The Effect of Jajar Legowo Planting System on Ciherang Paddy Varieties

Intensification on paddy is done one of them by setting the spacing. This study aims to examine the effect of spacing system on growth and paddy production. The research was conducted in Bojongmangu Village, Bekasi Regency, West Java Province. The study used an experimental method Randomized Completely Block Design (RCBD) with 1 factor that is planting system, namely tegel system 20 cm x 20 cm, tegel system 25 cm x 25 cm , jajar legowo 2:1 (25x12,5x50 ) cm, jajar legowo 4:1 full (25 x12,5x50 ) cm, jajar legowo 4:1 free space (25 x12,5x50 ) cm, and jajar legowo 6:1 (25x12,5x 50) cm. Each treatment is repeated 3 times. The results showed that jajar legowo planting system 2:1 gives the number of panicles per clump, number of grains per panicle, weight of 1000 grains and the average yield per hectare is highest, followed by jajar legowo 4:1 full planting system.


INTRODUCTION
In Indonesia, rice consumption from year to year continues to increase in line with the increasing rate of population growth.On the other hand, there is the conversion of wetland to non-agricultural such as residential complexes, shops, industrial areas, among others, especially in Java and Bali.This phenomenon will enlarge the food problem.For food security, the conversion of paddy fields is a serious threat because of its permanent and negative impacts on rice production.According to BPS (2018), average Indonesian rice consumption reached 1.571 kg/capita/week.BPS (2018) also reported that by 2017, the national paddy area reaches 15,696,915 ha, the national production is 81,072,701 tons and the average productivity is 5.165 tons/ha.Meanwhile, the import of rice in 2018 reaches 500 thousand tons (Sari, 2018).
One effort to increase the productivity of paddy plants is optimizing the population of plants per hectare through planting distance arrangement, known as Jajar Legowo planting system.The Jajar Legowo planting system is a pattern of planting that alternates between two or more (generally two or four) crop lines and one free space row.Thus, it will obtain an optimal growing space for the growth and development of plants, facilitate the conduct of the treatment plants, create a sub-optimal environment for the plant-disturbing organism and increase the population of more than 160,000 plants per hectare (Sarlan et al, 2013).In addition, the plants on the edge grow and develop better and the yield per clump is higher than that of the middle plants.This indicates that the more border side bordering plants in the paddy fields produce more grain, much because in this system there is open space of 25% -50%.The plant will receive sunlight optimally useful in the process of photosynthesis (Ikhwan et al, 2013).Setting the planting system determines the quantity and quality of the paddy clump, which then with the population/number of plant clumps per unit area affect the crop yield.Some research results related to the spacing arrangement is done by Meas et al. (2011).They found that the spacing of 20 x 20 cm planting density gives the best result with uptake TN 94.8 kg/ha and 29.9 kg/ha for P in Korea.Plant spacing of 20 x 35 legowo planting system gives the best result in Minahasa (Karokaro et al., 2015).A research Legowo planting system 2:1 yielded 6.08 ton per ha and was best treatment giving highest yield in Subang Indonesia (Kusyaeri et al., 2014).The report on Legowo apllication in Bajeng subdistrict, Gowa regency in technical irrigation paddy field showed dry grain yield reach 8.50 t / ha higher than tegel (Java language) system of 6.36 t / ha (Sarlan A. et al 2013).Plant spacing on the jajar legowo base of 25 cm has been provided more number of productive tillers than that of 21 cm (Hatta, 2012).The best results for a number of productive tillers, the average production of grain/plot, weight of 1000 grain was in the treatment plant system Legowo row 2:1 (Sari, 2014;Darmawan, 2016).The participation level of use Legowo system affected by economic characteristics, age, education, land and frequency following extension (Mulyati et al., 2017).
The effect of legowo row planting system application on paddy field has not been consistent, therefore further study is needed.This study aims to examine the influence of 6 (six) types of planting system to growth and yield of Ciherang paddy varieties.

