Evaluating gladiolus varieties for off-season planting using agro-meteorological indices
KIRANJEET KAUR DHATT* and SHALINI JHANJI
Commercial floriculture is an emerging profitable agro industry in the world with great demand of cut flowers but with a constraint to regulate the supply for longer duration in the markets. The off-season plucked flowers get better price, as glut during peak season affects the profits. This could be achieved by cultivating varieties over a wide range of planting times which demands evaluation of varietal performance under different sowing windows. The present study was conducted with five gladiolus varieties viz. Punjab glance, Punjab lemon delight, Novalux, Rose supreme and Alexander the great planted at six sowing dates starting from 5thJuly to 20th September at 15 days interval. All the varieties gave best performance in terms of days to flowering, plant height, spike length, number of florets per spike, vase life and number of corms per corm when planted on 20th September (nearest to normal planting season). The growth of all varieties was affected under early plantings as they produced taller plants with shorter spikes, reduced number of florets per spike and vase life; took more number of days to flower, accumulated more growing degree days (GDD), helio thermal units (HTU) and photothermal units (PTU). All the varieties under early plantings produced spikes of comparable quality that depicts their tolerance to unfavourable temperature and photoperiod. This characteristic could be used in breeding programmes for development of varieties that could efficiently channelize their accumulated heat units for spike production and could be grown in diverse agro climatic zones. The performance of early planted Punjab glance and Punjab lemon delight was at par to their respective normal plantings. Thus, early planting of these varieties will lead to spike production in September and at this time farmers can fetch good price.
Gladiolus, planting time, GDD, PTU, HTU, flowering