General Description of Legumes Plants and Their Uses

What are Legumes?

• Legumes are a diverse group of plants that are cultivated for their edible seeds or pods, which can be consumed in various forms, including fresh green vegetables, green shelled seeds, or dry seeds. The term “pulses” specifically refers to the dry seeds of these plants. Commonly known varieties of legumes include beans and peas, which are significant not only for their culinary uses but also for their nutritional benefits.
• One of the key features of legumes is their nutritional composition. On a dry weight basis, pulses can contain between 17% to 30% protein, making them a valuable source of plant-based protein. Soybeans stand out as the richest protein source among legumes, providing over 40% protein. In addition to protein, legumes are rich in carbohydrates, primarily in the form of starch, and they also supply essential fats, calcium, and iron.
• Furthermore, legumes offer enhanced nutritional value when sprouted. Soaking the seeds in water allows them to germinate, significantly increasing their vitamin C content. They are also rich in B vitamins, including niacin, thiamine, and riboflavin, which play crucial roles in energy metabolism and overall health.
• The amino acid profile of legumes is particularly noteworthy. While they contain adequate amounts of essential amino acids such as lysine, tryptophan, and threonine, they tend to be lower in methionine, cysteine, and cystine. These sulfur-containing amino acids are present in higher amounts in cereals, which are typically low in lysine and threonine. Therefore, the combination of legumes and cereals in a diet is common in various cultures worldwide, as it provides a balanced intake of amino acids necessary for human health.
• In terms of agricultural significance, several legume crops, including soybean, chickpeas (gram), and peas, are extensively cultivated and consumed globally. This overview will further explore the vital pulse crops of India, highlighting their role in local diets and agriculture.

Nutritional Value of Legumes

Legumes are highly regarded for their nutritional value, making them essential components of a balanced diet. These foods offer a wealth of benefits due to their rich nutrient profile, including proteins, carbohydrates, dietary fiber, vitamins, and minerals. Their bioactive compounds further enhance their appeal by contributing to various health benefits.

• Protein Content: Legumes provide a substantial amount of protein, typically ranging from 20% to 45% on a dry weight basis. This protein is accompanied by essential amino acids, making legumes an excellent source of plant-based nutrition. For instance, soybeans stand out with the highest protein concentration among legumes, exceeding 40% protein content.
• Carbohydrates: Comprising about 60% of their composition, carbohydrates in legumes primarily take the form of starch. They are a source of energy that is beneficial for various bodily functions.
• Dietary Fiber: Legumes are notable for their dietary fiber content, which can range from 5% to 37%. This fiber is divided into soluble and insoluble types, contributing to digestive health and promoting satiety.
• Vitamins and Minerals: Legumes are a good source of essential minerals such as iron, zinc, calcium, and magnesium, along with B-group vitamins like folate. Folate is crucial for DNA synthesis and repair, making legumes particularly beneficial during periods of rapid growth and development.
• Bioactive Compounds: The bioactive compounds found in legumes contribute to their medicinal value. Research indicates that these compounds possess antioxidant properties that help prevent degenerative diseases, including cancer, heart diseases, and osteoporosis. For example, the isoflavones present in soybeans may reduce the risk of hormone-related cancers and support heart health.
• Diabetic Benefits: Legumes are advantageous for individuals with diabetes due to their low glycemic index. They aid in blood glucose control and contribute to weight management, making them valuable in dietary strategies for diabetes.
• Cultural and Economic Value: Beyond their nutritional benefits, legumes hold cultural significance and contribute to the economy, particularly in developing regions of Africa and Asia. They are crucial in addressing protein-energy malnutrition and improving food security.
• Functional Foods: Legumes are increasingly utilized in the development of functional foods, which are designed to promote human health beyond basic nutrition.
• Health Benefits Summary:
  • High Protein: Legumes contain approximately twice the protein found in cereal grains.
  • Low Fat: They are generally low in fat and free of saturated fats, with no cholesterol, except for soybeans and peanuts, which have higher levels of mono- and polyunsaturated fatty acids.
  • Rich in Carbohydrates: Although they provide energy-yielding carbohydrates, legumes have a low glycemic index, making them suitable for blood sugar control.
  • Fibre-Rich: The high fiber content aids in digestion and helps maintain a healthy gut.
  • Phytonutrients: These include isoflavones, lignans, and protease inhibitors, particularly abundant in soybeans, contributing to lower risks of certain cancers and health issues associated with menopause.
  • Gluten-Free: Legumes are naturally free of gluten, making them safe for individuals with celiac disease or gluten sensitivity.
  • Amino Acids: While legumes have lower amounts of methionine, they provide sufficient lysine, balancing their amino acid profile when combined with cereal grains.

