In order to investigate the possibility of quinoa producing in Garmsar, Iran, a factorial experiment conducted in randomized complete block design with three replications in 2018-2019 growing season at Garmsar Agricultural Research Station. The factors were planting date at three levels (March 6th, April 1st and April 6th) and the three genotypes of quinoa (Q26, Q29 and Titicaca). Results showed that the effect of planting date was significant for all studied traits except the harvest index. Also, all studied traits were significantly different in all genotypes. Titicaca planted on March 6th had the highest yield (2276 kg.ha-1).The grain yield and yield components decreased with the delaying the planting date. Compared to early plantings, Latest date, April 6th, led to reduction of all traits, especially grain yield (about 50%). The results of simple phenotypic correlation between the studied traits showed that grain yield per hectare had the highest correlation with plant yield (0.877) and then with leaf area index (0.832), panicle weight (0.815) and number of branches per plant (0.745) that was significant at the 1% probability level.

To investigate the effect of weed interference and weed-free periods on Balangu (Lallemantia royleana Benth. in Wall) and to evaluate the critical period of weed control (CPWC) in this oilseed crop, an experiment was conducted as a randomized complete block design with three replications in Naghadeh region in 2018. Experimental consisted of two groups of treatments; weed infestation treatments (infestation for 144.2, 345.9, 574, 848.2, 1147.6 and 1451.3 growing degree day (GDD) after transplanting and then plots were remained weed-free the rest of the growing season) and weed-free treatments (weeding for 144.2, 345.9, 574, 848.2, 1147.6 and 1451.3 GDD after transplanting and then plots were remained infested until harvesting time). In each block, one weed free and weed infested control was for all the growing season. Results indicated that the density and dry biomass of weeds were increased as weed removal was delayed. In contrast, density and dry biomass of weeds were decreased as weeds establishment was delayed. Height, tetrachenes fruits, ripened achenes, 1000-seed weight and biological, seed and relative yields of Balangu were decreased and increased as the duration of weed-infested and weed-free period increased, respectively. Also, logistic and Gompertz curves fitted to data showed that the beginning and end of the CPWC based on a 10% yield loss of relative yield, was estimated to be from 11 to 108 days after transplanting (97 days weed-free period) in order to prevent a noticeable yield loss.

Identifying the constraining factors of production and yield gap is very important. Therefore; this research was performed to identify the production constraining factors of local rice cultivars. All management practices from nursery preparation to harvesting stages for 100 paddy fields of local rice cultivars were recorded through field studies, in Sari, from 2015-2016. In the CPA, the actual and calculated potential yield were 4495 and 5703 kg/ha, respectively and the gap was 1221 kg/ha. The yield gap caused by number of top-dressing variables was 324 kg/ha, equal to 27% of the total yield gap. The yield gap related to previous year of legumes cultivation was 218 kg ha-1, equal to 18% of the total yield variation. Among the 10 variables entered in the CPA model, the effects of top-dress fertilizer application and its application frequency and foliar application were remarkable, which could compensate a significant part of the yield gap (444 kg/ha, 37% of total) in the farmers’ fields by managing these variables. According to boundary line analysis (BLA) finding, actual yield mean on the basis of optimal limit related to 12 variables under study was 5369 kg/ha, with 881 kg/ha yield gap . Mean relative yield and relative yield gap for 12 variables (transplanting date, seedling age, number of seedlings per hill, planting density, nitrogen and phosphorous per hectare, nitrogen before transplanting, harvesting date, lodging problem, pest problem, diseases problem and weeds problem) were 83.64 and 16.35 kg/ha, respectively. Based on the finding, it can be stated that the model precision is appropriate and can be applied for both estimation of the quantity of yield gap and determining the portion of each restricting yield variables.

