As a new specialty crop with high market value, microgreens are vegetable or herb seedlings consumed at a young age, 7–21 days after germination. They are known as functional food with high concentrations of mineral nutrients and health beneficial phytochemicals. Microgreen industry lacks standardized recommendations on cultural practices including species/variety selection, substrate choice, and fertilization management. This study evaluated shoot growth and mineral nutrient concentrations in five microgreens including four Brassica and one Raphanus microgreens as affected by four hydroponic pad types and post-emergent fertilization in two experiments in January and February 2020. The five microgreens varied in their shoot height, fresh, dry shoot weights, and mineral nutrient concentrations with radish producing the highest fresh and dry shoot weights. Radish had the highest nitrogen (N) concentration and mustard had the highest phosphorus (P) concentrations when grown with three hydroponic pads except for hemp mat. Hydroponic pad type altered fresh, dry shoot weights, and mineral nutrients in tested microgreens. Microgreens in hemp mat showed the highest shoot height, fresh, dry shoot weights, and potassium (K) concentration, but the lowest N concentration in one or two experiments. One time post-emergent fertilization generally increased shoot height, fresh, dry shoot weights, and macronutrient concentrations in microgreens.

Microgreens have become an important specialty crop valued for their varying texture, vibrant colors, and nutrient-dense features. As the number of species and cultivars rapidly increases for microgreen production, fertigation requirements in relation to shoot production and nutrient composition remain unclear. This study aimed to investigate the shoot yield, visual quality, and mineral nutrient concentrations of five microgreens in the Brassicaceae family, including the ‘Waltham’ broccoli, ‘Red Acre’ cabbage, Daikon radish, ‘Red Russian’ kale, and Rambo radish, in two experiments conducted in December 2020 and January 2021. Each microgreen was fertigated with 120 mL of fertilizer solution daily for five consecutive days at a concentration of 0, 70, 140, 210, or 280 mg·L⁻¹ nitrogen (N) using a general-purpose fertilizer. Broccoli and Daikon radish produced the highest fresh shoot weights among the microgreen cultivars in both experiments. Fertigation rates of 140, 210, and 280 mg·L⁻¹ N resulted in similar fresh and dry shoot weights for the selected microgreens, suggesting that 140 mg·L⁻¹ N should be sufficient for microgreen fertilization. The mineral nutrients in microgreens varied among cultivars, with cabbage microgreens having the highest calcium (Ca) concentration in both experiments. Kale and Rambo radish contained higher concentrations of iron (Fe) and manganese (Mn) than other cultivars in December 2020. The fertigation rate affected macronutrient concentrations, but did not affect micronutrient concentrations, including Fe, Mn, and zinc (Zn).

Peppers (Capsicum annuum) are one of the most widely cultivated vegetable crops, with per capita consumption of bell and chile peppers being 11.4 and 7.7 pounds in 2017. Biostimulants are an emerging sustainable alternative to enhance plant health by increasing photosynthetic activity, stress tolerance, and nutrient uptake through various modes of action. The effects of different biostimulant applications largely remain unknown in containerized heirloom pepper production. This study evaluated plant growth, yield, and fruit quality of nine heirloom chile pepper cultivars, including ‘Anaheim Chili,’ ‘Ancho or Poblano,’ ‘Big Jim,’ ‘Cayenne Purple,’ ‘Chile de Arbol,’ ‘Jamaica Hot Red,’ ‘Mulato Isleno,’ ‘Padron,’ and ‘Pasilla Bajio’ in a container production system throughout the years of 2020 and 2021. Each cultivar was treated with three types of biostimulants, including Tribus^® Original (a mixture of Bacillus bacterias), Vitazyme (containing plant growth regulators and B vitamins), C-Bio CPS (seaweed extract of Ascophyllum Nodosum), and water as control. Pepper cultivars varied in yield and quality, including fruit length, diameter, single fruit weight, and fruit color in both years. ‘Anaheim Chili,’ ‘Big Jim,’ and ‘Jamaica Hot Red’ produced highest marketable yields similarly, with ‘Chile de Arbol’ and ‘Pasilla de Bajio’ producing the lowest marketable yields in both years. Biostimulant application did not affect marketable yield either in 2020 or 2021 but enhanced fruit quality, including fruit length, diameter, and green coloration.

