The bacterial mixture effect of Azotobacter and Azospirrilum on nitrogen content and harvest date of upland red rice cultivar

The research aims were to analyse the effect of bacterial mixture of Azotobacter and Azospirrilum on the nitrogen content and harvest date of upland red rice. This research was conducted in Agriculture Farm of Agriculture Faculty in Halu Oleo University. The research was arranged in a split plot design. The bacterial mixture dosage as main plot and different of cultivar as sub plot. The bacterial mixture dosage were without application bacterial mixture, Bacterial combination mixture of Azotobacter 2.5 L ha−1 + Azospirillum 2.5 L ha−1, and Bacterial combination mixture of Azotobacter 5.0 L ha−1 + Azospirillum 5.0 L ha−1. The cultivar tested were Labandiri, Jangkobembe, Ranggohitam, and Paedara. This research shows that application of bacterial mixture had no significant effect on nitrogen leaf content, but had a significant effect on flowering time and harvesting. It was found that flowering time tended to accelerate, but on harvesting-date parameters tended to be prolonged.


Introduction
Rice is a dominant staple food and the needed always to be increased every year follow the population increase [1]. Rice is not only as main source of carbohydrat but in the form of red rice, also source of anthocyanins [2], antioxidant [3-4] that good for healthy life [5]. Production of red rice always coincidence with the production of upland rice [6]. It must be developed in a healthy and eco friendly manner [7] as organic rice. To fulfill the rice need, various program introduced to maintain the rice sustainability. It is starting from the increase of seed quality [8-9], using plant breeding approach through the irradiance [10] or hybridization [11][12][13][14], development alternative farming system [15][16][17][18][19], using hybrid variety [20][21] and decreasing level rice consumption [22].
Most of the production-enhancing effort is achieved through the provision of inorganic fertilizer as one of the preferred technologies [23]. The main alternative is the use of inorganic fertilizers, as it is easy to observe the effects of fertilization [24]. Continued use of inorganic fertilizers can, however, lead to decrease in soil fertility [25] and environmental sustainability [26][27].
Another option that can be used and more secure is by fertilizing using organic fertilizer. Application of biological fertilizers non symbiotic fixing-nitrogen as Azotobacter sp [28][29] and Azospirillum sp [30][31] were able to reduce the use of inorganic fertilizer and preventing a decrease in  [32][33][34]. Azotobacter and Azospirillum produce growth hormones and have ability to fix nitrogen from the air [35][36]. The earlier researcher found that Azotobacter and Azospirillum can increase plant growth [37][38] and production [39][40]. The application of organic fertilizer that enriched with biological fertilizers had good prospects to increase growth of plant and also environmentaly sound. The research aims were to analyse the effect of bacterial mixture of Azotobacter and Azospirrilum on the nitrogen content and harvest date of upland red rice.

Materials and methods
The research was arranged in split plot design with three replication. The main plot was the different doses of bacterial fixator, consisting of three levels such as b0= without bacterial fixator, b1 = Azotobacter 2.5 L ha -1 + Azospirillum 2.5 L ha -1 , and b2 = Azotobacter 5.0 L ha -1 + Azospirillum 5.0 L ha -1 . While in subplot was the difference of upland red rice cultivar i.e., (v1) = Labandiri, (v2) = Jangkobembe, (v3) = Ranggohitam, (v4) = Paedara. A study was conducted in which different variables were measured including plant height, stem diameter, leaf area, and root length. The experimental data were analyzed by analysis of variance (ANOVA). If the study showed significant differences, then multiple comparisons were performed using Duncan's Multiple Range Test (DMRT) to determine if those differences are significant at the 5%.

Effect of bacterial fixator on leaf nitrogen
Results of analysis of variance show that the treatment of a bacterial mixture of Azotobacter and Azospirillum did not significantly affect the leaf nitrogen. Leaf nitrogen levels in each cultivar were relatively the same, and there was no significant increase due to the increased dose of nitrogen application (table 1) Remarks : v 1 = Labandiri Cultivar b 0 = Without bacterial mixture v2 = Jangkobembe Cultivar b1 = Azotobacter 2.5 L ha -1 + Azospirillum 2.5 L ha -1 v3 = Ranggohitam Cultivar b2 = Azotobacter 5.0 L ha -1 + Azospirillum 5.0 L ha -1 v4 = Paedara Cultivar

Flowering time
The results show that the bacterial mixture application had a significant effect on flowering age (table  2). Based on table 2, it appears that the Labandiri cultivar had the fastest time to reach flowering, followed by Paedara, Jangkobembe, and Ranggohitam cultivar. Remarks : v1 = Labandiri Cultivar b0 = Without bacterial fixator v2 = Jangkobembe Cultivar b1 = Azotobacter 2.5 L ha -1 + Azospirillum 2.5 L ha -1 v3 = Ranggohitam Cultivar b2 = Azotobacter 5.0 L ha -1 + Azospirillum 5.0 L ha -1 v4 = Paedara Cultivar Based on further tests with DMRT, it appears that there is a significant difference in the flowering age between Ranggohitam cultivar and the other three cultivars. Then there was a significant difference in the Labandiri and Jangkobembe cultivars' flowering time, but not significantly different from the Paedara cultivars. Likewise, there was a significant difference in flowering age between Jangkobembe and Ranggohitam cultivars, but not significantly different from Paedara (table 3).

Harvest date
The application of bacterial mixture has a significant effect on the harvest date. It appears that the Paedara cultivar has the fastest harvesting date compared to the other three cultivars (figure 1).  Based on further tests using DMRT, it appears that there was no significant difference in the harvest age between Paedara and Jangkobembe cultivar, and also between Labandiri and Ranggohitam. Paedara and Jangkobembe have a significant difference with Labandiri dan Ronggohitam cultivar.
In general, it appears that the application of a bacteria mixture can accelerate flowering in the Labandiri. Jangkobembe. and Paedara cultivars (table 2 and 3). The acceleration of flowering is in line with the increasing doses of the bacterial mixture application. On the other hand, the bacterial mixture application tended to prolong the harvest date, and correspondingly with the increase of the bacterial with the increasing doses of the bacterial mixture application (table 4). This situation can occur because the bacteria used is a non-symbiotic type of bacteria. Which besides having the ability to fix nitrogen also can extract other nutrient elements. It can affect the increase in production; in general, these bacteria's ability to improve plant growth increases with higher concentrations.

Conclusion
The research concluded that the application of bacterial mixture Azotobacter sp. and Azospirillum sp has no significant effect on nitrogen leaf content, but has a significant effect on flowering time and harvesting. It found that flowering time tends to accelerate, but on harvesting-date parameters tends to be prolonged.