Table 1 Planting System Treatment
Treatment Code

Planting System Type
Plant Population (clump per plot) (2.5mx 2.5m) T1 Tegel (20x20) cm 156 T2 Tegel (25x25) cm 100 T3 Jajar Legowo 2: 1 ( 25x12,5x50 ) cm 120 T4 Jajar Legowo 4:1 Full ( 25x12,5x50) cm 160 T5 Jajar Legowo 4:1 Free Space (25x12,5x50) cm 120 T6 Jajar Legowo 6: 1 ( 25x12,5x50 ) cm 160 The experiment was initiated by tilling the soil twice, hoeing and trimming, then plot experiments of 2.5 m x 2.5 m in size, made of roving and transverse trenches to remove excess water.Then followed by soaking seed varieties aimed at softening the husks of grain in order to accelerate the seed germinating.Immersion is conducted for 48 hours.Nurseries are done in a shaded place until the seeds aged 17 days to then ready to be planted.Planting to field plot with two seeds per hole, planting system as follows:  Fertilizer application is done by evenly sown into the soil during wet season conditions, carried out the day before planting, 21 wap (week after planting), 34 wap.Harvesting is done when 95% of panicles have been yellowing in the experimental plot.
Parameter observations include: plant height, number of tillers, number of productive tillers, panicle length per clump, panicle length, number of grains per panicle, number of fully grains per panicle weight 1000 grains, weight of grain/plant, weight of fully grain per plant, percent of empty grain per plant, yield of plant per plot (ton/ha).The observed data were analyzed for its diversity using F test at 5% level, followed by DMRT test at 5% level.

Plant Height and Number of Tillers
Jajar Legowo 2:1 planting system using spacing (25x12.5x50) cm resulting in less plant per hectare population over 213.300 clumps per hectare, and will increase the plant population by 33.31% compared to the cropping pattern (25x25) cm which is only 160.000 clump/ha.
Planting system jajar legowo 4: 1 full which is a legowo planting pattern with the whole line got plant inserts with the plant spacing of 25 cm x12,5 cm x 50 cm resulted in plant population reaching ± 256.000 clump/ha with the population increase of 60% compared to tegel pattern (25x25) cm.System of planting legowo 4:1 free space is a cropping pattern by simply providing additional plant inserts on both rows of edge plants with spacing of 25 cm x12.5 cm x 50 cm will be obtained population of ± 192.000 clumps/hectare plant with percentage increase only ± 20% compared pattern tegel (25x25) cm.Planting system jajar legowo 6: 1 which is the cropping pattern legowo with an entire line got crop inserts, with a spacing of 25x12.5x50cm then the plant population reached ± 274 000 clump/ha.

Figure 2 Plant Height of Ciherang Paddy Varieties on Various Treatments Planting System
Tegel planting system (20x20) cm; tegel (25 x 25) cm; jajar legowo 2: 1; legowo 4 : 1 full; jajar legowo 4: 1 free space and jajar legowo 6:1 did not give a significant effect on plant height and number of tillers for all observation period except at age 4 WAP (week after planting) for plant height (Table 2, Figure 2 and Figure 3).Spacing affects the number of plant populations.Based on Table 2, planting system jajar legowo 2:1; 4:1 full, 4:1 free space; 6:1 no causing an increase against the number of tillers, compare with system planting tegel 20 cm x 20 cm and 25 cm x 25 cm.According Sumardi (2010) increase in plant population, negatively correlated to the total produced tillers, panicle number per unit area.

Figure 3 Number of Tiller per Clump of Ciherang Paddy Varieties on Various Treatments of Planting System
The more the number tillers per clump per unit area of the fewer number of tillers and productive tillers.Clump derived from treatment jajar legowo row 6: 1 shows the plant height and number of tillers at least.Early competition between leaf sheets is alleged to have lowered plant height and strong tillers (vigorous).Increasing the number of clumps per unit area tends to increase competition between plants in clumps and clumps other to light, space, and nutrients that affect growth and production.The number of tillers of tegel system gives the number of tillers per clump higher than the jajar legowo system.Tillers grown from the roots of paddy plants are divided into primary, secondary and tertiary tillers whose growth is determined by the surrounding environmental conditions, such as plant spacing, radiation, mineral nutrient, and cultivation techniques.This is in accordance with the statement of Yoshida (1981) in Makarim and Suhartatik (2009) states that not all buds will grow into tillers because it is determined by spacing, radiation, mineral nutrients and cultivation.According to Ikhwani et . al. (2013) that p there are some particular variety or decrease the number of tillers because the number of panicles in right clump that is too tight.

