Introduction

Lima bean (Phaseolus lunatus L.) is an important legume belonging to the

family Fabaceae and subfamily Faboideae. It has a diploid chromosome number

of 2n = 22 (Rojas-Sandoval & Acevedo-Rodríguez, 2015). The crop is thought to

have originated in Central and South America, with archaeological evidence

suggesting its cultivation in Peru dating back to 6,000 BCE. Its name is derived

from the capital city of Peru, Lima (Ramsay & Koinange, 2018). The crop has

gained global significance due to its adaptability to varied agro-climatic

conditions, drought tolerance, and high nutritional value. They also play a role in

sustainable agriculture through their nitrogen-fixing ability (Urbano et al., 2017).

In India, lima beans are grown in tropical and subtropical regions, including parts

of northeastern states such as Sikkim, where diverse landraces adapted to local

conditions can be found. The crop is used in traditional recipes and integrated into

mixed cropping systems. Its adaptability to marginal soils and degraded lands,

coupled with its ability to enrich soil fertility, makes it particularly suitable for

organic farming practices, which are increasingly adopted in Sikkim, the first

Indian state to achieve 100% organic certification (Singh et al., 2022; Sikkim

Government, 2021).

Nutritionally, lima beans are rich in protein, dietary fiber, and essential

micronutrients such as iron, zinc, and magnesium. It offers 21.5 g of protein, 63.4

g of carbohydrates, and 19 g of dietary fiber per 100 g, making them an excellent

energy and protein source. They are low in fat (0.7 g) and high in minerals like

potassium (1,729 mg), magnesium (224 mg), and iron (7.5 mg), along with 395

μg of folate, covering nearly 99% of daily requirements. They also contain

bioactive compounds, including phenolics, which exhibit antioxidant properties

and are linked to various health benefits (Mimura et al., 2021). The potential of

this legume to contribute to nutritionally dense diets, particularly in regions where

malnutrition is prevalent, underscores the importance of exploring its cultivation

under different management systems.

Organic farming has emerged as a sustainable alternative to conventional

agricultural practices, focusing on ecological balance, biodiversity conservation,

and the exclusion of synthetic inputs (Sharma et al., 2020). The adoption of

organic systems is often associated with improved soil health, reduced

environmental pollution, and enhanced crop quality. Studies have indicated that

legumes, including lima bean, can thrive under organic systems due to their lower

nutrient requirements and symbiotic nitrogen fixation capabilities (Adewale et al.,

2017). However, limited research has been conducted to assess the performance

of lima bean in organic cultivation systems, particularly concerning growth

dynamics, yield potential, and nutritional quality.

The evaluation of crop performance under organic cultivation is crucial for

understanding its viability in sustainable agriculture. Organic farming practices

can influence plant growth, microbial interactions in the rhizosphere, and nutrient

availability, all of which play a role in determining crop productivity and quality

(Omondi et al., 2019). Moreover, legumes like lima bean have the potential to

contribute significantly to organic farming systems by enhancing soil health and

serving as a reliable source of protein and micronutrients for human consumption

(Muiruri et al., 2022).

Despite its many nutritional benefits, lima bean contains certain antinutritional

factors that may limit its utilization if not properly managed. The primary

antinutritional compounds in lima bean include cyanogenic glycosides, lectins,

hemagglutinins, phytic acid, trypsin inhibitors and tannins. Cyanogenic glycosides

can release hydrogen cyanide upon enzymatic hydrolysis, which is toxic when

consumed in large amounts. However, traditional processing methods such as

soaking, boiling, and fermentation can effectively reduce these compounds to

safe levels (Ajibade et al., 2017).

Lectins and hemagglutinins are antinutritional factors with significant biological

activity. Lectins are carbohydrate-binding proteins that can resist enzymatic

degradation in the human digestive system, potentially interfering with nutrient

absorption and causing gastrointestinal discomfort (Urbano et al., 2017).

Hemagglutinins, a specific type of lectin, have the capacity to agglutinate red

blood cells, leading to potential toxicity if consumed raw or undercooked (Arise et

al., 2021; Slavin, 2013).

Phytic acid, widely present in legumes, is known to form insoluble complexes with

essential minerals such as iron, calcium, and zinc, reducing their bioavailability

(Mekonnen et al., 2021). Although it is often considered an antinutritional factor,

phytic acid also has positive attributes, such as antioxidant properties and a

potential role in reducing the risk of certain chronic diseases when consumed in

appropriate amounts (Reddy et al., 2020)

Trypsin inhibitors, on the other hand, interfere with protein digestion by inhibiting

the activity of trypsin and other proteolytic enzymes in the digestive system. This

can lead to reduced protein utilization and possible gastrointestinal issues

(Holsinger et al., 2019). However, like cyanogenic glycosides, the levels of trypsin

inhibitors and phytic acid can be significantly reduced through traditional

processing techniques such as soaking, sprouting, and cooking (Akinmutimi et al.,

2018).

Similarly, tannins, known for their ability to bind proteins, can interfere with

protein digestibility. However, these compounds are also associated with potential

health benefits due to their antioxidant and anti-inflammatory properties when

consumed in moderation (Osman et al., 2018).

The dual nature of these antinutritional factors underscores the importance of

evaluating not only the nutritional attributes of lima bean but also the impact of

organic cultivation on the levels of these compounds. Research suggests that

cultivation practices, soil health, and environmental conditions significantly

influence the concentration of antinutritional factors in legumes (Meena et al.,

2020). Hence, understanding these dynamics is essential for optimizing the

nutritional quality and safety of lima beans produced under organic systems.

Objectives of the study :

I. To collect various Lima bean genotypes from different areas of Sikkim.

II. To assess the growth performance of lima bean under organic cultivation,

III. To evaluate the yield, nutritional and ant-nutritional components of the crop.

By addressing these objectives, the study contributes to the growing body of

literature on sustainable agriculture and organic crop production. It also highlights

the importance of legumes in promoting food and nutrition security while

maintaining ecological balance.