Rajasthan Faced a 35-Day Dry Spell, Which Moth Bean Varieties Kept Growing?

Moth bean farmers in western Rajasthan faced a prolonged dry spell during Kharif 2026. Rainfall stopped after August 3, and the crop went through about 35 days without substantial rain. Four recently developed varieties from ICAR-CAZRI continued growing and developing pods during this period.

The varieties are CAZRI Moth-4, CAZRI Moth-5, CAZRI Moth-6 and CAZRI Moth-7. Their performance is significant for western Rajasthan, where moth bean covers nearly 10 lakh hectares but average productivity remains around 350 kg per hectare.

What happened during the dry spell?

The crop received its last significant rainfall of 86 mm on August 2. Rainfall then stopped after an August 3 event, followed by three or four scattered showers of less than 2.5 mm each during the next month.

The resulting dry spell lasted from August 3 to September 7. During this period, cumulative pan evaporation reached about 180 mm, increasing the pressure on available soil moisture as the crop moved through flowering and reproductive development.

Surface soil moisture at 0–10 centimetres was around 15–16% until August 2. It later fell to about 5–6%. Moisture at 10–40 centimetres also declined, from around 23% to 16%, but continued supplying some water to the crop.

Despite the moisture decline, CAZRI reported that the four varieties maintained green foliage, vegetative growth and pod development. The crop had reached around 55 days after sowing when the institute assessed its field performance.

Why does moth bean struggle in Rajasthan?

Moth bean is suited to hot and dry conditions, but rainfall in western Rajasthan remains low and uncertain. The region receives around 150–250 mm of rainfall, while dry spells of 20–30 days are common during the crop season.

These conditions contribute to low productivity. The average moth bean yield in the region is around 350 kg per hectare. For rainfed farmers, the ability of a variety to continue developing when soil moisture falls can influence whether the crop reaches harvest.

CAZRI has spent more than a decade breeding moth bean varieties for these conditions. The institute has focused on traits including stress resilience, developmental plasticity and yield potential under the harsh environment of western Rajasthan.

Developmental plasticity is one feature highlighted by CAZRI. The varieties begin flowering at around 30 days after sowing and can adjust their growth and maturity according to available soil moisture.

What helped the crop survive?

The varieties were not grown without management. CAZRI says timely sowing with the onset of the monsoon helped establish the crop before the prolonged dry period began.

The recommended plant geometry was 45 × 10 centimetres. Mechanical interculture was carried out around 20 days after sowing to help conserve moisture, while mechanical and manual weed management reduced competition for available water.

Early canopy development also helped. CAZRI reported that soil binding and moisture retention around the roots supported crop establishment and helped plants use available soil moisture during the extended rainless period.

This means the performance cannot be attributed to seed alone. Variety selection, sowing time, plant spacing, weed management and moisture-conservation practices all contributed to the crop’s ability to cope with the dry conditions.

Can farmers get these varieties?

CAZRI has released all four varieties during the past three years. The institute is now multiplying seed to expand availability through the formal seed system.

Seed production is currently being carried out over seven hectares at the CAZRI research farm. The institute is working to meet a 2026 requirement of 23.32 quintals of breeder seed through the Saathi Portal.

The seed is being multiplied by Rajasthan State Seeds Corporation, National Seeds Corporation and selected private companies. In 2025, the combined seed requirement for the four varieties through the Saathi Portal was 63.2 quintals.

CAZRI estimates that one quintal of breeder seed can produce around 1,000–1,400 quintals of certified seed when properly multiplied and marketed. The institute says this could support cultivation over about 10,000 hectares.

What does this mean for farmers?

The 2026 field performance provides an early indication that these varieties can maintain growth under severe moisture stress in western Rajasthan. It does not mean every farmer will receive the same result under every rainfall or soil condition.

Farmers should also avoid changing varieties only because a seed is described as drought tolerant. They should check whether the variety is recommended for their area, whether certified seed is available and whether its maturity period fits their cropping system.

For rainfed farmers, the experience offers another lesson. A suitable variety can reduce some weather-related risk, but it works best with timely sowing, appropriate plant spacing, weed control and practices that conserve soil moisture.

The four CAZRI varieties are now moving through seed multiplication channels. If certified seed becomes available at scale, farmers in suitable parts of western Rajasthan will have more options for growing moth bean under uncertain rainfall.

The 35-day dry spell has given researchers a field-level opportunity to observe how these varieties respond to prolonged moisture stress. For farmers, the important question now is whether that performance can be repeated across more locations, seasons and farms.