JOURNAL OF CROP ECOPHYSIOLOGY (AGRICULTURE SCIENCE)
Year:2011 | Volume:5 | Issue:18|Papers Count:8

In order to evaluate interference of different growth period weeds such as Amarant (Amaranthus roflexus L.) and Lambs Quarter (Chanopodium album) on cultivars of oilseed rape, a factorial based on randomized complete block design with three replication was conducted in Agricultural Experiments at station the Islamic Azad University, Tabriz Branch in 2008. The factors were three oilseed rape fall cultivars (SLM046, Opera, Okapi) and six controlling methods at different growth period (complete weed control, controlling weeds at 3-5 leaves, at 5-8 leaves, at the beginning flowering, at 50% flowering, and competition of weeds in all of the time). Analysis of data revealed that effect of interference weeds on height, number of pod, oil yield was significant at 1% level of probability and on number of grains per pod, 1000-grains weight and grain at 5% probability levels. The effect of oilseed rape cultivars on height, number of grains per pod, oil yield was significant at 1% probability levels and number of pod and weight of 1000-grain in 5% probability levels. The highest grain yield and oil yield were found to be 54% and 55%, respectively as compared with those of control. Also, grain yield was correlated with number of pod (r=0.886), weight of 1000-grain (r=0.513), number of grain in pod (r=0.783) significantly at 1% probability levels. In order to increase grain yield, control with SLM046, recommend to farmers.

In order to study yield stability of bread wheat cultivars including Alvand, Alamout, Zarrin, Navid, Azar 2, Sabalan, Omid and Bezostiya under irrigation an experiment was conducted in RCBD for three cropping seasons (2007-2010) at six locations. Simple and combined analysis of variances for three years, each location and also combined analysis of variances for 3 years and 6 locations were implemented. Lin and Binns parameter, environmental coefficient of variations and rank method were used for determination of stable cultivars. Results of combined ANOVA (three years x six locations) showed that interaction effect of year x location x genotype was significant. The highest grain yield belonged to the Alvand cultivar with 3.74 tha -1. Results of stability analysis with Lin and Binns method also showed that Zarrin cultivar had the lowest within location variance for grain yield and lowest environmental coefficient of variations was belonged to cultivars Zarrin and Sabalan. The results of rank method showed that cultivars Alvand and Sabalan had the lowest ranking and cultivars Sabalan and Bezostiya had the lowest SDR among the experimental cultivars. It can be concluded that Zarrin and Sabalan cultivars had the highest yield stability and thus it can be recommended for locations in which it was studied.

In order to determine the most suitable planting date for maximum production of seed tuber yield in potato cultivars, this experiment performed with four potato cultivars (Agria, Marfona, Savalan and Ceaser) at four planting dates (April 9th, April 30th, May 20th and June 10th) by using split plot experiment based on randomized complete block design in three replications at Ardabil Agricultural and Natural Resources Research Station during 2009. During growth stage, the traits were like plant height, main stem number per plant, tuber number and weight per plant and total and marketable tuber yield were measured. Analysis of variance from measured traits showed that planting dates and cultivars in traits like plant height, main stem number per plant, tuber number and weight per plant and total and marketable tuber yield and interaction of between cultivar × planting date plant height, main stem number per plant and tuber number per plant were significantly different. The highest total and marketable tuber yield, tuber number and weight per plant, plant height and main stem number per plant were obtained from second planting date (April 30th) and the lowest from latest planting date (June 10th). The difference between total and marketable tuber yield in the second planting date (April 30th) as compared with the latest planting date (June 10th) was 13.35 ton ha-1. Savalan had the highest plant height, main stem number per plant, tuber number and weight per plant and total and marketable tuber yield. Relationship of total tuber yield with plant height, main stem number per plant, tuber number and weight per plant and marketable tuber yield were positive and significant. According to the results, planting date of April 30th was suitable for maximum production of tuber yield of cultivar Sabalan.

In order to detect the most effective characters on grain yield and its component in winter wheat genotypes, an experiment in a randomized complete block design with three replications was conducted at Research Station of the Islamic Azad University, Tabriz Branch. Planting seed, application of fertilizers and fertilizers and pesticides and irrigation regimes were processed as they are usually done in the region. Some traits such as days to heading, days to maturity, height plant, main spike weight, straw yield, grain number per spike, grain weight per spike, grain yield and harvest index were characterized. Analysis of variance revealed that there were significant differences among genotypes for most of the traits except the weight of main spike and grain number per plant. Results also showed that the highest phenotypic (19.77%) diversity belonged to the weight of main spike and least to days to maturity and days to heading (with 0.27% and 0.52% ) respectively. Results of factor analysis showed that four factors accounted for 82.73% of the total variation. Cluster analysis, based on traits under study, grouped the genotypes into two groups. The first group consisted of seven and the second on of five genotypes.

