THE SCIENTIFIC JOURNAL OF AGRICULTURE (SJA)
Year:2007 | Volume:30 | Issue:1|Papers Count:14

This study attempts to analyze the effects of wheat market liberalization and abolishing government intervention on social welfare, using time series data of 1961- 2000. Applying a partial equilibrium model (including wheat demand, supply and import functions) and Auto Regressive Distributive Lag (ARDL) model, price elasticities of wheat demand and supply were estimated which were found to be -0.12 and 0.19, respectively, implying inelasticity in both sides of the market. The calculated elasticity’s alongside with the method introduced by Dasilva and Grans (1999) were used to evaluate production, consumption and total welfare impacts of the wheat market liberalization.Base on the findings, whilst wheat market liberalization results in decreasing treasury cost, as well as social welfare and foreign exchange, it increases total social cost. However, the society is expected to gain from wheat market liberalization in Iran.

An experiment was conducted to determine the best level and: time of feeding rapeseed meal for broilers. In this study, under a 3 x 3 factorial experiment with control group, the effects of three levels of rapeseed meal (5, 10 and 15%) and three times of application in diets (SGF, GF and F) on broiler performance and economical parameters (such as production number and diet cost per Kg of body weight) were investigated.1400Ross day old male chicks were allocated to 10 treatments with four replications of 35 chicks in each in a randomized complete block design (RCBD). Using of rapeseed meal resulted significantly in decreasing the body weight (P<0.01). Its effect on FCR was also significant (P<0.05), but feed intake was not affected by using rapeseed meal in diets (P>0.05) By increasing rapeseed meal feeding duration, body weight was decreased and FCR increased significantly (P<0.01), but feed intake was not affected (P>0.05).Interaction effects between levels of rapeseed meal and feeding time on body weight, FCR and production number were not significant (P>0.05). Mortality was not affected by different levels of rapeseed meal, time of application and interaction between them (P>0.05). With the increasing of rapeseed meal level and its feeding duration, production number was significantly decreased (P<0.01), while the interaction effects between them were not significant on this trait (P>0.05). By increasing rapeseed feeding duration, cost of diet per Kg of body weight increased significantly (P<0.01), while the main effect of rapeseed meal and its interaction with time feeding were not significant on this parameter (P>0.05). Therefore, it was concluded that using 5% rapeseed meal in finisher diet resulted the best performance and economical parameters, although using 10 and 15% rapeseed meal in finisher diet can be considered profitable.

In order to study the effects of frequency and depth of irrigation on yield and quality of potato cultivars an experiment was conducted for two years (2002-2004) at Behbahan Agriculture Research Station. A split plot experiment in RCBD with four replications was used. Irrigation frequency considerd as the main factor had four levels: Irrigation after 50, 75, 100 and 125mm cumulative evaporation from class A pan. Cultivar was considerd as sub factor had three levels: Arinda, Piccaso and Sante. Tubers were planted in Mid January and harvested in Mid May. After harvesting the tuber yield of each treatment was divided in two parts: total and marketable yield. Results showed that irrigation after 50mm produced the highest total marketable yield. In regard to total and marketable yield the difference between irrigation after 50 mm and 75 mm was not significant but the treatment was beter than irrigation after 50 and 75mm at 1% level. By increasing the interval between two irrigation sequence. Unmarketable yield percent, small tuber percent and secondary growth percent were increased. The water applied for irrigation after 50, 75, 100 and 125mm were 9300, 8800, 7350 and 6200 m3/ha respectively. The total and mark table yield of Arinda and Sante cultivars were higher than Piccaso cultivar at 1% level. Arinda cultivar produced the highest mean tuber weight, unmarketable yield percent, tuber rottenness percent and secondray growth percent. Sante cultivar produced the maximum tuber number per plant, Tuber dry matter percent and small tuber percent. According to the obtaind results planting of Sante and Arinda cultivars with irrigation after 75 mm cumulative evaporation from class A pan for potato planting in Khouzestan province is recommended.