Microgreens are nutrient-dense foods rich in mineral nutrients and health-benefiting phytochemicals. They are a popular specialty crop with a rapidly increasing industry in the United States (U.S.A.) and worldwide. However, there is a lack of research-based recommendations regarding the feasibility of using hydroponic fiber mats in the production of herbal microgreens and their effects on yield, quality, and nutritional composition. This study assessed shoot development, yield, visual quality, and mineral composition of five herbal microgreen species, including basil, chives, dill, leek, and parsley when grown with four types of hydroponic fiber mats (BioStrate, hemp, jute, and MicroMat) and affected by a single post-emergent fertigation in two experiments. The five microgreens varied in yield, quality, mineral nutrient composition, and their response to substrate type. Chives microgreens produced the highest fresh and dry shoot weights among species when grown with BioStrate, jute, and MicroMat in both experiments. The four substrate types resulted in similar fresh and dry shoot weights in leek and parsley microgreens in both experiments. However, BioStrate and MicroMat increased fresh and dry shoot weights in chives in December compared with hemp or jute mats. Jute resulted in higher fresh and dry shoot weights in basil in both experiments compared with MicroMat. The fiber mats altered mineral nutrient concentrations in tested microgreen species. Hemp mats increased potassium concentrations in basil and dill, while jute mats produced the highest Fe concentrations in the two species and the highest Mn concentration in basil in both experiments. A single post-emergent fertigation increased shoot height and increased concentrations of nitrogen, phosphorus, potassium, sulfur, iron, zinc, manganese, and boron in one or both experiments.

Tomatoes (Solanum lycopersicum) are not only one of the most widely grown and consumed vegetables in the U.S., but are also one of the most economically important vegetables for Mississippi growers operating on small- to medium-sized farms. High tunnel production and vegetable grafting serve as effective approaches to provide season extension and improve productivity and resistance to a number of abiotic and biotic factors for tomato plants. Six tomato cultivars, including three hybrids (‘Big Beef’, ‘Early Girl’, and ‘Sun Sugar’) and three heirlooms (‘Brandywine’, ‘Mortgage Lifter’, and ‘San Marzano’), were evaluated for plant growth, fruit yield, and quality in a containerized high tunnel production system in 2020. Each cultivar was grafted onto two types of interspecific hybrid rootstocks ‘Emperador’, or ‘Maxifort’, or grown non-grafted as control. ‘Big Beef’ and ‘Early Girl’ produced comparable highest marketable yields of 9.62 to 11.12 kg per plant, compared with ‘San Marzano’ and ‘Sun Sugar’ producing the lowest marketable yields of 3.27 to 4.76 kg per plant due to small fruit sizes. Grafting the selected tomato cultivars with the two rootstock types did not alter total marketable yield of any cultivar, but affected overall stem diameter, fruit color, and β-carotene concentrations. The rootstock ‘Emperador’ decreased soluble solids content and titratable acidity in ‘Early Girl’ compared to ‘Maxifort’ grafted or non-grafted plants. The high tunnel enabled early transplanting and resulted in advanced tomato harvest by approximately three to four weeks compared to local field production.

Seed priming has been widely used as a strategy to improve germination and promote uniform seedling growth in horticultural crops, yet its application in microgreen production remains relatively underexplored. This study evaluated the impact of four priming treatments—hydrogen peroxide, Kelpak Maxx (a seaweed extract), Continuum^TM (a beneficial bacterial biostimulant), and hydropriming—on the germination, shoot growth, visual quality, coloration, and mineral nutrient composition of four herbal microgreen species compared with untreated raw seeds as a control treatment. Four species—chives (Allium schoenoprasum), dill (Anethum graveolens), scallion (Allium fistulosum), and shiso (Perilla frutescens)—were produced as microgreens under greenhouse conditions in two experiments in 2024 and 2025. Results revealed that early germination percentages at 3 days after treatment (DAT) in dill were increased by Kelpak Maxx, Continuum, and hydropriming by 11–18% in 2024 and by 20–40% in 2025, compared with increases for the control of 1% in 2024 and 5% in 2025. Germination percentages at 7 DAT in chives, scallion, and shiso all exceeded 88%, which were similar among priming treatments in 2024 and were not affected by priming in 2025. The four priming treatments resulted in similar fresh and dry shoot weights in chives, scallion, and shiso, but decreased fresh shoot weights in dill by 48.6% in 2024 and by 26.2% in 2025 compared with the control treatment. Species varied in mineral nutrient compositions. Priming altered concentrations of potassium, sulfur, magnesium, boron, and copper in certain species, but otherwise had minimal effects on mineral nutrient concentrations. Seed priming may potentially be used to enhance germination in slow-germinating species; however, it did not consistently improve shoot yield or mineral nutrient concentrations in the four tested microgreen species.