DISTRIBUTION MAPPING OF GLYPHOSATE-RESISTANT Eleusine indica IN SERDANG BEDAGAI REGENCY

The presence of Eleusine indica from oil palm plantations in Serdang Bedagai Regency has never been overall reported glyphosate-resistant. This study aims to distribution mapping and resistance classification of E. indica population to glyphosate herbicide of oil palm plantations in Serdang Bedagai Regency. This research was conducted on Weed Research Center Land in Faculty of Agriculture, Universitas Sumatera Utara in October 2016 to August 2017. This research used glyphosate herbicide with the recommended dose at 720 g ai ha and three replications. Population ESU0 (from Politeknik Negeri Medan Ball Field) as a comparison. Data analysis using IBM SPSS Statistics 20 software. The results showed there E. indica population classified as glyphosate-resistant amount 89.36% (42 population), classified as glyphosate-resistant moderate amount 10.64% (5 population) and there is no population glyphosatesusceptible on oil palm plantations in Serdang Bedagai Regency of recommended dose at 720 g ai ha.


I INTRODUCTION
Eleusine indica is a C4 plant that grows very rapidly at full sunlight intensity, but its growth is less developed in the shaded condition [1].In addition, E. indica weed is self-pollination, classified as the annual weed, have 2 sets of chromosomes (diploid), and relatively small genome size around 8.03 x 10 8 bp [2].These weeds can produce up to 140,000 seeds per plant [3].Full sunlight intensity conditions in oil palm plantations in Indonesia are at the seedling stage until immature.Based on the observation of experimental field, E. indica has fast growth and development from germination until seed production only takes ±2 mo.This effect on the presence of E. indica populations in the nursery until immature was more dominant than mature so as to decrease oil palm production.In general, weed control of oil palm plantations uses chemical control (herbicide) with rotation once in 3-4 mo.One of the most commonly used herbicides of oil palm plantations to weeds controlling is glyphosate.The glyphosate herbicide has an active ingredient namely N-(phosphonomethyl) glycine which is a derivative of glycine amino acid and phosphonic acid.Glyphosate is generally formulated as salt and water soluble.Salt on glyphosate is used as a non-selective, post-emergence herbicide that can control various types of annual and perennial weeds.Glyphosate inhibits 5-enolpyruvylshikimate-3phosphate synthase (EPSPS) enzyme that occurs in plant chloroplast tissue and converts shikimate-3-phosphate (S-3-P) to enolpyruvylshikimate-3-phosphate (EPSP) and leads to the production of amino acids, phenylalanine, and tyrosine, as well as tryptophan.Shikimate-3-phosphate (S-3-P) cannot be converted to EPSP because S-3-P is unstable, then quickly converted to shikimate more stable and accumulated [4].The use of herbicides with similar active ingredients be repeated can to resistance.If the weeds are already resistant then it is more difficult to control [5].This activity will enhance the evolution E. indica of herbicide-resistant in oil

II MATERIALS AND METHODS
Collecting seeds of glyphosate-resistant E. indica populations were taken the mature seeds are marked in panicles already tanned as many as 50 plants from oil palm estates in Serdang Bedagai Regency (Table 1).Collecting seeds of E. indica glyphosate susceptible population (ESU0) were taken from Politeknik Negeri Medan Ball Field, where the herbicide was never applied [11].Collecting seeds was conducted in September until December 2017.Seeds of E. indica are soaked in potassium nitrate solution (KNO3) with 0.2% concentration for 30 min [12].Soaking aims to break E. indica seed dormancy.The seedling medium used is topsoil and manure with a volume ratio of 1:1.After thoroughly mixed, the medium was put on a temperature 100 o C for 3 h [11] and then inserted into the germination trays measures 33 × 24 cm.After 2-3 leaf stage, seedlings from each species were transplanted into pots with topsoil, sand and manure medium was filtrated with volume 1:1:1 ratio.Transplanted 10 plants into pots.The pots were arranged in a randomized block design (RBD) non-factorial with three replications.
Before spraying first performed calibration (292 l/ha).Glyphosate spraying is were made at 3-4 leaf stage [13].The sprayed with glyphosate herbicide recommended dose at 720 g ai ha

