Overview of a Lab-scale Pilot Plant for Studying Baby Leaf Vegetables Grown in Soilless Culture

Abstract

Investigating several environmental factors affecting plant growth implies having sound experimental facilities equipped to test individual factors in lab-scale although applicable later at the industrial scale. Sometimes, detailed information is hardly given in a manuscript that allows for replications by other authors, maybe due to the shortening of pages requested by journal publishers and editors. A system and methodology was developed for qualitative and quantitative analyses of baby leaf vegetables (BLV) raised in floating growing systems (FGS). Lab-scale pilot plants (LSPP) were developed in 2 greenhouses differing in structure and equipment, suitable for different growing seasons in a continental climate. The equipment and technology allowed multiple treatments and replicates for sound statistical design and data analyses. Environmental conditions and cultural techniques were studied in major and minor species (white mustard, Brassica alba L. Boiss; black mustard, Brassica nigra L. Koch; garden cress, Lepidium sativum L.; water cress, Nasturtium officinale R. Br.; rocket salad, Eruca sativa Mill.; perennial wild rocket, Diplotaxis tenuifolia L. DC.; corn salad, Valerianella olitoria L.; baby spinach, Spinacia oleracea L.) to determine best cultivation techniques in a standard soilless culture system (SCS) for BLV, based on FGS. Considering that SCS can improve raw material quality at harvest, and enhance the postharvest shelf-life of many vegetables and herbs, a standardized growing system is required to obtain premium quality raw material in terms of commercial stage, low nitrate content and long shelf-life. Among the SCS used, the FGS are suitable systems to grow leafy vegetables because the plants can grow at high densities, thereby producing high yields, and in a short time. FGS are based on sub-irrigation technology, avoiding over-head irrigation and contact between nutrient solution and edible parts, and result in greater qualitative and quantitative yields than the traditional cultivation techniques, reducing pollution, crop and substrate residues, leading to clean raw material with potential low microbiological load. The FGS is a modern technology that could be exploited more to enhance yield, quality and safety of fresh and fresh-cut BLV. The LSPP installed are providing the basis for expanding the research to other species and agronomic factors.

Mixing fresh-cut baby green and red leaf lettuce from soilless cultivation preserves phytochemical content and safety

“…The growing systems, such as soilless culture systems (SCS), used in protected cultivations, have partially replaced traditional culture systems (TCS) in soil. Floating growing systems (FGS) can be implemented in SCS with continuous flotation (FL), that is, with trays floating continuously on a bed of water or on a hydroponic nutrient solution (HNS), or with ebb and-flow flotation system, in this way scheduling the drying period for species suffering from root hypoxia (Nicola et al 2015(Nicola et al , 2016. Tissue ions accumulation can easily be controlled with SCS by varying the N-ratio in the HNS or its composition.…”

Classification and Screening of Baby-leaf Vegetables on the Basis of Their Yield, External Appearance and Internal Quality

“…Very little technical information is available on the cultivation of baby-leaf vegetables in Japan, although there are some guidelines and reports in North America and Europe (Grahn et al, 2015a;Nicola et al, 2016). As far as agricultural practices are concerned, it is important to standardize the crop cycles in order to simultaneously harvest several different crops with the optimal timing: an early harvest leads to a low yield, while a late harvest leads to a non-commercial leaf size, as leaves become larger and older and are considered outside the category of "baby-leaf" vegetables.…”

“…"Baby-leaf vegetables" is a new category of leafy vegetables that are used in juvenile stage mixtures of baby-leaf vegetable production in Japan was much smaller than in the USA (more than 110,000 metric tons) in 2008 (Hardesty, 2015) and in Europe (303,000 metric tons in Italy, the UK, France, and Germany) in 2015 (Nicola et al, 2016). However, the distribution of baby-leaf vegetables in the Tokyo Metropolitan Central Wholesale Market has been increasing over the years, and the market is expected to grow to 30 billion yen, that is, Japanese consumers will consume the same volume as Europeans (50 g per capita) (Sato, 2016).…”

A Semi-Systematic Review of Capillary Irrigation: The Benefits, Limitations, and Opportunities

“…A number of researchers have experimented with different NPDI setups and studied their suitability in terms of crop growth and water savings [39][40][41][42]. In an NPDI system, the reservoir is placed at a lower level than the root zone and the water moves through a supply tube linking both the reservoir and the plant pot.…”