فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 60 (زمستان 1400)

In order to investigate the effects of foliar spraying of salicylic acid and beta-aminobutyric acid on yield, physiological and biochemical characteristics of Dracocephalum moldavica (L.), during cropping year of 2017-2018, in a experiment based on a randomized complete block design with 4 replications was carried out in Kerman. Foliar spraying was done one month before harvesting with three concentrations (0, 0.5 and 1 mM). Plant height, stem diameter, number of leaves, fresh matter yield, dry matter yield, number of lateral branches, yield of total extract and essential oil were measured. Identification of essential oil components was done by using a gas chromatography (GC) which was connected to a mass spectrometer (GC/MS) by comparing the inhibition indices and mass spectrometry study. According to the results, the effect of both elicitors of salicylic acid and beta aminobutyric acid on plant height, number of leaves, fresh matter yield and dry matter yield were significant at 1% level of probability; But, there was no significant difference in stem diameter and number of lateral branches. The interaction effect of both elicitors on plant height and dry matter yield was significant at 5% and 1% probability levels, respectively. While there was no significant difference on other traits under study. Also, the use of both elicitors increased the total extract and essential oil yields. The highest percentage of main compounds in essential oil was affected under the influence of the amount of 1 mM salicylic acid in absence of beta aminobutyric acid, including 36.8% geranyl acetate, 20.5% geraniol, 19.7% geranial, 14.9% neral and neral acetate 2.9%. In general, the use of salicylic acid was found and beta-aminobutyric acid to increase Dracocephalum moldavica (L.) yield.

This study was to investigate the phenological, physiological traits, seed yield and oil yield of six safflower genotypes under drought stress and non-stress conditions in two independent experiments. Each of the experiment was a factorial with randomized complete block design with three replications during cropping seasons of 2015-16 and 2016-17 at Sarabela Agricultural Research Station in ILAM province. In one experiment under non stress condition, irrigation was based on the need of the plant, while the in the other experiment, plant growth was as rainfed where rainfalls was enough. The total amount of precipitation during the plant growth period in 2015-16 and 2016-17 were 410.7 and 388.5 mm, respectively, but it occurred with inappropriate ditribution during the growing season. Experimental treatments consisted of six  safflower genotypes plus inoculation of seeds with Azotobacter and use of urea fertilizer application with four levels: 1- no fertilizer application (as control), 2- Azotobacter seed inoculation, 3- Azotobacter seed inoculation + 50% nitrogen from urea source and 4- to 100% nitrogen from urea fertilizer based on soil testing recommendation. The results showed that nitrogen source and genotype were significantly affected all traits both under drought and non-stress conditions. Under drought stress conditions, the highest grain yield belonged to Sina genotype by using 100% nitrogen fertilizer and Azotobacter + 50% nitrogen fertilizer treatments (with mean yield of 1408 and 1336 kg.ha-1 reapectively), which were not significantly different. Under non-stress conditions, the highest grain, with mean yield of 2185 kg.ha-1, was attributed to PI-306974 genotype with 100% nitrogen fertilizer treatment. Thus, this genotype, under non-stress conditions, by using 100% nitrogen fertilizer for maximum yield of safflower and under drought stress, it was Sina genotype by using 50% nitrogen fertilizer with Azotobacter can be recommanded to the experimental region.

To evaluate the effects of potassium and nitrogen fertilizers on yield and lodging characteristics of Gilaneh rice cultivar under two irrigation regimes (permanent flooding and irrigation with to 10 days interval) a field split split plot experiment based on complete randomized block design with 3 replications in Rasht. Nitrogen and potassium fertilizers used were at the 0, 60 and 120 kg.ha-1 and 0, 80 and 160 kg.ha-1 as sub and sub sub factor, respectively. The results showed that the highest seed yield obtained about 3713 kg.ha-1 from permanent flooding with the application of 120 kg.ha-1 of nitrogen fertilizer and 80 kg.ha-1 of potassium fertilizer and the lowest yield 634 kg.ha-1 from 10 days irrigation interval, without using of potassium and nitrogen fertilizers. The 10-day irrigation interval reduced the bending moment of the internode 4 by 40%. With increasing the rate of potassium fertilizer, the lodging index of intermediate 4 decreased, which was due to the increase of cellulose content by 60% in this intermediate. Increasing nitrogen and potassium fertilizers decreased the lodging index at internodes 3 and 4. Irrigation at 10 days intervals decreased plant height, internode bending moment, cellulose and hemicellulose and seed yield It increased lodging index of intermediate, butincreasing fertilizer levels in both irrigation regimes had adverse effect on the traits under study.

This experiment was conducted to evaluate the effect of micronutrients on physiological, biochemical and functional characteristics of the of SC704 hybrid maize at water deficit condition during two cropping years of 2016-2017 and 2017-2018 at Experimental Farm in northwest of Ahvaz. The experiment was conducted as split-split plots based on a randomized complete block design with three replications. Main plots consisted of water deficit stresses at three levels, complete irrigation, cutoff irrigation both at the vegetative growth stage (12-14 leaf) and early seed growth stage, sub-plots were zinc sulfate foliar application at three concentrations (0, 5 and 10 g.L-1) and sub sub-plots foliar solution of iron sulfate at three concentrations (0, 3 and 6 g.L-1). The results of this study showed that increasing ZnSO4 concentration from zero to ten per thousand at constant levels of FeSO4 application (6 per thousand concentrations) resulted in increase in leaf area index under water deficit condition at the vegetative growth stage and beginning of seed growth stage. The lowest current photosynthesis was obtained in the absence of foliar application of zinc and iron. The lowest content of intercellular carbon dioxide was obtained at the beginning of seed growth stage when irrigation was stopped. The use of zinc and iron sulfate increased the values of this trait and removed the photosynthetic limitations. The highest yield of ear was obtained in complete irrigation with 6 per thousand concentration FeSO4 spray (9135.66 kg.ha-1), which increased by 25.1% compared to non-spray at this irrigation level.