In order to study morphological characteristics, yield, elements and Gallic acid contents in Rhus coriaria L. fruits under the influence of manure and chemical fertilizers, a factorial experiment was conducted in a randomized complete block design with three replications at the Research Institute of Forests and Rangelands. Manure factor was included control, 20 and 40 tons per hectare and chemical fertilizers (Mixture of nitrogen, phosphorus and potassium) were N0P0K0 (control), N50P25K25 and N100P50K50 kg ha-1 from urea, triple superphosphate and potassium oxide sources. Results showed that the interaction of manure and chemical fertilizer on plant height and trunk diameter was significant at 1% probability level. Manure had a significant effect on leaf number and width, fresh and dry yield of cluster at a probability level of 5%, and on leaf length and leaf weight at 1% probability level. The effect of chemical fertilizer on leaf weight was significant at 1% probability level. The effect of manure fertilizer on nitrogen, phosphorus, potassium and iron was significant at 1% probability level. Mean comparisons of morphological traits showed that the highest number of leaves (683. 44 number per plant), leaf length (24. 06 cm), leaf weight (1754. 9 g per plant), fresh cluster yield (301 g per plant) and dry cluster yield (281. 2 g per plant) were achieved with using of 40 tons per hectare manure. The highest percent of nitrogen, phosphorus and potassium were obtained with mean of 1. 9, 0. 32 and 0. 71%, respectively with consumption of 40 tons per hectare manure. The highest amount of Gallic acid was obtained from manure application of 40 tons per hectare with 0. 44 mg/kg of fruit. Results showed that this plant has been affected by fertilizer and increased fruit and Gallic acid with the use of fertilizers.

In recent decades, drastic land use changes in Golestan province caused to reduce a substantial amount of Hyrcanian forest. To investigate the changes, land cover maps produced using Landsat satellite imagery classification of sensors TM from 1984, 2012 and 2016 respectively used as input data in Land Change Modeler (LCM) to predict land cover changes in 2030. In order to assess the accuracy of modeling, statistics of relative performance characteristic (ROC), ratio Hits/False Alarms and figure of merit was used. In continue to investigate the role of land use changes in water yield as one of ecosystem services was discussed. The results show the accuracy of artificial neural network with the ROC equal to 0. 949, the ratio Hits/False Alarms equal to 57 percent and the figure of merit is equal to 11 percent. Land use change modeling results showed that from 1984 to 2012, The most prominent changes were related to reduction of forest cover. This process modeling using artificial neural network showed, from 2016 to 2030 forest cover will be reduced about 30361 hectares. The results of water yield study showed that runoff in the area, particularly in the East and North East area has increased. This increase in the amount of runoff occurred as a result of land use change on forest ecosystems to agriculture. Results of this study improve our understanding of hydrological consequences of land-use changes, and provide needed knowledge for effectively developing and managing land-use for sustainability and productivity in the Gorgan-rood watershed.

This study was carried out in the year 2003 to investigate the effects of different water regimes (40, 60, 80, 100 and 120% of water requirement) and different amounts of nitrogen (60, 120 and 180 kg ha-1) as well as their interaction on quantity and quality of tomato ‘Early Urbana’. The experiment was performed in Research Farm of Faculty of Agriculture, Tehran University (a semi-arid area) on a clay loam soil, using a split plot design with three replications (irrigation treatments as the main plots and different amounts of nitrogen as sub-plots). Results indicated that different treatments of irrigation and nitrogen as well as their interaction have significant effects on tomato quantitative and qualitative characteristics including total yield, marketable yield, number of fruits per plant, average fruit weight, water use efficiency (WUE), early ripening, dry matter, total soluble solids, terrible acidity, pH, vitamin C, firmness and N-NO3. The maximum marketable yield and WUE were obtained at 100% water requirement with 120 kg ha-1 nitrogen (78.83 t ha-1 and 0.085 t ha-1 mm-1, respectively). In this study, third order and second order functions were obtained between applied water and marketable yield, and nitrogen and marketable yield, respectively. Also a multiple regression was found between marketable yield and water and nitrogen consumption.

