Tomato is one of the major agricultural products in Fars Province. Previous studies show that the tomato farms under current irrigation systems lose a large volume of water with low water productivity. In the present study, the irrigation requirement and the influence of different irrigation regimes on the yield and water productivity of three cultivars of tomato was studied. The farm under study was located in Marvdasht plain, with a heavy soil texture. The irrigation water was applied based on 60%, 80%, 100%, and 120 percent of Penman Montieth water requirement method, under drip irrigation system. Another treatment was considered and irrigated by the farmer management. Benefit-cost ratio and benefit-cost difference was calculated for economic analysis. Results show that the obtained yield increased with irrigation water while water productivity decreased. The irrigation volumes of water used for the treatments were about 3900 to 7800 cubic meters per hectare. However, only the differences between the treatments 60% and 120% were statistically significant. Economic evaluations showed that the tomato production was not economical with tomato price equal to 2500 Rials, while the water price varies from zero to 6000 Rials. In this situation, the benefit-cost ratios varied from 0.78 to 0.68, respectively. Increase in price of tomato could improve the benefit-cost ratio.

In order to identify the correlations and relationships between different traits in the bread wheat, 30 genotypes were investigated as sub-factors under the split plot experiment in the completely randomized design in greenhouse and the randomized complete block design in the field with three replications under the normal irrigation and post-anthesis water stress conditions. The results of the canonical correlation analysis showed that at both normal and moisture stress levels, there was a significant correlation between the pair of canonical variables obtained from the phenological traits and the yield components. Under the normal conditions in the greenhouse, to increase the spike density and length, the number of days to 50% flowering can be considered as a suitable selection criterion. According to the results of canonical correlation analysis, under the stressed conditions in greenhouse, to increase the spike length, the number of days to the heading, maturity and 50% of flowering were among the important and effective factors. Under the optimum irrigation conditions in the field, the number of days to maturity was considered as one of the factors influencing the seed weight per spike. The results of canonical correlation analysis under the field stress conditions showed that to increase the 1000-seed weight, the number of days to maturity can be considered an appropriate selection criterion.

To investigate the effects of fertilizer regimes on quantitative and qualitative traits of Dracocephalum kotschyi Boiss, a field experiment at three replications with the Split Plate arrangement in a completely randomized block design was conducted in the Research Field of Tarbiat Modares University during the 2017-18 growing season.Water deficit stress (irrigation after discharging 20 (optimal irrigation), 40 (mild water deficit stress), 60 (moderate water deficit stress) and 80% (severe water deficit stress) of water used (available water)) in the main plot and fertilizer regime (urea, nitroxin, vermicompost, azocompost and no fertilizer) in the subplot were studied. The results showed that the highest leaf fresh weight (1797 kg ha-1) and total biomass (2957 kg ha-1) were obtained by application of urea in mild water deficit stress condition and the highest dry matter digestibility percentage was observed in azocompost treatment in moderate water deficit stress condition (57.8%). The highest crude protein was produced in severe water deficit stress condition (19.72%) and moderate water deficit stress (18.4%), respectively.. The highest percentage of water soluble carbohydrate and neutral detergent fiber were obtained from no fertilizer in moderate water deficit stress (22.06%) and application of urea in severe water deficit stress conditions, respectively. Mild water deficit stress application to produce high biomass is recommended for Dracocephalum kotschyi Boiss. According to the results, application of urea in mild water deficit stress was selected as the best treatment to produce forage 32% more than control.

