Temperate carrot cultivars outperform tropical ones under hot and humid tropical plains

The suitability of leading carrot cvs. for cultivation under the hot and humid tropical plains of Kerala state was assessed. Sixteen cvs., including nine tropical varieties, two temperate varieties and five temperate hybrids, were evaluated. All tropical cvs. initiated bolting in 58.5 (Punjab Black Beauty) to 112.0 (CR29) days after sowing, whereas none of the temperate varieties bolted. Bolting per cent was low in 'Pusa Vrishti', 'Pusa Asita' and 'CR29', at 5.5, 7.5 and 8.5 %, respectively. Varieties 'Early Nantes' and 'Pusa Yamdagni' had smaller tops with 34.0 and 34.5 cm height and 5.1 and 6.2 leaves, respectively. 'Pusa Nayanjyoti', 'CR29', and Kuroda cvs. had maximum root length. In contrast, root width was highest in 'Pusa Vrishti', 'Pusa Rudhira', and Kuroda cvs. had maximum root length. In contrast, root width was highest in 'Pusa Vrishti', 'Pusa Rudhira', and 'Pusa Kesar'. In October planting, root weight was highest in 'Pusa Nayanjyoti', 'Pusa Rudhira', and 'Super Kuroda'. In contrast, in the November planting, it was highest in 'Pusa Nayanjyoti', 'Pusa Rudhira', 'Pusa Vrishti', and Kuroda cvs.. Due to extensive early bolting, root yield in 'Punjab Black Beauty' was the lowest in both seasons. Incidence of bacterial soft rot was highest in Kuroda types and 'Pusa Vrishti', and it was lowest in 'Punjab Black Beauty', 'Pusa Yamdagni', 'Pusa Nayanjyoti' and 'Pusa Asita'. Organoleptic analysis of the taste of freshly harvested roots has given the maximum score for 'Pusa Vrishti' and 'Pusa Asita' followed by 'Pusa Nayanjyoti'. This study has shown that temperate cvs. have to be chosen for cultivation in hot and humid tropical plains, and among the cvs. evaluated, 'Pusa Nayanjyoti' was the most promising.