Influence of duration of storage and pre-sowing electromagnetic treatment on the sowing qualities of cotton seeds III. Sprout and root mass

Abstract

The aim of this research was to study the influence of duration of storage and pre-sowing electromagnetic treatment on the development of primary root system of seeds of five Bulgarian cotton varieties - Chirpan-539, Trakia, Helius, Natalia and Nelina, stored before their treatment for one and two years. The seeds of each variety were treated in five electromagnetic fields, with different intensity and duration of exposure. It was found that the selected values ​​of controllable factors had stimulating effect on the mass of sprout (8,9-13,8%) and mass of root (3,5-11,3%). The total sprout and root mass increased by 7.8 - 12.7% and the best treatment options were 1 [U =(8…5)kV, τ =(15…35)s] and 4 [U=(6…3) kV, τ =(5… 25)s]. Electromagnetic treatments had stronger positive effect on the total mass of sprout and root of seeds stored for one year, the increase was of 10.8-16.5%, and less for the seeds stored for two years (1.8 - 3.9%). Compared to the control variant Chirpan-539, untreated seeds stored for one year, higher sprout mass was accounted for the same variety, treatment option 5 [U =(4…2) kV, τ =(5…25) s]. Higher mass of root and total mass of sprout and root was reported for Nelina variety, treatment options 1 [U =(8…5)kV, τ =(15…35)s] and 2 [U =(6…3)kV, τ =(15…35)s].The strongest stimulating effect of treatments on studied characteristics was observed for the Helius variety. As for seeds stored for one year, best treatment option was 1 [U =(8…5)kV, τ =(15…35)s], the increase in sprout mass was by 36.0-57.1%, in root mass was by 0.9 -24.8%, the total mass of sprout and root increased by 27.1-48.5% compared to the variety corresponding control (untreated seeds, one-year storage). In the case of seeds stored for two years, the increase in the total mass of sprout and root was by 6.5-23.0%, and the best treatment option was 4 [U =(6…3)kV, τ =(5…25)s].