Search

Pesticide residue has been detected not only on agricultural lands but also in bodies of water such as rivers, lakes, and the sea. This study was aimed at exploring the potency of local bacterial isolates to degrade carbofuran, an active pesticide compound. Two biosurfactant-producing bacteria were isolated from hydrocarbon-compound-contaminated seas (NF9) and agricultural land with a long-term history of pesticide application (AB2). Bacteria were selected according to their ability to grow on a mineral medium, Bushnell Haas Agar, with the addition of 41.86 ppm of carbofuran pesticide as the sole carbon source. Their growth was characterized morphologically, biochemically, and molecularly based on their 16S rRNA genes. All isolates were Gram+ and indicated as Bacillus thuringiensis KD168 for isolate NF9 and Bacillus paranthracis C9 for isolate AB2. Both of the isolates were immobilized in sodium alginate and polyurethane matrixes. Both B. thuringiensis NF9 and B. paranthracis AB2 were able to degrade carbofuran, as indicated by the presence of carbofuran residue that ranged from 1.03 to 1.89 ppm; however, the residue was undetected after 15 days of incubation. We also confirmed that bacterial cells were immobilized and retained in polyurethane as well as in the sodium alginate matrix. The immobilization of the bacterial cells showed the abilities of the cells to degrade pesticides and their potential to be developed as bioremediation agents in polluted areas. [ABSTRACT FROM AUTHOR]

The resistance status of Eleusine indica to the isopropylamine glyphosate herbicide leads to control losses in oil palm plantations. Appropriate management is needed to reduce the presence of glyphosateresistant E. indica. This study aimed to obtain the recommended sequence or pattern of pre- and post-emergence herbicides in controlling glyphosate-resistant E. indica biotypes. This study was conducted in Telaga Sari Village, Sunggal Subdistrict, Deli Serdang District, North Sumatra, Indonesia from January to August 2019. The seeds were used from a confirmed highly glyphosate-resistant biotype of E. indica at 1,080 g ai ha-1 . This study used the factorial Randomized Block Design with four replications. The first factor was the type of pre- and post-emergence herbicides at 1 l ha- 1, respectively. The second factor was E. indica biotypes. Parameters were analyzed by ANOVA and subsequently followed by DMRT at P < 0.05 with IBM SPSS. Results showed that pre-emergence herbicides were more effective in controlling biotypes of glyphosate-resistant E. indica or were classified as excellent than post-emergence at the similar dose. The percentage capability of pre-and post-emergence herbicides in sequence were indaziflam or oxyfluorfen > pendimethalin > propaquizafop > potassium glyphosate > mesotrione. The herbicide performance of propaquizafop was classified as very good compared to other post-emergent herbicides. [ABSTRACT FROM AUTHOR]

Clone PB 260 firstly planted in 1975 and popular due to its exeellent vigor and produetivity during maturity (1.5-2 tonnes/ha10), the dense foliage redueed extensive weeding and is resistanee against major leaf diseases. The knowledge on the bark reeovery rate is very important to maintain high yield of latex produetion on rubber plantation. The study whieh was eondueted on the experimental farm of Rubber Research Institute, Sungei Putih, Deli Serdang, north Sumatra, Indonesia was aimed to obtain the optimum eombination eoneentration of growth regulators (NAA+ and kinetin) and various oleo-ehemieals to aeeelerate bark reeovery and response of bark reeovery rate for rubber elones PB 260. Faetorial randomized bloek design, whieh eonsists of two faetors, namely growth regulatoreon eentrations (N1=50 ppm NAA+ + 50 ppm kinetin; N2=100 ppm NAA+ + 50 ppm kinetin; N3=150 ppm NAA+ + 50 ppm kinetin) and oleo-ehemieals (O1=palmitie aeid; O2=oleie aeid and O3=stearie aeid) were used in this study. The parameters measured were the number of latex vessels, skin thiekness, suerose levels, thiol levels, inorganie phosphate level, latex yield and total solid eontent (TSC). The results showed that growth regulator eoneentrations signifieantly affeet the number of latex vessels but did not signifieantly affeet the skin thiekness, suerose levels, thiol levels, inorganie phosphate levels, latex yield and total solid eontent (TSC). The most optimum growth regulator eombination was N2 at various parameters observed. Oleo-ehemieals applieation showed signifieant effeet on the number oflatex vessels, skin thiekness and latex yield, but showed no signifieant effeet on levels of suerose, thiol levels, inorganie phosphate level and total solid eontent (TSC). Thus, applieation of growth regulator and oleo-ehemieals are benefieial to aeeelerate bark reeovery rate in order to maintain latex produetion on rubber plantation. [ABSTRACT FROM AUTHOR]

Glyphosate has been used as the main tool for weed control in an oil palm plantation for about four decades. In the last five years, in an oil palm plantation of PTP Nusantara III, a population of Eleusine indica was reported to have been difficult to control using glyphosate. The objectives of this study were first, to confirm whether the population of E. indica in the oil palm plantation has evolved resistance to glyphosate. Secondly, to evaluate post-emergent alternative herbicides, premixed 39.5% MSMA + 7.8% diuron, glufosinate ammonium, topramezone and glyphosate as a comparison, which were all of them applied at field rates of 1975 g + 390 g, 450 g, 41,25 g, and 1080 g a.i. ha−1, respectively. While pre-emergent herbicides, indaziflam, diuron, and flumoxiazin were applied 75, 1500, and 160 g a.i ha−1, respectively. The results showed that the suspected glyphosate-resistant E. indica population has been confirmed to have developed resistance to glyphosate. The population is highly resistant with level of resistance 28-fold of the susceptible population. No resistant plant was killed at the rate of 4320 g. a.e. ha−1 glyphosate (four-fold field rate for E. indica control) whereas the susceptible plant was killed 77,5%. Alternative herbicides tested effectively suppressed glyphosate-resistant E. indica population when applied at field rate. The alternative herbicides could be used to overcome glyphosate-resistance in the oil palm plantation. [ABSTRACT FROM AUTHOR]

The glyphosate-resistant Eleusine indica (GR-ESU) case has dominated at oil palm plantations in North Sumatra Province, Indonesia and will increase evolution into resistance. This research was aimed to determine the role of Monosodium Methyl Arsenate (MSMA)+diuron to control the agronomic characteristics of GR-ESU biotypes. This research was conducted in the Weed Research Center Land, Faculty of Agriculture, Universitas Sumatera Utara in November 2017 until August 2018. This research used Randomized Block Design non-factorial with factor GR-ESU biotypes that were sprayed with glyphosate at the dose of 3 l.ha-1, and MSMA+diuron at the dose of 5 l.ha-1 within four replications. The parameters were analyzed using one-way ANOVA and were continued by DMRT at P < 0.05 with IBM SPSS Statistics v.20 software. The results showed that a decrease in the survival of GR-ESU at the changes from glyphosate to MSMA+diuron. The GR-ESU on MSMA+diuron showed leaf color changes (leaf green loss/chlorosis) at 3 until 21 days after sprayed. The ability of MSMA+diuron had completely (100%) controlled within 18 of 29 GR-ESU biotypes and had effectively controlled the tillers, flowering, fresh- and dry weight in GR-ESU biotypes of 87.53%; 66.88%; 95.66%; and 95.92% respectively compared to glyphosate. The use of MSMA+diuron as a different mode of action herbicide is highly recommended to control GR-ESU biotypes at oil palm estate. [ABSTRACT FROM AUTHOR]