Economic and biological characteristics of Lollo rossa lettuce varieties at cultivation in Astrakhan region

The purpose of the researches was to compare the productivity and quality of various varieties of Lollo Rossa lettuce cultivated in spring and summer periods of seedling cultivation in open ground and to select the most adapted ones to climatic conditions of Astrakhan Region for the expansion of varieties’ diversity. In 2018-2019 under production conditions of Astrakhan Region field experiments according to methodical recommendations on the cultivation of lettuce cultures and the technique of field experiment in vegetable growing were put. The varieties of Lollo Rossa lettuce grown up in seedling cultivation and planted into open ground during spring and summer periods were the objects of the researches: Tuska, Anthony, Kavernet, Constance. The choice of the varieties was proved by germination term, the relation to increased temperatures and the resistance to shooting. Comparative assessment of the specimens of Lollo Rossa lettuce on the efficiency and biochemical structure of production was given. Experimental data of key parameters of plants of salad at cultivation were given in seedling way and various terms of planting period of seedling into open ground. The main indicators of the formation of the productivity of various varieties of Lollo Rossa lettuce were defined. It was established that in Astrakhan Region in the group of Lollo Rossa varieties the variety Tuska had been the most adapted to climatic conditions. At planting period of lettuce seedling in the first decade of April the productivity of the variety of Tuska exceeded Anthony in 30.9 %, Kavernet - in 39.2 %. During summer period at planting period of seedling in the second decade of August the variety Tuska had the highest productivity - 20.1 t/hectare exceeding Anthony variety by 6.2 t/hectare and Kavernet variety by 5.3 t/hectare. By the results of biochemical analysis it was revealed that lettuce leaves of Lollo Rossa of various varieties accumulated solid on average 6.44-6.73 %; vitamin C - 21.36-23.58 mg%, nitrates - 1472-1458 mg/kg (maximum concentration limit - 2000 mg/kg).