International Journal of Botany

Year: 2006 | Volume: 2 | Issue: 1 | Page No.: 42-47
DOI: 10.3923/ijb.2006.42.47

Influence of Seed Treatment with Indole Acetic Acid on Mungbean Cultivation

Rumman Shafi Quaderi, Shah Md. Asraful Islam, A.F. M.G. Faruque Hossain, Md. Manzurul Hoque and Md. Shahidul Haque

Abstract: The study was carried out in the Field Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during the period from October 2000 to February 2001 to evaluate the influence of seed treatment with Indole Acetic Acid (IAA) by the concentration of 50 ppm, 100 ppm and 200 ppm on the growth, yield and yield contributing characters of two modern mungbean (Vigna radiata L.) varieties viz. Barimoog-4 and Barimoog-5. The two-factor experiment was laid out by Randomized Complete Block Design (RCBD) with 3 replications. In the experimental, seed treatment with 100 ppm IAA resulted the highest plant height, leaf area, leaf area index and number of seeds pod^-1 (7.73). On the other hand, seed treatment with 200 ppm IAA resulted the highest Relative Growth Rate (RGR), Crop Growth Rate (CGR), Net Assimilation Rate (NAR), total dry matter, number of pods plant^-1 (16.30), pod length (5.59 cm), fresh weight of pod plant^-1 (13.00 g), dry weight of pod plant^-1 (9.65 g), 1000-seed weight (40.10 g), seed yield plant^-1 (4.99 g), harvest index (38.48). In addition, among the mungbean varieties, Binamoog-5 performed better than that of Binamoog-4.

Keywords: growth, seed treatment, Indole acetic acid, Vigna radiata, Mungbean and yield

INTRODUCTION

Mungbean (Vigna radiata L.) is an important pulse crop of global economic importance. It ranks first position in price, fourth in acreage and sixth in production in Bangladesh (BBS, 2001). Mungbean covers an area of 55,100 ha and production was about 36,000 metric tons (BBS, 2001). Mungbean has a special importance in intensive crop production system of the country for its short growing period (Ahmed, 1989). Mungbean contains 51% carbohydrate, 26% protein, 10% moisture, 4% mineral and 3% vitamin. Hence, mungbean is the best of all pulses on nutritional point of view (Khan, 1981; Kaul, 1982). Mungbean is deep-rooted plant, opens up soil by penetrating root system where the roots decay and improve aeration. Moreover, it increases soil fertility through biological nitrogen fixation (Hoque, 1989). The average yield of mungbean in Bangladesh is about 570 kg ha^-1, which is much lower than that of India and some other countries of the world. The crop has received very little attention by the researchers in comparison to other cereals and grain crops. Indole Acetic Acid (IAA) is one of the important plant growth regulators, which can manipulate a variety of growth and developmental phenomena in various crops. A foliar application of IAA has bean found to increase plant height, number of leaves/plant, fruit size with consequent enhancement in seed yield in different crops like groundnut (Lee, 1990), cotton (Kapgate et al., 1989) and cowpea (Khalil and Mandurah, 1989). Research on pre-sowing seed treatment of mungbean is very limited. In view of above facts, the present research work was designed to evaluate the influence of pre-sowing seed treatment with indole acetic acid on the growth, yield and yield contributing characters of two modern mungbean varieties viz., Barimoog-4 and Barimoog-5.

