NEW FINDINGS IN AGRICULTURE
Year:2007 | Volume:1 | Issue:3|Papers Count:8

A field trial as a split plot design based on randomized complete block design with three replications was conducted on six winter Rapeseed (Brassica napus L.) varieties in 2005 season in research farm of Kabootar Abad, Esfahan. Treatments selected based on using three different moisture regimes including 1) Application of water when 80% evaporation occurred from class A evaporation pan to physiological maturity as control treatment 2) Stopping water application since flowering stage and 3) Stopping water application since grain fill stage. The results indicated that stopping water application since flowering stage caused yield components to reduce significantly and thus had undesirable effect on yield where reductions in number of pod per plant (from 79.2 to 50.1), number of grains per pod (from 50.8 to 40.8) and weight of 1000 grains (from 3131 to 2584 gr/ha) were observed. Seed oil content was also found to be reduced in that treatment (from 48.5% to 46.6%). The studied varieties revealed significant differences in all measured traits. The variety of Zarfam had the highest grain yield and seed oil content in various irrigation regimes and the SLMO46 ranked next. Considering the high potential of these two varieties in producing oil in stress condition, their capability to be cultivated in stress prone regions is realized.

In order to study the effects of late planting on vegetative traits, yield and yield components of rapeseed varieties, an experiment was conducted at research field of Seed and Plant Improvement Institute (SPII) in Karaj. The experiment laied out in split plot factorial arranged in a RCBD with 4 replications. Two planting dates (Sep.28th and Oct.22Th) were selected as main plots and 13 varieties (Elite, Olpro, Sinatra, Sahara, Modena, Geronimo, ARG-91004, Dexter, SLMO46, Okapi, Frederic, ORW20-3002, and RG4504) as subplots in a factorial arrangement were evaluated. Traits were considered as plant height, stem diameter, number of pods per plant, number of seed per pod, thousand grains weight and the grain yield. Results showed that delay in planting date, the height of the plant, stem diameter and number of seed per pod were reduced, but it was not significant, and regarding the number of pods in the plant, the delay increased the afore–mentioned characters. Among rapeseed varieties, the Olpro variety has the highest height plant by 126 cm. But, regarding stem diameter no significant decrease was observed. The greater number of pods per plant was observed in Sinatra variety with an average of 78.47 and also the greater number of seed per pod belonged to SLM046. The highest thousands grain weight was observed in RG4504 variety and about the grain yield, the lightest yield belonged to the first planting time and in Elite variety with a rate of 5271 kg/ha.

Estimating flood events sediment yield and its temporal variation are of the main and basic issues in watershed management strategies. On the other and there are little investigations about sediment yield behavior of the flood events and applicability of the sediment rating curves to estimate sediment load of flood events. In this study in order to investigate bias and errors of the sediment rating curves in estimating sediment load of the flood events, the estimated values of 10 types of rating curves compared by the observed values of some hourly monitored flood events in the Gharachay River of Markazi provinces. By considering accuracy and precision indexes the results shows that in all of treated sediment rating curves underestimated (40-80%) flood hydrograph sediment yield in this case the FAO’s method has relatively closer estimates to the observed data and despite of suitable applicability of the MVUE method in estimating annual sediment yield it could not prove to be applicable in the flood events cases.

Two spotted ladybird, Adalia bipunctata is one of the biological control agents of some pests. In this research functional response of fourth instar larvae and adults of A.bipunctata reared on Aphis punicae was studied in controlled condition at temperature on fixed 27±2oC, %45±10 relative humidity and a photoperiod of 16: 8 (L: D) hours. The results were analyzed according to Juliano method using SAS software. Logistic regression was used for determining type of functional response. In this case functional response of fourth instars larves and adults of A. bipunctata was determined as type II. It emphasised by negative slope Logistic regression Na/Nt line. The non-linear regression and the Rogers model were used for estimating searching efficiency (a), handling time (Th) coefficient of determination (R2) and maximum attack rate (T/Th) that the estimated values were 0.220±0.037, 0.073±0.021, 0.951 and 82.192 for 4th instar larvae and 0.144±0.031, 0.084±0.037, 0.8905 and 71.428 for adults of Adalia bipunctata, respectively. So 4th instar larvae beause of higher searching efficiency and lower handling time is more effective than adults for controlling of A. punicae.