The nutritional profiles of various legumes highlight their unique contributions to human health. The following table summarizes the nutritional content of selected legumes:

Nutritional Parameters	Peanut	Chickpea	Lentil	Pea	Kidney Bean	Black Bean	Soybean	Pinto Bean
Calories	427	269	230	125	215	227	298	245
Protein (g)	17.3	14.5	17.9	8.2	13.4	15.2	28.6	15.4
Folate (%)	27	71	90	24	23	64	74
Manganese (%)	76	84	49	22	22	38	71	39
Copper (%)	–	29	29	–	17	20	–
Iron (%)	–	26	–	–	17	–	49
Fiber (g)	5.9	12.5	15.6	8.8	13.6	15	10.3	15.4
Thiamine (%)	22	–	22	30	20	28	23	22
Vitamin K (%)	–	–	–	48	–	–	41	–

Bioactive Compounds and Health Benefits

Bioactive compounds in legumes are pivotal in promoting health and preventing various diseases. These compounds include phytosterols, isoflavones, saponins, alkaloids, and carbohydrates, each contributing unique health benefits. Understanding the specific functions and effects of these bioactive substances provides insight into the nutritional value of legumes.

• Lunasin: This peptide is present in soybeans, wheat, barley, rice, and rye. It is known for its anti-inflammatory, antioxidant, and cholesterol-lowering properties. Lunasin effectively arrests cell division in cancer cells, protecting DNA from oxidative damage. As an anticancer agent, it disrupts histone acetylation and deacetylation, which are processes involved in gene expression.
• Bowman-Birk Inhibitor (BBI): This protease inhibitor, found in soybeans, lentils, and peas, plays a crucial role in cancer prevention. BBI inhibits proteasome activity, which is often increased in cancer cells. By disrupting homeostasis in these cells, BBI helps prevent prostate, breast, and colon cancers.
• Lectins: These proteins, found in legumes, exhibit anticancer properties by agglutinating cells through their binding to specific carbohydrate residues on cell surfaces. Soybean agglutinins have demonstrated the ability to inhibit tumor growth in experimental models, such as rats.
• Isoflavones: These compounds are associated with several biological activities, including the reduction of osteoporosis, prevention of cancer, and cardiovascular disease. Isoflavones contribute to the overall health benefits of legumes.
• Saponins: Present in soybean, lentils, chickpeas, and other beans, saponins also possess anticancer properties. They have been shown to reduce hyperlipidemia and lower the risk of coronary heart disease due to their high phytosterol and saponin content.
• Health Benefits Summary:
  • Cancer Prevention: Legumes such as soybeans, lentils, and chickpeas help prevent various types of cancer.
  • Cardiovascular Health: Regular consumption of legumes supports improved blood circulation and helps maintain healthy blood pressure levels.
  • Metabolic and Digestive Health: Legumes enhance metabolic activity and digestion, contributing to better overall digestive health.
  • Bone Health: They are beneficial for maintaining bone health and preventing osteoporosis.
  • Diabetes Management: Legumes play a role in controlling diabetes by lowering blood glucose and insulin responses. Their high fiber content and low glycemic index make them particularly effective in managing type 2 diabetes mellitus.
  • Weight Management: Legumes can aid in both weight gain and weight loss, depending on dietary context.
  • Anti-Inflammatory Properties: The presence of bioactive compounds in legumes contributes to their anti-inflammatory effects, reducing the risk of chronic diseases.
  • Immune System Support: Regular legume consumption boosts immunity and helps in the prevention and treatment of anemia.
  • Support for Pregnancy: Certain legumes help prevent birth defects, making them beneficial during pregnancy.

