Paclobutrazol 40% SC in paddy: registration status, uses and dose
Last reviewed: 12 November 2026
Is paclobutrazol registered for rice in India?
Not as 40% SC. The Central Insecticides Board & Registration Committee (CIB&RC) publishes the approved crops and doses of products registered under the Insecticides Act, 1968 in its “Major Uses of Pesticides” lists. The plant growth regulator list as on 30.09.2026 has these paclobutrazol entries (CIB&RC PGR list):
| Formulation | Crop | Dose per ha (CIB&RC) | Waiting period before harvest |
|---|---|---|---|
| 40% SC | Pigeon pea | 30 g a.i. (75 ml) per ha in 500 L water | 48 days |
| 40% SC | Soybean | 30 g a.i. (75 ml) per ha in 500 L water | 56 days |
| 23% SC | Cotton | 34.5 g a.i. (150 ml) per ha in 500 L water | 42 days |
| 23% SC | Groundnut | 28.75 g a.i. (125 ml) per ha in 500 L water | 70 days |
| 23% SC | Mango, pomegranate, apple | Per-tree soil application (apple also foliar spray) | Varies |
| 0.4% + propiconazole 0.2% GR | Rice (blast / PGR) | 12.5 kg product per ha (granules), 25 days after planting | Not specified |
The doses above are for the crops and products named only. Do not convert the 40% SC or 23% SC doses into a paddy dose. The rice entry is a granule (GR) applied to the field at 12.5 kg per hectare (about 5 kg per acre, our conversion) 25 days after planting; it is not a spray and gives no per-litre dose.
What paclobutrazol does in rice
Paclobutrazol is a triazole that blocks gibberellin production in the plant. A review by ICAR-IARI scientists says that this shortens internodes and plant height and makes stems thicker and stronger, so the crop is less likely to lodge (fall over) in heavy rain and wind. Research has also reported better yield components, such as number of panicles and panicle length (Ali et al., Indian Farming, 2024).
The review lists tall plants, high planting density, poor water management and too much fertilizer as causes of lodging. It says growth regulators should be combined with proper nitrogen management, and that the response differs by variety.
Paclobutrazol dose and timing in paddy
There is no public-sector recommendation for paclobutrazol dose or timing in rice in India. The figures below are research trial results summarised in the ICAR-IARI review. They are not recommendations, and the rates are given in different units because the trials used different products:
| Trial (as cited in the review) | Rate used | Reported result vs untreated |
|---|---|---|
| West Bengal, India (Mukherjee, 2020) | 50 g a.i./ha | Plant height −10.1%, lodging −67.3%, grain yield +33.5% |
| Karnataka, India (Meena et al., 2020) | 23% SC at 200 ml/ha | Lodging −62.9%, grain yield +2.2% |
| Kedah, Malaysia (Syahputra et al., 2016) | 400 mg/L | Plant height −10.4%, lodging −21.8%, grain yield +10.7% |
On timing, the review says studies found the best time to apply growth regulators against lodging is the panicle initiation stage, typically 30–45 days after transplanting. It also notes that higher rates worked but the extra benefit may not justify the extra cost (Ali et al., 2024).
For comparison, the registered dose of 40% SC on soybean and pigeon pea is 75 ml in 500 litres of water per hectare — about 0.15 ml per litre (CIB&RC). Advice of 2–4 ml per litre is more than 13 times that concentration.
Risks: soil persistence and residues
An ICAR review of paclobutrazol use in fruit crops describes it as environmentally stable in soil and water, with a half-life of more than a year under both aerobic and anaerobic conditions. It also affects soil microbes. Residues were not found above 0.01 ppm in soil and fruit when it was applied at optimised rates. The risk to aquatic life is high, and it is considered moderately hazardous to people (Kishore et al., Indian Journal of Agricultural Sciences, 2015).
Paddy fields hold standing water and drain into canals and ponds, so the warning about aquatic life matters here. The sources above give no data on carry-over to the crop grown after rice, so that risk is unknown.
What to do instead
- To reduce lodging, choose varieties recommended for your area and apply nitrogen as per a soil test — see the rice crop calendar and Soil Health Card.
- Before using any growth regulator on paddy, ask your Krishi Vigyan Kendra or the rice institutes ICAR-IIRR and ICAR-NRRI.
- Use only products registered for the crop and follow the label — see integrated pest management for safe pesticide use.
Frequently asked questions
- What are the uses of paclobutrazol 40 SC in paddy?
