by Genotype, N Application Rate and Location

“…However, the flavonoid Q-3-G was significantly increased with elevating N application rate and was present in the highest concentration under the 189 kg·ha −1 N treatment and lowest in the 42 kg·ha −1 N treatment. Consequently, Hoque et al [9] demonstrated that increasing levels of N ranging from 0 to 337 kg·ha −1 significantly increased lettuce yields. Thus, there have been mixed results when examining the effect of N on lettuce yields.…”

“…Previous studies have indicated that damage incurred by heat stress may be mitigated by volumes and timing of nutrient applications [9]. Nitrogen (N) is a primary, essential plant nutrient that serves many functions in plant metabolism, such as photosynthesis, production of enzymes, and energy relations [10].…”

Lettuce (Lactuca sativaL.) growth, yield and quality response to nitrogen fertilization in a non-circulating hydroponic system

“…The strong positive effect of N fertilization on leaf area development can be beneficial in commercial production of leafy vegetables such as spinach and lettuce. Hence, it is often suggested that high N supply rates are needed to ensure maximum yields (Carling et al, 1987;Hoque et al, 2010). However, some studies have demonstrated that optimum yields can be achieved with relatively lower N application rates (Soundy and Smith, 1992).…”

Influence of nutrient solutions in an open‐field soilless system on the quality characteristics and shelf life of fresh‐cut red and green lettuces (Lactuca sativa L.) in different seasons

“…Although some reports indicate that nutrients can affect lettuce quality,, , limited studies are available about their effect on lettuce production in soilless systems in open field and post‐harvest quality, particularly for fresh‐cut lettuces , . It is well known that the quality of the raw material has to be excellent to ensure excellent quality of the fresh‐cut product.…”

“…The results show that an increase in electrical conductivity (EC) improves quality and shelf life of baby lettuces, 14 increases leaf mineral content 13 and reduces the activities of oxidative enzymes. 15 Although some reports indicate that nutrients can affect lettuce quality, 2,16,17 limited studies are available about their effect on lettuce production in soilless systems in open field and postharvest quality, particularly for fresh-cut lettuces. 18,19 It is well known that the quality of the raw material has to be excellent to ensure excellent quality of the fresh-cut product.…”