In this study, using a sample of 300 Iranian pistachio producers, the possibility of using area yield crop insurance for reducing production risk was investigated. In this way, township was considered as the appropriate level of geographic aggregation to use in area yield index. The results showed that, according to Miranda criteria, pistachio area yield crop insurance is a risk reducing tool. More investigations showed that the risk reduction degrees are 40% and 52% for full coverage and optimal coverage respectively. The results, also, showed that the optimal geographic region over which the area yield index is defined is smaller than township. Thus the investigation of finding the optimal level of geographic region for area yield crop insurance program should be continued in the future. At last some solutions were proposed.

To investigate the effect of planting date on canola (Brassica napus L.) growth period, yield, and yield components and to study the possibility of a correlation between these characters in three canola cultivars (Hyola 401, RGS003, and Pf 704), an experiment was conducted in an experimental field at Agricultural College of Shahid Chamran University of Ahwaz during 2003-4 cropping season. The experiment was designed as split plot planned as complete randomized blocks with three replications. Plots and sub-plots respectively consisted of four planting dates (November 16, December 6, December 26, January 15) and three cultivars.Results indicated that with different planting dates, there were significant differences in seed yield and pods per plant at the probability level of %99. Significant differences were also found in seed per pod, oil contents, and protein percentages at the probability level of %95, but not in 1000 seed weight. Three cultivars exhibited considerable differences in the characters yield, pods per plant, and seed per pod at the probability level of %99 but not in 1000 seed weight, oil and protein percentages. Moreover, phenological traits like lengths of growth period, periods of planting date till the apperance of flower buds, lengths of flowering period, lengths of podding period, and grain filling differed significantly at the probability levels of %99 as the result of different planting dates and canola cultivars. Among the yield components, pod per plants was the trait with the highest correlation with yield (r=0.7), however, no significant correlation was found between 1000 seed weight and yield production which was highly correlated with all phenological characteristics mentioned above.

With development of sugarcane cultivation in Khuzestan province and vast use of nitrogen fertilizers, it is be necessary to use biological huge fertilizer and decrease nitrogen chemical fertilizer. Three varieties of sugarcane were inoculated with Gloconacetobacter diazotrophicusin pots under green house condition. Three months after planting the average of dry matter and absorbed total nitrogen were determined in plant tissues of these varities. The results showed that bacterial treatments increased 29-66% dry matter and 29-55% absorbed nitrogen.

In order to study the effect of crop rotation and crop residue managament (CRM) on yield and yield components of mung bean, a field experiment was condueted in 2005 in Mashhad. The experiment was laid out in a split plot design with 3 replications. The main plot treatments were previous crops (i.e. wheat and canola) and sub plot treatments were CRM (i.e. incorporation, elimination and burning the previous crop residue). Results showed that effect of wheat on mung bean yield was better than canola. Wheat with incorporation of residue and canola with burning of residue treatments had a highest and lowest mung bean grain yield, respectively. Also, wheat with elimination of residue and canola with elimination of residue had the highest and lowest mung bean grain protein percentage, respectively. Among yield components, grain and pod number had the highest and grain 1000 weight had the lowest changes between the treatments. Wheat mung bean rotation and incorporation of residue was a better cropping management than other treatments.

Drought is a creeping environmental phenomenon which occurs notably in arid and semiarid regions such as central, eastern and southern regions of Iran that causes many damages and losses. Sistan-Balouchestan province suffers from extremely drought periods due to being far away from rainfall bearing systems. In this paper, dry periods in Sista-Baloochestan province were determined and investigated using Standardized Precipitation Index (SPI) in 3 and 6 months time scales based on 1965-2000 common period. Severity and duration of dry periods as two major drought characteristics were determined and analyzed for both 3 and 6 months SPI. The results showed that time evolution of SPI time series and drought event frequencies are affected by latitudinal lines across the province. Therefore, the stations that are situated in north and south of the province have different time evolution patterns. In order to analyze drought spatial pattern across the province, the SPI results were also mapped and analyzed.

