Water regime parameters in Chrysanthemum

In introduction studies, it is urgent to determine how favorable the water balance of the species studied is under defined environmental conditions. The research aimed to scrutinize the water regime of Chrysanthemum × hortorum Bailey and select drought-resistant varieties to replenish the range of plants used for floriculture in the Republic of Bashkortostan on grey forest (Haplic Greyzems) loamy soil. The studies were conducted in 2018‒2020. Irrigation frequency – twice a week. After each watering, soil loosening was carried out. One week before sampling for analysis, we stopped watering flowers. Water regime indicators were analyzed according to the method of artificial wilting (V. N. Tarenkov et al. 1990) and methodology of saturation of plant samples (V. P. Moiseev et al. 2009). Sublethal water deficit was determined by the method of T. K. Goryshina et al. 1965 modified by N. I. Bobrovskaya 1971. Observations and analyses were carried out once a month from May to September in the regrowth, budding and flowering phases. The value of the sublethal water deficit was clarified (28.4 %). During the growing season, the varieties did not experience irreversible moisture deficit in the tissues. Chrysanthemum varieties under identical soil-climatic and agrotechnical conditions had the following range of indicators of total water content and water-holding capacity – 70.0‒90.4 % and 19.00‒64.6 %, respectively. It indicates a considerable degree of adaptation. Analysis of variance revealed that varietal differentiation significantly affects the indicators of the water regime; the share of influence varied from 21.17 to 31.72 %. Direct dependence of the indicators of the content of ‘mobile’ moisture on the total water content (y = 0.74x – 21.377) was revealed, as well as the inverse one ‒ the indicators of the content of ‘mobile’ moisture and water-holding capacity (y = 0.74x – 21.377). According to the scale developed by Denisova S. G. and Reut A. A. (2020), four highly drought-tolerant varieties ‘Volny Agideli’, ‘Regina’, ‘Sakmara’, ‘Bardo’ were identified.