Pheromone Receptors Help Cnaphalocrocis medinalis Avoid Competition in Rice Fields

Cnaphalocrocis medinalis (Guene'e) (Lepidoptera: Pyralidae) is one of the most important insect pests that attack the rice crop, Oryza sativa L., in China, feeding on rice leaves. Chilo suppressalis and Sesamia inferens are two common insects living within the same ecological system that feed on rice stalks. Their behavior could affect C. medinalis's choice of oviposition place, so we tested the electroantennogram (EAG) response of C. medinalis to a conspecific sex pheromone (Z11-18:OH; Z11-18:Ald; Z13-18:OH; Z13-18:Ald) and two other insects' pheromone compounds (Z9-16:Ald; Z11-16Ald; Z11-16:OH;Z11-16:Ac and 16:Ald). The results indicate C. medinalis can detect those pheromones and is sensitive to Z11-16:Ald and Z9-16:Ald. In the heterologous expression system of Xenopus oocytes, we cloned three pheromone receptor genes, CmedPR1, CmedPR2, and CmedPR3. These had the same electroantennogram response, in addition to the response to the conspecific pheromone. CmedPR2 and CmedPR3 displayed strong sensitivity to Z11-16Ald and Z9-16:Ald. These results may contribute to clarifying how C. medinalis recognizes pheromones and interspecies communication.

Prototype Development of Small Mobile Robots for Mallard Navigation in Paddy Fields: Toward Realizing Remote Farming

This study was conducted to develop robot prototypes of three models that navigate mallards to achieve high-efficiency rice-duck farming. We examined two robotics navigation approaches based on imprinting and feeding. As the first approach, we used imprinting applied to baby mallards. They exhibited follow behavior to our first prototype after imprinting. Experimentally obtained observation results revealed the importance of providing imprinting immediately up to one week after hatching. As another approach, we used feed placed on the top of our second prototype. Experimentally obtained results showed that adult mallards exhibited wariness not only against the robot, but also against the feeder. After relieving wariness with provision of more than one week time to become accustomed, adult mallards ate feed in the box on the robot. However, they ran away immediately at a slight movement. Based on this confirmation, we developed the third prototype as an autonomous mobile robot aimed for mallard navigation in a paddy field. The body width is less than the length between rice stalks. After checking the waterproof capability of a body waterproof box, we conducted an indoor driving test for manual operation. Moreover, we conducted outdoor evaluation tests to assess running on an actual paddy field. We developed indoor and outdoor image datasets using an onboard monocular camera. For the outdoor image datasets, our segmentation method based on SegNet achieved semantic segmentation for three semantic categories. For the indoor image datasets, our prediction method based on CNN and LSTM achieved visual prediction for three motion categories.

Feasibility of biogas as a green energy source in the central part of South Sulawesi

The goal of this work is the feasibility of biogas as a green energy source produced from organic matter from ruminants, equine and farming activities in the central part of South Sulawesi. The study was conducted with survey and laboratory analysis to calculate the number of ruminants, corn, and rice stalk using supporting data from the South Sulawesi Statistics office. Amounts of 84,567, 112,915, and 3,579 ruminants have been raised in Maros, Gowa, and Makassar, respectively. While 6,757, 9,529, and 50 monogastric are raised in Maros, Gowa, and Makassar. Corn and rice stalks were produced 465,878.06 tons year-1 in Gowa and Maros. Every cattle and equine can produce feces up to 25 kg day-1 and 30 kg day-1, daily feces production equals 2,316,885; 3,108,745; and 90,975 kg day-1 in Maros, Gowa, and Makassar, respectively. These waste products can be converted to biogas as source of green energy with a total yield of 667,752,675,489.20 x 103 cc. Its production ratio is 1 kg dry matter: 1,051.3-liter biogas for beef feces and 1 kg dry matter: 3,980-liter biogas for equine feces and corn and rice stalks can be applied as organic fertilizer as a significant factor in anaerobic fermentation of biogas production.

A newly isolated Cerrena unicolor capable of laccase production and lignin degradation in agricultural wastes

Lignin is main residue of agro-industrial biomass which can be decomposed through enzymatic hydrolysis by fungi. In this study, a strain was isolated from birch forest and identified as Cerrena unicolor GC.u01 by 18S rDNA gene-sequencing technology. The activity of laccase (Lac) reached maximum 1605.28 ± 32.21 U·L-1 at 8th day via submerged fermentation, while the highest Lac activity by solid-state fermentation 1280.04 ± 48.11 U·g-1 with rice stalks and 566.83 ± 47.02 U·g-1 with wheat stalks were both obtained at 10th day, and 2677.50 ± 49.38 U·g-1 with corn stalks at 12th day. Then the lignin degradation ratios were up to 24.3%, 34.3% and 26.2% in wheat stalks, rice stalks and corn stalks, respectively, suggesting that the newly isolated Cerrena unicolor GC.u01 is potential for laccase production and lignin degradation by solid-state fermentation.