Important legumes

1. Soybean

Soybean, scientifically known as Glycine max L., belongs to the family Fabaceae and is commonly referred to by names such as soybean, bhat, and ramkurthi. This ancient legume has emerged as a critical source of oil and protein, alongside its use as animal feed. Over the past three decades, interest in soybean has surged due to its recognition as a “wonder bean.”

• Origin and Distribution:
  • The soybean originated in China and is considered one of the oldest crops cultivated in the Orient. Food products made from soybean seeds have been integral to the diets of people in the region for centuries.
  • The cultivated soybean, Glycine max, does not exist in a wild state but is believed to have developed from Glycine soja, also known as Glycine ussuriensis. The latter is a slender, prostrate, twining legume that can be found in various parts of Eastern Asia.
  • Another wild species, G. tomentella (or G. tomentosa), may have contributed to the evolution of cultivated soybean through hybridization with G. soja.
  • Post-World War II, the United States became the leading producer of soybean, with China following in second place, and Brazil ranking third. Other significant soybean-growing countries include Indonesia, Mexico, Russia, Korea, Japan, Argentina, Colombia, and India.
  • Soybean was introduced to India around 1880, although large-scale cultivation only commenced recently. This legume can be grown successfully across India, with commercial cultivation occurring in states such as Assam, Uttar Pradesh, Himachal Pradesh, Nagaland, Manipur, Madhya Pradesh, Maharashtra, and Gujarat.
• Cultivation:
  • Soybean thrives as a subtropical plant, with cultivation extending from tropical to temperate regions. The climatic conditions required for its growth resemble those ideal for maize.
  • The crop is typically grown in areas where summer temperatures are hot and damp. Adequate rainfall during the growing season and dry weather during seed maturation are crucial for successful cultivation.
  • Soybean can adapt to various soil types, but soils rich in calcium are considered optimal. Additionally, the plant requires a specific strain of the bacterium Rhizobium japonicum for nitrogen fixation, which must be inoculated into the soil when soybean is introduced to a new area.
  • Soybean is classified as a short-day plant, with the maturity period ranging from 75 to 200 days, depending on the variety and its adaptation to specific latitudes. The crop is cultivated from seeds and can be harvested manually or using combines.
• Morphology:
  • The soybean plant is characterized as an erect, much-branched annual herb, typically covered with grey hairs. Certain varieties may exhibit creeping or twining habits, which tend to increase in shaded conditions.
  • The tap root system is well developed, extending 30 to 60 cm into the soil, with small spherical nodules present for nitrogen fixation.
  • The erect stem can reach heights between 50 and 180 cm, depending on the variety. Soybean leaves are large, hairy, and alternate, with a long petiole. Each compound leaf is generally trifoliate, with leaflets that are ovate to lanceolate.
  • The inflorescences are short axillary racemes containing 3 to 15 flowers, although many flowers may not develop into fruits and instead drop off. Flower colors vary from nearly white to deep purple.
  • Pods arise in clusters, are hairy, and are usually compressed and slightly curved. Each pod typically contains 2 to 3 small, globose seeds, with colors ranging from creamy white to yellow, grey, brown, or various combinations thereof.
• Uses:
  • Soybean’s high protein and oil content render it one of the most valuable legumes. Primarily grown as a food crop in China, Japan, and other Southeast Asian countries, soybean has multiple culinary applications.
  • Unripe seeds are consumed as vegetables, while mature dried seeds can be eaten whole, split, or sprouted. They can also be ground into flour and combined with other flours to produce bread, chapattis, and various baked goods. This combination enhances nutritional value by providing a balanced diet with high protein and low carbohydrate content.
  • Whole seeds can be prepared through boiling, baking, or roasting. Soybean can also be processed into soymilk, a valuable protein source for infant food, curds, and cheese. A popular condiment, soy sauce, is created by fermenting cooked seeds with wheat flour and salt using the fungus Aspergillus oryzae.
  • The oil extracted from soybean seeds serves as an important fat source in cooking and is also used in the production of soaps, printing inks, lubricants, greases, and other industrial products. Additionally, it is combined with other drying oils in the paint and varnish industries.
  • The whole soybean plant can be utilized as forage or fodder and as green manure. The oil cake produced after oil extraction is a rich protein source for livestock feed. Furthermore, synthetic fibers can be derived from soybean protein, showcasing the plant’s extensive utility.

