JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2015 | Volume:25 | Issue:2.1 (SUPPLEMENT)|Papers Count:14

To determine the critical period of weed control in Dragon’s head (Lallemantia iberica Fisch. Et Mey), field study were conducted in 2011 at the Agricultural Research station of University of Tabriz. Experiment were conducted in randomized complete block design with 3 replications and treatments relevant included 13, 23, 33, 43, 53 and 63 days weeding during the growing season (free of weeds), and 13, 23, 33, 43, 53 and 63 days without weeding (weed infested) in the growing season and includes free of weed, weed infested in the entire growing season and pure weed treatments in each block. The prevalent weed species were Setaria viridis L., Chenopodium album L., Acroptilon repense L., Cichurium intybus L., Amaranthus retroflexus L., Xanthium strumarium L., Anchusa italica Retz., Convolvulus arvensis L. and Salsola kali L. respectively. These species constituted 23, 18, 15, 15, 9, 7, 6, 3 and 2% of total weed population, respectively. Analysis of variance results showed that weed dry weight with increasing duration of infection and reduce weed-free period was significantly increased. The constructed models for Critical period of weed control in Dragon’s head showed that in order to prevent grain yield loss of 10%, weeds must be removed from the field after 19 until 55 days after crop emergence, and during 36 days respectively.

In order to investigate the effect of different levels of bio and chemical fertilizers on yield and macro and micro nutrient elements absorption in maize (Zea mays L.) grain, a field experiment was carried out at the faculty of Agriculture, University of Maragheh in 2013 growing season. Experiment was arranged as factorial based on randomized complete block design (RCBD) with four replications. The first factor (A) included 3 levels of chemical fertilizer including a1: control, without any fertilizer, a2: %100 nitrogen fertilizer and a3: %50 nitrogen + 50% phosphorus and the second factor (B) comprised of biofertilizer application with 4 levels as b1: control, without any biofertilizer, b2: inoculation by Nitroxin, b3: inoculation by Phosphate Barvare-2 and b4: inoculation by Nitroxin and Barvare-2. Results showed that chemical fertilizer application improved quantitative and qualitative yield of maize grain, especially, as phosphorus and nitrogen were applied together. Application of 50% (N+P) in comparison to non-application of chemical fertilizer, increased grain yield (23.63%), grain protein content (10%), phosphorus (9%), potassium (10%), iron (5%) and zinc (7%) concentrations. Also co-application of Nitroxin and Barvare-2 were more effective than application individually. According to interaction between two factors, maize quantitative and qualitative yield improved by together application of fertilizers better than they applied individually. Nitroxin +Barvare-2+50% (N+P) increased grain yield by 80%, protein 22%, phosphorus and potassium 50% and iron 9% compared with control. Also phosphor availability by chemical and biofertilizers had competition effect for Zn absorption, and caused reduction in grain.

A pot experiment was carried out to investigate competition of wheat against wild mustard affected by salinity and N fertilizer levels, in Ramin Agriculture and Natural Resources University of Khouzestan greenhouses during 2012-2013. Experiment was Factorial in a completely randomized design in four replication. Experimental factors in trials was nitrogen levels (0, 60, 120 and 180 kg.ha-1 from Urea fertilizer sources) and irrigation water salinity (0, 3, 6 and 9 ds.m-1 by NaCl). Result show that the highest dry matter of wheat was obtained in 120 and 180 kg N.ha-1 without salinity. In the rate of 120 kg N.ha-1, there was no significant difference between salinity levels, in term of wheat dry matter. The lowest dry matter of wheat was observed in 9 ds.m-1 without nitrogen. Increase of nitrogen levels in saline conditions, caused to alleviate effect of salinity stress on wheat growth. However, further increase of N levels caused to decrease the competition ability of wheat against wild mustard and that failed to reduce the high levels of salinity reduces of wheat growth.

Cover crops are an effective tool in the non- chemical weed management in sustainable agriculture. In order to evaluate the effect of type and time planting of cover crops on weed control in tomato, a factorial experiment was established using a randomized complete block design with three replications at 2013 on personal farm located about 65 kilometers from Shiraz province. The factors were included the type of cover crop at four levels (rye, red clover, rapeseed and control (no mulch)) and time of planting in three levels (one month before tomato transplanting, at the same time and one month after transplanting).The results showed that the type and time of planting of cover crops had a significant effect on the weed density and weed dry weight and tomato yield. Planting cover crops decreased weed density up to 35% and the weed dry weight of 67% compared with control. Also, cover crops reduced density of Convolvulus arvensis, Portulaca oleraceae and Echinochloa crus-galli as 8, 4 and 6 times compared with control. Tomato yield increased 60.42% with cover crop. The results showed that cover crops are appropriate tool for weed management in sustainable agricultural systems and can be used in integrated weed management.

