bahman amiri larijani

Focusing the value chain of products is one of the most important new approaches in agricultural development. Nevertheless, very a few researches related to the rice value chain across the country have been done , especially in the Mazandaran province, where it is considered as the most important producer of rice. Therefore, the main goal of this research was to the study of challenges of rice value chain from the view point of farmers. This is an applied research which needed data collected through systematic literature review and survey method. In qualitative part of research, inductive analysis method applied as a guide for data collection and analysis.  The target population consisted of active paddy farmers which 15 out of them purposefully selected as a sample. For data collection, field observations and in-depth interviews used in the framework of the focus group. The validity of the findings was also confirmed by the triangulation process. The research finding indicated that the region's rice value chain face many challenges in the pre-production, production and post-production process.

Neglecting market conditions and emphasizing merely on production increase is one of the basic problems of agricultural extension systems. Institutionalizing extension services based on a market-oriented approach can play a useful and effective role in increasing the quantity and quality of production and optimizing the value chain of products with a focus on employment growth, entrepreneurship and economic prosperity in rural areas. Therefore, this study aimed at identifying the components for institutionalization of market-based extension services in the rice value chain in rural areas of Mazandaran Province, as Iran’s most rice producing province, in 2019. The required data were collected through semi-structured interviews with 29 purposefully selected rice experts and were analyzed through an inductive analysis method. The results showed that based on the value chain approach, the activities were classified in the two categories including ‘primary activities’ such as the supply of inputs, production, processing, marketing and consumption of rice and ‘support activities’ comprising providing training and advisory services, financial supports, human resource management, supportive policies, and the provision of the necessary infrastructure. It was also found that support activities were identified as effective factors in the institutionalization of market-oriented extension services in the rice value chain.

Iran is one of the richest sources of medicinal plants in the world due to its high climatic diversity. Cumin is one of the most important and economical medicinal plants of the Umbelliferae family, which has a high distribution in different parts of the country and is one of the most important export plants of Iran. This study was conducted to investigate the quantitative and qualitative diversity of cumin essential oil in Khorasan Razavi province in 2018-2019. For this purpose, seeds were collected from farms in 6 different regions of the province at the harvest time. Seeds were extracted by water distillation for 2 hours. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC / MS) devices were used to identify the essential oil compounds and determine their percentage. Nine compounds in the essential oils of Gonabad (N1), Neishabour (N2), Taybad (N3) and Khoshab (N4), 15 compounds in the essential oils of plants in Fariman region (N5) and finally 13 compounds in the essential oils of Dargaz region (N6) were identified. In total, 9 compounds; gamma-terpinene-7-al, cuminaldehyde, terpinene-4-ol, gamma-terpinene, α-phellandrene, p-cymene, sabinene, β-Pinene, α-Pinene were common in cumin essential oil extracted from 6 regions of Khorasan Razavi province. The two compounds cis-dihydrocarvone and (E) -Caryophyllene were identified exclusively in region (N5) with of 0.45% and 0.19%, respectively. α-thujene, α-terpinene, limonene and 1,8-cineol were obtained only from essential oils of (N5) and (N6).

The formation of grain yield depends on fators such as available radiation and the genetic  characteristics of plant like radiation interception rate, radiation use efficiency and biomass contribution. In regard to climatic changes, for studying the effect of environmental conditions on this characteristics, a factorial experiment in randomized complete block design with three replications was conducted at Haraz Extension and Technology Development Center, Iran, in two crop seasons, 2013 and 2014. Three transplanting dates were used to encounter rice varieties under different environmental conditions. Treatments included rice cultivars (Tarom Samadi, Tarom Hashemi, Local Tarom, Shiroudi, Keshvari and Gohar) and transplanting dates (5th may, 20th may and 10th June). Results showed that grain yield, biomass, LAI at heading and 20 days after heading, harvest index, accumulated intercepted photosynthesis active radiation (PAR), radiation use efficiency, grain filling rate, grain filling period and panicle number.m2 varied significantly between rice varieties. Transplanting date had significant effect on all traits, except radiation use efficiency. Highest grain yield, biomass, harvest index, accumulated incident PAR, accumulated intercepted PAR, grain filling period and growth duration were obtained  in transplanting on 5th may ( 7204 kg.ha-1, 17229 kg.ha-1, 41.9%, 1050 MJ.m-2, 827 MJ.m-2, 20.6 and 105 days, respectively) and lowest in transplanting on 10th June. Results of this experiment showed that changing in transplanting date of rice varieties caused changing in mean temperature during growth period, accumulated incident PAR and accumulated intercepted PAR as fallow, but had non significant effect on radiation use efficiency.

To assess the radiation use efficiency (RUE) of different rice cultivars under transplanting (TP) and direct-sowing (DS) systems and scrutiny of weed effect، a split-plot factorial experiment was conducted based on a randomized complete block design with three replications in 2011 at Haraz Extension and Technology Development Center in Mahmoudabad city، Mazandaran. The main plots were two planting systems (TP and DS) and subplots were factorial combinations of three rice cultivars under weed infested and weed free conditions. The results showed that RUE and grain yield of rice cultivars significantly reduced in weed infested plots especially in DS system. The average RUE of line 843، Khazar and Tarom in weed-free conditions were 3. 18، 3. 22 and 2. 69 g MJ-1، respectively، while it reduced to 3. 08، 2. 57 and 2. 35 g MJ-1، respectively، under weedy conditions. The differences of yields were mainly due to differences in biomass and harvest index، and were not associated with RUE. Light extinction coefficient (K) of line 843، Khazar and Tarom were 0. 44، 0. 45 and 0. 71، respectively. Under high weed interference (as seen under DS method)، Tarom could better suppress weeds and had lower yield loss due to its taller plant height and greater K. Under no or low weed interference (as seen under TP method)، line 843 was ranked higher in terms of final yield due to its smaller K، greater leaf area and higher harvest index.