- Paclobutrazol is a growth retardant: it blocks gibberellin production, so rice plants grow shorter with shorter internodes and stronger stems, which reduces lodging (ICAR-IARI, Indian Farming 2024). But paclobutrazol 40% SC is registered in India only for pigeon pea and soybean, not for paddy. The only paclobutrazol product registered for rice is a granule mixed with a fungicide, paclobutrazol 0.4% + propiconazole 0.2% GR, for rice blast and growth regulation (CIB&RC list as on 30.09.2026).
- What is the paclobutrazol 40 SC dose per acre in paddy?
- There is no registered dose of paclobutrazol 40% SC for paddy, and we found no ICAR or state agricultural university recommendation for it in rice. A 40% SC per-acre dose printed on a label or advertised for paddy is the manufacturer's claim, not a government recommendation. The only paclobutrazol product registered for rice is paclobutrazol 0.4% + propiconazole 0.2% GR: 12.5 kg of product per hectare (about 5 kg per acre, our conversion), applied 25 days after planting (CIB&RC list as on 30.09.2026).
- What is the paclobutrazol 40% SC dose per litre?
- For its registered crops, pigeon pea and soybean, CIB&RC lists 75 ml of 40% SC per hectare in 500 litres of water — about 0.15 ml per litre (CIB&RC list as on 30.09.2026). That is for those two crops only; there is no approved per-litre dose for paddy. Advice of 2–4 ml per litre is more than 13 times that concentration.
- When should paclobutrazol be sprayed in paddy?
- There is no official timing for paclobutrazol 40% SC on rice. (The registered granule, paclobutrazol 0.4% + propiconazole 0.2% GR, is applied to the field 25 days after planting, not sprayed — CIB&RC.) An ICAR-IARI review of research says studies found growth regulators work best for lodging when applied around panicle initiation, typically 30–45 days after transplanting — not in the first two weeks after transplanting (Indian Farming, 2024).
- Is paclobutrazol 23% SC approved for rice?
- No. CIB&RC lists paclobutrazol 23% SC for mango, pomegranate, apple, cotton and groundnut only. For rice, the only registered paclobutrazol product is the granule paclobutrazol 0.4% + propiconazole 0.2% GR (CIB&RC list as on 30.09.2026).
- धान में पैक्लोब्यूट्राज़ोल 40 SC की मात्रा कितनी है?
- भारत में CIB&RC की सूची (30.09.2026 तक) में पैक्लोब्यूट्राज़ोल 40% SC धान के लिए पंजीकृत नहीं है, इसलिए धान में 40% SC की कोई सरकारी अनुशंसित मात्रा (प्रति एकड़ या प्रति लीटर) नहीं है। 40% SC केवल अरहर और सोयाबीन के लिए पंजीकृत है। धान के लिए पंजीकृत एकमात्र पैक्लोब्यूट्राज़ोल उत्पाद दानेदार पैक्लोब्यूट्राज़ोल 0.4% + प्रोपिकोनाज़ोल 0.2% GR है (ब्लास्ट रोग / वृद्धि नियंत्रण के लिए): 12.5 किलो उत्पाद प्रति हेक्टेयर (लगभग 5 किलो प्रति एकड़, हमारी गणना), रोपाई के 25 दिन बाद खेत में डालें — यह छिड़काव नहीं है। प्रयोग से पहले अपने कृषि विज्ञान केंद्र (KVK) या राज्य कृषि विश्वविद्यालय से सलाह लें।
Related
- Paclobutrazol 40% SC in paddy crop (farmer Q&A)
- More paddy articles in the Knowledge Base
Sources
- Major Uses of Pesticides: Plant Growth Regulators, as on 30.09.2026 — CIB&RC, Directorate of Plant Protection, Quarantine & Storage (PDF)
- Major Uses of Pesticides (all lists) — CIB&RC, ppqs.gov.in
- Enhancing rice plant architecture and reducing lodging: A novel approach with growth regulators — Ali, Kaur, Ezing & Nandipamu, Indian Farming 74(8), August 2024, ICAR-IARI
- Paclobutrazol use in perennial fruit crops and its residual effects: A review — Kishore, Singh & Kurian, Indian Journal of Agricultural Sciences 85(7), 2015
Last reviewed: 12 November 2026. This guide is general information, not a recommendation to use any product. Use plant growth regulators only on crops they are registered for, and follow the label.