My Syahrawati^*, Ongki Aditia Putra, Rusdi Rusli, Eri Sulyanti

Plant Protection Department, Faculty of Agriculture, Universitas Andalas, Padang, Indonesia

Abstract

Endemic areas of brown planthopper or BPH (Nilaparvata lugens Stal 1854, Hemiptera: Delphacidae) is an area that always provides BPH in each planting season. Kuranji and Nanggalo Sub-districts are two endemic areas in Padang City. The study aimed to determine the population structure of BPH on IR 42 variety in endemic area of Padang City. The study used a survey method by collecting BPH using a modified hand vacuum, collected from 20 samples of IR 42 variety randomly on two fields in each sub-district. The collections were carried out 3 times at 2-week intervals. The research in vegetative phase was began when rice plant was 3 weeks old after planting, while the research in generative phase was began when the rice plant released the first panicle. The results showed that overlapping generations occurred between nymph and adult (brachypteran & macropteran, male and female). The dominance as a whole was nymph (70.7%). Macropteran population was higher than brachypteran. Based on the phase of rice, BPH in generative phase was higher than vegetative meanwhile based on district, BPH in Kuranji was higher than Nanggalo. Attack percentage ranged from 51.6 – 94.1% and attack intensity ranged from 6.01-10.55%.

Keywords: Nilaparvata lugens, Nymph, Adult, Attack level, IR 42 variety

Nur Ain Izzati Mohd Zainudin*, Munirah Mohd Sattar

Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia

Abstract

Colletotrichum is one of the important postharvest pathogens to cause anthracnose, which is a threatening disease for mango in Malaysia. The information regarding pre-harvest anthracnose disease on mango in Malaysia is still inadequate, therefore encouraging the commencement of this study. The objectives of this study are to identify fungi species from mango anthracnose disease, and to determine the pathogenicity of Colletotrichum isolates obtained from the infected mango. During a series of sampling in July 2014 to May 2015 throughout Peninsular Malaysia, the symptom of anthracnose disease was observed in the Malaysian mango plantation. There were 33 isolates of Colletotrichum species were purified and successfully identified as Colletotrichum gloeosporioides species complex. The identity of the isolates was confirmed and classified into C. gloeosporioides (15 isolates) and C. asianum (18 isolates). For pathogenicity test using a non-wounded method, the mango was inoculated with a young mycelial disk. Disease symptoms were observed as a brown to black circular or irregular shape of the lesion with the sunken effect on the infected fruits. Colletotrichum asianum R2262 appeared as the most pathogenic isolate with DSI of 50% on day 8 after inoculation. The pathogens identified in this study were successfully re-isolated from all the symptomatic mango tissues that resulted in fulfilling the Koch’s postulates. Meanwhile, control mango inoculated with non-colonized PDA plugs remained symptomless until the end of the test. The data obtained from this study is crucial to design an effective strategy to control anthracnose disease of mango.                                                                                   

Keywords: Colletotrichum, Mango, Internal transcribed spacer (ITS), Malaysia, Anthracnose

Herviyanti^*, Azwar Chan, Yusnaweti, Teguh Budi Prasetyo, Mimien Harianti

Soil Science Department, Faculty of Agriculture, Universitas Andalas, Padang, Indonesia

Abstract

One way to improve soil chemical properties of Oxisols is by adding ameliorant, for instance humic substance (HS), to the soil. As there are many kinds of organic matter being a source of humic matter, to investigate a specific type of humic substance for improving the soil chemical properties of Oxisols is necessary. This research was aimed to study the capability of humic substance derived from non-productive coal (sub-bituminous) powder which was extracted with Urea, KCl, NaCl, and NaOH and then it was used to improve the soil chemical properties of Oxisols. The improvement of chemical properties of Oxisols was expected to be achieved by adding humic substance from sub-bituminous. Urea could be used to substitute the role of NaOH in solving humic materials and improving soil chemical properties of Oxisols. Humic materials which were extracted by Urea 0.2 g (kg)^-1 of soil and sub-bituminous in concentration 0.5 % to improve soil chemical properties of Oxisols.                                                                                   