Introduction Watermelon (Citrullus lanatus) is a widely recognized product with high demand, nutritional value, and export potential worldwide. Since the ultimate goal of agricultural production systems is to maximize plant yield, providing sufficient water to the plant is one of the most critical factors influencing yield. Therefore, investigating the effects of water limitation is an essential and undeniable necessity. On the other hand, deficit irrigation has been introduced as an approach to increase water productivity. Therefore, it is essential to consider the effects of this water-saving method on plant production, which highlights the need for further research. Deficit irrigation involves supplying only a portion of the plant's water requirements, while regulated deficit irrigation is a specific type of deficit irrigation that can be applied in various ways, such as irrigation based on growth stages, or allocating water to stages that are more sensitive to drought. It is important to recognize that plant response to water deficit depends on several factors, including climatic conditions, plant type, the intensity and method of deficit irrigation application, soil condition, and management practices.   Materials and Methods In order to determine the effect of deficit irrigation and regulated deficit irrigation on yield and water productivity of the watermelon, an experiment in the form of randomized complete blocks with 8 treatments including three irrigation levels of 100, 70 and 50 % of the plant's water requirement (evapotranspiration estimated by the FAO-Penman-Monteith method) and 5 regulated deficit irrigation levels including 50% of the water requirement in the stages of seedling, vine, flowering, fruit expansion and fruit maturity were carried out with three replications under black plastic mulch, during 2020-2022, in the Research and Education Center of Agriculture and Natural Resources in the south of Kerman province. Irrigation as the main plot at three levels of 100, 70 and 50% of water requirement and mulching at three levels of crushed date palm leaf, black plastic and no mulch, as the sub-plot, were considered. Crimson B 34 watermelon seeds produced by Seminis company, were planted on January 2021, in plots with the size of 13.5 × 7 m, on furrows and ridges planting system (the width of furrows and ridges were 0.5 and 4 meters, respectively). After planting, bow-shaped wires were put on the planting rows and a transparent plastic was placed as a tunnel on them. In the first year, the total depth of the irrigations in aforesaid treatments were respectively 444, 321, 237, 413, 389, 435, 345 and 425, and in the second year 427, 303, 223, 395, 373, 416, 331 and 405 mm. Results and Discussion The results showed that the highest and lowest yield were observed in full irrigation and irrigation 50 % (60.1 and 16.3 t ha-1 respectively). Among the regulated deficit irrigation treatments, irrigation 50% at the seedling stage was the closest to full irrigation, and the irrigation 50 % at the fruit expansion stage had the lowest yield. The highest water productivity belonged to the irrigation 50 % in the seedling and vine stages (15.9 and 1.15 kg m-3 respectively). Irrigation 50% at fruit maturity stage despite half irrigation, improved Qualitative characteristics such as soluble solids, vitamin C, dry matter, lycopene and fruit taste.   Conclusion Applying deficit irrigation led to a significant decrease in watermelon yield compared to full irrigation (control). Water productivity remained nearly constant, and there was no significant improvement in the quality of the edible part. However, treatments involving regulated deficit irrigation, such as irrigation during the seedling stage, showed similar yield to full irrigation, while the 50% irrigation during the vine stage resulted in higher water productivity. Additionally, 50% irrigation during the fruit maturity stage produced superior fruit quality compared to the control. Overall, regulated deficit irrigation yielded better results than deficit irrigation due to less yield reduction, increased water productivity, and improved fruit quality, especially under water-restricted conditions. Finally, it is recommended that milder intensities of deficit irrigation that seem to have more favorable results in this plant should be investigated in the next studies.

In the current experimental study, economic analysis of deficit irrigation was conducted for an orange orchard and results were evaluated based on the highests net income. This experiment was performed as a split plot in the form of a randomized complete block design with five replications in 2018. The main treatments were two types of irrigation management including variable irrigation interval and 4 days irrigation interval. Sub factor was 4 irrigation levels including 100%, 80%, 65% and 50% of soil readily available water (RAW). For economic evaluation, production, cost and income functions and optimum water use depths were calculated using English method. Results showed that irrigation water depth for maximum yield for two types of irrigation management was 148. 3 and 186. 5 mm, respectively. When land is limiting, the best irrigation water depths were 146. 2 mm and 184. 0 mm. When water is limiting, the irrigation water depths are 109. 3 and 136. 9 mm, respectively, which caused more than 16percent increase in net income per unit volume of water both two types of irrigation managements. With this amount of saved water, if land is not limited, the cultivated area can be increased up to 36% and 36%. Results showed that the optimum irrigation water management (in unlimited conditions) is 4 days irrigation interval and 80%RAW irrigation depth. For this situation, the yield was 55 ton/ha. The net income for this case is more than 483 million Rials per hectare and B/C equals to 1. 78. The highest net income (for no land limitation and irrigation depth equivalent to full irrigation), is irrigation as large as Ww (water limitation conditions) that net income for the without and 4 days irrigation interval are more than 476 and 611 million Rials, respectively. This case generates the most net income per unit volume of used water. Results showed that in both unlimited condition and in water limitation condition, having an irrigation schedule and also applying deficit irrigation has a positive effect on the gardener's income that for deficit irrigation in unlimited condition 1492 and in water limitation condition 1369 m3/ha water is needed.

