Low toxicity, no residue green plant growth regulator – prohexadione calcium

Prohexadione is a new type of plant growth regulator of cyclohexane carboxylic acid. It was jointly developed by Japan Combination Chemical Industry Co., Ltd. and Germany’s BASF. It inhibits the biosynthesis of gibberellin in plants and makes plants The gibberellin content is reduced, thereby delaying and controlling the leggy growth of plants. Mainly used in cereal crops, such as wheat, barley, rice lodging resistance, can also be used in peanuts, flowers and lawns to control their growth.

1 Product Introduction

Chinese common name: procyclonic acid calcium

English common name: Prohexadione-calcium

Compound name: calcium 3-oxo-5-oxo-4-propionylcyclohex-3-enecarboxylate

CAS accession number: 127277-53-6

Molecular formula: C10H10CaO5

Relative molecular mass: 250.3

Structural formula:

Physical and chemical properties: Appearance: white powder; melting point >360℃; vapor pressure: 1.74×10-5 Pa (20℃); octanol/water partition coefficient: Kow lgP=-2.90 (20℃); density: 1.435 g/mL ; Henry’s constant: 1.92 × 10-5 Pa m3mol-1 (calc.). Solubility (20℃): 174 mg/L in distilled water; methanol 1.11 mg/L, acetone 0.038 mg/L, n-hexane＜0.003 mg/L, toluene 0.004 mg/L, ethyl acetate＜0.010 mg/L, iso Propanol 0.105 mg/L, dichloromethane 0.004 mg/L. Stability: stable temperature up to 180℃; hydrolysis DT50<5 d (pH=4, 20℃), 21 d (pH7, 20℃), 89 d (pH9, 25℃); in natural water, water photolysis DT50 is 6.3 d, the photolysis DT50 in distilled water was 2.7 d (29～34℃, 0.25W/m2).

Toxicity: The original drug of prohexadione is a low-toxicity pesticide. The acute oral LD50 (male/female) of rats is >5,000 mg/kg, the acute percutaneous LD50 (male/female) of rats is >2,000 mg/kg, and the acute oral LD50 of rats (male/female) is >2,000 mg/kg. Inhalation toxicity LC50 (4 h, male/female)> 4.21 mg/L. At the same time, it has low toxicity to environmental organisms such as birds, fish, water fleas, algae, bees, and earthworms.

Mechanism of action: By interfering with the synthesis of gibberellic acid in plants, it reduces the content of gibberellic acid in plants, controls leggy growth, promotes flowering and fruiting, increases yield, develops root systems, protects cell membranes and organelle membranes, and improves crop stress resistance. So as to inhibit the vegetative growth of the upper part of the plant and promote reproductive growth.

2 Registration

According to the inquiry of China Pesticide Information Network, as of January 2022, a total of 11 prohexadione calcium products have been registered in my country, including 3 technical drugs and 8 preparations, as shown in Table 1.

                                                              Table 1 Registration of prohexadione calcium in my country

3 Market prospects

As a green plant growth regulator, prohexadione calcium is the same as the plant growth regulators of paclobutrazol, niconazole and trinexapac-ethyl. It inhibits the biosynthesis of gibberellic acid in plants, and plays a role in dwarfing crops, The role of controlling plant growth. However, prohexadione-calcium has no residue on plants, no pollution to the environment, and less impact on subsequent crops and non-target plants. It can be said that it has a very broad application prospect.