2. Cowpea

Cowpea, botanically classified as Vigna unguiculata L., is a significant pulse crop belonging to the Fabaceae family. Commonly known as cowpea, lobia, or chowli, this legume has been cultivated for centuries and holds importance in both tropical and subtropical regions.

• Taxonomy:
  • The various cultivated forms of cowpea are often considered distinct varieties due to their ability to cross freely, leading to gene flow. Consequently, all forms are classified under a single species, Vigna unguiculata, with notable varieties including:
    • V. unguiculata var. unguiculata
    • V. unguiculata var. sinensis (Common cowpea)
    • V. unguiculata var. sesquipedalis (Yardlong cowpea or asparagus pea)
• Origin and Distribution:
  • Cowpea is an ancient pulse crop with a rich history of cultivation in Africa and Asia, as evidenced by references in ancient Sanskrit literature. In Africa, this legume thrives in both wild and cultivated states, believed to have originated from wild types in Central Africa.
  • Some researchers, including Vavilov, propose that cowpea may have originated in India before spreading globally. Currently, cultivated cowpeas are prevalent in many tropical and subtropical regions, with the primary producers including Nigeria, Uganda, the United States, India, China, the Mediterranean region, South Africa, and Australia.
• Cultivation:
  • Cowpea is adaptable to a variety of environmental conditions, thriving in warm weather. This pulse crop exhibits drought resistance, making it suitable for cultivation in areas with low rainfall.
  • The crop is capable of growing in different soil types and generally matures in about three months.
• Morphology:
  • The cowpea plant is characterized as an annual herb, exhibiting an erect, prostrate, or climbing growth habit. It grows vigorously, becoming bushy and reaching heights of about 1.5 meters.
  • The stem is typically glabrous but may present hairs at the nodes. The tap root system is well developed, featuring numerous large nodules that host bacterial colonies crucial for nitrogen fixation.
  • Leaves are large, trifoliate, and possess long petioles, with a pair of large stipules surrounding each petiole. Each leaflet is subtended by small stipels.
  • The inflorescence consists of an axillary raceme or fascicle, featuring a few flowers generally clustered near the tip. The flowers occur in alternate pairs on the thickened nodes of the inflorescence axis and exhibit the typical papilionaceous structure. Flower colors can range from white, light pink, purple, and violet to light blue.
  • The fruit produced is a legume or pod, which varies significantly in size across the different cowpea varieties. Pods are long and cylindrical, with a constriction between the seeds. In the yard-long cowpea (Vigna unguiculata var. sesquipedalis), the pods can measure between 30 to 100 cm in length, while other varieties typically feature pods ranging from 10 to 30 cm.
  • The number of seeds per pod varies based on pod length. Cowpea seeds can be globular or kidney-shaped, smooth or wrinkled, and come in various colors including white, cream, yellow, green, red, brown, or black. The commonly cultivated white-seeded types often have a distinctive black mark around the hilum, leading to their nickname “black-eyed cowpeas.” Cowpea seeds are rich in protein, constituting more than 20 percent of their dry weight, and also contain around 50 percent carbohydrates, along with minerals and small quantities of fats.
• Uses:
  • Tender cowpea pods are utilized as a green vegetable, while mature dried seeds are consumed primarily as a pulse, often in whole or split forms. The seeds can be ground into flour for use in various food preparations.
  • Beyond human consumption, cowpea plants serve as valuable livestock feed when fresh, or they can be dried and used as hay. Additionally, the plants may be incorporated into the soil as green manure, contributing to soil fertility and sustainability.

3. Pigeon Pea

Pigeon pea, scientifically known as Cajanus cajan L., belongs to the Fabaceae family and is commonly referred to as red gram or Congo pea. This pulse crop holds significant agricultural and nutritional value, particularly in tropical regions.