The objective of current study was to perform screening experiment, (phase zero of response surface methodology) the analysis of salinity and water tensions for spring wheat in Mashhad region and derive water production functions. The experiment was performed in the Research Field of Agricultural Faculty of Ferdowsi University of Mashhad in 2009-2010. Two water sources were selected: saline water (10 dS/m) and water without salinity limitation (0.5 dS/m). A single replicate factorial experiment with four variables and water requirements in different growth stages, was done with each variable having two levels, 20% and 100% of water requirements. The central points of experiment area with two replications were added for estimating the curvature in the fitted response surface. The results showed the water requirements in heading and flowering were the most important variables. The fitted water production functions estimated the yield of saline and non-saline plots with correlation coefficients equalsing 0.95 and 0.99. In general, the obtained results proved the efficiency of the screening experiment in identifying the relative importance of variables and excluding the ineffective variables.

The paper offers a distinctive reading of Popper’s work, suggesting that his Logic of Scientific Discovery (LScD) might be re-interpreted in the light of his Open Society. Indeed, Popper can be interpreted as criticising certain aspects of his first book, and as a result improving upon them, in his second. It suggests translating what Popper says about ‘conventions’ into his later vocabulary of ‘social institutions’. Looking back, I believe that Popper never intended the language of conventions and decisions to be read individualistically. I remain unsure whether Popper was himself quite as clear about this as he could have been.  My reading makes Popper a pioneer in the sociology of science. Scientific institutions are arenas of political power; but Popper did not discuss the structure and inter-relations of the social institutions of science, or offer a politics of science in the context of his methodology. What is missing from the skeletal sociology of LScD is the politics. We could put it in Popperian terms this way: scientific institutions are both open and closed. They are closed, firmly, to the inexpert, to the non-members; supposedly they are open to the qualified, provided the prerogatives of seniority and leadership are acknowledged. Despite these shortcomings, Popper’s critical and rational approach and his insistence on openness and intellectual honesty are still important today.

This research was conducted at Torogh Agricultural Research Station in Khorasan-e Razavi province to determine the impact of irrigation cutoff at different growth stages and percentage of water use on the yield and water use efficiency (WUE) of wheat cultivars using sprinkler irrigation. The study was done from 2006-2008. The experimental design was a randomized complete block design with a strip split plot layout and three replications. The three vertical plots were for irrigation (70%, 85%, 100% of plant requirement), the three horizontal plots were for irrigation cutoff point (full irrigation, irrigation cutoff at stem elongation, cutoff at pollination) Three wheat cultivars (Alvand, Toos, Gaskozhen) were the subplots. The yield means at 70%, 85% and 100% water consumption were, respectively, 3182, 4639, and 4748 kg/ha. Water consumption of 85% and 100% fell into statistical group A. The highest value for WUE was 1.849 kg/m3 at 85%, followed 1/389 kg/m3 for 70%, and 1.618 kg/m3 for 100%. The irrigation cutoff treatment showed significant differences (P£ 0.05) for grain yield and WUE. Full irrigation showed the highest grain yield (4557 kg/ha) and irrigation cutoff at stem elongation and cutoff at pollination actually decreased yield to 4195 and 3817 kg/ha, respectively. Full irrigation and irrigation cutoff at stem elongation fell into statistical group A. Cutoff at stem elongation had the highest WUE (1.778 kg/m3). Combined analysis showed that wheat cultivar had a significant effect on grain yield and WUE. Alvand cultivar had the highest yield (4447 kg/ha) and WUE (1.718 kg/m3). The results showed that, where water shortage was not an issue, full irrigation produced the best results. In areas of water shortage, 85% irrigation using the cutoff at stem elongation method is recommended for the best results in yield, water consumption and WUE.