Life Cycle Assessment (LCA) is a decision-making tool that assesses the environmental status, production activities, and processes during the useful life of a crop. It should be borne in mind that the LCA uses a variety of techniques for economic, social, and environmental estimates of crops, as well as their activities, processes, and the consumed energy efficiency.The present study evaluates the LCA in corn seed and corn stover production systems in Karaj by the use of two cropping systems: corn produced for seed only, without collecting corn stover (CRN) (seed corn production system) and corn produced to harvest stover (CSR) (corn stover production system). Which were investigated during the years of 2011-2016. Environmental indices were calculated for the CRN and CSR based on six impact categories under Karaj climatic conditions. The highest pollutant index, after resource depletion, was found in acidification impact category (0.90 and 0.34 for the CRN and CSR, respectively), followed by the highest environmental impacts for global warming or climate change impact categories (0.51 and 0.18 for the CRN and CSR, respectively). Therefore, it seems that different methods of farming system management can be utilized based on the use of low-input principles, such as using various organic inputs, planting nitrogen-fixing and perennial plants, the use of crop rotation, utilizing different planting patterns such as intercropping, minimum tillage, and decreased use of chemical inputs, to reduce the environmental impact of this production system, particularly the CRN, on fossil fuel depletion, acidification, and climate change impact categories, thereby reducing the shares of these environmental impacts.

High quality standards in vegetables is one of the most important expectation of consumers presence of weeds would also reduce the quantity and quality of crops produced. Use of cover crops could be an environmentally friendly alternative to conventional chemical and mechanical methods. To this end for controlling weeds, a factorial experiment based on a randomized complete block was conducted at the Research Farm of Mohaghegh Ardabili University with three replications in 2017. Experimental treatments were the first factor, consisting of mono culture and intercropping of rye (Secale cereal L.), hairy vetch (Vicia villosa Roth.) and control treatment (no cover crop) and the second factor consisting of one time hand weeding and two times weeding, with 15 days intervals, and without hand weeding, as control. The results showed that the highest dry biomass of cover crops obtained from rye mono culture (530.59 g.m-2) and the lowest biomass (47.85 g.m-2) from hairy vetch mono culture. The highest reduction of total weed biomass (83.24%) obtained from rye with hairy vetch without hand weeding. The highest yield of iceberg lettuce was obtained from hairy vetch mono culture with one-time hand weeding or from without hand weeding treatment (5025 and 4965 g.m-2, respectively). Also, the highest plant height, number of leaves and diameter of lettuce stem was not statistically significant difference from mono culture and intercropping of cover crops. The results showed that the combination of hand weeding and cover crop residues were more effective in controlling and reducing weed biomass, but the presence of cover crop residues in the shortron also increased the yield of iceberg lettuce through weed control.

The effects of transplanting and direct-seeding on agronomic traits and white sugar yield of sugar beet were studied in a split-plot experiment based on randomize complete blocks with three replications two regions of Miandoab and Bokan in 2016.  Treatments were three planting date (25 March, 8 and 18 April) and two planting systems (transplanting and direct-seeding .(Planting systems were assigned in the main plot and planting date in the subplots. The difference between direct and transplanting systems in terms of leaf area index, sugar extraction coefficient, root yield, white sugar yield and molasses sugar percentage were significant at 1% and sugar content and sugar yield at the 5% probability levels. The effect of sowing time on leaf area index, dry matter yield, sugar extraction coefficient, root yield, white sugar yield and sugar content of molasses were significant at 1%, and sugar content and sugar yield at 5% probability levels. The interaction effect of sowing time and planting system was significant on leaf area index, dry matter yield, sugar extraction coefficient, and root yield, white sugar yield at 1% and on sugar content at 5% probability levels. The transplanting system reduced the amount of molasses sugar by 32.41% compared to the direct planting system and the lowest percentages of molasses sugar were attributed to 25th of March planting date.  In the present study the highest leaf area index, dry matter yield, and sugar content, sugar extraction coefficient, root yield, and white sugar yield were allocated to the 25th of March planting date and transplanting system.

To investigate the effect of different planting densities on yield and yield components of quinoa (Titicaca cultivar), a factorial experiment based on complete randomized block design was studied at the Research Farm of the Agricultural and Natural Resources Research and Training Center of Kerman province in 2018-2019. Two inter-row space (30 and 50 cm) considered as the first factor and four intra-row space including 5, 10, 15 and 20 cm as the second factor. Increasing the intra-row and inter-row spacing resulted in significant reduction in CGR. Thus, the lowest value of this index, at both intra-row spacing attributed to 20 cm the inter-row spacing. The lowest grain yield (225.76 g.m-2) was related to the treatment of 50 cm inter-row and 20 cm intra-row spacings, Reduction intra-row spacing up to 10 cm resulted in a significant increase in seed yield. However, at in the inter-row spacing of 30 cm, there was no significant difference between the intra-row spacings in seed yield. The highest seed yield value was obtained from the intra- row spacing of 20 cm, with an average of 386.36 g.m-2. In general, the inter-row spacing of 30 cm and intra-row spacing of 15 and 20 cm resulted in highest seed yield and 1000 seed weight of quinoa in this research.