• Origin and Distribution:
  • Pigeon pea is native to Africa, with evidence suggesting its cultivation in Egypt as early as 2000 B.C. Today, India stands as the largest producer of pigeon pea, where its cultivation is primarily concentrated in the states of Maharashtra, Uttar Pradesh, Madhya Pradesh, Gujarat, Karnataka, Andhra Pradesh, and Orissa.
  • The plant’s adaptability allows it to thrive in both the New and Old World tropics, establishing itself in various climates.
• Morphology:
  • Pigeon pea manifests as a perennial woody shrub, typically reaching heights of 1 to 4 meters. It features trifoliate compound leaves characterized by relatively narrow, lanceolate, and hairy leaflets.
  • The flowers of the pigeon pea plant are borne on racemes measuring between 4 to 12 cm in length. Each flower is arranged in a way that facilitates pollination and subsequent pod formation.
  • The pods of pigeon pea are elongated, ranging from 5 to 10 cm in length, and are essential for seed development and dispersal.
  • Within the species, two notable varieties are recognized:
    • Cajanus cajan var. bicolor, a perennial bushy plant that matures late and produces purple flowers.
    • Cajanus cajan var. favus, a relatively short and early-maturing variety characterized by small plants with green, glabrous pods, typically containing three seeds.
• Cultivation:
  • Pigeon pea is a deep-rooted, drought-resistant crop, making it well-suited for semi-arid regions where annual rainfall is less than 60 cm. Its deep root system enables it to access moisture from deeper soil layers, contributing to its resilience.
  • The crop is predominantly cultivated in conjunction with sorghum and bajra, reflecting a common practice in traditional agriculture. This intercropping helps optimize land use and enhance soil health.
  • Pigeon pea is generally grown under rainfed conditions to allow for optimal root development. The time required for the crop to mature ranges from six to ten months, depending on environmental conditions and specific varieties.
• Uses:
  • The seeds of pigeon pea are primarily consumed in the form of split pulses, known as dal, which is a staple food in South India. This preparation is a vital source of nutrition for many communities.
  • Pigeon pea is rich in proteins, calcium, and phosphorus, making it an essential dietary component that supports health and well-being.
  • Additionally, the green pods of pigeon pea are harvested and utilized as vegetables, contributing to culinary diversity and nutritional value in various dishes.

4. Gram

Gram, scientifically known as Cicer arietinum L., is commonly referred to as chickpea or Bengal gram and belongs to the Fabaceae family. This pulse crop is one of the oldest known to humankind, with a rich history of cultivation spanning across Asia and Europe. Over time, it has been introduced to various regions worldwide, including tropical America, Africa, and Australia.

• Origin and Distribution:
  • Cicer arietinum is believed to have originated in Southwest Asia. Its long-standing significance as a food source has led to its widespread cultivation.
  • In India, chickpeas are primarily grown in the states of Madhya Pradesh, Rajasthan, Uttar Pradesh, Maharashtra, Haryana, Karnataka, Bihar, and Gujarat. These regions provide favorable growing conditions that contribute to the successful cultivation of this pulse.
• Morphology:
  • The chickpea plant exhibits a branched, erect, and spreading growth habit, typically reaching heights of 20 to 25 cm. Its structure is designed to maximize exposure to sunlight and enhance photosynthesis.
  • The leaves of the chickpea plant are imparipinnate, comprising 9 to 15 pairs of leaflets that can be ovate, elliptic, or obovate in shape, with serrate margins. This leaf structure aids in efficient water use and adaptation to arid climates.
  • The flowers vary in color, ranging from white to pink, which contributes to its aesthetic appeal and helps attract pollinators.
  • The pods are small and inflated, containing one or more angular seeds. These seeds feature a prominent beak and a small hilum located at the anterior end, aiding in seed dispersal.
  • Gram is well adapted to arid and semi-arid regions characterized by low to moderate rainfall and a cool, dry climate. This adaptability makes it a vital crop in regions with challenging agricultural conditions.
• Nutritional Profile:
  • The seeds of chickpeas are nutritionally rich, providing significant amounts of proteins, carbohydrates, and dietary fiber. This makes them an essential food source, particularly in vegetarian diets, where they contribute to daily protein intake.
• Uses:
  • Chickpeas serve as a nutritious pulse crop in India, where they are consumed in various forms. The seeds can be eaten raw, roasted, parched, or boiled and are often prepared in split form, known as dal, which is a staple in many households.
  • Tender leaves of the chickpea plant are harvested and used as vegetables, adding diversity to the diet.
  • Additionally, gram flour, or besan, is produced from ground chickpeas and is widely used in the preparation of snacks and sweets, showcasing the versatility of this pulse crop in culinary applications.

