Effects of paclobutrazol, chlormequat chloride, and mepiquat chloride on lodging resistance and seed yield in oats

This study aimed to explore suitable growth regulators for seed production in oats, enhance lodging resistance, and improve seed yield. The experiment was designed with different levels of paclobutrazole 0.6 g·L⁻¹ (P₁), 0.9 g·L⁻¹ (P₂), and 1.2 g·L⁻¹ (P₃), chlormequat chloride 3.0 mL·L⁻¹ (C₁) and 4.0 mL·L⁻¹ (C₂), and 5.0 mL·L⁻¹ (C₃), and mepiquat chloride 3.0 mL·L⁻¹ (M₁), 3.5 mL·L⁻¹ (M₂), and 4.0 mL·L⁻¹ (M₃), and studied the growth and development, lodging resistance and seed yield at various levels. The results showed that paclobutrazol, clormequat chloride, and mepiquat chloride could reduce plant height and increase the stem diameter. The plant height for M₃ was 21.88% lower than CK and the stem diameter of M₂ was 22.67% higher than CK. All three modulators could shorten the length of the second internode of oats and increase the fracture resistance. The length of the second internode of M₃ was 21.52% shorter than CK, and the fracture resistance was 36.36% higher than that of CK. The three regulators could effectively promote the grain number per spike, 1000-grain weight, and seed yield of oats, The most effective treatment was to spray mepiquat chloride. Compared with CK, the seed yield of M₁, M₂m and M₃ increased by 4.63%, 16.54%, and 21.00%, respectively. Detailed analysis showed that mepiquat chloride could effectively increase lodging resistance and improve seed production. Treatment with 4.0 ml·L⁻¹ (M₃) of mepiquat chloride was most effective in supporting oat seed production.