Abstract: Effect of seed inoculation and different fertilizer levels on the yield and yield components of mungbean and subsequent rice crop was studied. Results showed that seed inoculation and different fertilizer levels significantly affected yield and yield components of mungbean and rice crops. Treatment (T6) exhibited superior performance for exploiting maximum potential of mungbean crop (954.8 kg ha-1 grains), which was 50% more than that of control. Whereas T7 gave maximum residual effect (4075 kg ha-1 paddy yield), however statistically it was at par with T3, T4, T5 and T6. In conclusion, T6 proved better for getting maximum mungbean yield while T7 produced highest paddy yield.
Introduction
Mungbean (Vigna radiata L.) and rice (Oryza sativa L.) are important crops of Pakistan. Former is popular for its nutritive value and digestibility. It is short duration, drought tolerant and fits well in our crop rotation program. In Pakistan annually 202.7 thousand hectares are put under its cultivation and 94.8 thousand tons of yields are achieved with an average of 468 kg ha-1. Latter is the second largest staple food crop in Pakistan and is also a major export item. Rice is grown on 2515 thousand hectare with an estimated production of 5156 thousand tons, with an average of 2050 kg ha-1 (Anonymous, 2001). The average yield of both the crops is too low. A tangible approach to solve this problem may be the use of fertilizers along with beneficial microbes in agriculture.
Singh et al. (1993) reported that grain yield of mungbean was increased by the application of 20 kg N ha-1 and 40 kg P2O5 ha-1, whereas K2O application has no significant effect. Bahlu et al. (1995) concluded that seed yield of Vigna mungo was increased by seed inoculation, seed yield was also increased when N was applied @ 20 kg ha-1. Patra and Bhattacharyya (1997) observed that highest nodule numbers and seeds yield were obtained by treating the mungbean seeds with rhizobium and applied urea @ 25 kg ha-1. Ali et al. (1998) reported that rice biomass was maximum for azolla (30 kg N + azolla, 7.2%) followed by bacterial treatment (30 kg N + bacteria, 7.0%) and minimum was with 60 kg N ha-1 (-2.3%). Provorov et al. (1998) observed in field trials that inoculation of mungbean seeds with brady rhizobium increased the herbage mass by 6%, seed mass by 3.6 %, mass of 1000-seeds by 0.8%, nitrogen content in seeds by 8.9%, starch content in seeds by 5.5% and number of nodules by 2.54%.
Ahmad (2000) found that PGPR increased paddy yield of two rice cultivars over control. Numbers of tiller hill-1 were significantly affected by all the PGPR inoculants. Straw yield was increased by all bacterial cultures in both cultivars. Kashem et al. (2000) observed that brady rhizobium inoculation and NPK fertilization increased the grain and straw yields of mungbean significantly and obtained the highest grains yield by the treatment 0-30-20 NPK kg ha-1 + inoculum. Shivesh et al. (2000) observed that seed inoculation + 20 kg P2O5 ha-1 to mungbean gave high growth, seed yield and dry matter accumulation. Van et al. (2000) reported that the inoculation had a significant effect on shoot weight (33 %), root weight (57 %) number of tiller hill-1 (13 %) and grain yield (22 %) over uninoculated control. Ashraf (2001) found that in mungbean number of pod plant-1, no. of seeds pod-1 and 1000 grain weight were affected significantly by the application of 50 kg P2 O5 with varying level of N from 20 to 50 kg ha-1 in addition to seed inoculation.
It was therefore, felt that there was an urgent need to determine the effect of seed inoculation and appropriate level of NPK for getting higher seed production of mungbean and subsequent rice crop under Farooqabad (Sheikhupura) conditions.
Materials and Methods
The present studies were carried out at the Agronomic Research Station Farooqabad, District Sheikhupura for two consecutive years (1999, 2000). Experiments were laid out in randomized complete block design with three replications. After harvest of wheat, mungbean variety NM-92 was sown during the 1st fortnight of May and harvested during 2nd week of July. The mungbean seeds were inoculated with Rhizobium phaseoli just before drilling. The whole quantity of fertilizers was side dressed just after sowing. All other agronomic practices for mungbean crop were kept uniform for all the treatments. Subsequently after the harvest of mungbean crop, a fine rice variety Basmati-385 was transplanted during the 2nd week of July in the same plots and harvested during 2nd week of November keeping all other management practices uniform. The following treatments were used:
T1 = No seed inoculation + No fertilizer (control)
T2 = Seed inoculation alone + No fertilizer
T3 = Seed inoculation+20-50-0 NPK kg ha-1
T4 = Seed inoculation+30-50-0 NPK kg ha-1
T5 = Seed inoculation+40-50-0 NPK kg ha-1
T6 = Seed inoculation+50-50-0 NPK kg ha-1
T7 = Seed inoculation+50-50-25 NPK kg ha-1.