5. French Bean or Common Bean

French bean, scientifically classified as Phaseolus vulgaris, is a widely cultivated species within the Fabaceae family, often recognized by various common names such as kidney bean, runner bean, shap bean, and salad bean. This legume holds significant agricultural importance and is known for its versatility in culinary applications.

• Origin and Distribution:
  • The common bean is of New World origin, believed to have originated in North, Central, and South America. Historical records suggest its cultivation dates back to approximately 6000 B.C. in Peru.
  • The introduction of Phaseolus vulgaris to Europe occurred during the sixteenth century, facilitated by Spanish and Portuguese explorers. Subsequently, this crop spread to Africa and other regions, establishing its presence in a variety of climates.
  • Today, common beans are extensively cultivated in several countries, including Brazil, the United States, Mexico, Italy, and Turkey, demonstrating their global significance as a food source.
• Morphology:
  • The species exhibits polymorphism, with numerous varieties adapted to meet local agricultural requirements. Differences in habitat, flower color, pod size, and shape are commonly observed among the cultivated varieties.
  • French beans can be categorized into bush (or dwarf) cultivars and trailing vine (or pole) cultivars. The bush types display determinate growth, while the trailing varieties continue to grow indefinitely, producing racemes in their leaf axils.
  • The stem of the plant is slender, herbaceous, and angled, providing support for the leaves and pods. The leaves are alternate and trifoliate, characterized by a hairy texture and well-defined pulvinus at the base. Their ovate shape enhances photosynthesis by maximizing sunlight absorption.
  • Flowers are arranged in axillary racemes and exhibit the typical structure of the subfamily Papilionoideae. The pods, which can be yellow or green, are slender and straight, featuring prominent beaks. Each pod typically contains four to six seeds.
  • This crop is adaptable to a wide range of climatic conditions, flourishing during warm periods in temperate areas and thriving in cooler conditions in tropical regions. Additionally, Phaseolus vulgaris performs best in loamy soil, which provides the necessary drainage and nutrient content.
• Uses:
  • The green, immature pods of French beans are consumed as a vegetable, prized for their tender texture and flavor. They are often used in salads, stir-fries, and various culinary dishes.
  • The straw resulting from the harvest serves as an important feed source for cattle, contributing to livestock nutrition.
  • French beans are rich in essential nutrients, including proteins, fats, carbohydrates, and dietary fibers, making them a valuable addition to human diets. Their nutritional profile supports overall health and wellness, reinforcing the significance of this legume in diverse diets.

6. Pea

Peas, known scientifically as Pisum sativum L., belong to the Fabaceae family and are an important leguminous crop. Domesticated in Central or Western Asia, peas have a long history of cultivation, spreading throughout Europe and reaching regions as far as India, Tibet, and China. The species thrives in the temperate zones of the Northern Hemisphere, with approximately ninety percent of global pea production occurring in France, the Russian Federation, Ukraine, China, Bangladesh, and Canada. Other significant producers include India, Denmark, Switzerland, and the United States. In India, peas are cultivated as a winter crop in the plains and as a summer crop in the hilly regions, with Uttar Pradesh and Madhya Pradesh being the primary producing states, followed by Bihar and Assam.

