scholarly journals ANALISIS KORELASI DAN REGRESI DINAMIKA POPULASI HAMA DAN MUSUH ALAMI PADA BEBERAPA VARIETAS UNGGUL PADI SETELAH PENERAPAN PHT DI KABUPATEN BONE PROVINSI SULAWESI SELATAN

2015 ◽  
Vol 22 (1) ◽  
pp. 29
Author(s):  
Asriyanti Ilyas

<div data-canvas-width="788.5133333333328">Different types of rice pests, have been reported. The explosions and a potential pests are Rice Stem Borer (Tryporiza</div><div data-canvas-width="802.6483333333334">sp.), Brown Planthoppers (Nilaparvata lugens), Green Leafhoppers (Nephotettix virescens), and Rats (Rattus sp.), wich</div><div data-canvas-width="802.7016666666667">an obstacle in creating stability of rice production in Bone. In rice ecosystem, natural enemies of arthropod predators</div><div data-canvas-width="802.703333333333">are most instrumental in suppressing the pest population. Fluctuation in population density of natural enemies, affecting</div><div data-canvas-width="802.6466666666668">pests presence. Efforts to suppress pest proportions through IPM, is a strategy of lowering the level of pests and damage</div><div data-canvas-width="802.6933333333333">to rice crops. This study aims to identify and measure the relationship strength between pests and natural enemies</div><div data-canvas-width="802.6733333333332">populations in some rice varieties after IPM, using correlation and regression analysis. Observations conducted in Bone,</div><div data-canvas-width="802.6600000000001">from May to August 2012, with 2 observed variables, pests and natural enemies populations in Inpari 6, Inpari 10, Inpari</div><div data-canvas-width="802.6633333333332">16, Ciherang, Cigelis, and Mekongga. Data analysis were performed using correlation and regression analysis. The</div><div data-canvas-width="802.6833333333332">results showed a high degree of correlation between pest and natural enemies (predators) populalions, characterized by</div><div data-canvas-width="802.7066666666666">a positive correlation coefficient (0.957) and significant at the level of 0.01, where each increase in the intensity of pest</div><div data-canvas-width="564.7166666666665">populations, will be followed by increase in the number of natural enemies captured.</div>

2018 ◽  
Author(s):  
C. Coy ◽  
A.V. Shuravilin ◽  
O.A. Zakharova

Приведены результаты исследований по изучению влияния промышленной технологии возделывания картофеля на развитие, урожайность и качество продукции. Выявлена положительная реакция растений на подкормку K2SO4 в период посадки. Корреляционно-регрессионный анализ урожайности и качества клубней выявил высокую степень достоверности результатов опыта. Содержание нитратов и тяжелых металлов в клубнях было ниже допустимых величин.The results of studies on the impact of industrial technology of potato cultivation on growth, yield and quality of products. There was a positive response of plants to fertilizer K2SO4 in the period of planting. Correlation and regression analysis of yield and quality of tubers revealed a high degree of reliability of the results of experience. The contents of nitrates and heavy metals in tubers was below the permissible values.


EUGENIA ◽  
2018 ◽  
Vol 23 (3) ◽  
Author(s):  
J. Manueke ◽  
B. H. Assa ◽  
E. A. Pelealu

ABSTRACT The purpose of this research is to know  the pest species in wetland rice crops at Makalonsow Village of East Tondano Distric in Minahasa Regency. The study used a descriptive obsevational method that is observing directly the pests found in rice paddy fields by means of sweeping with insect net and observing directly on paddy fields plaot and paddy fields clumps. The identified pests were identified and made in accordance with the results of identification for each species of pest.  The results showed that 11 species of pests and 4 spesies of natural enemies found in paddy fields of wetland rice at Makalonsow Village of East Tondano District in Minahasa Regency.  The pests are White Rice Stem Borer (Tryporyza innotata), Rice Cherry Stem Borer (Chilo suppressalis), Purple Rice Stem Borer (Sesamia inferens), White Pest (Nymphula depunctalis), Brown Planthopper (Nephotettix virescens), Green Planthopper (Nilaparvata lugens), Paddy Stink Bug (Leptocorisa acuta), Black Lady Bug (Pareaucosmetus sp.), Rice Weevil   (Sitophilus oryzae), Golden Snail (Pomacea caniculata), Hous and Tre Sparow (Passer spp.), and Rice-field Rat (Ratus argentiventer.). Natural enemies are Worship Grasshopper (Mantis sp.), Dragonflies (Sympetrum flaveolum), Coccinelid Beetle (Coccinella septempunctata), and Spider Hunters (Pardosa sp.).Keywords : plant pest, wetland rice crops,  natural enemies of pest ABSTRAK Tujuan penelitian adalah mengetahui jenis-jenis hama pada tanaman padi sawah di Kelurahan Makalonsow Kecamatan Tondano Timur Kabupaten Minahasa. Penelitian menggunakan metode obsevasional deskriptif yaitu mengamati langsung hama yang ditemukan pada areal tanaman padi sawah dengan cara penyapuan dengan net serangga dan mengamati langsung pada petakan sawah dan rumpun tanaman padi sawah. Hama-hama yang ditemukan diidentifikasi dan dibuat deskripsi sesuai dengan hasil identifikasi untuk setiap jenis hama. Hasil penelitian menunjukkan bahwa ditemukan 11 jenis hama dan 4 jenis musuh alami padahabitat tanaman padi sawah di Kelurahan Makalonsow Kecamatan Tondano Timur Kabupaten Minahasa. Hama-hama tersebut yaitu Penggerek batang padi putih (Tryporyza innotata), Penggerek Batang Padi Bergaris (Chilo suppressalis), Penggerek Batang Padi Ungu (Sesamia inferens), Hama Putih (Nymphula depunctalis), Wereng Coklat (Nephotettix virescens), Wereng Hijau (Nilaparvata lugens), Walang Sangit (Leptocorisa acuta), Kepik Hitam (Pareaucosmetus sp.), Bubuk Beras (Sitophilus oryzae), Keong Emas (Pomacea caniculata), Hama Burung Padi Sawah (Passer spp.), dan Hama Tikus Sawah (Ratus argentiventer).  Musuh alami yaitu  Belalang Sembah (Mantis sp.), Capung (Sympetrum flaveolum), Kumbang Coccinelid (Coccinella septempunctata), dan Laba-Laba Pemburu (Pardosa sp.).Kata kunci : hama tanaman, tanaman padi sawah, musuh alamiah hama


