tailieunhanh - Correlation studies of growth and flowering of Dendrobium cv. sonia with microclimatic variables in different protected structures

The present investigation entitled “Correlation studies of growth and flowering of Dendrobium cv. Sonia with microclimatic variables in different protected structures” was conducted in the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during 2017-2018. The experiment was laid out with 5 treatments replicated three times viz. G1 (Bamboo frame structure covered with fixed 200 micron UV film with top ventilated and 50% agro shade net as ceiling), G2 (Bamboo frame structure with fixed 50% agro shade net as cladding material), G3 (Bamboo frame structure covered with fixed 200 micron UV film with side removable and 50% agro shade net as ceiling), G4 (Bamboo frame structure with fixed 50% agro shade net and 200 micron UV film as top covering) and G5(Bamboo frame structure with 200 micron UV film side removable and fixed 50% agro shade net as covering). It was observed that all the microclimatic parameters of protected structures were found to be lower than the open field condition. The highest maximum and minimum temperature were found in G3 while the highest morning and evening humidity were found in G2 during 2017 and 2018, respectively. The highest average light intensity was found in G1. It was found that all the growth characters highly correlated with maximum temperature and minimum temperature under G1 condition. For flower characters mean microclimatic parameters calculated from 5 different phenophases viz. PP1 (planting to bud visibility), PP2 (planting to full bloom), PP3 (bud visibility to opening of first floret), PP4 (bud visibility to full bloom) and PP5 (opening of first floret to full bloom). The highest negative correlation coefficient of most of the flower characters was found at PP1 and PP4 phase in respect of maximum temperature and minimum temperature. | Correlation studies of growth and flowering of Dendrobium cv. sonia with microclimatic variables in different protected structures