Phenology of two hybrids of artichoke (Cynara cardunculus L.) in Junin, Buenos Aires

Abstract

In Argentina, artichoke (Cynara cardunculus var. scolymus (L.) Hayek L.) production areas are well-defined, corresponding 64% to La Plata (Buenos Aires), 14% to Rosario (Santa Fe) and 19% to the region of Cuyo. Given the need to seek alternative sustainable productions in Junin (Buenos Aires), a study was conducted with the aim of evaluating phenology of two hybrids of artichoke. The essay was carried out in the Experimental Field of Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA) located at 34°28'57.47”S; 60°52'39.91”W. Two commercial artichoke hybrids, obtained by seed, were used: 'Opal' (violet) and 'Madrigal' (white). Transplant was performed on June 27, 2014 at 0.80 m between rows and 0.50 m between plants. A randomized complete block design with 12 replications and 5 plants per plot was used. During the growing season, daily maximum (TM) and minimum (Tm) temperatures were recorded with a data-logger Wash-Dog and number of chilling hours (CH) was estimated by Crossa-Reynaud modified formula: CH=24*(4°C-Tm)/(TM-Tm), using 4°C as base temperature instead of 7°C. Number of leaves to first flowering and days between transplant and first harvest were also registered. Data were subjected to variance analysis. From transplant to flowering (Tr-FL)252 chilling hours were accumulated, an amount that was enough to reach harvest. 'Madrigal' showed more precocity, starting flowering period after forming four leaves, and reaching first harvest date 172 days after transplant, while 'Opal' formed 6 leaves and required 185 days to first harvest, differences which were statistically significant.