DYNAMIC AGRICULTURE
Year:2009 | Volume:6 | Issue:1|Papers Count:8

Milk thistle (Silybum marianum) is an important annual/biennial herbaceous plant which belongs to the Asteraceae family. The effective substance of this plant (Silymarin) is used for chronic hepatits, liver toxic damages caused by alcohol and mushroom poisoning and stomachs problems treatments. To study the effect of plant density and N-fertilizer on extinction coefficient and radiation use efficiency (RVE), an experiment in factorial experiment with the base randomized complete blocks design with three replication was conducted in spring 2005 at Research Station of Hammand Absard Damavand. The treatments were plant density in 3 levels (50x20 – 50x30 – 50x40 cm2) and N-fertilizer in 4 levels (0-50-100-150 kg/ha). During ontogenesis, the growth and development in each treatment were observed and leaf area index (LAI) and plant biomass were calculated to determine the extinction cofficient (K) and radiation use efficiency (RUE) in each treats ment.The results were analyzed with SAS program and the means were assessed by Duncan test at a=0.05% and the curves were drawn with Excel program. The light measure operation in field was done 5 times and the results showed, that by an increase in plant density, the extinction coefficient would decreas, although the radiation use efficiency was increased but the difference levels of N-fertilizer hadn’t shown any effects on extinction coefficient and radiation use efficiency.

To determine the best amount of nitrogen fertilizer and plant distance of canola (hyola 401) and studying their parts of yield in primary level, an experiment was conducted the from of spilt plot in basic blocks randomly in 3 repelications in which, the consumption of urea fertilizer in 4 levels 100, 200, 300, 400kg in hectare as a main factor and plant distance in 3 levels: 20, 30, 40, cm as a sub- factor in agricultural year 2005-6 in the field of country rice research institute in Amol. the results obtained from the statistical analysis of qualities showed that the effect of nitrogen fertilizer and plant order distance is possibly significantat1% level on seed yield, number of plants (m) and the number of sub- branches. Also reciprocal effects of treatment on seed yield and plant number (m), is significant, possibly at both 1% and 5% levels. Also the most plant height, silk length, Numbero of grain in silk, number of fructify in the layers of plant the use nitrogen about 400 kg in hectare obtained, also the highest yield of seed with 4410 kg in hectare with conditions of plant distance 30 cm, and the use nitrogen about 400 kg, and the least of this amount with conditions of plant distance 20 cm and the use of nitrogen 100 kg in hectare obtained.

A field experiment was conducted in Shirvan, Khorasan-e-Shomali province, Iran, during 2005 growing season to study the effect of sowing date and plant density on growth, phenology, yield and yield components of corn (Zea mays L.). Treatments were arranged in a randomized split-plot design with three replications. Main plot consisted of three sowing dates (4 and 19 May, and 5 June), and sub- plot consisted of three plant densities (75000, 95000 and 115000 plants/ha). The results showed that the duration of phenological stages decreased with delay in planting from 4 May to 5 June. However, cumulative degree days were largely similar at different planting dates. The effect of sowing date on morphological characteristics including plant height, ear length, stem base diameter, number of leaves, ear diameter, number of grain rows on the ear, grain length, wood ear length, ear axle weight and distance of ear from the ground was significant at 1% level. These properties had a decreasing trend with the delay in planting. Effects of different densities on morphological characteristics were significant. Different planting date and planting density had significant effect at 1% level on yield components, including number of ear per plant, number of seeds per ear row, ear weight and one hundred seed weight. The effect of planting date and also plant density on grain yield, biological yield and harvest index was significant at 1% level. The highest grain yield and biological yield were obtained at 19 may and 115000 plants per hectare. Light interception was effected significantly by sowing date and decreased with delay in planting.

In order to measure the effects of redroot pigweed emergence time and density to light absorption and leaf chlorophyll content at interference with three sunflower hybrids, a two years experiment was conducted during 2005-2006 based on additive design at islamic azad university of Tabriz. Treatments were combination of three different weed densities (8.3, 25 and 41.7 plants m-2) at three relative times of weed emergence (coincident with sunflower; and 15 and 30 days after sunflower emergence) using three different sunflower cultivars (Azarghol, Hysun and Allstar). Results revealed that in Azarghol and Hysun mixed canopy closure with increasing of density and early emergence times was happened. Because of short stem height and lower leaf area, Allstar could transmit 8% of total PAR at 60 days after sunflower emergence. In full-season interference of 41.7 weeds m-2, light absorption by redroot pigweed in three sunflower cultivars increased 23%, 31% and 37%, respectively.With increasing of density and earlier interference times of redroot pigweed, leaf chlorophyll content index decreased in all studied treatments except in treatments of different weed densities at 30 days after sunflower emergence, and the Allstar was tolerated higher negative effect from weed density than other cultivars. With a view to grain yield in sunflower, compatibility of redroot pigweed with Allstar was higher than Azarghol and Hysun cultivars.In Allstar because of lower competitive power with weeds, redroot pigweed control is recommended at early interference times.