Keywords: Sub-bituminous powder, humic substance, fertilizer, salt and base solvent

PK Dewi Hayati^*, Sutoyo

Department of Agro-Technology, Faculty of Agriculture, Universitas Andalas, Kampus Unand Limau Manih, Padang – 25163, Indonesia

Abstract

Drought stress limits maize production. We studied the drought stress tolerance level of maize inbred lines to select potential parental lines for hybrid production. Glasshouse scale pot experiment was arranged in Completely Randomized Design with eight inbred lines as the treatment. Each inbred line was placed in two conditions; normal and drought stress with three replications. Drought stress condition was achieved by suspending water supply when 50% of the plants had approached V11 phase where maize has grown 11 open leaves, until one plant in the same inbred lines shown heavy withered response. Results showed that line of Gg44 consistently revealed the lowest increase of leaf rolling score (3.8%), the lowest reduction of plant height (3.9%) and plant top dry weight (2.3%) on drought stress condition. The line of Gg44 also produced the lowest stress sensitivity indices (SSI) and the highest stress tolerance indices (STI) for these three traits indicating high tolerance of the line to drought stress. Hence, the line has the potential use in producing maize hybrids that are able to alleviate the negative impacts of drought and high temperature on its growth.

Keywords: Inbred lines, Selection criteria, Drought stress, Tolerant

Warnita Warnita^*, Ardi Ardi, Yopi Zulfa

Department of Agronomy, Faculty of Agriculture, Universitas Andalas, Padang, Indonesia

Abstract

The research was conducted at the Center for Technology and Development of Agricultural Area (PAPTKP) Universitas Andalas, which was located at Jorong Galagah, Solok District from December 2016 to March 2017. The purpose of this study was to determine the interaction between indigenous rhizobacteria and plastic mulch, and the effect on growth and yield of potato. The method used was Randomized Block Design (RBD) with 2 factors (2×5) in 3 replications. The first factor was the use of plastic mulch (with and without plastic mulch) and the second factor was the indigenous rhizobacteria isolates (A1.1a1, A3.2a2, A3.2b1, BT1.2a2, and without rhizobacteria). The variables observed were morphological and physiological characteristics of indigenous rhizobacteria, plant height, tubers number, tuber weight per plant, and tuber diameter. The data were analyzed by using analysis of variance (ANOVA) and Duncan's New Multiple Range Test (DNMRT) at a significant level of 5%. The results showed that there was no interaction between plastic mulch and indigenous rhizobacteria isolates on growth and yield of potato. The plastic mulch increased tuber weight and tuber diameter but the A3.2b1 isolate of indigenous rhizobacteria tended to increase plant height and increased significantly tuber weight of potato.

Keywords: Potato, PGPR, mulch, indigenous, rhizobacteria

Mohammad Nurcholis^*, Susila Herlambang

Department of Soil Science, Faculty of Agriculture, Universitas Pembangunan Nasional “Veteran” Yogyakarta

Jalan SWK 104 (Lingkar Utara) Condongcatur Yogyakarta 55283 Indonesia

Abstract

Agricultural development in Bintuni Bay requires detail information of soil properties, however, current data is inadequate. To provide the information on soil chemical properties in its ​​coastal sediment area, we surveyed landform and soil morphology of Aroba and Sumuri Districts, each of ​​200 ha. The forest land in Aroba was composed of thick mudstone (claystone) with some inserts of sandstones, while that of Sumuri was dominated by sandstone with insert of mudstone and some lenses of conglomerates. The soils showed variation of pH, CEC, exchangeable bases, Organic-C, total-N, and available P in a relatively narrow area. The CEC value was positively correlated with clay content and total organic carbon. There were also variation of soil forming materials and serial processes of transportation, deposition, denudation, and pedogenesis that occurred in the studied lands.