Yields Component
Table 3 and Figure 4 show that there are differences in the number of panicles per clump, number of grains per panicle, number of fully grains per panicle and weight of 1000 grains due to differences in spacing of the system.It is not obvious that the pattern of plant spacing type in tegel and jajar legowo, to the length of panicle because the length of panicle is only influenced by the variety (genetic factor) and not the environment.
According to Sumardi (2010), the increase in plant population per unit area is negatively correlated with the number of panicles per clump.The number of panicles per clump highly positive correlates with the number of grains per panicle and the weight of a thousand grains of grain.It shows the increasing number of panicles increasing the number of grains per panicle and the weight of a thousand grains.The number of panicles per clump, the number of grain per panicle and the weight of 1000 grains of the highest were obtained on the spacing pattern of legowo 2: 1 spacing followed by a full 4:1 legowo and 25 cm x 25 cm tegel system.The jajar legowo planting system provides a different space for obtaining the sunlight used in photosynthesis.The more sunlight the plant can absorb the faster the process of photosynthesis takes place and ultimately accelerate plant growth.When the need for glucose is sufficient, the excess glucose is converted into carbohydrates and stored as food in the roots, stalks, and grains of rice.Planted paddy planted with full jajar legowo 4:1 planting system gives the number of panicles per clump, the number of grains per panicle and the weight of a thousand grains better than jajar legowo 4:1 free space because this full 4:1 legowo planting system is grown on a grain jelly of poor nutrient -grumusol soil that has a low P and K high element content and has ph 5.2.According to Sarlan et al (2013) that the jajar legowo planting system 4: 1 full compatible with the conditions of the infertile land.The number of fully grains per panicle is not significantly correlated with the number of grain per panicle.According to Darwis (1982), that the more of grain formed then the heavier the burden of plants to form the loaded grains.Matsushima (1975) in Sugiono and Saputro (2016)   The Yield Per plot Yield per plot of Ciherang paddy varieties on various planting system treatments showed on Table 4 and Figure 5.The system spacing legowo 2:1 yielded the highest average yield of 6.23 kg/plot equal to 9,968 ton/ha.It was followed by full 4:1 legowo spacing which reached 6.15 kg/plot equivalent to 9,840 tons/h.On average, both cropping systems produced paddy per hectare higher than the 20 cm x 20 cm tegel system which yields an average of 5.41 kg or equivalent to 8.565 tons/ha and 25 cm x 25 cm tegel system which produces an average 5.95 kg or equivalent 9.5 20 tons/ha.

Table 4 The effect of plant spacing on average of the yield of Ciherang paddy varieties
Planting System cm Yield per Plot kg DGH Average yield per hectare kg DGH T1 = tegel ( 20 x 20 ) cm 5.41 b 8565 a T2 = tegel ( 25 x 25 ) 5.95 bc 9520 a T3 = legowo 2: 1 (25 x12.5x50) cm 6.23 cd 9968 a T4 = legowo 4:1 Full (25x12.5x50 )cm 6.15 c 9840a T5 = legowo 4:1 free space (25x12.5x50)cm5.05 a 8080 a T6 = legowo 6: 1(25x12.5x50)cm4.85 a 7760 a The legowo row planting system in the direction of the outer crop line provides a relaxed growing space as well as a higher population.In addition, this planting system is able to provide a better air circulation and utilization of sunlight for cropping.The more intensity of sunlight, then, the process of metabolism, especially photosynthesis of plants that occur in the leaves will be higher.It results good quality of the plant.The reseach also found that the lowest yield was obtained from the planting distance treatment of legowo 6:1 which only reached 4.85 kg/plot or equivalent 7.760 ton/ha.

CONCLUSION
The use of the 2: 1 jajar legowo planting system provides the highest of the number of panicles per clump, the number of grains per panicle, the weight of 1000 grains and yield per hectare, followed by a full 4:1 jajar legowo planting system.Further studies are needed on different paddy planting systems, different varieties and combinations with fertilizer treatment or others.

Figure 1
Figure 1 Jajar Legowo Planting System (Sarlam A. et al., 2013)Fertilizer application is done by evenly sown into the soil during wet season conditions, carried out the day before planting, 21 wap (week after planting), 34 wap.Harvesting is done when 95% of panicles have been yellowing in the experimental plot.Parameter observations include: plant height, number of tillers, number of productive tillers, panicle length per clump, panicle length, number of grains per panicle, number of fully grains per panicle weight 1000 grains, weight of grain/plant, weight of fully grain per plant, percent of empty grain per plant, yield of plant per plot (ton/ha).The observed data were analyzed for its diversity using F test at 5% level, followed by DMRT test at 5% level.
stated that there are several factors causing a decrease in percentage of grain contents: (1) increasing number of grains per panicle, (2) increasing number of unproductive caryopsis and (3) low starch content (photosynthesis) in the vegetative organs before the flowering period.

Figure 4 .
Figure 4. Yield Component of Ciherang Paddy Varieties on Various Treatment Planting System

Figure 5
Figure 5 Yield (tons/ha) Ciherang Paddy Varieties on various planting system treatments