Praveen KV*, Patel SR, Choudhary JL and Bhelawe S
Department of Agrometeorology, College of Agriculture, IGKV, Raipur 492012, Chhattisgarh, India
Received date: July 30, 2013; Accepted date: September 26, 2013; Published date: October 02, 2013
Citation: Praveen KV, Patel SR, Choudhary JL, Bhelawe S (2013) Heat Unit Requirement of Different Rice Varieties Under Chhattisgarh Plain Zones of India. J Earth Sci Clim Change 5:165. doi:10.4172/2157-7617.1000165
Copyright: © 2013 Praveen KV, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Field experiment was carried out during kharif season of 2012 at Research and Instructional Farm of Indira Gandhi Agricultural University, Raipur to examine yield and Heat unit requirement of rice with three genotypes as influenced by three sowing dates in factorial Randomized Block Design. Higher grain yield was recorded with Mahamaya as compared to Karma Mahsuri and MTU-1010 under 10th June sowing also with respect to heat units the cumulative growing degree day at maturity stage was (2410˚C) for Karma Mahsuri followed by Mahamaya (2365˚C) and MTU-1010 (2161˚C) when sown on 10th June. Maximum growing degree days were observed in early sown crop (10June) as compared to late sown crop (20 and 30June). Similar results were found in the case of photo thermal unit and helio thermal unit also. At maturity stage, highest radiation use efficiency in 10th June sowing might be due to better conversion of light in to dry matter, better yield component and harvest index in 10th June sowing as compared to 30th June sowing.
Growing degree days; Pheno thermal unit; Heat use efficiency; Helio thermal unit; Sowing dates
Weather and climate greatly influence the agricultural productivity in any region. Agricultural production and productivity of any region is being regulated by the prevailing climate of that area through temperature, rainfall, light intensity, radiation, sunshine duration etc. . The importance of temperature and humidity in enhancing plant nutrient availability and absorption and also the role they play in disease and pest infestation is well documented.
Rice is the most consumed cereal grain in the world constituting the dietary staple food of more than half of the world population. Apart from food rice is intimately involved in the culture as well as economy of many societies. India is the second largest producer of rice after China having an over of 44.10 million hectare with the production of 105.31 million tonnes (United State Department of Agriculture, 2011-12).
Chhattisgarh popularly known as “Rice Bowl of India” occupies an area around 3610.47 thousand hectare with the production of 5.48 Mt and productivity of 1517 kg per hectare .
The experiment was set at Research and Instructional farm of Indira Gandhi Krishi Vishwavidyalaya; Raipur situated in Eastern Central part of Chhattisgarh at latitude of 21°.16’ N, longitude 81°.36’ E and altitude 289.5 m above mean sea level. The present experiment was conducted during the kharif season of 2012. Three rice cultivars, viz. Karmamasuri, Mahamaya and MTU-1010 were used and cultivated in a factorial Randomized Block Design (RBD) with three sowing dates. The GDD, PTU, HTU, PAR and HUE were computed by using following formula:
Accumulated Growing Degree Days (GDD)
GDD = Σ [(Tx + Tn) / 2 - Base temperature]
Tx=Daily maximum temperature
Tn=Daily minimum temperature
Accumulated Photothermal Unit (PTU)
PTU is calculated by multiplying GDD with maximum possible sunshine hours (N)
PTU = GDD X N
N = maximum possible sunshine hour.
Accumulated Heliothermal Unit (HTU)
HTU is calculated by multiplying GDD with actual sunshine hours (n)
HTU = GDD X n
n = actual sunshine hour.
Heat Use Efficiency (HUE)
Heat Use Efficiency (HUE) for total dry matter was obtained as under
Radiation Use Efficiency (RUE)
RUE (gMJ-1)=Biomass (g/m2)/Radiation intercepted (MJ/m2/day)
Grain yield (kg/ha)
Grain yield as influenced by different sowing dates are given in Table 1. Sowing dates and verities showed significant variation on grain yield. On the mean basis the higher grain yield (5950 kg/ha) was recorded in variety Karma Mahsuri followed by Mahamaya (5399 kg/ ha) and MTU 1010 (5216 kg/ha). On an average the first date of sowing shows maximum yield (6021 kg/ha) followed by second date of sowing and then third date of sowing.
Figure1 shows on an average basis Grain yield trend of different rice varieties as influenced by different sowing dates in three successive years. It is clear from figure that karma masuri is the highest yielding verity (5950 Kg/ha) in the region followed by Mahamaya (5399 kg/ha).
Phenology and heat units
The heat units acquired by different varieties during growth stages are shown in Table 2.The higher GDD was accumulated in the first date of sowing during all the growth stages starting from planting to maturity. Among the different varieties the higher GDD was accumulated in Karma Mahsuri whereas, the least GDD accumulated in MTU 1010. From the table it was also observed that the highest Photo thermal Unit during maturity was recorded in 10th June sowing followed by 20th June sowing. Among the varieties the higher PTU was observed in variety Karma Mahsuri followed by Mahamaya, while the least PTU is observed in variety MTU-1010.
With regard to phenol thermal index the minimum values were recorded in 30th June sowing during all the stages and the maximum values were recorded in 10th June sowing. Among different rice varieties, Karma Mahsuri recorded minimum phenol thermal index whereas, the maximum phenol thermal index was observed in variety MTU-1010.
The data on yield attributes are shown in Table 3. It was observed from the table that sterility % straw yield and harvest index were recorded highest with 10th June sowing, whereas the number of grains/ panicle was recorded highest with 20th June sowing but the test weight and number of panicle/m2 were recorded maximum with 30th June sowing among the different dates of sowing. Among the different varieties, the maximum values of number of grains/panicles, sterility %, number of panicle/m2 and harvest index was recorded in variety Karma Mahsuri. Whereas the maximum values of test weight were recorded in Mahamaya, straw yield was maximum in MTU-1010. It was also observed that first date of sowing D1 (10th June) got highest harvest index (45.96) followed by third date of sowing D3 (30th June) 42.73.
Highest radiation use efficiency in 10th June sowing might be due to better conversion of light in to dry matter, better yield component and harvest index in 10th June sowing as compared to 30th June sowing. Similar results are also reported [3-6].
Based on the above findings it was concluded that higher grain yield and straw yield along with the heat units viz. accumulated growing degree days, photo thermal unit, helio thermal unit, radiation use efficiency and heat use efficiency were recorded maximum in crop sown on 10th June as compared to on 20th June and 30th June sown. On the other hand it can be concluded that early sowing dates is better than delayed sowing. With respect to varieties Karma Mahsuri recorded maximum grain yield and straw yield along with heat units viz. growing degree day, photo thermal and helio thermal units whereas, radiation use efficiency and heat use efficiency were maximum in Mahamaya.
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