• Morphology:
  • The plant exhibits notable morphological differences, with Pisum sativum sp. hortense, commonly known as garden pea, being a robust but less hardy variant characterized by large pods containing seeds that are green, round, smooth, and high in sugar content.
  • Conversely, P. sativum sp. arvense, or field pea, is a hardier variant that features stipules marked with red spots, pink or purple flowers, and smaller pods and seeds. The seeds of field peas are angular and exhibit a brownish-grey hue, rich in starch.
  • It is believed that P. arvense descended from P. sativum subsp. elatius, which is a wild relative indigenous to the Mediterranean region. The evolution of P. sativum is attributed to mutations from P. arvense or a hybridization event between P. sativum subsp. elatius and P. arvense, followed by subsequent backcrossing.
  • Pea plants are typically climbing or trailing annuals, with a slender hollow stem. They exist in both bush and vine forms, allowing for various growth habits.
  • The leaves are pinnately compound, consisting of three pairs of leaflets that end in branching tendrils. The leaflets can be ovate or elliptic in shape and possess entire margins. The stipules are large, leaf-like, and can sometimes exceed the size of the leaflets.
  • Flowers, which can be pink, white, or purple, are borne singly in the axils of leaves or in racemes, contributing to the plant’s reproductive success. The pods of the pea plant are swollen, compressed, and can be either straight or curved. They range in length from 3 to 12 cm and typically contain two to ten seeds.
  • The seeds themselves can be angular or globose and may appear smooth or wrinkled, depending on the variety.
  • Pea plants thrive in moderately cool growing seasons, requiring a fair amount of rainfall and a temperature range between 13°C and 18°C. They grow best in soils with a pH level ranging from 6 to 7.5, which allows for optimal nutrient absorption.
• Uses:
  • Peas are commonly harvested while still immature to be used as a fresh vegetable, known for their sweetness and versatility in culinary applications.
  • Additionally, the dry, mature seeds serve as a rich source of essential nutrients, including protein, fats, carbohydrates, and dietary fiber, making them an important component of a balanced diet.

7. Beans

Beans are a diverse group of leguminous crops cultivated globally, encompassing varieties such as kidney beans, lima beans, soybeans, wax beans, string beans, and green-shelled beans. They are not only rich in vitamins and minerals but also serve as an excellent source of protein and carbohydrates, providing significant energy to those who consume them. Beans can be enjoyed as green vegetables or as dried seeds. In addition to their nutritional benefits, they play an essential role in enriching the soil and providing valuable green fodder for livestock. Below is a detailed overview of several important bean varieties.

• Lima Bean (Phaseolus limensis = Phaseolus lunatus):
  • The lima bean is recognized as the most nutritious member of the pea family, offering high protein content along with substantial amounts of iron, calcium, and vitamins.
  • This wide, flat bean is native to tropical America and thrives in many warm regions across the globe, making it a widely cultivated crop.
• Green Gram (Phaseolus aureus):
  • Also known as mung bean, the green gram is a crucial pulse crop in India, characterized by its erect and branched growth, reaching heights of 0.3 to 1.3 meters.
  • The leaves are alternately arranged and trifoliately compound. Its purplish-yellow flowers appear in clusters of 10 to 22 on long axillary racemes.
  • The pods mature to a grey, green, or brown color and typically contain 15 small seeds. Green gram is considered one of the most wholesome pulses available.
  • The dried beans can be consumed whole or split as dal, while the green pods are edible as vegetables. Additionally, the seeds can be sprouted and enjoyed as a nutritious salad or snack.
• Black Gram (Vigna mungo):
  • Commonly referred to as urd, black gram is highly valued in vegetarian diets, particularly in India, where it likely originated before spreading to other tropical regions.
  • This erect, sub-erect annual herb can grow up to 0.8 meters tall and is characterized by its reddish-brown hairy leaves and stems.
  • The leaves are large and trifoliate, with each leaflet being ovate to lanceolate, measuring 5 to 10 cm in length. The small yellow flowers cluster at the top of short hairy peduncles.
  • The pods are narrow and cylindrical, septate, and covered with hairs, featuring short hooked beaks. Each pod typically contains six to ten oblong seeds.
• Cluster Bean (Cyamopsis tetragonoloba):
  • Commonly known as guar, cluster bean is believed to be indigenous to India, where it has been cultivated since ancient times for various uses, including fodder, green manure, and as a vegetable.
  • In recent years, it has gained prominence in the United States for gum production. The seeds of cluster bean contain a mucilaginous substance utilized in the paper and textile industries.
  • The plant is bushy and annual, with stiff branches that are angular, grooved, and covered with white hairs. Small pinkish-white flowers arise in dense axillary racemes, and the pods are linear, ridged, and compressed, growing in clusters.