September 2011

Effects of irrigation regime and plant density on harvest index of German chamomile (Matricaria chamomilla L.)

Alireza Pirzad, Mohammad Reza Shakiba, Saeed Zehtab-Salmasi, Seyed Abolghasem Mohammadi, Hashem Hadi, Reza Darvishzadeh

Abstract

To evaluate the effect of irrigation regime on yield of biomass, dried flower, essential oil, and seed yield as well as harvest index of dried flower, essential oil and seed at different plant densities of German chamomile, a two-year factorial experiment was conducted in Randomized Complete Block Design. Factors were irrigation regime (Irrigation at 25, 50, 75 and 100mm evaporation from pan class A) and plant density (5, 10, 15, 20 and 25cm intra-row spaces with 30cm inter-row space) with three replications. Results showed the significant effect of irrigation and plant density on the yield and harvest index of dried flower, essential oil, and biomass. The highest yield of dried flower (1,136kg/ha) was obtained from irrigation at 50mm evaporation from pan, followed by 75, 25 and 100mm evaporation. The highest (7,474g/ha) and lowest (5,812g/ha) essential oil yield were obtained from irrigation at 50 and 100mm evaporation, respectively. The greatest biomass (2,989kg/ha) observed at 25mm evaporation, as well as irrigation at 50 and 75mm, and the minimum one (1,882kg/ha) was at 100mm. The highest yield of dried flower (1,241kg/ha), essential oil (8,057g/ha), seed (765kg/ha) and biomass (2,716kg/ha) were obtained from 10cm intra-row distance, whereas the lowest yield of dried flower (765kg/ha), essential oil (4,921g/ha) and seed (574kg/ha) observed at 25cm distance. The minimum biomass (1,768kg/ha) was obtained from 5cm intra-row space. The maximum (39%) and minimum (33%) harvest index of dried flower were obtained from irrigation at 100 and 25mm evaporation, while, the highest (47%) and lowest (29%) harvest index belonged to 5 and 25cm planting spaces, respectively. The largest and smallest harvest index of essential oil concerned to 5 (0.324%) and 25cm (0.192%), respectively. Our finding showed that the best irrigation was irrigation at 50mm evaporation from pan and the optimal plant distance was 10cm intra-row space.

Pages 120-126 Full Text PDF

Monitoring of live chick embryo based on acoustic and vibration signals with a new semi-invasive technology

Sen Liang, Jianwei Liu, Z.S. Zhang, Xuan Li

Abstract

A new semi-invasive technology is developed in this paper to measure the heartbeat of live chick embryos. A small hole is made by a pin at the top of egg air cell in order to let the heartbeat signal after amplification coming out. Two methods are presented, one is to measure the acoustic signal by installing a microphone over the small hole at the top of air cell of chick embryo (called acoustic signal method), and the other is to measure the vibration signal of a thin tinfoil which is glued on the hole at the top of egg air cell (called vibration signal method). According to the signals measured, we can know the semi-invasive technology not only identifies the live embryo but also distinguishes the strong and weak embryo. By comparison, the signals measured by acoustic signal method and vibration signal method are in good agreement with each other, which demonstrates the validity of semi-invasive technology. The conclusion will lay an important foundation for the further exploring automatic monitoring of chick embryo development.

Pages 127-131 Full Text PDF

Comparison of mechanical and thermal properties between two varieties of barley (Hordeum vulgare L.) grains

A. Nouri Jangi, S.A. Mortazavi, M. Tavakoli, A. Ghanbari, H. Tavakolipour, G.H. Haghayegh

Abstract

In this research, the effect of moisture content and grain orientation on the mechanical properties of two barley grain varieties is investigated. For this purpose, the barley grains were quasi-statically loaded in horizontal and vertical orientations with moisture content in four levels ranging from 7.3 to 21.6% d.b. and 6.7 to 21.2% d.b. for Nosrat and Kavir varieties, respectively, and loading rate of 10 mm min-1. Some thermal properties of the grains were also determined at moisture content of 7.3 and 6.7% d.b. for Nosrat and Kavir varieties, respectively, and at temperature of 25°C. For both varieties, with increasing moisture content the rupture force decreased while the rupture energy increased. Furthermore, for both varieties the rupture force and energy of the grain were higher under horizontal loading direction than under vertical loading. The rupture force of Nosrat variety was greater than that of Kavir variety, while in the case of the rupture energy, it was vice versa. This means higher flexibility and resistance of Kavir variety during compressive loading. There were no significant differences between the varieties in the thermal properties.

Pages 132-139 Full Text PDF

Review article

An analytical review of parameters and indices affecting decision making in agricultural mechanization

Mohammad Bagher Lak, Morteza Almassi

Abstract

Agricultural Mechanization (AM) has been one of 20th century’s most important innovations followed by producers to meet the world increasing demand for food, feed and fiber. The main purpose of AM is to achieve a stable approach for optimum productivity. Therefore, AM is considered as concepts and functions resulting in determination and definition of parameters and indices, which are required for implementation, application, and evaluation of AM. Decision Makers (DMs) require the parameters/indices as criteria to make the best decisions. Therefore, this paper seeks to define the concepts and functions as tools to estimate the criteria. Technical, economic, ergonomic, environmental, and cultural aspects of agriculture are the main criteria which influence the AM. A DM must be aware of the effect of each one and make the best decisions using the data. MCDM methods, such as AHP, LINMAP, and TOPSIS, are suggested to be used more in AM analyses. Fuzzy logic is the approach that helps DMs make better decisions.

Pages 140-146 Full Text PDF

Influence of soilless growing media, pot size and sieved media on the production of Hibiscus Sabdariffa L. seedlings

Boodia Navindra, Dursun Gianjeet and Govinden-Soulange Joyce

Abstract

This study was conducted to determine the potential of raising roselle (Hibiscus sabdariffa L.) seedlings, using different types of coarse and sieved media in various pot sizes up to thirty days after germination. Roselle seeds of cultivar ‘Locale’ and formulated rooting media were characterized for certain physico-chemical characteristics. The media were different in terms of pH, electrical conductivity (EC), container capacity and percent aeration porosity (p<0.05). Root dry weight (DW) of roselle seedlings differed significantly among rooting media (p<0.05) and pot sizes (p<0.05). Root DW of roselle seedlings from medium M4 (2-mm sieved scoria) was 0.188±0.046 g, while under the control treatment (soil), root DW was much lower (0.069±0.020 g). Number of leaves and shoot DW of seedlings from M4 treatment were considerably higher than the control seedlings. An interaction effect between type of media and pot size on the whole seedling DW (p<0.05) was also observed. Pot size P1 produced roselle seedlings of higher seedling DW in the coarse media. Under sieved media, pot sizes differed in shoot DW (p<0.05), whereby P2 and P3 produced roselle seedlings of higher seedling DW than P1. Scoria has the potential as soilless substrate for roselle seedling production.

Pages 147-154 Full Text PDF