In order to study the effects of biofertilizer and phosphate fertilizer on yield and yield components of spring wheat a factorial experiment based on randomized completed blocks design with replications was conducted at the Mohsenabad, Mehran Research station in Ilam, Iran during 2009-2010. Experimental factors consisted of phosphorus chemical fertilizers at four levels (0, 90, 135 and 180 kg ha-1) and bio-fertilizer at four levels (non-inoculation, inoculating with Azotobacter chroococcum, Pseudomonas Putida and Azotobacter plus Pseudomonas). Results of analysis variance showed that using chemical fertilizer significantly effected grain yield, harvest index, biological yield, plant height and protein content. The highest grain and biological yields were produced by applying180 kg ha-1, while its effects on other traits were not significantly different from that of 135 kg ha-1. Biological fertilizers, on the other hand increased grain yield, harvest index, biological yield, plant height and protein content as compared to non inoculation treatment. The highest grain yield, harvest index, biological yield, plant height and protein content obtained from application of Azotobacter plus Pseudomonas. Grain yield, harvest index, biological, plant height were affected by interaction effects of chemical fertilizer and biological fertilizers. The highest and lowest grain yield belonged to the application of 180 kg ha-1 of chemical fertilizer and Azotobacter plus Pseudomonas and non- chemical fertilizer and non-inoculation, respectively, but the difference between 135 and 180 kg.ha-1 was not statistically different. Thus, it is cheaper to recommend use of 135 kg ha-1 of chemical fertilizer and Azotobacter plus Pseudomonas to get acceptable grain and biological yields.

In order to evaluate the effect of Metham Sodium and Sulfosulforon dosages on broomrape control and tomato yield an experiment was conducted using randomized complete block design with 4 replications in Mashhad Iran. Treatments were Metham Sodium and Sulfosulforon at the rates of 26.5, 53, 79.5, and 106 gr.ha-1, at the rates of 400, 600.800, and 1000 kg. ha-1. The results showed that Metham Sodium was more effective than Sulfosulforon. The highest dry matter, number of broomrape foliage and tomato yield were obtained by using 1000 and 800 kg. ha-1 of Metham Sodium. Sulfosulforon was applied as post emergence once in this experiment. It seems that because of this reason efficiency is less than that of comparison with Metham Sodium. Thus pre and post multi - applications of the herbicide was suggested during cropping season.

In order to evaluate the effects of integrated weed management on weed control by using reduced herbicide dose, a field experiment was conducted in 2010 in Qazvin. The experiment was conducted in randomized complete block design with 24 treatments and 4 replications. The treatments were: different planting patterns at three levels (single row, square double rows and zigzag double row plantings) and doses of Nicosulfuron and Foramsulfuron application at four levels (1, 1.5, 2 and 2.5 liters per hectare), The results showed that among the different planting patterns, zigzag planting reduced weed populations and their dry weights significantly. Foramsulfuron herbicide could control weeds better than Nicosulfuron. Among the herbicide dosages, 2.5 litter dose per hectare highly reduced weed density its dry weight as compared to one litter dose.

As factorial experiment based on randomized complete block design with four replications was carried out to evaluate the effects of weed management on yield and components yield of corn silage in Miyaneh region in the summer of 2009. Treatments were cultivation (with and without), herbicides (Foramsulfuron, Nicosulfuron and 2, 4-D+MCPA) and without controlling weed as control treatment. The results indicated that application of herbicides significantly influenced weeds dry weight at 1% probability level. The highest and lowest percentage loss of weeds dry weight were related to Foramsulfuron and 2, 4-D+MCPA, respectively, which were significantly different from other herbicides (Nicosulfuron). Cultivation was significantly effective on weeds dry weight as compared with non cultivation treatment. The results, also, indicated that cultivation and herbicides significantly affected increasing the biological and grain yields compared to non weeds control treatment. The highest biological and grain yield increase were obtained by 59.1% and 57.2% due to cultivation treatment and by 51.8% and 58.2% due to Foramsulfuron herbicide application, respectively. The lowest biological and grain yield was obtained by application of Nicosulfuron herbicide which was statistically comparable to that of 2, 4-D+MCPA herbicide treatment.