The practice of producing vegetables on green roofs has been gaining momentum in recent years as a method to facilitate agricultural sustainability in urban areas. Rooftop gardens are becoming an important part of the recent rejuvenation of urban agriculture, and offers alternative spaces to grow vegetable products for urban markets. Green roofs create spaces for the production of vegetable crops, which then generate opportunities for integrating agriculture into urban communities. However, vegetable production activities on rooftops are currently minimal due to multiple challenges that must be overcome before widespread implementation will occur, and these are presented and discussed herein in great detail. Although intensive green roof systems (>15 cm medium depths) are thought to be most suited for vegetable production, the greatest potential for sustained productivity is probably through extensive systems (<15 cm depths) due to weight load restrictions for most buildings. Thus, shallow-rooted vegetables that include important salad greens crops are thought to be the most suited for extensive systems as they can have high productivity with minimal inputs. Research presented herein agree that crops such as lettuce, kale and radish can be produced effectively in an extensive green roof medium with sufficient nutrient and moisture inputs. Other research has indicated that deeper-root crops like tomato can be produced but they will require constant monitoring of fertility and moisture levels. Vegetable production is a definite possibility in urban areas on retrofitted green roofs using minimal growing substrate depths with intensive seasonal maintenance. Rooftop agriculture can improve various ecosystem services, enrich urban biodiversity and reduce food insecurity. Food production provided by green roofs can help support and sustain food for urban communities, as well as provide a unique opportunity to effectively grow food in spaces that are typically unused. The utilization of alternative agricultural production systems, such as green roof technologies, will increase in importance as human populations become more urbanized and urban consumers become more interested in local foods for their families. Although cultivation of food on buildings is a key component to making cities more sustainable and habitable, green roofs are not the total solution to provide food security to cities. They should be viewed more as a supplement to other sources of food production in urban areas.

Since weed management is such a critical component of agronomic crop production systems, herbicides are widely used to provide weed control to ensure that yields are maximized. In the last few years, herbicide-resistant (HR) crops, particularly those that are glyphosate-resistant, and more recently, those with dicamba (3,6-dichloro-2-methoxybenzoic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) resistance are changing the way many growers manage weeds. However, past reliance on glyphosate and mistakes made in stewardship of the glyphosate-resistant cropping system have directly led to the current weed resistance problems that now occur in many agronomic cropping systems, and new technologies must be well-stewarded. New herbicide-resistant trait technologies in soybean, such as dicamba-, 2,4-D-, and isoxaflutole- ((5-cyclopropyl-4-isoxazolyl)[2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone) resistance, are being combined with glyphosate- and glufosinate-resistance traits to manage herbicide-resistant weed populations. In cropping systems with glyphosate-resistant weed species, these new trait options may provide effective weed management tools, although there may be increased risk of off-target movement and susceptible plant damage with the use of some of these technologies. The use of diverse weed management practices to reduce the selection pressure for herbicide-resistant weed evolution is essential to preserve the utility of new traits. The use of herbicides with differing sites of action (SOAs), ideally in combination as mixtures, but also in rotation as part of a weed management program may slow the evolution of resistance in some cases. Increased selection pressure from the effects of some herbicide mixtures may lead to more cases of metabolic herbicide resistance. The most effective long-term approach for weed resistance management is the use of Integrated Weed Management (IWM) which may build the ecological complexity of the cropping system. Given the challenges in management of herbicide-resistant weeds, IWM will likely play a critical role in enhancing future food security for a growing global population.

Vermicomposts (VC) improve plant growth and development beyond that normally observed from just soil nutrient transformation and availability. These increases in plant productivity have been attributed to improved soil structure and soil microbial populations that have higher levels of activity and greater production of biological metabolites, such as plant growth regulators. Although there have been many studies on the benefits of VC as a fertilizer source, little research has focused on the effects and/or interactions of soil type and VC application rates on vegetable crop productivity. This paper identifies optimum application rate(s) of VC on tomato growth responses for three different textural classes of soils (loamy sand, silt loam, and silty clay). Soils with high VC rates (0.4 and 0.8 g/g) produced taller plants with more leaf and flower numbers, higher leaf chlorophyll content, greater plant biomass, and more total leaf area compared to soils with low VC rates (0.05, 0.1, and 0.2 g/g). Tomato growth increases were also observed at the low VC soil amendment rates compared to the nontreated control. Tomatoes grown in the sandy soil amended with VC generally had the greatest growth responses (plant height, leaf and flower number, and leaf chlorophyll content) compared to the clay or silt loam soils, with the silt loam soil generally providing the least response. This research indicated that VC is a suitable alternative fertilizer for tomato, with approximately 0.5–0.6 g/g VC added to soil resulting in optimal tomato plant growth. Moreover, this rate provided tomato growth results similar to the standard inorganic fertility program. The sandy soil with VC amendments generally increased tomato plant growth parameters the most compared to the clay and loam soils, with the loam soil generally providing the least.

