INFLUENCE OF RESIDUAL LIME AND PLANT GROWTH REGULATOR ( NAA ) ON THE MORPHOLOGICAL AND PHYSIO-CHEMICAL TRAITS OF AROMATIC RICE CV . KATARIBHOG

Aromatic rice possess high potential to draw attention rice consumer of the world for its aroma, fragrance, grain morphology, quality and other desirable traits. The production of aromatic fine rice is profitable due to its prices up to 10 times more than common rice on international market (Chaudary et al., 2001). In Bangladesh, a number of fine rice cultivars are grown by the farmers specially Kataribhog, Chinisagar, Badshabhog, Kalizira, Tulsimala, Dulabhog, Basmati, Banglamoti (BRRI dhan50), BRRI dhan34, BRRI dhan37 and BRRI dhan38. Liming is a normal agronomic practice to manage acid sulfate soils for crop production. In Malaysia, some areas of acid sulfate soils have been reclaimed for rice cultivation using lime. In the acid sulfate soils of the Muda Agricultural Development Authority (MADA) granary areas in Kedah-Perlis coastal plains (northwest coast of Peninsular Malaysia), for instance, rice yield improved significantly after applying 2.5 tons of ground magnesium limestone (GML) ha -1 . However, over liming may reduce crop yields due to lime induced P and micronutrient deficiencies (Fageria, 1984). Plant growth regulators (PGRs) are organic compounds, other than nutrients that modify plant physiological processes and also called biostimulants or bioinhibitors that act inside plant cells to stimulate or inhibit specific enzymes or enzyme systems and thus regulate plant metabolism. Recently, there has been global realization of the important role of PGRs in agriculture for better growth and yield of crop (Prasad and Paudel, 1994). These (PGRs) are being used as an aid to enhance yield. Naphthalene Acetic Acid (NAA) is one of the growth promoting hormones, which may play significant role to change growth characters and yield in BRRI dhan28.