Keywords: Soil chemical characteristics, sedimentary rocks, Bintuni Bay

Sri Budiyanti^*, Hidrayani, Hasmiandy Hamid

Agriculture Quarantine Office, Class 1, Padang 25217, Indonesia

Abstract

Vegetables in Padang are generally attacked by fruit flies. A study has been done to investigate the fruit flies’ species diversity and measure the damage they have caused on these vegetables. Four kinds of vegetables viz. bitter gourd, cucumber, angled loofah, and chili pepper were sampled in the subdistricts of Pauh, Kuranji, Lubuk Kilangan, and Koto Tangah using purposive sampling. There were three species of fruit flies found in four vegetables in Padang, viz. B. cucurbitae, B. dorsalis and Bactrocera species. The highest percentage of plants infested was on angled loofah (20.34%). The highest diversity of fruit flies based on commodity was found on bitter gourd (0.010). Based on location, the highest species diversity was found in subdistrict of Lubuk Kilangan (0.240). The diversity and attack level of fruit flies in Padang City are relatively low, but the control of these pests is required to avoid the spread of them widely in West Sumatera.

Keywords: Diversity, fruit flies, Bactrocera cucurbitae, B. dorsalis, vegetables

Hidrayani^*, Yunisman

Plant Protection Department, Agriculture Faculty, Universitas Andalas, Padang, Indonesia

Abstract

Species diversity of Trichogrammatid egg parasitoids parasitized lepidopteran pests was studied in West Sumatera. The lepidopteran eggs were collected from rice plants, corns, cabbages, and tomatoes distributed in five regencies with different altitudes. Three species of Trichogrammatid were recorded. Trichogramma japonicum parasitized Schirphopaga incertulas and distributed in all regencies planted rice with their parasitization ranged between 3.5-27.8%. Trichogramma chilotreae parasitizing Crocidolomia binotalis was distributed in all regencies planted cabbages with parasitization ranged between 5.3-5.6%. Trichogrammatiodea sp. parasitizing Helicoverpa armigera attacking corns was only found in Solok with parasitization 18.4%. Only one species of Trichogrammatid was found to parasitize each of lepidopteran eggs. None of egg parasitoid was found to parasitize H. armigera attacking tomatoes.  No difference was shown on the parasitization level of T. japonicum between high and low land planted rice.

Keywords: Diversity, Trichogrammatidae, Lepidopteran pests

Siska Kurniawati¹, Irawati Chaniago^2*, Irfan Suliansyah³

¹Postgraduate student, Department of Agronomy, Faculty of Agriculture, Universitas Andalas, Indonesia

²Associate Professor, Department of Agrotechnology, Faculty of Agriculture, Universitas Andalas, Indonesia

³Professor in Plant Physiology, Department of Agrotechnology, Faculty of Agriculture, Universitas Andalas, Indonesia

Abstract

Brown rice has recently become more popular following an increase in people awareness for healthy life style in Indonesia. “Sigah” is one of brown rice local to West Sumatera and is in high demand for its taste and aroma. However, this rice genotype, as for other landrace, is a tall and long-lived type. Tall rice is very susceptible for lodging due to flooding or strong wind. The research was aimed at determining the stability of mutant of Sigah, brown rice genotype with desired characters i.e plant height and early maturing; plant height and number of tillers. The experiment was carried out at irrigated paddy field at Sungai Sapih Kuranji, the City of Padang from April to July 2018 using 13 mutant lines of M2 that was previously irradiated with 200 Gy gamma rays. Twenty sister lines were used as control plants. Individual selection of every single plant was conducted through the experiment. Eight early maturing mutant lines and seven plant height mutants were found for their character of number of tillers. Number of mutants according to short-statured and early maturing mutants characters are 7 and 8 mutants respectively. Early maturing mutants were recorded for mutant lines 47, 89, 53, 58, 76, 111, 4 and 68.

Keywords: Brown rice, Irradiation, Mutation, West Sumatera, Sigah