Loose Leaf Lettuce Quality Grown in Two Production Systems

Abstract

Horticultural crops have a strong impact on human nutrition. Lettuce is the most important leafy vegetable in Argentina and it is cultivated mainly in green belts, in greenhouses or open field. The aim of this study was to evaluate growth and phytonutrients concentration of leaf lettuce under greenhouse and field production. Crop establishment was made from seedlings produced in a commercial greenhouse. Loose lettuce cv. Brisa was used for field and greenhouse growth. Experimental design with complete random block with 4 replicates per treatment was used. Fresh and dry weights of shoot, number of leaves, color, ascorbic acid, chlorophyll content were measured. Absolute and relative growth rate and commercial yield were calculated. Lettuce grown under greenhouse system showed, as expected, a higher value of fresh and dry weight, number of leaves, leaf area, yield and absolute and relative growth rate. Ascorbic acid value of the leaves decreased during lettuce growth in both production systems. Chlorophyll content was higher in the greenhouse cultivation but the antioxidant capacity was lower in lettuce leaves from greenhouse than the leaves grown on open field.

Predictive Model to Evaluate Water and Nutrient Uptake in Vertically Grown Lettuce under Mediterranean Greenhouse Conditions

“…All the mean values of water content were within the general range published for the lettuce crop (90-99%) [80], being the more common value [81]. Likewise, they were close to the values informed for lettuce in the HHG (94-95%) [75,82,83] and the VHS systems (97%) [78].…”

“…The LD system had a mean of 74.3 t•ha −1 , 61% higher than the top limit of the range reported for lettuce in HHG (12-46 t•ha −1 ) [66,75,82,84], roughly 20 times more than the yield of the OFS systems, 3.73 t•ha −1 , noted by Barbosa et al [66], 55% higher than the value published by Orsini et al for urban agriculture, 48 t•ha −1 [18], and two times higher than the value described by Voutsinos et al for a PFAL (19-37 t•ha −1 ) [44], but 20% lower than the bottom limit of the range reported for VHS (93-125 t•ha −1 ) [78], which requires high energy input, while the yield of the HD vertical crop was 40% higher than that of lettuce in HHG, 17 times higher than that of the OFS, 34% higher than urban agriculture, 74% higher than that of a PFAL, but 31% lower than the VHS. The average value of the low level in the HD was within the range for lettuce in HHG, and the medium level was closer to the value reported for urban agriculture since it differed by only 20%; the mean value of the upper level in the HD was within the VHS range, and the mean values of the PP levels in the LD were closer to the VHS range since the difference was between 7 and 27%.…”

Efecto multivariado de mezclas de fertilizantes orgánicos e inorgánicos sobre el crecimiento de Lactuca sativa L.

“…Statistics has become a fundamental tool for all areas of knowledge (Diggle, 2015;Gupta et al, 2018;Jalajakshi & Myna, 2022;Weihs & Ickstadt, 2018), especially in agriculture (Bender, 2020), however, it needs to be rigorously applied to avoid misinterpretation or confusion. In our research, we employed a multivariate analysis to evaluate the effect of the variables number of leaves and height of L. sativa L., a widely cultivated vegetable and on which several studies have been conducted on its cultivation (Muscolo et al, 2022;Travieso et al, 2016), physiology (Tang et al, 2015;Zhao et al, 2022) and hydroponics (Jung & Kim, 2020;Lei & Engeseth, 2021). Table 1 displays the growth of L. sativa L. in relation to the number of leaves.…”

Life Cycle Assessment of Leafy Vegetable Consumption in Urban Taipei, Taiwan

“…Protected cultivation can overcome the disadvantages of open-field cultivation. In protected cultivation, fresh weight, dry weight, leaf number, and chlorophyll content of leafy vegetables can be increased, thus enhancing yield [4], [5]. However, the production cost of protected cultivation is much higher than that of open-field cultivation; such costs include capital used to construct facilities, the replacement cost of consumables such as plastic cloth, and the energy cost of lamps inside greenhouses.…”