MATERIALS AND METHODS

The experiment was conducted at the Field laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during the period from October, 2000 to February, 2001. There were four treatments viz., (I) T₁= Control (untreated), (ii) T₂= 50 ppm IAA, (iii) T₃= 100 ppm IAA and (iv) T₄= 200 ppm IAA. Two mungbean varieties viz., (I) V₁= Barimoog-4 and (ii) V₂= Barimoog-5 were used in the experiment. The land was prepared by three ploughing followed by laddering. The stubbles were removed from the land. The two-factor experiment was laid out by Randomized Complete Block Design (RCBD) with three replications. The two varieties were considered as the factor A and the treatments were considered as the levels of factor B. There were altogether eight treatment combinations. So the total numbers of plots were 24 and the size of unit plot was 2x1 m. The block-to-block and plot-to-plot distance was 1m and 0.5 m, respectively. The land was fertilized at 6 ton cowdung ha^-1, 66 kg ha^-1 urea, 82 kg ha^-1 TSP and 33 kg ha^-1 MP. The fertilizers were applied at final land preparation (BARC, 1997). Seed rate was 25 kg ha^-1. Seeds were soaked in IAA solution as per treatments for 3 h. In case of control, seed were soaked only in water. Seeds were sown in line sowing method maintaining 2 to 3 cm depth. Line to line and seed to seed distance was 30 cm and 15 cm and 2 seeds were placed in each point. The young plants were irrigated by water cans. Moreover, first weeding and second weeding followed by thinning was done at 15 and 45 days after sowing. Besides, Dimecrone 50 EC was sprayed at 1 L ha^-1 to prevent pod borer infestation. The first crop sampling was done on 25 days after sowing and it was continued up to 55 days after sowing at 10 days interval. At the time of each harvest, five plants were selected from each plot and leaf area, plant height, number of leaves per plant was recorded separately at each harvest. Physiological parameters like Leaf Area Index (LAI), Crop Growth Rate (CGR), Relative Growth Rate (RGR), Net Assimilation Rate (NAR) and total dry matter were also measured (Hunt, 1978). In addition, different yield contributing characters viz., number of pods plant^-1, pod length, fresh weight of pod plant^-1, dry weight of pod plant^-1, number of seeds pod^-1, thousand seed weight, seed yield/plant, seed yield was recorded and harvest index was measured (Donald, and Humblin, 1976). The collected data were statistically analyzed and the treatments mean were compared by DMRT (Gomez and Gomez, 1984).

RESULTS AND DISCUSSION

Influence of seed treatment with IAA on morphological characters of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 1). It was revealed that seed treatment with IAA had stimulatory effect on plant height. The application of 200 ppm IAA had superiority influence over 50 and 100 ppm IAA. It indicates that, plant height increase proportionately the increasing of the concentration of IAA in seed treatment from 50 ppm to 200 ppm. IAA induced higher plant height was reported earlier in soybean (Reena et al., 1999), grasspea (Rahman et al., 1989) and groundnut (Lee, 1990). The stimulatory effects of IAA on plant height in the present experiment agree well with the above findings. However, The maximum number of leaves plant^-1 was achieved by 50 ppm IAA at 35 and 55 DAS and 100 ppm IAA at 25 and 45 DAS. It means that the maximum number of leaves vary in between 50 ppm to 100 ppm from 25 to 55 DAS. In case of leaf area, 200 ppm IAA had the majority of higher leaf area throughout the earlier growth stages (25 and 35 DAS). But in the later two stages (45 and 55 DAS), the highest leaf area was found at 100 ppm IAA. Deotale et al. (1998) reported that when soybean seeds were treated with 0-150 ppm GA₃, the highest leaf area was obtained with 100 ppm. This finding is evident that plant growth regulators have influence on leaf area in pulses. The effect of IAA on leaf area index was significant at all the growth stages. The highest LAI was found at all the growth stages expect 25 DAS with 100 ppm IAA.

Influence of varieties on morphological characters of mungbean was studied at 10 days interval from 25 to 55 days after sowing (Table 2). Significant variation in plant height between the two varieties was found at different growth stages. Barimoog-5 had the highest plant height and always remains higher than that of Barimoog-4 in all growth stages. It was in agreement with the result of Thakuria and Saharia (1990) who reported that plant height differed among the varieties. However, higher number of leaves was found in Barimoog-4. The highest leaf area per plant was produced in Barimoog-5 at all stages expect 45 and 55 DAS. Similarly, Barimoog-5 had the highest leaf area index at all growth stage. The superiority of the varieties to each other seems to be due to its genotypic influence.

Interaction effect of seed treatment with IAA and varieties on morphological characters of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 3). The tallest plants were found in V₂T₄ at all counting dates. However, maximum number of leaves was found in V₁T₃ at 25 DAS and V₂T₂ at other counting dates.

On the contrary, maximum leaf area per plant and leaf area index was found in V₂T₃ at all counting dates.

Influence of seed treatment with IAA on physiological characters of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 4). The relative growth rate was maximized at 25 DAS and decreased with the advancement of crop growth in all treatments. However, crop growth rate increased gradually with the advancement of crop growth and maximized in 100 ppm IAA at 45 DAS and 200 ppm IAA at 55 DAS. Katiyar (1980) observed that application of IAA increase crop growth rate. This finding agreement with the above report. The highest NAR was obtained by 200 ppm IAA at 25, 35 and 55 DAS. But in 45 DAS obtained highest NAR by 50 ppm IAA. The highest total dry matter (2.601 g) was found at 55 DAS with 200 ppm IAA. Total dry matter of a crop is the output of net assimilation. It is mainly depended on the size of photosynthic system (Watson, 1947). In this study IAA increased the plant growth as well as the total dry matter by creating more activity of photosynthesis. Besides, Thakur and Panwar (1995) reported that IAA and GA₃ increased total dry matter in faba bean, it indicate that plant hormones can influence the total dry matter in plants.