Unveiling the Feeding Behavior of Tibraca limbativentris (Hemiptera: Pentatomidae) on Rice Using an Electropenetrography Waveform Library

The rice stalk stink bug, Tibraca limbativentris Stål, damages plant stalks while feeding, making it one of the most important rice pests in South America. Because the feeding behavior of T. limbativentris has not yet been studied in rice, we investigated T. limbativentris stylet penetration (probing) in rice stalks. A waveform library was created using the new AC-DC EPG monitor with different levels of input resistance (Ri). Six different waveforms were recorded and correlated via histological studies and grouped into three phases: non-probing waveforms (Z and Np), pathway waveforms (Tl1), and ingestion waveforms (Tl2 and Tl3). The Z waveform was observed when the stink bug was standing still on the plant surface, Np when the stink bug was walking on plant surface, Tl1 was associated with stylet insertion and deep penetration into the plant tissue, and Tl2 when the stink bug was feeding on xylem vessels. The Tl3 waveform was associated with the rupture of stalk cells and was divided into two subtypes (Tl3a and Tl3b). The Tl3a waveform probably represents cell laceration with combined enzymatic maceration of stalk tissues, while Tl3b represents a short ingestion period of macerated tissues. Tibraca limbativentris uses two strategies to feed on rice stalks: a salivary sheath for feeding on xylem vessels and cell rupture (laceration and maceration) for feeding on parenchyma cells. Our study provides crucial benchmark definitions of waveforms. Future studies can now compare effects of treatments on stink bug feeding, to ultimately improve management of this pest in rice.

A Improvement of efficiency in Tanjung Marolan farmers harvest process with thresher technology

Human power which is relied on every harvest season becomes a big concern for farmers. Farmers in Ajibaho Village, Dusun VII Tanjung Marolan still utilize a simple equipment with human power to harvest rice. Some processes of harvest require longer time. It is started from cutting rice stalks, collecting rice stalks, and threshing rice by hitting it on a drum to thresh the rice from the stalks. After that, the rice was collected, put into white sack, and delivered to houses. This condition also depends on the weather which becomes longer when it is rain or sunny. A simple technology which uses thresher can be a good solution to achieve an efficiency of harvest process specially for the threshing process. The application of thresher machine is able to give a positive impact to increase harvest, to decrease daily cost, and to effectuate harvest process

Assessment of Crop Residues Energy Potential and Efficient Usage in the South-western Zone of Afghanistan

In the south-western zone of Afghanistan (Kandahar, Helmand, Urozgan and Zabul) about 807,890 tons of wheat, 945 tons of rice, 46,164 tons of barley and 105,276 tons of maize were produced in 2016-17. Based on the residues to product ratio (RPR) of the crops (1.8 for wheat straw, 1.5 rice stalks, 0.2 for rice husk, 1.3 for barely straw and 2 for maize stalks) about 1,454,202 tons of wheat straw, 1,418 tons of rice stalks, 189 tons of rice husk, 60,013 tons of barely straw and 210,552 tons of maize stalks were generated in the south-western zone of the country. By considering the lower heating values (LHV) of the crop residues (13.76 MJ/kg for wheat straw, 12.81 MJ/kg for rice stalks, 16.33 MJ/kg for rice husk, 13.97 MJ/kg for barely straw and 13.22 MJ/kg for maize stalks), it was resulted that 20,010 TJ energy can be generated from wheat straw, 18 TJ from rice stalks, 3 TJ from rice husk, 838 TJ from barely straw and 2,783 TJ from maize stalks. Cumulatively, around 23,653 TJ of energy can be generated from the selected crop residues in the south-western zone of Afghanistan in 2016-17. These crop residues are mainly used for cooking by using the very inefficient three stone cook stoves (η = 12.6%) and two support cook stoves (η = 13%). To use these crop residues more efficiently, it is advised to replace the mentioned inefficient cook stove with improved Chulha and Anagi II cook stoves, which have an efficiency of 21% and 22% and can save off to 43% and 40% fuel wood, respectively compared to the traditionally used cook stoves.

Numerical Calculation Method of Deflection Deformation of Rice Stalk

This paper deals with the numerical calculation method of deflection deformation of rice stalks. Due to large deflection of rice stalks caused by reel operation, it is improper to adopt the conventional formula that is usually used in small deflection calculation to fit rice stalk deformation curves. Therefore, a large deflection calculation formula in combination with Simpson’s formula was utilized to compute flexural rigidity (EI) and to fit curves. The experiments were conducted under different loads (0.03, 0.04, 0.05, 0.06, and 0.07 N) on a self-established deflection testing rig to verify this method. As a result, the measured results corresponded considerably to ones predicted by this method; furthermore, the flexural rigidity was maintained at a stable level under different loads. This study can provide the basis for establishing a complete deformation model of rice plant and can also be applied in deflection calculation of other stalk crops.