In order to determine the critical period of weed damage in peanut a field experiment was laid out based on randomized complete block design (RCBD) with three replications in 2012. Treatments consisted of two series of weed interference and weed-free periods of 15, 30, 45, 60 and 75 days after planting of peanut. Full-season control of weeds and full-season interference of weeds were also included as control treatments. Seed yield was affected significantly by control and weed-free treatments. Increasing of weed interference periods decreased peanut seed yield, while increasing of weed control periods increased peanut seed yield. Mean comparisons showed that the highest (2100 kg.ha-1) and lowest (294 kg.ha-1) of peanut yield observed at full season weed-free and 75 days weed interference after planting, respectively. Full season weeds interference reduced peanut yield by 81% compared with full season weed-free plots. Beginning and end of the critical period of weed damage were determined by Gompertz and Logistic equations with high accuracy (R2=0.96 and R2=0.95, respectively). Based on 5, 10 and 15% acceptable seed yield losses, the critical period of weed control were 9 to 76, 12 to 63 and 16 to 54 days after planting at Sari condition.

Using productivity index is one of the important tools in evaluating performance of agricultural systems in achieving self-sufficiency and also agricultural sustainability. In this regard, if the productivity of an agricultural production system is higher than another system, it would be economically sustainable. Therefore, it seems that there is a relationship between the sustainability of production system of agricultural sector and factor productivity. For this reason, the objective of this research is considering the relation between factor productivity and agricultural sustainability in potato farms in Ardabil plain. For this research 231 samples determined by Cochran’s formula. Research data belongs to 2012-2013 crop period and was gathered through field surveys and questionnaires complete by means of two-stage random sampling. The result of this research has shown that the most and limited amount of the partial productivity respectively are related to the land and water. The total factors productivity average of the evaluated units are 0.011, therefore in average for each unit usage of total input in potato farms 0.011 tone potato has been produced at the region. Also the result of the Senanayak has been shown that the farms in studied area has intent to sustainability. Results of multiple regression models showed that the variables; the total factor productivity, farmer income, type of land ownership, education level, experience of potato cultivation, land, the knowledge of sustainable agriculture, separately has explain 25 percent of the sustainability index changes.

The field experiment was conducted in order to study the interaction of velvetleaf densities and Imazethapyr doses on yield and yield components of red bean in factorial randomized complete block design with four replications in 2013. The factors were included four levels of velvetleaf densities (0, 5, 10, and 15 plant.m-2) and five levels of Imazethapyr doses (0, 0.25, 0.5, 0.75, and 1 lit.ha-1). Grain yield at weed-free plots with increasing herbicide dose did not change, but it is increased at other velvetleaf densities with increasing doses of herbicide. Grain yield at 4, 8, and 12 velvetleaf plant.m-2 densities at the recommended dose compared to no-herbicide plots increased by 43, 92, and 127%, respectively. The number of pods per plant at no-herbicide plots and 4, 8 and 12 velvetleaf plant.m-2 than velvetleaf weed-free plots reduced by 29, 44 and 48%, respectively. The number of grains per pod at densities of 4, 8 and 12 velvetleaf plant.m-2 than weed-free conditions reduced to 8, 12 and 4%, but the hundred grain weight did not affected by levels of weed densities and herbicide doses.

Application of Methanol solution on plant shoots increase yield and decrease water stress effects. The research was conducted in the Research Farm in the Agriculture Faculty of the University of Tabriz, in order to evaluate the effect of different concentration of Methanol solution spraying on different growth stages of P. vulgaris L. before and after flowering, in water stress conditions. It was conducted in split plot form in completely random blocks with three replications. The methanol solution densities were five percent and ten percent by volume. The water stress included three levels of irrigation after 70, 120 and 170 millimeters evaporation, as the main factor and different volumetric densities of Methanol solution spraying as the sub factors in five different levels. Based on the results, effect of treatments on height of plant, number of pods in main stem, dry weight, number of pods in the plant, number and weight of empty pods, weight of 100 seeds, biological performances were meaningful and harvest index with one percent probability. Furthermore, the best performance was obtained with the ten percent density of Methanol solution spraying after flowering stage of P. vulgaris L. and the irrigation after 70 millimeter evaporation.

