NEW FINDINGS IN AGRICULTURE
Year:2007 | Volume:1 | Issue:4|Papers Count:8

The effects of different irrigation regimes and verities on yield and yield components of four corn verities were studied (2004-2005). In this case an experiment was carried out in research farm of Sarab-e-Changaee related to agricultural research center of Lorestan. A split plot based on RBCD with 4 replications was used. Treatments were 3 indexes of irrigation and assigned as main plots (irrigation after 75, 100 and 120mm from class A pan) and four hybrid varieties 500, 647, 700, 704 were assigned as sub plot. Results showed that among irrigation regimes treatments of irrigation after 75 and 120 mm had highest and lowest grain yield respectively. In this way yield reduction had caused by reducing in number of row per ear and seed per row. Also the sensibility of seed yield against drought stress was more than biological yield. This fact was confirmed by harvest index. Comparison of results shows that in late mature variety the growth and yield were increased.

Climatic parameters effects as day length and air temperature were studied on phenologic characteristics of soybean. Four separated experiments were done at May 21st till Jul.5th of 2008 by 15 days increment as four planting dates were used for evaluating of 15 soybean cultivars and lines. Selected varieties were Williams, Zane, M4, M12, S.R.F., A3935, A3237, L17, Union, Grangelb, Clark, Tns95, Elf, Miandoab and Calland. The experiments laid out in RCBD with 3 replications. Williams variety was set as control and the effect of day length and temperature were considered by planting dates treatment. The characteristics such as day to flowering, day to pod and seed formation, day to end of flowering and maturity, reproductivity and maturity development stage growth period were selected as main phonologic aspects. The results indicated that all phenologic characteristics were affected by planting date, cultivars factors and their interaction.Delaying in planting date caused to facilated in flowering, pod and seed formation, end flowering, full maturity times, flowering and reproductive development stages.Photoperiod was effective on all cultivars and lines. Increasing of photoperiod made delaying on maturity time in all cultivars and lines.

To study the competitive effects of redroot pigweed (Amaranthus retroflexus) and lambsquarter (Chenopodium album) on potato, an additive experiment was conducted in the spring of 2004 and 2005 in split-split plot based on randomized complete block design with 4 replications at the Seed Potato Production Station of RAN in Firouzkooh.Treatments were included 2 weed species in main plots (Amaranthus retroflexus and Chenopodium album), weed density in sub plots (2, 4 and 8 plants per meter of row) and relative time of weed emergence in sub-sub plots (8 and 4 days prior to potato and the same time with potato emergence in 2004 and the same time with potato, 2 and 4 weeks after potato in 2005). Results showed increasing weed density resulted in reduction in potato LAI, but leaf area distribution in canopy layers was not affected and maximum LAD was recorded in second layer (20-40 cm) in all treatments. In 2004, redroot pigweed in 2, 4 and 8 plants per meter of row put 29, 42.1 and 44.6 percent of LAI above the potato canopy, respectively. These amounts for lambsquarter were 30.6, 38 and 43 percent.

In order to investigation the effects of mycorrhiza inoculation in different levels of irrigation and nitrogen on morphological and physiological traits of corn variety ksc 704 an experiment was carried out on factorial based on RCBD whit 3 replications. Experiments were done in research and education station of Islamic Azad University of Firouzabad branch in 2004. Results showed that simple effects of nitrogen, mycorrhiza, irrigation levels and interaction effect of mycorrhiza and irrigation levels and nitrogen on patterns such as plant height, shoot dry matter, root dry matter, leaf area and root length were significant. When mycorrhiza rose it caused increase of shoot and root dry matter and root/shoot ratio nitrogen fertilizer addition, increased shoot dry matter and root length of corn but also root dry matter was reduced by adding nitrogen. Root/shoot ratio and root length and percent of root colonization effected due to different levels of irrigation, in this case with increase of drought stress intensity, root length and percent of root colonization was decreased but ratio of root/shoot increased. Generally, the mycorrhiza growth response with drought stress intensity and root/shoot in mycorrhiza treatment toward check in drought stress were increased.

Study of weed competition with crops is necessary for better weeds management. In order to determine the interaction of some related traits with green bean yield on different times on interference on red root pigweed (RP), a two years experiment was conducted at Islamic Azad University of Tabriz, Iran. Experiment was based on randomized complete blocks design. The treatments were RP interference times (2, 4, 6, 8, 10 weeks after green bean emergence, full season interference and weed free plot as control). In all treatments RP was seeded immediately after green bean planting and removed after treatment levels.Results indicated that effect of treatments on all traits was significant. Interference of RP in four weeks of early growth stage of green bean has not significant effect on green cover at flowering stage of green bean. Green bean biomass in weed free plot (673.6 kg ha-1) was similar to treatments of two and four weekly RP interference in early growth stage of green bean. Also, pod yield in treatment of two weekly RP interference in early growth stage of green bean was similar to weed free plots. Yield loss of full season RP interference was 67% compared with control. In term of considering maximum permissible yield loss (10%) and results of this research, RP must be controlled, if its interference time was longer than 4 weeks in early growth stage of green bean.

