New varieties of vegetable cowpea (<i>Vigna unguiculata</i> subsp. <i>sesquipedalis </i>(L.) Verdc.) and prospects of their cultivation in southern Russia

Relevance. Currently, there is an interest in this country in vegetable varieties of Vigna unguiculata subsp. sesquipedalis (L.) Verdc. However, a small number of varieties adapted to different cultivation conditions prevents a wider distribution of this crop. The present work was aimed at creating new vegetable cowpea varieties adapted to the climatic conditions of southern regions of Russia.Materials and methods. The study was carried out in 1998-2018 in the Astrakhan Province (Astrakhan Experiment Station) and in 2012-2018 in Primorsky Territory (Far East Experiment Station). Vegetable cowpea accessions from the global VIR collection were studied.Results. Many years of breeding have resulted in creation of such varieties as ‘Astrakhanskaya krasavitsa’, ‘Kaspiyskaya zarya’, ‘Zhemchyuzhina Kaspiya’ and ‘Lyanchihe’, which were included in the State Register of Breeding Achievements in 2019. All varieties are characterized by earliness, high productivity, excellent quality of vegetable pods, high protein content in pods in the technical ripeness phase (29.5-33.5%), and by low demand to the soil fertility. ‘Zhemchyuzhina Kaspiya’, ‘Astrakhanskaya krasavitsa’ and ‘Kaspiyskaya zarya’ are tolerant to high temperatures, air drought and soil salinity. The growing season for these varieties lasts 62-68 days in the Astrakhan Province under irrigation, while technical ripeness of pods occurs in 46-50 days. The green pod yield is 16.1–28.2 t/ha and the seed yield is 1.91-2.71 t/ha. The ‘Lyanchihe’ variety tolerates humidity well; its growing season in southern Primorsky Territory is 97-110 days, and pods reach technical ripeness in 61-70 days. The green pod yield is 21.0-24.0 t/ha, and that of seeds is 2.38-2.64 t/ha. The released varieties will broaden the range of vegetable crops cultivated in this country and improve the quality of nutrition of the population.