Efficacy of Preplant Treatment of Tubers by Growth Regulators in Potato Seed Breeding
The efficiency of tuber treatment by promising growth regulators during cultivation of seed potato was studied in 2014-2015. The investigation was carried out under conditions of Kostroma region on sod-podzol medium loamy soil according to conventional techniques. We studied the efficiency of nine preparations: Al'bit, Artafit, Zeromiks, Mival-Agro, Prorastin, Tsirkon, Ekogel', Ekstrasol and Epin-Ekstra. The treatment of tubers by pure water was a control. The significant increase in the number of stems per plant (LSD05 is 0.37 pcs/plant) for Udacha variety was noted with the treatment of tubers by Artafit, Zeromiks, Prorastin, Tsirkon and Epin-Ekstra; for Skarb variety (LSD05 is 0.35 pcs/plant) - by Al'bit, Artafit, Zeromiks, Mival-Agro, Tsirkon, Ekstrasol and Epin-Ekstra (by 0.4-0.7 pcs/ plant). The application of Zeromiks regulator significantly (LSD05 is 4.9 cm) increased the stem length (by 5.0 cm). The treatment of tubers before planting by preparations Al'bit, Artafit, Zeromiks, Mival-Agro, Prorastin, Ekstrasol and Epin-Ekstra ensured the highest increase in the yield of seed potato cv. Udacha in comparison with the control (by 3.8-10.1 t/ha, or 13.5-36.0 %). For Skarb variety the best preparations in this case were Al'bit, Artafit, Zeromiks, Ekstrasol and Epin-Ekstra, they promoted the growth of productivity by 2.5-5.1 t/ha, or 9.7-19.8 %. Among all studied preparation three growth regulators: Al'bit, Zeromiks and Epin-Ekstra ensured significant (LSD05 is 1.8-3.0 t/ha) increase in the yield of both varieties during both years of investigation. Mival-Agro phytoregulator showed individual selective manner of action; during both years of investigation it was reliably efficient for Udacha variety, but it did not ensure the growth of productivity of Skarb variety, in comparison with the control. Meteorological conditions specifically influenced the productivity of the studied varieties and efficacy of the preparations. Certain deficiency of moisture in the soil during the first half of potato vegetation in 2014 had a negative effect on the yield of early variety Udacha. Under conditions of 2015 the same variety, due to the earlier formation of yield, avoided the negative effect of moisture excess.