2020 ◽  
Vol 12 (3) ◽  
pp. 349-353
Author(s):  
J Mary Lisha ◽  
R. Kanagarajan ◽  
S. Vijay ◽  
V. Baskaran

Rice is the cereal grain that feeds half the planet. Rice fields are economically important as well as ecologically valuable. Rice fields are one of the biggest ecosystems that can be found in the tropics, including diverse insect pests and their natural enemies. In this view, rice varieties were sown in experimental plots of Faculty of Agriculture, Annamalai University, Chidambaram. The values are found significant at 5% level. To monitor the pest and natural enemies by using net sweeping and yellow pan trap method was used. The results showed that the maximum number of yellow stem borer was observed in the direct-seeded rice variety of CR Dhan 209 (7.33) and the leaf folder population was maximum in the direct-seeded rice variety of CR Dhan 204 (7.33). The peak population of grasshopper and green leafhopper was recorded in the transplanted rice variety of CR Dhan200 (11.33), CR Dhan 209 (8.00). The values were found significant at 5% level. The maximum number of Braconidae was observed in direct-seeded rice variety of CR Dhan 205 (3.66), and Ichneumonidae was recorded the highest number of direct-seeded and transplanted rice in the variety of CR Dhan 202 (3.00). The peak population of Trichogrammatidae was recorded in direct-seeded rice of CR Dhan 207 (3.66). The presence of Platygastridae was high in the transplanted rice variety of CR Dhan 201 (8.66), respectively. Among the rice ecosystems, more insect pests and crop damage were noticed in direct-seeded rice more than the transplanted rice.


Author(s):  
Ritesh Mishra ◽  
Hara Prasad Mishra ◽  
Sophia Subhadarsini Pradhan ◽  
Govindharaj Guru-Pirasanna-Pandi ◽  
Gadratagi Basana Gowda ◽  
...  

Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.


ENTOMON ◽  
2020 ◽  
Vol 45 (3) ◽  
pp. 181-188
Author(s):  
T. Sharmitha ◽  
C. Gailce Leo Justin ◽  
S. Sheeba Joyce Roseleen ◽  
P. Yasodha

Three species of parasitoids viz., Telenomus dignus Gahan, Trichogramma japonicum, Ishii and Tetrastichus schoenobii Ferriere were recorded from the egg masses of rice yellow stem borer, Scirpophaga incertulas (Walker) in a field study. The extent of parasitism was high during Rabi (43.33 – 93.33 %) and low during Kharif (0 - 40.00 %). Parasitism by T. dignus was maximum in October (50.00 %), T. japonicum, in November (23.08 %) and T. schoenobii in February (55.55 %). dignus and T. schoenobii in combination parasitized maximum number of egg masses (41.82 %). Multiple parasitism by the three species was high in December (8.33 %) and January (7.14%). Parasitic potential was maximum, when T. schoenobii alone parasitised the egg masses followed by T. dignus and T. schoenobii in combination. Host density in the field influenced the extent of parasitism.


2020 ◽  
Vol 26 (7) ◽  
pp. 1610-1630
Author(s):  
E.L. Prokop'eva

Subject. The article investigates and quantifies factors of insurance markets functioning in Russian regions, and reveals possibilities to manage them. Objectives. The purpose of the study is to substantiate regional factors that determine the specifics of regional insurance market development; to quantify them to increase the efficiency of regional insurance. Methods. The study draws on statistical methods, functional analysis, algorithm development, correlation and regression analysis. Results. I calculated coefficients of pair and multiple correlation with the indicators of insurance markets in the context of the subjects of the Russian Federation, and composed regression equations. Based on the analysis, I determined the algorithm for inverse effect of the insurance market on the economic, social, fiscal and environmental performance of the region, offered appropriate measures aimed at developing the economic potential of the region and its social sphere. Conclusions. The paper considers the case of the Republic of Khakassia, one of depressed subjects in the Siberian Federal District. The developed models can be used for other regions of Russia, given the geographical and economic features of development. The findings may help generate regional strategies for socio-economic development at the country level. The scientific contribution and the novelty of the work consist of systematizing and quantifying the factors affecting the insurance mechanisms of regional markets, and assessing the inverse effect of insurance mechanisms on integrated development of the region.


Sign in / Sign up

Export Citation Format

Share Document