Abstract:
Objective Effects of seed treatment with growth regulators on the growth and yield of potato plants were studied to select the suitable regulators for small potato.
Method Using randomized block design, seeds of Hongmei potatoes were treated with 6 formulated growth regulating solutions (D1—D6) or water as control (CK). The solutions contained 5% amino-oligosaccharides (AO), chitosan oligosaccharide (CO), iodine oligosaccharide acids (IOA), and/or 6-BA in varied concentrations. After treatment, the seed germination as well as the plant growth, development, photosynthesis, and yield were determined for an analysis.
Result The seeds treated with D2 (10 mL·L−1 AO + 2.5 mg·L−1 6-BA+7.5 mL·L−1 IOA) or D5 (5 mL·L−1 CO + 2.5 mg·L−1 6-BA+7.5 mL·L−1 IOA) germinated 2 d earlier than the others. The flowering stage of the plants began 5 d earlier with D2 and 4 d earlier with D5 than with CK. Treatment D3 (10 mL·L−1 AO + 2.5 mg·L−1 6-BA) or D4 (5 mL·L−1 CO+7.5 mL·L−1 IOA) increased the plant height by 12 cm and 9 cm, respectively, over those of CK. Among all treatments, D2 produced the least number of main stems but the largest stem girth and the greatest growth rate that was 79.16% higher than CK; whereas D3 the smallest stem girth and the largest number of main stems. The plant photosynthetic rate was significantly enhanced by D2 with a 53.86% increase over CK. The CO2 concentration and stomatal conductance of D2- and D5-treated plants were not significantly different but significantly higher than the others. On tuber productivity, D2 significantly increased the proportion of tuber weighed ≤50 g, while D5 significantly raised that of>50 g. D2 gave the highest number of tubers per plant with a yield of 35 335.94 kg·hm−2, whereas D5 the greatest weight of tubers per plant with a yield of 30572.42 kg·hm−2.
Conclusion It appeared that the seeds treated by D2 could increase the stem girth, chlorophyll content, photosynthetic rate, and tuber weight per plant of the potato plants. As a result, the plant yield and small tuber rate were increased making it desirable for mechanized cultivation. On the other hand, the seed treatment of D5 boosted the tuber weight per plant and the number and yield of large-sized tubers.