Vol 7, No 2 (2020): December

Mercury waste from gold mining activities that contaminate the environment is very harmful to the living organisms including aquatic insects. This study aims to analyze the acute toxicity of mercury on Trichoptera larvae that commonly used as a bioindicator of water quality.The study was arranged in a completely randomized design with six-levels  of mercury chloride (HgCl2) concentrations, namely: 0.00; 0.001; 0.005; 0.1; 0.2; and 0.3 mg / l HgCl2.  A total of 20 insects larvae were used for each concentration and the insect mortality was observed in four times (30, 60, 90, and 120 minutes). The results showed that the mortality of Trichoptera larvae had occurred at 30 minutes after observation. The LC-50 value of mercury chloride against Trichoptera was 0.048 ppm. Larval mortality increased with the increase of the mercury concentration and the exposure time. These results indicate the acute toxicity of mercury chloride to Trichoptera larvae. The effect of mercury on morphological changes of the Trichoptera larvae is also observed and discussed.

Black rice is a functional food so that it is not only to meet food needs, but also to maintain the health of consumers. For farmers, producing black rice will be more profitable because the selling value is higher than other types of rice. However, not many consumers and farmers are aware of this, resulting in unstable black rice production. In this free trade era, the opportunity to export a commodity or penetrate the international market is getting bigger. Therefore, it is necessary to study the competitiveness of black rice to determine its potential.The purpose of this research was to identify competitiveness through competitive advantage and comparative advantage as well as the impact of government policies. The research design used was quantitative with survey techniques. Data were analyzed using the Policy Analysis Matrix (PAM). The results showed that black rice was competitive both competitively and comparatively, indicated by the value of PCR < 1 = 0.568 and DCR < 1 = 0.521. Therefore, 1) black rice farming was efficient financially and economically, and 2) black rice has the potential to be exported. The impact of government policies on black rice farming has overall reduced farmers' income. In addition, government policies also inhibited black rice exports as indicated by the value of NPCO < 1 = 0.793 and prevented farmers from exporting inputs as indicated by the value of NPCI < 1 = 0.565.

This study aims to examine the effectiveness of gibberellins in breaking dormancy to produce high viability snakefruit (Salacca snakefruit Geartner) seeds. The materials used are snakefruit seeds from Tamareja Village, Donggala Regency, sterile sand media, aquades, and GA₃ solution. This research was arranged using a completely randomized design (CRD) with one factor, namely the provision of gibberellin, consisting of five levels of concentration, namely P0 = control (without treatment), P1 = 30 ppm and P2 = 40 ppm P3 = 50 ppm P4 = 60 ppm. each treatment was repeated five times so that there were 25 experimental units. Each experimental unit used 20 seeds. Observation data were analyzed using analysis of variance (ANOVA), followed by Tukey' HSD test if the treatment tested showed a significant effect. The results showed that gibberellin administration effectively broke snakefruit seeds' dormancy and produced seeds with high viability. The higher the gibberellins' concentration would increase germination speed plumule length, radicle length, and faster embryo axis emergence. Gibberellin 60 ppm resulted in germination power 98%, germination rate 20.97 days, plumule length 5.52 cm, radicle length 5.15 cm, and embryo axis emergence 9.2 days.

Applying organic matter to the soil surface is an effective effort to increase soil resilience in the Palu valley, which is classified as low. This study aimed to determine: 1) the effect of several doses of compost on the physico-chemical properties of the soil, 2) the correlation between the percentage of organic carbon and total nitrogen in the soil to several physico-chemical properties of the soil. The research was based on a randomized block design in a greenhouse of the Faculty of Agriculture, Tadulako University, Palu. Compost uses raw materials for plantain stems (Musa textilia) and leaves of Gamal (Gliricidia sepium). The compost doses used in the experiment consisted of 0%, 1%, 2%, 3%, 4%, and 5% of the weight of air-dry soil, respectively. The treatment was repeated three times. The results showed that compost application significantly affected soil content weight, total porosity, saturated hydraulic conductivity, field capacity moisture content, percentage of organic carbon, total nitrogen, and cation exchange capacity. The correlation test results showed a powerful relationship between the percentage of organic carbon or total soil nitrogen to other soil physico-chemical properties observed in the experiment.