Influence of varieties on physiological characters of mungbean on physiological characters of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 5). Maximum relative growth rate (RGR) was found in Barimoog-5 at 25, 35 and 45 DAS. But Barimoog-4 resulted highest RGR at 55 DAS. In case of crop growth rate, Barimoog-4 responded better than Barimoog-5 at 25 and 55 DAS. On the contrary, Barimoog-5 responded better than Barimoog-4 at 35 and 45 DAS.

Barimoog-4 resulted higher net assimilation rate (NAR) than Barimoog-5 at all growth stages. In contrast, Barimoog-4 resulted higher total dry matter at all growth stages except 45 DAS.

Interaction effect of seed treatment with IAA and varieties on physiological characters of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 6). Maximum relative growth rate was found in V₂T₁ at 25 DAS, V₁T₁ at 35 and 55 DAS and V₂T₃ at 45 DAS. The highest crop growth rate was found in V₁T₄ at 25, 35 and 55 DAS and V₂T₃ at 45 DAS. The highest net assimilation rate was found in V₁T₄ at 25 and 35 DAS, V₁T₂ at 45 DAS and V₁T₄ at 55 DAS. The highest total dry matter was found in V₁T₄ at 25, 35 and 55 DAS and V₂T₃ at 45 DAS.

Influence of seed treatment with IAA on yield and yield contributing characters of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 7). Yield and contributing characters varied significantly from one treatment from another. Number of pods plant^-1 ranged from 13.34 to 16.30, where the highest count of pods plant^-1 was made in the plots of 200 ppm IAA, which was identical to the application of 100 ppm IAA. Similarly, Lee (1990) reported that soaking groundnut seed in solutions of 50, 100 and 200 ppm IAA prior to sowing produced plants with greater number of pods per plant. Pod length was varied from 4.63 to 5.95 cm, where the tallest pod was found by the treating seed with 200 ppm IAA. The highest fresh weight of pod plant^-1 (13.00 g) and dry weight of pod plant^-1 (9.65 g) was found by the treating seed with 200 ppm IAA, which were identical to the application of 100 ppm IAA. But the highest count of seeds pod^-1 (7.73) was made in the plots of 100 ppm IAA, which was identical to the application of 200 ppm IAA. Abdul et al. (1996) noted that the number of seeds pod^-1 was increased by 10^-5 M IAA. Similarly, IAA treated plants had higher number of seeds pod^-1 compared to the control in the present study. The highest 1000-seed weight (40.10 g) was found with 200 ppm IAA and the lowest in control. The seed yield of mungbean was influenced by the treating seed with IAA. Seed yield plant^-1 varied from 2.99 to 4.99 g, where the maximum seed yield plant^-1 was obtained by the treating seed with 200 ppm IAA and the lowest in control. Arora et al. (1988) reported that application of IAA at the 50 % flowering stage increased yield per plant compared with control. Zarrin and Asghari (1998) also found that seed treatment with 10^-6 M IAA increase seed yield plant^-1 in soybean. The highest harvest index (38.48%) was obtained by 200 ppm IAA and the lowest in control. Khan (1997) noted that application of IAA and GA₃ had favorable influence on harvest index.

Influence of varieties on yield and yield contributing characters of two cultivars of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 8).

The highest number of pods plant^-1, fresh weight of pod plant^-1, dry weight of pod plant^-1, 1000 seed weight, seed yield plant^-1 and harvest index was found in Barimoog-5. On the other hand, the highest pod length and number of seeds^-1 pod was found in Barimoog-4.

Interaction effect of seed treatment with IAA and varieties on yield and yield contributing characters of mungbean was recorded at 10 days interval from 25 to 55 days after sowing (Table 9). The highest number of pods plant^-1, fresh weight of pod plant^-1 and dry weight of pod plant^-1 was found V₂T₃. The highest pod length and 1000-seed weight was found in V₁T₄ and V₂T₄, respectively. On the other hand, the highest seed yield plant^-1 and harvest index was found in V₂T₃.

REFERENCES