Performance, dormancy and disease screening studies in Gladiolus

Abstract

Gladiolus is one of the most important bulbous ornamentals grown commercially for cut flower purpose. An investigation was carried out on performance of cultivars, breaking of dormancy and screening of cultivars against fusarial wilt disease at Indian Institute of Horticultural Research, Hessaraghatta, Bangalore. The performance was best adjudged in Gladiolus cultivars ‘Sapna’ for days to flower, floret diameter and florets open at one time, ‘Sagar’ for plant height and corms and cormels produced per corm, hybrid ‘87-22- 1’ for spike and rachis length, ‘Meera’ for number of florets per spike and ‘Darshan’ for number of marketable spikes per corm. High phenotypic and genotypic co-efficient of variation, heritability and genetic advance were found for the characters viz., rachis length, number of side spikes per corm, duration of flowering, cormels produced per corm, cormel size and cormel weight. Marketable spikes per corm had significant and positive genotypic correlation co-efficients with number of side spikes per corm and cormel size. It also had positive direct effects with rachis length, number of florets per spike, vase life and corms produced per corm. Treatment of small sized corms of Gladiolus hybrid ‘87-22-1’ with ethrel at 250 ppm for 48 hours reduced the days to sprout, while treatment with ethrel at 1000 ppm resulted in maximum sprouting percentage. Whereas, the treatment of medium sized corms of Gladiolus hybrid ’87-22-1’ when treated with thiourea at 500 ppm resulted in early sprouting, while the maximum sprouting percentage was recorded from the corms treated with 50 ppm BA for 48 hours. Pollen from the second basal floret collected after one day of tying and incubated for 3½ hours showed maximum pollen germination. Fresh pollen had maximum germination than room temperature and cold stored (-65 ºC) pollen. Pollen of all the cultivars germinated well in the absence of fusaric acid, while with the addition of fusaric acid there was drastic reduction in germination and there was complete inhibition of pollen germination at higher levels of fusaric acid. 150