Horseradish ( Armoracia rusticana ) is a hardy perennial that is grown for its white, fleshy, and pungent roots. Illinois leads the United States in production of horseradish, with ≈1500 acres and an annual farm-gate value of about $10 million, with most processed and added as an ingredient to various commercially produced condiments. Horseradish in Illinois is primarily grown in the Mississippi River Valley region adjacent to St. Louis due to the well-drained, deep friable, high organic matter, moist loam soils that are present in this area. Most of the production is located in Madison and St. Claire counties. This region of southwestern Illinois has been producing horseradish commercially for over 150 years. This review provides an overview of the basics of horseradish production in Illinois, including propagation, cultivars, planting, cultivation, fertilization, pest management, harvest, grading, storage, and marketing. Horseradish is one of the most important specialty crops grown in Illinois, and current and future production concerns are also discussed.

Crop domestication and breeding efforts during the last half-century in developed countries has significantly reduced the genetic diversity in all major vegetable crops grown throughout the world. This includes developing countries such as Morocco, in which more than 90% of all farms are less than 10 ha in size, which are generally maintained by subsistence farmers who try to maximize crop and animal productivity on a limited land area. Near Agadir, in the remote Anti-Atlas mountain areas of the Souss-Massa region, many small landowner vegetable growers are known to still utilize crop populations (landraces). Thus, an assessment of the current status of vegetable landraces was made in this mountainous region of Southwestern Morocco during 2014. This assessment indicated that a significant loss of vegetable crop landraces has occurred in the last 30 years in this region of Morocco. Although many vegetable crops are still maintained as landrace populations by small subsistence farmers in remote areas in the Souss-Massa region, only 31% of these farmers cultivated landraces and saved seed in the villages assessed, with the average farmer age cultivating landraces being 52 years old. Moreover, the approximated loss of vegetable crop landraces over the last 30 years was an astounding 80 to 90%. Vegetable crops notably lost during this time period included carrot (Daucus carota), fava beans (Vicia faba), melon (Cucumis melo), pea (Pisum sativum), watermelon (Citrullus lanatus), and tomato (Solanum lycopersicon). The most significant loss was tomato as no landraces of this crop were found in this region. The vegetable crop landraces that are still widely grown included carrot, melon, onion (Allium cepa), turnip (Brassica rapa var. rapa), and watermelon, while limited amounts of eggplant (Solanum melongea), fava bean, pea, pepper (Capsicum annuum), and pumpkin (Cucurbita moshata and C. maxima) were found. This recent genetic deterioration will have a profound influence on future Moroccan agricultural productivity, as the genetic diversity within these landraces may be the only resource available to allow these smaller subsistence farmers to cope with changing environmental conditions for the optimization of crop production in their harsh climate.

During the 1999 and 2000 growing seasons in Illinois, studies were conducted to determine the influence of two pollinizers (`Crimson Sweet' and `Fiesta') and three pollinizer frequencies (11%, 20%, and 33%) on `Millionaire' seedless watermelon ( Citrullus lanatus ) quality and yields. More large-sized [>16 lb (7.2 kg)] `Millionaire' watermelons were produced when `Crimson Sweet' was used as the pollinizer compared to `Fiesta', which resulted in `Crimson Sweet' leading to greater marketable and total `Millionaire' yields. Pollinizers responded similarly over the pollinizer frequencies for `Millionaire' watermelon yields as no pollinizer by pollinizer frequency interaction was observed. The 20% and 33% pollinizer frequencies produced similar `Millionaire' yields per acre and both resulted in greater yields compared to the 11% pollinizer frequency. Soluble solids in `Millionaire' fruits were not influenced by pollinizer or pollinizer frequency. However, hollow heart disorder followed a quadratic response with respect to pollinizer frequency with the lowest amount of hollow heart observed at the 33% pollinizer frequency and greatest at the 11% pollinizer frequency. No significant interaction ( P ≤ 0.05) was observed for pollinizer by pollinizer frequency for hollow heart disorder in `Millionaire'; although, more hollow heart disorder in `Millionaire' was observed when `Fiesta' was used as the pollinizer.