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

Four moth bean varieties developed by ICAR-Central Arid Zone Research Institute, Jodhpur, maintained growth and pod development during a 35-day dry spell in western Rajasthan this Kharif season. The varieties, CAZRI Moth-4, 5, 6 and 7, were tested under prolonged moisture stress during crop development.

Moth bean is an important pulse crop in western Rajasthan, where it covers nearly 10 lakh hectares. Productivity remains around 350 kg per hectare because farmers often depend on 150–250 mm of erratic rainfall and face dry periods lasting 20–30 days.

What happened during the 2026 dry spell?

The crop received its last significant rainfall of 86 mm on August 2. Rainfall then stopped after August 3, creating a 35-day period without substantial rain until September 7. During this period, scattered rainfall events contributed less than 2.5 mm each.

The moisture stress came during an important stage of crop development. The varieties were around flowering, pod formation and reproductive growth when rainfall became scarce. Despite the prolonged dry period, CAZRI reported green plants, continued growth and profuse pod development at about 55 days after sowing.

Surface soil moisture at 0–10 centimetres was around 15–16% until August 2. After the dry spell began, it declined to around 5–6%. Moisture at the deeper 10–40 centimetre layer fell from approximately 23% to 16%.

The deeper soil layer still supplied moisture to the crop during the dry period. CAZRI also recorded around 180 mm of cumulative pan evaporation during the 35-day dry spell, showing the high atmospheric demand for available water during this period.

What helped the plants survive?

The varieties were not grown without management. Farmers and researchers used timely sowing with the July monsoon, a plant spacing of 45 × 10 centimetres and mechanical interculture about 20 days after sowing.

Weed management and early canopy development also helped the crop use available soil moisture. CAZRI said soil binding and moisture retention around the rhizosphere supported crop establishment during the prolonged dry period.

This distinction matters for farmers. The performance cannot be attributed to seed genetics alone. The field conditions included specific sowing, spacing, weed-control and moisture-conservation practices that contributed to the crop’s performance.

What makes these varieties different?

CAZRI developed the four varieties through more than a decade of moth bean breeding and genetic improvement. The breeding programme focused on developmental plasticity, stress resilience and yield potential under the harsh conditions of western Rajasthan.

Developmental plasticity allows the plants to adjust their growth and maturity according to available soil moisture. The four varieties begin flowering at about 30 days after sowing, which can help them move toward reproduction before severe moisture stress becomes prolonged.

The latest field observation was focused on resilience during moisture stress rather than reporting a final commercial yield from the 2026 season. Farmers should therefore not interpret the 35-day dry-spell result as a guaranteed yield figure.

Earlier ICAR data provide useful context. CAZRI Moth-4 and CAZRI Moth-5 recorded average yields of 596 and 585 kg per hectare respectively across three years and 15 locations, according to ICAR’s 2024-25 annual report.

The same ICAR report says both varieties showed yield potential above 1,500 kg per hectare under optimum management. Such potential figures come from favourable conditions and should not be treated as expected farm yields.

Are the seeds available?

Seed multiplication is already underway for all four varieties. CAZRI is producing seed across seven hectares at its research farm to meet a Saathi Portal-indented requirement of 23.32 quintals for 2026.

The seed demand was higher in 2025. The combined requirement for the four varieties through the Saathi Portal was 63.2 quintals. Rajasthan State Seeds Corporation, National Seeds Corporation and selected private companies are involved in seed multiplication.

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

The institute estimates that even at 50% of this multiplication potential, wider adoption could eventually cover around 25% of Rajasthan’s moth bean area. This is a projection based on seed multiplication capacity, not an existing area under the four varieties.

The experimental fields had poor fertility conditions. Organic carbon ranged from 0.13–0.18%, soil pH was 7.9–8.1, available nitrogen was 90–100 kg per hectare, phosphorus was 10–15 kg and potassium was 250–260 kg per hectare.

These details matter because farmers cannot assume that a variety will respond identically on every farm. Soil texture, fertility, rainfall distribution, sowing time, plant population and weed management can all affect crop performance.

The varieties are particularly relevant to farmers in western Rajasthan and other areas with similar hot, dry and rainfed conditions. Their development was specifically aimed at the unpredictable moisture conditions of the arid region.

Farmers outside the recommended adaptation area should first check whether the variety is officially suitable for their location. Seed availability, local rainfall, soil conditions and recommendations from agricultural departments or KVKs should guide the decision.

What should farmers check before buying seed?

Farmers should first verify the variety name, seed source, certification and recommended area of adaptation. They should also check the expected maturity period and whether their local rainfall pattern suits the variety.

Sowing time remains important. CAZRI’s 2026 field performance came from sowing with the onset of the July monsoon. The institute also used 45 × 10 centimetre spacing and mechanical interculture for moisture conservation.

They cannot eliminate drought risk. Their value lies in their ability to maintain growth under moisture stress when combined with suitable management.

The 2026 observations provide field-level evidence of resilience during one prolonged dry period. More seasons and locations are needed to understand how consistently the varieties perform under different rainfall patterns and farm conditions.

For farmers in western Rajasthan, the result offers another seed option to consider where moisture stress regularly affects pulse production. But variety selection should still be matched with local recommendations and available water.

The four CAZRI varieties survived a difficult period in which surface soil moisture fell sharply and substantial rainfall stopped for 35 days. Their continued growth and pod development show why breeding for drought resilience matters in rainfed farming.

But the field result also shows that genetics and farm management work together. Timely sowing, suitable spacing, weed control and moisture conservation supported the crop during the dry spell.