🍲Mungbean, Urdbean, and Moth Bean -- Short-Duration Pulse Crops

In the previous lessons, we covered the major Rabi pulses — chickpea, pigeonpea, lentil, and field pea. Now we turn to three closely related Kharif/Zaid pulses from the genus Vigna that are often compared in exam questions.

Between the harvest of wheat in April and the sowing of rice in June, Indian farmers squeeze in a quick crop of mungbean or urdbean to earn extra income and add nitrogen to the soil. These short-duration pulses are the backbone of India’s Zaid and Kharif pulse production. Mungbean holds the record for the highest protein content among all pulses (24%), while moth bean survives on little more than morning dew in the deserts of Rajasthan.

This lesson covers:

1. Mungbean (greengram) — highest protein pulse, day-neutral, YVMV resistance
2. Urdbean (blackgram) — indigenous to India, comparison with mungbean
3. Moth bean (dew bean) — most drought-tolerant Kharif pulse, soil-binding role
4. Vigna trio comparison — side-by-side table for exam revision
5. Key varieties and mutants — T1, T9, Dhulia, Pant Mung 3

All sections are high-yield for IBPS AFO, NABARD, and FCI exams.

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Mungbean / Greengram — Basics

Mungbean is the most versatile among Indian pulses — its day-neutral photoperiod response allows cultivation in Kharif, Rabi, and Zaid seasons, and its short duration (60-75 days) makes it ideal for fitting between two main-season crops.

• The name radiata refers to the radiating lines on the pod surface.
• As a legume, mungbean fixes atmospheric nitrogen through Rhizobium bacteria, improving soil fertility for subsequent crops.

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Climate (Mungbean)

Mungbean thrives in hot conditions and can tolerate moderate drought — characteristics that make it the hardiest pulse. Its day-neutral photoperiod allows multi-season cultivation that no other major pulse can match.

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Seed Rate and Sowing

Mungbean’s low seed rate reflects its small seed size and vigorous branching habit. The relatively wide row spacing allows adequate air circulation, reducing humidity-related diseases like YVMV.

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Important Mungbean Varieties

Mungbean variety development has focused on two key goals: YVMV resistance (the most devastating viral disease) and short duration for fitting into rice-wheat and wheat-rice cropping systems.

• Yield: 12-15 q/ha

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Urdbean / Blackgram — Basics

Urdbean is the only major pulse that is indigenous to India — all others were domesticated elsewhere and introduced. This origin fact is frequently tested. Urdbean is the key ingredient in idli, dosa, and vada batters, making it culturally indispensable in South Indian cuisine.

Mungbean vs Urdbean — Comparison

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Urdbean Varieties

Urdbean variety development has focused on disease resistance and seasonal adaptation. Note the unusual green-seeded variety T-77, which is a common exam trap.

• Yield: 10-12 q/ha

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Moth Bean (Dew Bean) — Basics

Moth bean occupies a unique ecological niche that no other pulse can fill — it thrives in the extreme arid conditions of western Rajasthan where annual rainfall is as low as 200-300 mm. Its ability to survive on dew moisture alone earned it the name “Dew Bean.”

• The species name aconitifolia refers to the deeply lobed leaves resembling those of the Aconitum plant.
• Particularly well-suited to sandy soils and hot, dry conditions of western India.

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All Three at a Glance — The Vigna Trio

All three crops belong to the genus Vigna and family Papilionaceae — this shared taxonomic lineage is an important exam fact. The following comparison table covers the key distinguishing features that exams test repeatedly.

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Important Greengram Varieties

These varieties are frequently asked in AFO, NABARD, and IBPS SO papers. Focus on the “firsts” and YVMV-resistance categories.

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Summary Table — Key Exam Facts

This table consolidates the most frequently tested one-liner facts from all three Vigna crops — ideal for last-minute revision before exams.

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Summary Cheat Sheet