A survey was conducted to identifying long-horned beetles (Col.: Cerambycidae) in Shiraz and its vicinities during July 2005-Sept.2006. The specimens were collected using different methods such as hand collecting, light trap, screen light trap, barking, rearing, and sugar trap and sweeping net. To collecting those beetles, different areas like forests, fruit trees, plateau and mountains had been searched. A total of 210 specimens related to 12 species were collected. These species have been identified and verified by Mr. Gianfranco Sama from Italy. Species were belonging to 4 subfamilies: Cerambycinae: Cerambyx cerdo (L., 1758), Xenopachys matthiesseni (Reitter, 1908), Ospheranteria coerulescens (Redtenbacher, 1850), Plagionotus bobelayei (Brulle, 1832), Hesperophanes sericeus (Fabricius, 1787), Jebusaea hammerschmidti (Reiche, 1877), Certallum ebulinum (L., 1767) Lamiinae: Pedestredorcadion brunneicolle (Kraatz, 1873) Prioninae: Prinobius myardi (Mulsant, 1842), Mesoprionus persicus (Redtenbacher, 1850), Pogonarthron minutum (Pic., 1905) Lepturinae: Stictoleptura rufa (Brullè, 1832) The external morphology of the species was illustrated using a stereomicroscope equipped with drawing tube. A key for identification of the long horned beetles, which occurred in Shiraz and surrounding is presented. The collected specimens were keeping in the collection of entomology of the Shiraz history of nature museum.

In this study species diversity of Coccinellids (Col. Coccinellidae) was studied in Lorestan province during 2001-2005. Altogether 28 species from 14 genera, 7 tribe and 4 subfamilies were collected and identified. External characters plus characteristics of the male and female genitalia were used in order to diagnose species. Among Coccinellid species collected, two species were new records in Iran. The scientific names of the species according to their subfamilies and tribes are as follows. Species marked with * and ** are considered as new records in Lorestan province and Iran respectively. Some species wereidentified or confirmed by Dr. Helmut Fursch in Germany.1- Coccinella septempunctata Linnaeus 1758                    15- E. gebleri Weise 1878 *2- Hippodamia variegata (Goeze) 1777                                 16- E. undulates Weise 1878 *3- Oenopia conglobata (Linnaeus) 1758 *                            17- Platynaspis luteorubra (Goeze) 1777 *4- O. oncina (Olivier) 1808                                                          18- Scymnus apetzi Mulsant 1847 *5- Adalia bipunctata (Linnaeus) 1758 *                                  19- S. pallipes Mulsant 1850 *6 6- A. decimpunctata (Linnaeus) 1758 *                               20- S. pallipediformis Gunther 1958 *7- Aphidecta obliterata (Linnaeus) 1758 **                          21- S. frontalis (Fabricius) 1787 *8- Propylea quatuordecimpunctata (Linnaeus) 1758 *    22- S. apetzoides Capra & Fursh 1967*9- Psyllobora vigintiduopunctata (Linnaeus) 1758 *         23- S. subvillosus (Goeze) 1777 *10- Chilocorus bipustulatus Linnaeus 1758                           24- S. syriacus (Marseul) 186811- Exochomus melanocephalus Zoubkoff 1833 *             25- S. mediterraneus Khnzorian 1977 **12- E. nigromaculatus (Goeze) 1777 *                                      26- S. araraticus Khnzorian 1977 *13- E. quadripustulatus Linnaeus 1758 *                                 27- Stethorus gilvifrons Mulsant 185*14- E. pubescens Kuster 1848 *                                                   28- Pharoscymnus ovoideus Sicard 1759*

In order to identify the plant parasitic nematodes of Chrysanthemum in greenhouses and open fields in Mahallat region located in Markazi province in Iran, about 67 soil and root samples were collected during 2007 and 2008. The nematodes were extracted by centrifugal technique, killed, fixed and transferred to glycerine. Morphological and morphometrical characters were studied by light microscope. In our study, one of the most important nematodes was root-lesion nematode Pratylenchus pseudocoffeae. Root tissues were invaded by the nematode, which caused distinct necrosis and large cavities within cortical parenchyma. All developmental stages were observed in the root tissues.Morphometrics of P. pseudocoffeae is characterised by a labial region with three annuli, vulva located at 79-82% of body, long differentiated post-vulval uterine sac, tail sub hemispherical or bluntly pointed with smooth terminus, presence of males, spermatheca oblong. The species resembles P. coffeae, P. gutierrezi and P. penetrans from which it differs by a number of morphometric features (position of the vulva, the shape of the tail tip and head shape). This is a new occurrence and first record of the species in Iran and becomes the third world record after his original description.