Agribusiness may potentially develop on Palu Riversides. This research aims to formulate a sustainable agricultural spatial innovation for the Development of Agribusiness Places on Palu Riversides. The methods used for this study were field observation, satellite image map observation, and literature review. The results showed that the implementation of sustainable agriculture through the development of agribusiness places in urban areas could take advantage of the open spaces designated as green open space zone on the Palu Riversides, namely the River Green Area which is outside the riparian zone, the river overflow runoff area. To achieve this objective, it requires ability to innovate in spatial planning so that an urban agricultural area that is neatly arranged into an agribusiness places can also be developed into one of the city landmark.

The primary commodity consumed by people is reflected in the highest expenditure to fulfill it within a specific period, the dominance of expenditure in all consumption expenditures indicates the importance of commodities in all households' consumption. This study aims to identify the dominant consumption patterns of food commodities using descriptive analysis of 6,178 households obtained through national secondary data from the 2017 national socio-economic survey (Susenas). Several commodities categorized by largest to smallest expenditure are the basis for determining the largest consumption expenditure as essential commodities. Based on the ranking of consumption expenditures, the three most prominent consumption groups were identified, namely: (1) rice, (2) rice with assortment of side dishes, and (3) fish. Rice, detected through 4,771 households, is the largest consumption commodity, and expenditure on this commodity increases in line with the rise in income, reflected in the mean value of expenditure which is higher in the increasing income group. The expenditure of rice with assortment of side dishes was detected through 3,150 households and had the same tendency as rice, particularly increased expenditure in the higher income groups. Fish consumption expenditure was detected through 3,488 households following the conditions for the two previous commodities, and expenditures increased with higher income. The increased expenditure on the consumption of essential commodities by income groups demonstrates that the tendency to consume is in accordance with Keynes's relationship between consumption and revenue. The higher the income, the greater the consumption expenditure. However, to a certain extent, the specific relationship is that the proportion of increased consumption expenditure decreases with higher income. Based on the elasticity coefficient, it was found that three essential commodities were normal goods. However, the level of consumption sensitivity to rice and fish income was higher than for processed food. In contrast to elasticity, the tendency to consume processed food is higher; the share of the increase in revenue is used to increase consumption of processed food, compared to adding rice and fish. This finding acts as provisional evidence that food consumption has undergone a fundamental change to become more consumptive.

Low of relations between farmers and the market causes the marketing of vegetable commodities to not run optimally. The relationship between various marketing agencies and farmers produces a social network. Based on this, the social network in the marketing aspect is the main capital for the development of farming. The objectives of this study were (1) to identify the characteristics of farmer members of the Katenzo Farmers Group, (2) to analyze the structure of the social network on the marketing aspects of vegetable commodities in the Katenzo Farmer Group, (3) to analyze the position of actors in social networks on the marketing aspects of vegetable commodities based on the degree of centralism. at the Katenzo Farmers Group. This study used a qualitative research design with a case study approach. Samples were taken using census techniques to all member farmers, amounting to 13 people. The analysis method used is Social Network Analysis (SNA). The results of this study indicate that all respondents are male farmers who are included in the category of young farmers who have an average high school education level and have business experience under 5 years. The network structure that is formed is a personal radius network structure (Radial Personal Network), with the central actor is the Head and Public Relations Division of the Katenzo Farmers Group.

Instant noodles are generally made from wheat flour as raw material. The abunandce of purple sweet potatoes can substitute the wheat flour. The purpose of this study was to determine the effect of substitution of purple sweet potato flour at various concentrations on the physical, chemical, and sensory test of instant noodles. The research was conducted at the Agro-Industry Laboratory, Faculty of Agriculture, Tadulako University, from June to December 2019. The experiment was arranged using a completely randomized design (CRD) with 1 factor, namely the substitution of instant noodle purple sweet potato flour at a concentration of 0.5, 10, 15, 20, 25, and 30%. The treatments were repeated three times so that 21 experimental units were obtained. For the sensory test using a randomized block design (RBD) with 30 panelists. The parameters of the observation consisted of the loss of solids due to cooking, water absorption, water content, ash content, and sensory tests. The results of research on substitution of purple sweet potato flour at various concentrations gave the best effect at a concentration of 30% on instant noodles produced based on physical, chemical, and sensory properties. With the highest loss of solids due to cooking, the absorption of instant noodles decreased as the concentration of purple sweet potato flour increased. Instant noodle moisture content constant tendency at each treatment. The ash content of instant noodles increased with increasing concentration of purple sweet potato flour and the sensory properties of color, texture, aroma, and taste of the instant noodles increased with the increasing concentration of purple sweet potato flour on the hedonic scale category. Noodles substituted with purple sweet potato flour can be consumed as instant noodles, such as those circulating in the market.