Aromatic rice possess high potential to draw attention rice consumer of the world for its aroma, fragrance, grain morphology, quality and other desirable traits.The production of aromatic fine rice is profitable due to its prices up to 10 times more than common rice on international market (Chaudary et al., 2001).In Bangladesh, a number of fine rice cultivars are grown by the farmers specially Kataribhog, Chinisagar, Badshabhog, Kalizira, Tulsimala, Dulabhog, Basmati, Banglamoti (BRRI dhan50), BRRI dhan34, BRRI dhan37 and BRRI dhan38.Liming is a normal agronomic practice to manage acid sulfate soils for crop production.In Malaysia, some areas of acid sulfate soils have been reclaimed for rice cultivation using lime.In the acid sulfate soils of the Muda Agricultural Development Authority (MADA) granary areas in Kedah-Perlis coastal plains (northwest coast of Peninsular Malaysia), for instance, rice yield improved significantly after applying 2.5 tons of ground magnesium limestone (GML) ha -1 .However, over liming may reduce crop yields due to lime induced P and micronutrient deficiencies (Fageria, 1984).Plant growth regulators (PGRs) are organic compounds, other than nutrients that modify plant physiological processes and also called biostimulants or bioinhibitors that act inside plant cells to stimulate or inhibit specific enzymes or enzyme systems and thus regulate plant metabolism.Recently, there has been global realization of the important role of PGRs in agriculture for better growth and yield of crop (Prasad and Paudel, 1994).These (PGRs) are being used as an aid to enhance yield.Naphthalene Acetic Acid (NAA) is one of the growth promoting hormones, which may play significant role to change growth characters and yield in BRRI dhan28.
The PGRs play vital roles in coordination of many growth and behavioral processes in rice, which regulates the amount, type and direction of plant growth (Anjum et al., 2011).The use PGRs, as NAA, GA 3 or their compounds, is becoming popular to ensure efficient production.Remarkable accomplishments of PGRs such as manipulating plant growth and crop yield have been actualized in recent years (Morinaka et al., 2006;Zvi and Eduardo, 2011).The PGRs modify growth and development in various ways under different growth conditions.NAA and GA3 is responsible for stimulating the production of mRNA molecules in the cells, which in turn improves the chances of fast growth (Olszewki and Gubler, 2002;Emongor, 2007).Recently, the scientists of Bangladesh are being advised to use PGRs to get higher rice production.But the research on examining the combination effect of NAA and lime application in acid piedmont soil for better rice yield is still in initial stage.Yield is the cumulative effect of a variety with its inherent characteristics, management practices and the environment in which it is grown.Variety is one of the most important factors for increasing yield.Thus a study was undertaken with the objectives of identifying the suitable dose of NAA in order to achieve both quantitative and qualitative effect on aromatic rice production.Work on NAA with lime is limited to improve the rice yield in Northwest Bangladesh.Studies in other countries of the world although provides useful information, that cannot be recommended or practiced without trial in our local condition.Therefore, more researches or trials are necessary to investigate the efficacy of NAA on aromatic rice.Thus, the present study was carried out -i) to study the effect of NAA and residual lime effect on growth characteristics of Kataribhog.ii) to know the flag leaf composition of aromatic rice and the yield of Kataribhog.
The study was conducted at agricultural farm, Department of Agricultural Chemistry, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during February to May, 2011.The rice variety Kataribhog rice was used as a test plant.Lime were applied (see modification in abstract) @ T 1 = 0 t ha -1 (Control), T 2 = 1.0 t ha -1 , T 3 = 1.5 t ha -1 , T 4 = 2 t ha -1 , T 5 = 2.5 t ha -1 used in previous crop at summer mungbean cv.BARImung-7.Treatment @ H 0 = 0 ppm NAA (Control), H 1 = 100 ppm NAA, H 2 = 150 ppm NAA and H 3 = 200 ppm NAA spraying at vegetative and pre-flowering stages while water was used as control (H 0 ).The experiment was laid out in a randomized complete block design with three replications.Thirty five days old seedlings were transplanted in February, 2012 using three seedlings hill -1 .Recommended dose of triple super phosphate (180 kg ha -1 ), muriate of potash (100 kg ha -1 ), gypsum (20 kg ha -1 ) and zinc (7.5 kg ha -1 ) were incorporated to soil at final land preparation.Urea (215 kg ha -1 ) was applied in three equal splits at 20, 35 and 55 DAT.Data on yield and yield contributing parameters, plant height, flag leaf length, flag leaf width, leaf numbers plant -1 , tiller numbers hill -1 were recorded at maturity, while the panicle numbers hill -1 , filled grains panicle -1 , unfilled grains panicle -1 , 1000-grain weight, grain length, grain width, grain yield ha - 1 , straw yield ha -1 , harvest index were recorded after harvest (synchronized all parameter).Chemical compositions of flag leaves under different treatments using PGR in the lime tested plots were estimated.The K, Ca, Mg, Zn, Cu and Fe content of flag leaves were estimated as per standard methods.Leaf chlorophyll-a, chlorophyll-b and total carotenoid were also monitored from green flag leaves.The data were statistically analyzed to compare treatment means using the MSTATC computer software developed, (Russell, 1986).If the treatments were significant the differences between pairs of means were compared by LSD followed by Duncan's Multiple Range Test (DMRT) (Gomez and Gomez, 1984).