III RESULT AND DISCUSSION
Population E. indica survival on glyphosate dose at 720 g ai ha -1 from oil palm plantations in Serdang Bedagai Regency (Figure 1).respectively.This show the use of glyphosate 720 g ai ha -1 or 2 L ha -1 can be suppressing the growth biotype E. indica glyphosate-resistant at 6 WAA (weeks after application) from oil palm plantations in Serdang Bedagai Regency with average dry weight ranges from 4.60 to 6.07 g.This is suitable research with [19] which states that glyphosate potassium herbicide dose at 330 g ai ha -1 (1.5 L ha -1 ), 660 g ai ha -1 (3 L ha -1 ), and 990 g ai ha -1 (4.5 L ha -1 ) can suppress the growth of grasses weed (dry weight) at 6 weeks after planting with three soybean cultivars amount 2.80 g; 2.89 g; and 2.76 g respectively.In addition, [7] also stated the dry weight biotype E. indica glyphosate-resistant from Adolina Estate on the application of glyphosate dose at 480 g ai ha -1 amount 7.00 g pot -1 and decreased dry weight with dose at 960 and 1920 g ai ha -1 amount 5.37 and 0 g pot - 1 respectively.
The percentage of E. indica resistance classification from oil palm plantations in Serdang Bedagai Regency (Figure 2).There are 42 populations of E. indica classified as glyphosate-resistant (89.36%), 5 populations classified as developing resistance (10.64%), and there is no glyphosate-susceptible population (0%) from oil palm plantations in Serdang Bedagai Regency.This resistant information describes the difficulty of oil palm plantations in controlling weeds especially E. indica.The higher percentage of E. indica glyphosate resistance, the more difficult to control the weeds.This condition is very disturbing the production and quality of oil palm.Glyphosate herbicides have been used intensely to controlling weeds on oil palm plantations at several regencies in Sumatera Utara.According to [11] reported the E. indica populations from oil palm plantations in Padang Lawas and Tapanuli Selatan Regency was the glyphosate-resistant dose at 720 g ai ha -1 or equivalent 2 L ha -1 amount 36.36% and 83.33% respectively.According to [9] reported the E. indica populations from Adolina Estate, Serdang Bedagai also glyphosate-resistant dose at 480 g ai ha -1 amount 98.28%.According to [11] reported the E. indica populations from oil palm plantations in Padang Lawas and Tapanuli Selatan Regency was the glyphosateresistant dose at 720 g ai ha -1 or equivalent 2 L ha -1 amount 36.36% and 83.33% respectively.
According to [9] reported the E. indica populations from Adolina Estate, Serdang Bedagai also glyphosate-resistant dose at 480 g ai ha -1 amount 98.28%.According to [21] reported the E. indica populations from Langkat Regency also glyphosate-resistant dose at 720 g ai ha -1 amount 42.11%.Source : [20] The presence of E. indica weed has been widely reported glyphosate-resistant from 1997 to 2017 in various countries (Table 3).It is found the E. indica populations were first glyphosate-resistant in 1997 in Malaysia.However, the presence of E. indica of glyphosate-resistant from oil palm plantations was first reported in 2009 (oil palm nursery) in Malaysia and in 2012 in Indonesia (oil palm nursery).While the results of this study show the E. indica populations has been glyphosateresistant amount 89.36% from oil palm plantations in Serdang Bedagai Regency.The E. indica populations classified as developing resistance is also feared to be evolution and potentially resistant to glyphosate herbicide if the herbicide is used continuously with rotation once in 3-4 months of oil palm plantations in Serdang Bedagai Regency.Therefore management of E. indica glyphosate-resistant is needed more appropriate so that production and quality of oil palm produced can be maximized.
-1 (Round-up 486 SL, PT.Menagro Kimia).Parameters observed among E. indica survival, dry weight and resistance classification.Observation of E. indica survival was made at 21 days after application (21 DAA) for pot respectively [14].The percentage of E. indica survival (% ES) was calculated using the formula of sum E. indica survival (SES) per sum E. indica was planted (SEP) x 100%.The mortality of E. indica (MEi) was calculated using the formula of sum E. indica die (SED) per sum E. indica was planted (SEP) x 100%.Observation dry weight of goosegrass was made at 6 weeks after application (6 WAA).Above-ground shoots were harvested and dried in the oven (65°C) for 72 h [14] for dry weight measurements.classification measured by the percentage of survival populations.Populations were classed as resistant (20% or more survival), as developing resistance (2-20% survival), or as susceptible (less than 2% survival) [15].Data analysis using mean at the level of 5% with IBM SPSS Statistics v. 20 software (New York: United States).

Figure 2 .
Figure 2. Percentage of E. indica resistance classification to glyphosate at 720 g ai ha -1 from oil palm plantations in Serdang Bedagai Regency.

indica populations to distribution mapping. This study aims to distribution mapping and resistance classification of E. indica to glyphosate herbicide from oil palm plantations in Serdang Bedagai Regency.
Distribution Mapping Of Glyphosate-Resistant Eleusine Indica In Serdang Bedagai Regency (Koko Tampubolon, Edison Purba, Mohammad Basyuni and Diana Sofia Hanafiah) [6] palm plantations in Sumatera Utara Province.Several research was reported that E. indica has been glyphosate-resistant of oil palm plantations in Sumatera Utara, especially in Serdang Bedagai Regency.According to[6]has reported E. indica populations from Adolina Estate has been glyphosate-

Table 1 .
E. indica populations were taken from oil palm plantations in Serdang Bedagai Regency E. indica population was glyphosate-resistant ranged from 23.33 to 100%.E.indica population as highest glyphosate-resistant (100%) was found in 2 afdeling of Paya Mabar Estate (ESU4.3), 6 and 7 afdeling of Adolina Note : ESU (Eleusine indica from Sumatera Utara)Figure 1. E. indica survival populations to glyphosate at 720 g ai ha -1 from oil palm plantations in Serdang Bedagai Regency The average of E. indica mortality, dry weight and resistance classification from oil palm plantations in Serdang Bedagai Regency (Table 2).It was found the mortality and dry weight of 42 E. indica populations glyphosate-resistant on oil palm plantations in Serdang Bedagai