Background: Macrophytes (fresh water plants) comprise a diverse group of the flora which play important roles in the maintenance of trophic food chains and biogeochemical processes, but are deleterious when present in excess.However, due to various anthropogenic activities, there is accumulation of nutrients in aquatic ecosystems resulting in massive macrophytic growth. These weeds do not possess any economic value and remain laid on lake shores after harvesting and become a source of odor problem, thus posing a challenge to the lake management authorities regarding their proper disposal. However, vermicomposting turns these macrophytes into materials useful in horticulture/ agriculture for restoration of soil fertility, in addition to providing a solution to the nuisance of harvested weeds.Results: The study was conducted to investigate the effect of different rates (2, 4 and 6 t/ha) of macrophyte-based vermicompost on germination, growth and yield of Solanum melongenaunder field conditions. The data revealed that different rates of vermicompost produced varied and significant effect (P<0.05) as compared to the control on germination, growth and yield parameters with maximum value recorded at 6 t/ha, followed by 4 t/ha and the least at 2 t/ha. The dose of 6 t/ha significantly (P<0.05) increased germination (22.56±2.5 %), number of fruits per plant (3.55±0.07) mean fruit weight (73±5.0g), yield per plant (1.48±0.05 kg) and marketable fruits (28.66±3.0 %) when compared with the control. The study suggests that macrophyte-based vermicompost as a potential source of plant nutrients for sustainable crop production.Conclusion: Macrophyte-based vermicompost is an efficient quality yielder and economy enhancer for sustainable agriculture especially for the communities having vegetable gardens around lakes will benefit by using macrophyte vermicompost, a balanced and low-cost organic fertilizer.

Background Macrophytes (fresh water plants) comprise a diverse group of the flora which play important roles in the maintenance of trophic food chains and biogeochemical processes, but are deleterious when present in excess.However, due to various anthropogenic activities, there is accumulation of nutrients in aquatic ecosystems resulting in massive macrophytic growth. These weeds do not possess any economic value and remain laid on lake shores after harvesting and become a source of odor problem, thus posing a challenge to the lake management authorities regarding their proper disposal. However, vermicomposting turns these macrophytes into materials useful in horticulture/ agriculture for restoration of soil fertility, in addition to providing a solution to the nuisance of harvested weeds.Results The study was conducted to investigate the effect of different rates (2, 4 and 6 t/ha) of macrophyte-based vermicompost on germination, growth and yield of Solanum melongenaunder field conditions. The data revealed that different rates of vermicompost produced varied and significant effect (P<0.05) as compared to the control on germination, growth and yield parameters with maximum value recorded at 6 t/ha, followed by 4 t/ha and the least at 2 t/ha. The dose of 6 t/ha significantly (P<0.05) increased germination (22.56± 2.5 %), number of fruits per plant (3.55± 0.07) mean fruit weight (73 ± 5.0 g), yield per plant (1.48± 0.05 kg) and marketable fruits (28.66± 3.0 %) when compared with the control. The study suggests that macrophyte-based vermicompost as a potential source of plant nutrients for sustainable crop production.Conclusion Macrophyte-based vermicompost is an efficient quality yielder and economy enhancer for sustainable agriculture especially for the communities having vegetable gardens around lakes will benefit by using macrophyte vermicompost, a balanced and low-cost organic fertilizer.

Iran is one of the leading countries in the world in production of many horticultural commodities such as pistachios, walnuts, almonds, apricots, apples, dates, grapes and others. In recent years, the areas under horticultural crops have increased, mainly due to high exchange rate and income as well as improvement in water consumption efficiency, the possibility of export and increasing demand. There is also a possibility of their sustainable development and production in the future. On the other hand, as the world's population grows, the need for food is increasing at an alarming rate. Using the latest statistics published by the Ministry of Agriculture Jihad and other sources, the present status of the horticultural products of each sub-sector of pomology in the years 2012 to 2018 were examined. From temperate zone fruits apple, pear, cherry, peach and apricot,from nut fruits pistachio, almond, walnut and hazelnut, from tropical and subtropical fruits dates and citrus, and from small fruits grapes and strawberries were selected. Considering that the coefficient of selfreliance of horticultural products, except for a small number of tropical fruits, is 100%, in this article, after presenting the statistics, the challenges of the current situation of pomology in the country are analyzed and approaches to overcome the problems of this sector of horticulture are suggested.