One of the most important variables that affect shape of flood hydrograph is the temporal distribution pattern of rainfall.Therefore, information about this pattrn to estimate flood could be one of the desireable aims for hydrologists. To reach this aim, storms for a period of 33 years from four recording raingages of RoodZard catchment with 875 km 2 area located in North-East of Khozeatan province were considered. Then 13overall storms which covered all 22 raingages around the catchment were selected from the considered data to extract their temporal patterns as a base for generating general patterns for the studied catchment. Due to the mean of the cumulative percentage of rainfalls, temporal patterns were extracted with the same common base time as a result of this study. Then a unique generalized pattern was calculated from the extracted patterns for all the catchment to use for design rainfalls.

A rice thresher in which crop stalks are fead into threshing unit by a chain conveyer and holding rail was tested and evaluated with two rice varieties (binam and 507).Independent variables were drum speed, feed chain speed and crop stalks length. The dependent parameter of these variables was threshing losses. Regression analysis was conducted on the obtained data using spss package. Threshing losses models were determined for two rice varieties. Correlation and R square coefficient for binam and 507 varieties were respectively 0.852, 0.726 and 0.904, 0.817. Drum speed was the most important factor affecting loss rates.

In onder to study the effect of sowing dates on yield and yield components of pop com hybrids an experiment was conducted for two years (2001-2002 growing seasons) at Behbahan Agricultural Research Station. A split plot design with randomized complete blocks design with four replications was used. Three sowing dates were considered as main plots (Aug.5, Aug.15, Aug.25) (The mean air temperatures were 35.6oC, 37.7ooC and 33.0oC in Aug.5, Aug.15, Aug.25 in 2001 and 37.4oC, 34.5oC, 35.4oC in Aug.5, Aug.15, Aug.25 in 2002 respectively). Sub plots were included of three hybrids: ZK1533x ZK4722AA (KSC600), ZKl53312 x ZK4722AA, ZK298/111 III x ZK4722.Analysis of yield variance showed that the effects of sowing date and hybrid were significant at I% level and interaction effect of sowing date and hybrid was not significant. Aug.5 (The mean air temperatures were 35.6oC and 37.4oC in 2001 and 2002 years respectively) was the most suitable sowing date with yield of 8.512 t/ha. The best hybrid was ZKl533x ZK4722AA (KSC600) and producedthe heightestyield (8.108 t/ha). interaction effect of sowing date and hybrid KSC600 hybrid in Aug.5 had the heightest yield (9.375 t/ha). KSC600 hybrid in Aug.5 was the supperior treatment for yield components (172.5 g thousand kernel weight, 16.75 kernel row, 40.38 kernel per row).Therefore, KSC600 hybrid in Aug.5 (The mean air temperatures were 35.6oC and 37.4oC in 2001 and 2002 respectively) sowing date is recommended in Behbahan region.

Population fluctuations and spatial distribution of sugarcane spider mite, Oligonychus sacchari, and its predatory ladybird, Stethorus gilvifrons, were studied in sugarcane fields of Ahvaz, southwestern Iran, during the growing seasons of 1998 and 1999. Effects of mean temperature, relative humidity and prey density on ladybird population were also studied by multiple-linear regression analysis. In sugarcane fields the annual activities of O. sacchari started late spring and first ladybirds were observed 10-14 days after mite appearing. Population fluctuations of both species correlated and continued during spring and summer seasons. In late summer and early autumn population of O. sacchari was significantly reduced and ladybirds began to immigrate to other fields. No hibernated ladybirds were found in late autumn and winter in sugarcane fields. Multiple regression results showed that the relative humidity and prey density were the most influential variables affecting ladybird population development. Both mite and ladybird had contagious dispersion and negative binomial model was the best fitted data for their distribution pattern. The k aggregation index values were low and changed within aggregated dispersion ranges.