In order to evaluate the effects of planting date on yield and yield components of winter safflower genotypes, this study was carried out in the Research Field of Farahan University in Markazi province in 2006. A split-plot arranged of treatment in a randomized complete block design with three replications was used. Planting dates (23/9/2006, 7/10/2006, 22/10/2006, 6/11/2006, 21/11/2006, 6/12/2006) were assigned in the main plots and cultivars (L. R. V.51- 51, zarghan-279, IL-111) in sub- plots. In this study characteristics such as plant height, number of branches per plant, number of boll per plant, number of grain per boll, 1000 grain weight, cold damage percent, oil percent and grain yield were assessed. The effects of planting date and the interaction effects of planting date and varieties were significant on traits such as number of boll per plant, number of grain per boll, cold damage percent and grain yield at the 1% level of probability (DMRT). Results indicated that second planting date with grain yield equal to 1893 (kg. ha-1) and L. R. V.51-51 variety with grain yield of 1898 (kg. ha-1) were significantly superior to other treatments. Study of interaction effects between planting date and varieties, showed that the highest grain yield with average 2476 (kg. ha-1) and the lowest one with average 1120 (kg. ha-1) were obtained by L. R. V.51-51 genotype at second planting date and by Zarghan-279 genotype at fifth planting date, respectively. The highest oil yield with average 477.5 (kg. ha-1) and the lowest with one average 305.6 (kg. ha-1) were obtained at second and sixth planting date, respectively. The purpose of fifth and sixth planting date, was to study thesafflower dormant seeding and climate of Farahan zone.

In order to examination of effects of cultivation density on agronomic traits in different rice Genotype, the experiment was carried out as split plot in Randomized complete Block design (RCB) with 3 replications at 2006. The rice jenotype has been chosen as main plot at 3 Leveles which are Tarom Hashemi (early maturity), Fajr (middle maturity) and Neda (late maturity). Cultivation density has been also chosen as sub plot at 6 leveles which are 20, 40, 60, 80, 100 and 120 plant per square meter. The results showed that, the number of days transplanting to%50 flowering and the period of duration of vegetative growth were the maximum values in neda variety, but thes, characteristics were not influenced by cultivation density. The maximum and minimum plant height and panicle length were attained for Tarom Hashemi and Neda varieties, respectively. The plant height decreased significantly, with in`creasing cultivation density. The maximum number of spikelets per panicle, the percentage of filled spikelets and 1000-grain weght were attained by Tarom hashemi, Fajr and neda Varieties, respectively. With increasing cultivation density, the total number of tillers and effective tillers per plant decreased but, the number of panicle per square meter and grain yield increased significantly. The maximum grain yield was attained by neda late maturity jenotype. The intraction effects between jeno type and cultivation density did not affect on the studied characteristics, signi ficantly.

Due to fall rapeseed this research was done in experimental form of complete random blocks in four replication during two farming years 82-83 and 83-84 in the research farm in the faculty of agriculture of Azad University of Saveh located in the university campus. Experimental samples consist of five varieties of rapeseed Ocapy, Orient, Licord, Opera and Seen4. This compounded analysis results of two year showed that the characteristic performance of seed and the oil of seed, performance of oil, number of capsules in plant were meaningful where as the rate of performance seed and oil of Opera variety were 3919 and 1587 kg/hec. respectively. The most capsules in plant (105) as the most important component performance of seed was received from Licord variety. Due to ecological climate condition in Saveh region it seem, Opera variety is the most suitable of all.

In order to study the effect of water stress and Micro elements (B. Zn. S) on physiological aspects of Rapeseed varieties, 5 varieties, Hyola - 42, Syn1, Pf 7045.01, Symbol and Mohican, as a subplot have been studied under water stress and non stress condition (0, 25 and 75 percent of Fc) as main plot in split plot design with four replication on varamin. Results showed significant between irrigation treatment and varieties in pods per plant, grains in pod and yield. Between varieties most yield and yield component had been seen for Hyola 42 and lowest yield was for Symbol.1000 grain weight and another characteristics was effected by water stress, . there were no significant difference between varieties in response to Boron and Zinc in leaf dry matter. so there were in water deficit (O percent of Fc) treatment reduced than normal treatment reduced and showed significant difference between varieties in level %1 In split plot design, water stress Increased micro element concentration In leaved. Sulfur reduced from.0198 to.0101 and Zinc from 29.6 to 15.2 mg/kg of dry matter. Plant characters evaluated in this study were: Plant weight, number of pods per plant, number of grains per pod, 1000 grain weight, grain yield, percent oil content and yield of oil. Analysis of data showed significant different cen between irrigation treatment and varieties in pods per plant, grains in pod and grain yield. Between varieties the highest yield and yield component was for Hyola 42 (with 3377/5 Kg/ha) and lowest yield was for Symbol (with 1947 Kg/ha). 1000 grain weight and another characteristics was effected by water stress, so there were in water deficit (0 percent of FC) treatment reduced than normal treatment. and showed significant difference between varieties in level%1. In split plot design, water stress increased nitrogen concentration of %2.5 reached to %3.7 of leaved in dry matter. But decreased phosphor from 0/35% to 0/18% and Potassium percent from %2.73 reached to %1/09 in leaved dry matter. Water stress (75%. 0% percent of FC) decreased grain yield and Oil yield. Grain yield from 3340 Kg /ha decreased to (1788 Kg/ha) and oil yield from (1343 kg/ha) reached to (753 kg/ha). cultivars were not significantly different in percent oil content. But water stress decreased percent oil content from %43/1 on %75 FC to %40/2 on %0 FC. In conclusion, differences is exist between rapeseed cultivars and lines in response to water stress, and this may be due to different accumulation of compatible solutes, and physiological aspects example yield and yield component.