Much of coastal and southern California has a Mediterranean climate, which is characterized by cooler, wetter winters and hotter, drier summers. Only drought-resistant plant species can survive without irrigation in this type of climate. Turf grass, for example, most certainly will not survive such dry summers without irrigation. And yet in 2015, four years into the latest California drought, some homeowners in southern California continue to grow turf grass and water their lawns. See also: Drought; Irrigation (agriculture); Lawn and turf grasses; Plant-water relations

Ethylene, CH₂=CH₂, the most-produced organic chemical in the world, is used to make hundreds of products. The major product is polyethylene, but other important ones include poly(vinyl chloride), polystyrene, antifreeze (ethylene glycol), adhesives, solvents, and detergents. See also: Adhesive; Detergent; Ethylene; Ethylene glycol; Polyolefin resins; Polystyrene resin; Polyvinyl resins; Renewable resources; Solvent

Two varieties of apples that have been genetically engineered not to turn brown when cut or bruised were cleared in February and March of 2015 for growth and sale in Canada by the Canadian Food Inspection Agency (CFIA) and Health Canada (HC) and in the United States by the U. S. Department of Agriculture (USDA) and U.S. Food and Drug Administration (FDA). See also: Apple; Genetic engineering; Genetically engineered plants; Genetically modified crops

Bananas (Musa genus) are one of the world's most valuable and popular primary agricultural commodities. However, the most prevalent naturally occurring bananas, that is, those of the Cavendish variety, are being severely decimated by Panama disease in Africa, Asia, and Australia. This deadly fungal disease, which was first noted in Panama in the late 1800s, is caused by a soilborne fungus, Fusarium oxysporum f. sp. cubense (Foc), and experts fear that new strains (pathotypes) of this Fusarium wilt disease will spread throughout the Americas, leading to the ultimate demise of the Cavendish bananas. However, genetically modified Cavendish banana trees are being field tested in Australia, and they have exhibited notable resistance to the disease-inducing fungus, providing hope to plant breeders and fruit crop growers. See also: Banana; Fruit; Fruit, tree; Fungal infections; Fungi; Genetic engineering; Genetically engineered plants; Horticultural crops; Panama disease of bananas

In the future, will global demand for coffee outstrip supply? The International Coffee Organization thinks so, based on droughts in Central America, crop-destroying freezing weather in Brazil, and global climate change. In general, coffee is a very temperature- and drought-sensitive crop. Coffee is also susceptible to more than 350 known diseases. Add in the growing popularity of coffee—currently the second most consumed beverage worldwide (excluding water), after tea—and a potential coffee shortage looms. Because the coffee plant grows best high up in tropical mountain forests, cultivating more coffee plants through deforestation is not a sustainable option. To sustainably shore up the coffee supply, researchers at the Technical Research Center (VTT) in Finland have developed a process for producing coffee in the laboratory by growing the product in bioreactors. The ultimate question that the researchers had to answer was, “How does lab-grown coffee taste?” The short answer is that it tastes and smells just like natural coffee. See also: Coffee; Bioreactor; Deforestation; Extreme weather events; Global climate change; Sustainability

Marijuana is the Spanish-derived name for the dried leaves, stems, seeds, and flowering tops of the hemp plant (Cannabis sativa). For thousands of years, humans have consumed marijuana (in edible, smokeable, and vaporized forms) because of its psychoactive effects and its purported medical efficacies. Although its cultivation, distribution, and commercialization are sharply restricted or criminalized in most nations, the use of marijuana has not been eliminated. In fact, marijuana remains as the most common illicit drug in the world. See also: Brain; Cannabis; Hemp; Psychotomimetic drugs

Pesticides—including insecticides and herbicides—are chemical products used to control, reduce, or eliminate organisms that are harmful to cultivated plants. However, the use of pesticides on plants that provide foods for human consumption is often controversial because the benefits stemming from the unmatched ability of certain pesticides to control pests can be counterbalanced by adverse effects on the environment. In particular, numerous fruits and vegetables that are commonplace food items are prone to be contaminated by pesticide residues. Therefore, governmental protection agencies routinely monitor and test fruits and vegetables to ensure that these foods are safe for human consumption. In the United States, the Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) are responsible for verifying that pesticide-residue levels in foods are low and that quality production standards are met. See also: Agricultural chemistry; Agricultural science (plant); Chemical ecology; Environmental toxicology; Food; Fruit; Fruit, tree; Herbicide; Horticultural crops; Insecticide; Pesticide

To better understand the nutritional effects (health benefits), chemical composition, growing conditions, and shelf life of microgreens, a team of researchers reviewed the science behind them in the Journal of Agricultural and Food Chemistry (October 2018). Microgreens are one- to three-inch-tall herb and vegetable seedlings harvested above their roots about 10 to 14 days after germination just as their first pair of leaves appear, visually looking more like stems and seed leaves (cotyledons). These very young vegetable greens have been used by chefs for years as a garnish because of their colors and flavors. Beyond esthetics, microgreens are packed more densely with nutrients than mature vegetables, making them an interesting subject for food and nutritional scientists. Among commercially grown microgreens are arugula, broccoli, green daikon radish, purple mustard, and red cabbage. See also: Broccoli; Cabbage; Food; Mustard; Nutrition; Radish; Seed; Seed germination

More apples are consumed worldwide than any other temperate-zone tree fruit. Apples are eaten fresh, processed into jellies and preserves, cooked in pies and pastries, and made into sauces. Therefore, the cultivation of the trees (genus Malus) that produce the many varieties of apple fruits is a tremendously important agricultural industry. One of the most productive areas for apple production is North America, particularly in the United States (including New York, Pennsylvania, Ohio, Virginia, and North Carolina in the eastern half of the country and Washington, Oregon, and Idaho in the western half) and in Ontario and British Columbia in Canada. However, apple producers in these regions are noticing an increase in the number of orchard trees (especially young trees) that are dying or suffering plant tissue damage and necrosis in their lower trunks. See also: Agricultural science (plant); Apple; Fruit; Fruit, tree; Horticultural crops; Plant pathology

Cannabidiol (CBD) is the predominant cannabinoid (chemical constituent) of the more than 100 cannabinoids found in the hemp variety of the plant Cannabis sativa. There are preliminary, yet unproven, claims that CBD may offer benefits for treating specific ailments such as epilepsy, neuropathic pain, joint pain, inflammation, psychosis, anxiety, and insomnia. At present, the U.S. Food & Drug Administration (FDA) has approved only one CBD drug—Epidiolex—for treating childhood epilepsy. See also: Anxiety disorders; Epilepsy; Hemp; Inflammation; Pain; Psychosis; Sleep disorders