Effects Of Plant Growth Regulators On Potato Production

This test in 2014²015, in Heilongjiang Keshan Farm and Heilongjiang Jiusan Board, was carried out for screening plant growth regulators concentration, filtering out spraying optimal period and optimum density. The test by plant growth regulators in the process of potato growth metabolism of photosynthate and the change of key enzyme activity, under the condition of the different periods and different density studied spraying regulator on potato yield and quality formation. The influence of the system revealed the regulator control mechanism of potato yield and tuber quality, for the application of control technology in the potato production provide a theoretical basis. The main results were:1. Foliar spraying regulator could improve the yield, the rate of big tuber and weight of big tuber under the condition of different periods. The increase rate of the tuber formation period was 6.80%⁶.80%, 5.00%¹0.96% and 1.98%¹8.39%, respectively. The increase rate of the tuber expansion period was 10.28%²6.64%, 1.14%¹.14% and 0.76%¹4.15%, respectively. In addition, under the condition of different density, PGRs also improved the potato production, the rate of big（middle） tuber and weight of big（middle） tuber. Conventional density, conventional+20% and conventional+40%, the increase rate were 5.80%³1.05%, 1.40%¹7.97%, and 1.27%¹1.08%, respectively. In terms of potato yield and commodity character, tuber expansion period and conventional spraying density regulator control effect were best.2. Under the condition of different periods and different density, foliar spraying regulators were increased starch and protein content. The starch content was increased rate of 2.92%².11% in tuber formation stage, and the tuber expansion period was increased 0.31%¹.66%. For tuber starch, the growth rate of conventional density, conventional+20% and conventional+40% were 1.98%⁴.26%, 0.08%¹.47% and 0.25%³.44%, respectively. In terms of potato quality, tuber formation period and conventional spraying density regulator control effect were best.3. Foliar spraying regulators were significantly or extremely significantly higher than CK. The chlorophyll content（SPAD）, net photosynthetic rate（Pn）, transpiration rate（Tr） and intercellular CO₂ concentration（Ci） were showed "V" type rule changes in leaves. In most of the measurement period, the starch and soluble sugar content were higher than CK. In a word, Foliar spraying regulators could improve the supply of assimilate.4. After foliar spraying PGRs, regulator treatments were significantly or extremely significantly increased the tuber starch and sucrose content in most of the measurement period. The soluble sugar content and sucrose invertase activities of CK and treatments showed inverted "V" type changes. Treatments and CK were maximum values at after spraying PGRs 18 d. Tubers amylase activity showed "reduce-high-trend".5. The starch and soluble sugar content showed inverted "V" type changes in stolons after foliar spraying regulator. At after spraying regulator 18 d, the decline range was 3.39%³6.10%. Stolons sucrose content showed inverted "V" type change, after spraying regulator 18 d reaching maximum value, the increase rate was 4.19%²2.76%. Amylase activity of treatments and CK was slowly fall-trend, after spraying regulator 18 d, and the decline range was 40.05%⁶2.22%. After spraying regulator 18 d³4 d, regulators were significantly reduced the invertase activities within stolons, and the decline range were 3.37%¹9.07%.