Plant height (cm) at maturity stage in table 1 indicated that combined effect of different levels of plant growth regulator (PGR) and residual lime had significant stimulatory effect.Maximum height (138.70 cm) was obtained from the application of both 2 t ha -1 residual lime and 100 ppm NAA while shortest plant (107.00)cm was recorded from T1 × H 2 and T 2 × H 0 treatments respectively.It seems to be due to intact cells elongation.Watanabe and Saigusa, 2004 stated that plant height was significantly increased by the application of 50 ppm ethephon, 100 ppm GA 3 alone or in combination over that of control.The number of tillers is one of the most important factors for yield.Tiller production especially the number of effective tillers is the potential factor for yield component.Both the number of tillers and effective tillers hill -1 was significantly increased with the concentrations of 100 ppm NAA and 2 t ha -1 residual limes.The highest number of tillers and effective tillers hill -1 were 14.67 and 12.00 respectively while the lowest tiller numbers and effective tillers (10.00) were recorded from 200 ppm NAA and no residual lime application (Table 1).Similar trend was reported through Miyodo application by (Islam, 2007).Leaf numbers, flag leaf length and flag leaf breadth are the most important growth characters of plant on which crop yield depends.The number of leaves was highest at maximum tillering stage of growth and decreased thereafter (Islam, 2008).The decreased in leaf number at later stages of growth might be due to senescence or drying up of leaves.Maximum number of leaves (7.00) was obtained from 100 ppm NAA with 1.5 t ha -1 residual lime application.Both NAA and residual lime markedly increased flag leaf length and breadth (Table 1).Plant hormones play important role in regulating the leaf numbers and leaf area (Liu et al., 2012).
The panicle length and number of filled grains panicle -1 as well as number of unfilled grains panicle -1 are very important parameters to evaluate the yield performance of a variety in response to a specific treatment.Table 2 showed that the highest values of panicle length, filled grains panicle -1 , unfilled grains panicle -1 , grain yield and straw yield (28.00 cm, 139.30, 39.67, 1.63 t ha -1 and 7.00 t ha -1 respectively) where as the lowest values of panicle length, filled grains panicle -1 , unfilled grains panicle -1 , grain yield and straw yield (18.00 cm, 105.7, 18.00, 0.80 t ha -1 and 4.25 t ha - 1 , respectively).Panicle length, filled grains and grain yield differed significantly and increased by the application of both PGR and lime (Table 2).Maximum grain yield was observed due to application of 100 ppm NAA and 2 t ha -1 residual effect of lime Here, T 1 = 0 t ha -1 (Control), T 2 = 1.0 t ha -1 , T 3 = 1.5 t ha -1 , T 4 = 2 t ha -1 , T 5 = 2.5 t ha -1 and H 0 = 0 ppm NAA (Control), H 1 = 100 ppm NAA, H 2 = 150 ppm NAA, H 3 = 200 ppm NAA application.(Gurmani et al., 2006), they stated that ABA, BA and CCC plant growth regulators increased grain yield of rice.The finding is also similar with Pandey et al., 2001, whom reported that IAA @ 50 ppm produced significantly maximum grain yield plant -1 , 1000-grain weight and yield kg ha -1 .The present result also agrees with the findings of previous studies (Andreevska et al., 2004;Islam et al., 2008).Harvest index is the ratio of economic yield and biological yield, and the ultimate partitioning of dry matter between grain and vegetative parts is indicated by HI, the economic yield of rice is its grain, biological yield of a crop is the TDM at final harvest (Davald and Hamblin, 1976).Table 2 showed that, the highest percentage of Harvest Index (HI) was found at T 3 ×H 1 (21.22%) and lowest was at T 2 ×H 2 (13.07%).This result confirmed the results of previous studies (Islam, 2007;Islam et al., 2008).Chlorophylls are the most widely distributed plant pigments responsible for the characteristic green color of fruit and vegetables (Almela, 2000).A significant variation was found in chlorophyll-a, chlorophyll-b, total chlorophyll and total caroteinoid content through combined effect of PGR and lime (Table 3).The highest amount of chlorophyll-a content of flag leaf was observed in T 4 ×H 1 (20.60 mg g -1 FW) followed by T 1 ×H 1 (20.32 mg g -1 FW) and T 4 ×H 3 (20.13mg g -1 FW) combination while the lowest chlorophyll-a content of flag leaf was observed in T 4 ×H 2 (16.49mg g -1 FW).The highest value of chlorophyll-b content were found in both T 2 ×H 2 and T 4 ×H 1 (11.78 mg g -1 FW) and while the lowest chlorophyll-b content was found in T 5 ×H 1 (5.69 mg g -1 FW).The highest total chlorophyll was obtained in T 4 ×H 1 (32.38 mg g -1 FW) followed by T 1 ×H 1 (31.40 mg g -1 FW) while the lowest total chlorophyll content was happen in T 5 ×H 1 (24.12 mg g -1 FW) treatment combination (Table 3).The highest mean value of total carotenoid content was found in T 4 ×H 0 (2.15 mg g -1 FW) while the lowest carotenoid content was obtained in T 5 ×H 2 (0.76 mg g -1 FW).Table 4 showed there is no significant variation in K content in flag leaves.The highest K content were found in T 2 ×H 3 and T 4 ×H 3 (0.59 mg l -1 ) while the lowest was obtained in T 1 ×H 3 (0.47 mg l -1 ).The residual effect of 2 ton ha -1 lime along with 200 ppm NAA helps to uptake highest rate of K in flag leaves.The status of K improved the rice straw quality.The variation of K content in different varieties was variable (Sarwar et al., 2010).A significant variation was found in flag leaves Ca content in relation to application of various levels of residual lime and NAA (Table 4).Maximum Ca content was found in T 3 ×H 1 (131 mg l -1 ) while the lowest was found in T 1 × H 3 (100 mg l -1 ).This result revealed that 100 ppm NAA may have positive impact on Ca content in rice leaf.Secondary nutrient plays important roles in plant life.Calcium is an essential part of cell structure and plays its role in cell division (Tandon, 2000).The total Mg uptake differed significantly with respect to application of different levels of lime and PGR applied in combination (Table 4).The highest Mg content was recorded in T 3 ×H 1 (33.60 mg l -1 ) followed by T 4 ×H 1 (31.1 mg l -1 ).On the other hand, the lowest was recorded in T 1 ×H 3 (20.70mgl -1 ).Magnesium is an integral part of chlorophyll and thus, linked with photosynthesis.It plays an important role in energy transfer processes in plants (Tandon, 2000).
There is no significant variation in Zn and iron content in flag leaves (Table 4).Similar result was obtained by (Tomasevei and Anicic, 2010).The iron content of the flag leaf of Kataribhog rice cultivar also showed a significant variation in relation to NAA and residual effect of lime (Table 2).The highest amount of flag leaf iron content was found in T 1 ×H 0 (2.56 mg l -1 ) followed by T 3 ×H 3 (2.54mg l -1 ) treatments.On the other hand, the lowest was found in T 5 ×H 0 (1.07 mg l -1 ).
From the above findings, it can be concluded that Napthalene Acetic Acid and residual effect of lime significantly affected the yield as well as yield contributing parameters of Kataribhog rice, especially at 100 ppm NAA and 2 t ha -1 of lime application.

Table 1 .
Effect of PGR and residual lime on morphological and growth characters of Kataribhog rice

Table 2 .
Effect of PGR and residual lime on yield attributes and yields of Kataribhog rice

Table 3 .
Effect of PGR and residual lime on Chlorophyll content (mg g -1 ) in flag leaf of Kataribhog rice

Table 4 .
Effect of PGR and residual lime on leaf nutrient composition (mg g -1 ) in flag leaf of Kataribhog rice