Lima bean

Phaseolus lunatus is found in Meso- and South America. Two gene pools of cultivated lima beans point to independent domestication events. The Mesoamerican lima bean is distributed in neotropical lowlands, while the other is found in the western Andes. The Andean domestication took place around 2000 BC and produced a large-seeded variety (lima type), while the second, taking place in Mesoamerica around AD 800, produced a small-seeded variety (Sieva type). During the Spanish Viceroyalty of Peru, lima beans were exported to the rest of the Americas and Europe, and since the boxes of such goods had their place of origin labeled "Lima, Peru", the beans got named as such.). In the United States, Sieva-type beans are traditionally called butter beans, also otherwise known as the Dixie or Henderson type. In the United Kingdom and the United States, "butter beans" refers to either dried beans, which can be purchased to rehydrate, or the canned variety, which are ready to use. == Domestication ==

The lima bean is a domesticated species of economic and cultural importance worldwide, especially in Mexico. The species has two varieties. The wild variety is silvester and the domesticated one is lunatus. == Crop ==

In the U.S., it is a warm-season crop, grown mainly in Delaware and the mid-Atlantic region for processing and in the Midwest and California for dry beans. Baby lima beans are planted in early June and harvested about ten to twelve weeks later. In western New York State, baby lima bean production increased greatly from 2011 to 2015. ==Cultivation and cultivars==

Cultivation In Oaxaca, Mexico, the main rainy season lasts from June to August, and most of the above-ground parts die during the dry season. Germination or budding occurs in June or July. The first inflorescence is in October or November. The production of flowers and fruits usually ends between February and April. Cultivars Both bush and pole (vine) cultivars exist; the latter range from in height. The bush cultivars mature earlier than the pole cultivars. The pods are up to long. The mature seeds are long and oval to kidney-shaped. In most cultivars, the seeds are quite flat, but in the "potato" cultivars, the shape approaches spherical. White seeds are common, but black, red, orange, and variously mottled seeds are also known. The immature seeds are uniformly green. Lima beans typically yield of seed and of biomass per hectare. The seeds of the cultivars listed below are white unless otherwise noted. Closely related or synonymous names are listed on the same line. Bush types • 'Henderson' / 'Thorogreen', 65 days (heirloom) • 'Eastland', 68 days • 'Jackson Wonder', 68 days (heirloom, seeds brown mottled with purple) • 'Dixie Butterpea', 75 days (heirloom, two strains are common: red speckled and white seeded) • 'Fordhook 242', 75 days, 1945 AAS winner Pole types • 'Carolina Sieva', 75 days (heirloom, suffered a seed crop failure in the years 2011 and 2012, causing this variety to still not be widely sourced ten years later) • 'Christmas' / 'Chestnut' / 'Giant Speckled' / 'Speckled Calico', 78 days (heirloom, seeds white mottled with red) • 'Big 6' / 'Big Mama', 80 days • 'Willow Leaf', 80 days (heirloom, there are white-seeded and variously mottled strains) • 'Mezcla', 82 days • 'King of the Garden', 85 days (heirloom) File:Lima Bean Time Lapse.webm|Phaseolus lunatus growth, time-lapse File:Speckled butterbeans.jpg|Speckled butterbeans from Jesup, Georgia File:Garrofón. Concurso Internacional de Paella de Sueca 2016 01.jpg|Garrofón beans at a paella contest File:Phaseolus lunatus MHNT.BOT.2008.1.40.jpg|Phaseolus lunatus cultivar 'Christmas' == Ecology ==

Pathogens/disease Phytophthora phaseoli is one example of a pathogen of the lima bean. It is an oomycete plant pathogen that causes downy mildew of lima bean during cool and humid weather conditions. To combat this pathogen, developing lima bean cultivars with resistance is a relatively cost-efficient method that is also environmentally safe as compared to using pesticides. Predators/hosts The two-spotted spider mites or Tetranychus urticae lay eggs on lima bean leaves. It prefers lima bean plants as a host food source over other plants such as tomato or cabbage plants. Spider mites pose the greatest threat to lima bean plants compared to other species, such as the Common cutworm (Spodoptera litura), which is also known to feed on lima bean plants. These plants are host plants for their larvae. Other predatory insects include ants, wasps, flies and beetles. Defenses Lima beans use extrafloral nectar (E.F.N.) secretion when exposed to volatiles from other plants infested by herbivore species. Producing E.F.N. can be an indirect defense since it supplies enemies of herbivores with an alternative food source. The predator of lima beans, spider mites, also have their own predators, the carnivorous mite Phytoseiulus persimilis. These predatory mites use E.F.N. as an alternative food source, and thus the production of this by the lima bean can attract P. persimilis and thus deter their herbivorous hosts. One of these adaptations includes a particularly effective induced herbivory defense. The lima bean is able to signal to the carnivorous natural enemy of herbivores, the carnivorous mite, mediated by herbivore-induced plant volatiles (H.I.P.V.s) in an attempt to save itself from further predation. The lima bean plant does this as an induced defense when being eaten by herbivorous predators. It is the mechanical wounding and chemical elicitors from insect oral secretions that first begin the signaling pathway to induce H.I.P.V. production. Once this pathway is induced, the plant produces H.I.P.V.s which are released into the air and can be received by any organisms that have receptors capable of receiving H.I.P.V.s, which includes: carnivores, conspecific and heterospecific herbivores, as well as neighboring plants. One particular experiment in which this was made apparent was in the understanding of the tritrophic system between the lima bean plant, two-spotted spider mite, and the carnivorous mite. Here, experimenters noticed an increase in H.I.P.V.s when the lima bean plant was preyed on by the two-spotted spider mite. Then, when the carnivorous mite was introduced, it had increased prey-searching efficacy and overall attraction to the lima bean plant, even once the two-spotted spider mite was removed, but the H.I.P.V.s remained high. == Toxicity ==

Like many beans, raw lima beans are toxic (containing e.g. phytohaemagglutinin) if not boiled for at least ten minutes. Canned beans can be eaten without having to be boiled first, as they are pre-cooked. The lima bean can contain anti-nutrients like phytic acids, saponin, oxalate, tannin and trypsin inhibitor. These inhibit the absorption of nutrients in animals and can cause damage to some organs. In addition to boiling, methods of roasting, pressure cooking, soaking, and germination can also reduce the antinutrients significantly. == Nutrition ==

The most abundant mineral in the raw lima bean is potassium, followed by calcium, phosphorus, magnesium, sodium, and iron. When lima beans germinate, there is increased bioavailability of calcium and phosphorus. Additionally, it is a good source of vitamin B6. == Uses ==

Culinary Like many other legumes, lima beans are a good source of dietary fiber and a virtually fat-free source of high-quality protein. Lima beans contain both soluble fiber, which helps regulate blood sugar levels and lowers cholesterol, and insoluble fiber, which aids in the prevention of constipation, digestive disorders, irritable bowel syndrome, and diverticulitis. In Spain, the butter bean is called in Catalan and constitutes one of the main ingredients of the famous Valencian paella. In India, they are called double beans. Dried beans are soaked overnight and pressure-cooked as ingredients in curries. Medical Blood sugar level The high fiber content in lima beans prevents blood sugar levels from rising too rapidly after eating them due to the presence of those large amounts of absorption-slowing compounds in the beans, and the high soluble fiber content. Soluble fiber absorbs water in the stomach, forming a gel that slows down the absorption of the bean's carbohydrates. They can, therefore, help balance blood sugar levels while providing steady, slow-burning energy, which makes them a good choice for people with diabetes suffering from insulin resistance. ==References==