In order to comparision the effect of biological and chemical fertilizer on grain yield components and fertilizer use efficiency in sunflower, this study was carried out in Markazi province in 2009. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Treatments included inoculation with Nitroxin (N0=Control, N1=Inoculation), Inoculation with Barvar-2 (B0=Control, B1=Inoculation) and application of chemical fertilizer combination of nitrogen and phosphorus (C0=N0+P0, C1=N50+P25, C2= N100+P50, C3=N150+P75 kg.ha-1). Each plot consisted of four rows, 6 m long with 60 cm between rows space and 21 cm between plants on the rows. In this study characteristics such as: plant height, head diameter, 1000 grain weight, number of grain per head, grain yield, harvest index, N and P use efficiency and chlorophyll index were assessed. Results indicated that the effect of Barvar-2 biological fertilizer on the harvest index and inoculation with Nitroxin on number of grain per head, grain yield, harvest index were significant. Chemical fertiliser combination of nitrogen and phosphorus on charecteritics such as: plant height, head diameter, 1000 grain weight, number of grain per head, grain yield, nitrogen use efficiency and chlorophyll index was significant, too. Among the different levels of combination application of chemical fertiliser, that 100 kg.ha-1 nitrogen+50 kg.ha-1 phosphorus with average of grain yield equal 1603 kg.ha-1 and 50 kg.ha-1 nitrogen+25 kg.ha-1 phosphorus treatment, with average of grain yield equal 1283 kg.ha-1 were significantly superior to the other treatments. Therefore, it seems that quantity and quality of crops yield increased by integrative using of different fertilizers.

In order to evaluate the seed and oil yields and yield components in spring safflower during different planting times and study the possibility of reducing growth period with the conservation of yield, an experiment was carried out in Khosrovshah station of Agriculture and Natural Resources Research Center of East Azarbaijan, Iran in 2014. A factorial experiment including 4 planting dates (30th Marth, 9th, 19th and 29th April) and 3 spring safflower cultivars (Goldasht, Soffeh and Sina) based on randomized complete block design with 3 replications, was used. The results showed that simple and interaction effects of studied factors were significant on the capitulum relative growth rate, plant height, capitulum diameter, capitula per plant, seeds in capitulum, 1000 seeds weight, oil percent, seed and oil yields. Among yield components, capitula per plant showed positive and significant correlation with the seed and oil yields. In addition, cultivars under consideration had the higher seed and oil yiels on 30th Marth of planting time. In cultures 30th Marth and 9th April, Soffeh had higher seed and oil yields but the cultivation of Goldasht on 19th April and late sown of Sina on 29th April showed the highest production of yields. The correlation of plant height with capitula per plant, seeds in capitulum, seed and oil yields was positive and significant. It seems that, by planting in Tabriz plain during late Marth and early April can be achieved acceptable performance in spring safflower with respect to the principles of better agronomic during stem stage.

One of the problems of potato breeding in Iran like the most other countries is the lack of enough genetic diversity due to asexual propagation and the availability of just foreign imported commercial cultivars. In order to evaluate the potential of yield and also selecting promising clone for use in breeding programs an experiment using 6 families of true potato seed including Fanta op, selected Andigena (Adg), hybrids of Agria×Caeser (Agr×Cas), Agria×Savalan (Agr×Sav), family of the BC1 of S. stoloniferum×S. tuberosum (sto×tbr) with the cultivated parent (tbr) and families of inter-mating between sto × tbr hybrids (HS-sto×tbr) were compared with using a randomized complete block design with three replications. The results has been showed significant difference between families for the total tuber yield, plant height, leaf area, pollen stainability (p≤0.01) and tuber and haulm dry weight, and number of stem per plant (p≤0.05). According to mean comparison results family Agria×Savalan with 526.66 grams per plant had the highest tuber yield but its difference with the families of Adg; (HS-sto×tbr) were not significant. The BC1 of sto×tbr family with 19.7 tubers per plant had the maximum tuber number but its difference with the families of the Adg, Agr×Sav and (HS-sto×tbr) were not significant. The (HS-sto×tbr), BC1 and Fanta OP had the highest and hybrids of (Agr×Sav) lowest pollen fertility.