Observations regarding various agronomic characteristics of both the crops were recorded by using standard procedure. Data collected and analyzed statistically by using the analysis of variance technique and Duncan's new multiple range tests at 5% probability was applied to compare the treatment means (Steel and Torrie, 1984).
Results and Discussion
Mungbean
Number of pod plant-1: Number of pod plant-1
was significantly (P<0.05) affected by seed inoculation and fertilizer application.
T7 (seed inoculation + 50-50-25 kg NPK ha-1) gave maximum
number of pods plant-1 (26.07) but was statistically at par with
T6 (25.03). While T1 (no seed inoculation + no fertilizer)
produced minimum number of pods plant-1 (13.92) (Table
1). Results are in line with those obtained by Ashraf (2001).
Number of grain pod-1: Seed inoculation and fertilizer application exhibited a positive effect towards number of grain pod-1 (Table 1). Maximum number of grain pod-1 was noted in plot treated with T6, which was statistically at par with T5 and T7. Whereas minimum number of grains pod-1 were received in case of T1. Ashraf (2001) also reported similar results.
1000-grains weight (g): Seed inoculation and NPK application significantly affected 1000-grains weight. Maximum 1000-grains weight was recorded in plots having T6 (42.22 g) with minimum in case of plot applied T1 (37.06). The heavier seed could be because of favorable soil environment and better fertilizer supply, which finally improve the grain weight. Provorov et al. (1998) also reported almost similar results.
Biological yield (kg ha-1): Seed inoculation +50-50-0 kg NPK ha-1 (T6) produced highest biomass (4668 kg ha-1), which was (36%) higher than that of control. Provorov et al. (1998) and Kashem et al. (2000) are in agreement with these results.
Grain yield (kg ha-1): Final grain yield is a function of cumulative effect of various yield parameters. Data reflects that seed inoculation and fertilizer application has a significant effect on grain yield hectare-1. Maximum grain yield (954.8 kg ha-1) was noted in plots applied with T6, while the T1 produced only 635.5 kg ha-1 grains. This increase in yield is due to the better N supply and growth promoting effect of inoculation. These results are in conformity with those of reported by Bahlu et al. (1995), Patra and Bhattacharyya (1997), Kasheem et al. (2000) and Ashraf (2001).
Rice
Number of tiller hill-1: Seed inoculation and fertilizer
application affected number of tiller hill-1 significantly (Table
2). T6 produced maximum number of tiller hill-1, nevertheless
it was statistically at par with T3, T4, T5
and T7. Whereas T1 and T2 produced minimum
number of tiller hill-1. The results are similar with those obtained
by Ahmed (2000), who found that numbers of tiller hill-1 were significantly
affected by all the PGPR inoculants and Van et al. (2000), who stated
that 13 % increase in number of tillers per hill than uninoculated control.
Number of grain panicle-1: The data (Table 2) revealed that different treatments significantly affected number of grain panicle-1. T4 produced maximum number of grain panicle-1 (75.17), while T2 produced minimum number of grain panicle-1 (65.67). Van et al. (2000) reported 13-22% increase in grains per panicle in rice by inoculation.
Biological yield (kg ha-1): Data (Table 2) indicated that seed inoculation and fertilizer had a concrete effect towards biological yield. T4 produced maximum biomass (17460 kg ha-1), however statistically it was at par with T3, T5, T6 and T7. The results are in conformity with the results got by Ali et al. (1998).
Straw yield (kg ha-1): Maximum straw yield was obtained from plot treated with T4 (13390 kg ha-1), however statistically it was at par with T3 and T 7. T2 produced the minimum straw yield (10970 kg ha-1) (Table 2).
| Table 1: | Various agronomic characteristics of mungbean as affected by seed inoculation and different fertilizer levels |
| Table 2: | Various agronomic characteristics of rice as affected by seed inoculation and different fertilizer levels |
| Means followed by different letters differ significantly at 5% level of probability. | |
Results are in line with those maintained by Ahmed (2000) who reported that straw yield of rice was increased by all bacterial cultures.
Paddy yield (kg ha-1): T7 (Seed inoculation+50-50-25 NPK kg ha-1) produced maximum paddy yield kg ha-1 (4075); nevertheless, statistically it was at par with T3, T4, T5 and T6. This yield of T7 was about 16% higher than that of control. This increase in yield is due to the residual effect of P2O5 and K and growth promoting effect of inoculation. Results rare in agreement with those obtained by Ali et al. (1998), Ahmed (2000) and Van et al. (2000).
In conclusion, T6 (Seed inoculation+50-50-0 kg NPK ha-1) exhibited superior performance for exploiting maximum potential of mungbean, while T7 has better residual effect on rice crop as it produced 16% more paddy yield over control. Alone inoculation is not sufficient for getting higher yield of both crops and mungbean can be successfully grown between wheat and rice crop.