No abstract

Pea leafminer (Liriomyza huidobrensis) is the major pest of potato crop in Indonesia. The use of insecticides to control the pest is ineffective and harmful to the natural enemies. The study aimed to find out a promising cultural practice for leafminer management on potato crop. The study was conducted at a farmer's field in Bali in 2004. Potato plants (Granola variety) were grown in a raised-bed plot of 10 m x 1 m. The treatments evaluated were standard cultural practice (C), C plus reflective plastic mulch (RPM) (CM), farmer's practice (F), vermicompost (V), and V plus RPM (VM). All treatments were arranged in RCBD with five replications. From each plot, 10 plant samples were randomly taken to observe the presence of larvae, mines, and adults. Larvae and adults of leafminer and mines were separately counted from the top, middle, and bottom parts of the plant samples. Parasitoids were collected from the infested leaves of the plant samples. Emerged parasitoids were counted and put into vials with 70% ethyl alcohol and then identified. The results showed that the population of adults, larvae of L. huidobrensis, and mines were less in C, CM, V, and VM treatments compared to farmer's practice (F). However, RPM (CM and VM) treatments significantly reduced population of leafminer and mines. The highest population of adults, larvae, and mines on RPM treatment were less than 1.5, 8.5, and 10 per plant, respectively compared to other treatments which were greater than 3.2 for adults, 12.4 for larvae, and 12.7 for mines. Parasitoid population and parasitism level were more in vermicompost treatments (V and VM) compared to other treatments (C, CM, and F). The results showed that application of pesticides was ineffective against leafminer and reduced parasitoid population; in the other hand RPM was effective to control leafminer although the effect on parasitoids was not clear. Parasitoid species that were found associated with potato crop were Hemiptarsenus varicornis, Neochrysocharis sp., and Opius sp. Combination of RPM with standard practice and vermicompost are prospective for leafminer management in potato crop, however, VM is friendlier to environment regarding sustainable agriculture.

Research was conducted in Subak Guama, Selanbawak Village, Marga District, Tabanan Regency from January up to April 2017 and Subak Dlod Sema, Sading Village, Mengwi District, Badung Regency from January up to May 2017. This study aims to understand the growth, productivity and resistance to brown planthopper pest in superior rice varieties cultivated in Bali Province, Indonesia to substitute Ciherang variety utilization. Research were arranged by using Randomized Block Design with some superior rice varieties as treatment namely Inpari 30 and Inpari 40 for research in Tabanan Regency. And also, Inpari 16, Inpari 24, Inpari 28, Inpari 30, Towuti and Situ Bagendit for research in Badung Regency. Meanwhile, Cigeulis and Ciherang were utilized as comparison. Each of treatments were replicated for 5 times. Variable observed consisted of performance of agronomy and productivity namely plant height, number of tillers, number of grains per panicle, 1000 grains weight and yield. Besides that, resistance to brown planthopper pest also observed by evaluation of damage per plant caused by brown planthopper with using six scale standard of scoring. Results showed that Inpari 40, Inpari 28 and Situ Bagendit were resistant to pest of brown plathopper according to their percentage damage were 1%; 9% and 1% with scoring rate were 1; 3 and 1 respectively. Inpari 40 and Inpari 30 can be considered as candidate to substitute Ciherang according to their agronomy performance and productivity in Bali Province were closest similar to Ciherang variety meanwhile Inpari 40 was most suitable to substitute Ciherang variety according to its agronomy performance, productivity and resistance to pest of brown planthopper.

Pea leafminer (Liriomyza huidobrensis) is the major pest of potato crop in Indonesia. The use of insecticides to control the pest is ineffective and harmful to the natural enemies. The study aimed to find out a promising cultural practice for leafminer management on potato crop. The study was conducted at a farmer's field in Bali in 2004. Potato plants (Granola variety) were grown in a raised-bed plot of 10 m x 1 m. The treatments evaluated were standard cultural practice (C), C plus reflective plastic mulch (RPM) (CM), farmer's practice (F), vermicompost (V), and V plus RPM (VM). All treatments were arranged in RCBD with five replications. From each plot, 10 plant samples were randomly taken to observe the presence of larvae, mines, and adults. Larvae and adults of leafminer and mines were separately counted from the top, middle, and bottom parts of the plant samples. Parasitoids were collected from the infested leaves of the plant samples. Emerged parasitoids were counted and put into vials with 70% ethyl alcohol and then identified. The results showed that the population of adults, larvae of L. huidobrensis, and mines were less in C, CM, V, and VM treatments compared to farmer's practice (F). However, RPM (CM and VM) treatments significantly reduced population of leafminer and mines. The highest population of adults, larvae, and mines on RPM treatment were less than 1.5, 8.5, and 10 per plant, respectively compared to other treatments which were greater than 3.2 for adults, 12.4 for larvae, and 12.7 for mines. Parasitoid population and parasitism level were more in vermicompost treatments (V and VM) compared to other treatments (C, CM, and F). The results showed that application of pesticides was ineffective against leafminer and reduced parasitoid population; in the other hand RPM was effective to control leafminer although the effect on parasitoids was not clear. Parasitoid species that were found associated with potato crop were Hemiptarsenus varicornis, Neochrysocharis sp., and Opius sp. Combination of RPM with standard practice and vermicompost are prospective for leafminer management in potato crop, however, VM is friendlier to environment regarding sustainable agriculture.