A survey was conducted to identification, host ranges and abundance of parasitoids of stored product pests in Mashhad, Iran. Stored product pests and their parasitoid were collected during the period from Jul. to Nov.2006 from different storages in Mashhad. The survey revealed on fifteen types crop commodities (Rice, Corn, Lentil, Vetch, Wheat, Split Pea, Pea bean, Wheat flour, Rice flour, Rainsin, Mealed wheat, Dryed fig, Peanut and Walnut meat) stored in ways (Basket, Bag and Flat stores). As a result of this study, 10 species of stored product pests and five species of their parasitoid were identified. The parasitoids were: Habrobracon hebetor (Say) (Hym. Braconidae), Cephalonomia tarsalis (Ashmead) (Hym. Bethylidae), Theocolax elegans (Westwood) (Hym.: Pteromalidae), Anisopteromalus calandrae (Howard) (Hym.: Pteromalidae) and Venturia canescens (Gravenhorst) (Hym.: Ichneumonidae). The existence of these natural enemies particularly C. tarsalis and A. calandrae may encourage using them as potential biological control in food stored products at this area.

A tractor-mounted, automated soil cone penetrometer was designed, constructed and tested for the purpose of measuring cone index throughout the entire soil profile. We propose the use of cone penetrometer profile to assist in mapping 3-dimensional spatial variability of soil strength. The apparatus consisted of a mechanical frame, an assemblage of control hardware and a laptop computer with the controlling software. A double-acting hydraulic jack with 80 cm stroke was mounted on the frame to push the cone into soil. A load cell and a digital caliper were used for measuring pushing force and depth, respectively. A DC motor was mounted on a power screw to activate a directional control valve and. The data acquisition module and an external global positioning system (GPS) were used to assist in real-time measuring, displaying, and recording the tractor position and soil penetration resistance. Soil strength maps of five layers with 10 cm increment and mean soil moisture content were plotted. Results showed that in the first 10 cm layer, soil compaction was related to the soil moisture content but it was not occurred about other layers. Finally combining maps of soil strength made an effective soil profile in order to tillage with different depth.

This experiment was done for quality improvement and decrease ensiling period from 21 to 14 day. Experimental design was completely randomized design with 5 treatments by adding Lactobacillus plantarum (LP) and Saccharomyses cervicea (Sc). Treatments were, 1) Without any additive such as control (LP0-SC0), 2) 0.5 gr Lactobacillus Plantarum in 100 kg corn forage (LP1-SC0), 3) 0.75 gr L. plantarum in 100 kg corn forage (LP2-SC0), 4) 0.5 gr Saccharomyses Cervicea in 100 kg corn forage (LP0-SC1) and 5) 0.5 gr L. plantarum and 0.5 gr S. cervicea in 100 kg corn forage (LP1-SC1). Silo construction was simulated by dark barrel bung. Sampling and evaluating was done for pH, DM, lactic acid, acetic acid and apparent specifications at the end of 7, 14, 21th days. In each sampling at the end of 14 and 21th days LP2-SC0 had lowest pH and highest lactic acid.. pH and lactic acid at 21 day in LP2-SC0 was significant with other treatment (P<0.05). Therefore by using of suitable microbial additives, can decrease ensiling period from 21 to 14 day and prevent from harmful facts. But corn silage consumption is not recommended less than 21 day.

The research was descriptive-analytic and was performed with a relative-causal method. The population of this study were rice-field women, over 25 years old, who are living in Sangachin and Abkenar villages-located in Chaharfarizeh County-and Lijareky Hasanroud and Talebabad villages-located in Lijareky Hasanroud county. In this research, 275 people were randomly selected with systematic sampling method. Questionnaire reliability was estimated by calculating Cronbach's alpha coefficient by SPSS and it calculated as 0.80. The descriptive findings of study showed that the highest of field-rice women participation was in weeding and generally, they are observing sustainability criteria in agriculture. The analytical finding showed that there was significant difference (P<%1) between the mean of observing sustainability criteria in agriculture, regarding the research's villages, level of education, kind of ownership to rice-field and kind of used seed. Also, there was positive correlation (p=%99) between age, years of experience in rice-field, the amount of rice production, rice-field size, the amount of social participation and rice-field annual income with observing sustainability criteria in agriculture. But there exists negative correlation (p=%99) between the amount of rice-field participation and number of household members with observing sustainability criteria in agriculture. The amount of rice production and rice-field annual income as independent variables had the main role in explaining dependent variable.