نشریه علوم به زراعی گیاهی
سال نهم شماره 2 (پاییز و زمستان 1398)

In order to investigate the effect of acid modifiers in lands with high pH on improving morpho-physiological characteristics of wheat, a factorial experiment was conducted in a randomized complete block design with three replications. The factors included, sulfur sulfate in three levels (0, 250 and 500 kg ha-1) and thiobacillus in three levels (0, 5 and 10 kg ha-1). The results showed that the effect of sulfur fertilizer and thiobacillus bacteria on total dry weight, leaf area index, crop growth rate, net assimilation  rate and plant height were significant at 1% probability level. The interaction between sulfur and thiobacillus fertilizers on total dry weight was significant at 1% probability level and on plant height at 5% probability level and was not significant for other traits. The maximum crop growth rate were obtained by 12.5 and 11.6 g m-2 under 500 kg ha-1 sulfur fertilizer and 10 kg ha-1 thiobacillus, respectively and the minimum by 9.7 and 10.6 were under non-application of sulfur fertilizer and non-application of thiobacillus. The maximum plant height (94.3 cm) was observed under application of 500 and 10 kg ha-1 of sulfur and thiobacillus fertilizer and the minimum by 74.6 was under non-application of sulfur fertilizer and thiobacillus. In general, the results of experiment showed that the application of sulfur fertilizer and thiobacillus bacteria in lands with high pH improved morpho-physiological characteristics of wheat, which could be interest to researchers and farmers.

In order to study effect of seedling age and plant density on yield and yield components of rice (Sadri cultivar), a field experiment was conducted at the Ordukhan Agricultural Research Center, Heart Province - Afghanistan (Geographical longitude: 62°11'29" east and geographical latitude: 34°20'35" north) during the cropping season 2017-2018. The experiment was laid out in complete block design with three replications. Seeding ages with three levels (20, 30 and 40 days) were considered as main plots and plant densities with four levels (13, 17, 22 and 33 plants/m2) were allocated as sub plots. Analysis of variance showed that the effect of seedling age on number of tillers per plant, numbers of grains per panicle and grain yield was significant. The plant density had significant effect on all traits (expect, 1000grains weight). Interaction of two factors had no significant effect on any of the traits. The means comparison showed that the highest of number grains per panicle and grain yield were obtained for 30 days seedling age. Also, the highest of number of tiller per plant, number of fertile tiller per plant, number of grains per panicle and percent of unfilled grain were obtained by 13 plants per m2. But the highest biological yield, harvest index (HI) and grain yield obtained by 33 plants per m2. Based on simple correlation coefficient of traits, grain yield had significant positive correlation with biological yield, number fertile tiller per plant and number grains per panicle.

In order to effect of humic acid on yield, yield components and physiological parameters of wheat in deficit irrigation conditions this research was done as split plot in randomized complete blocks design with three replications. main plots consisted: full irrigation, no irrigation at the beginning of stem elongation, and no irrigation at the pollination stage and sub plots included different levels of humic acid fertilizer (0, 100, 200 and 300 mg/L). Results showed that interaction of irrigation and humic acid on number of seeds per spike and 1000 grain weight at 1% probability level and number of spikes per unit area and harvest index was significant at 5% probability level. Grain yield under the effect low irrigation and humic acid was significant at 1% probability level. The highest leaf area index and crop growth rate were affected in full irrigation and 300 mg.L-1 humic acid and least of them were obtained in low irrigation stress conditions in different periods and no foliar application of humic acid. The highest grain yield was obtained in full irrigation (5035 kg.ha-1) and foliar application with 300 mg.L-1 humic acid (4462 kg.ha-1). The lowest grain yield was obtained in no irrigation at the pollination stage (2355 kg.ha-1) and no-humic acid (2667 kg.ha-1). As a result, foliar application 300 mg.L-1 of humic acid in different periods of low irrigation stress improved the physiological indices and increased yield components compared to control (no foliar application).

A better understanding of factors affecting competition between wheat and weeds can facilitate the development of more effective crop management methods. In order to quantification wheat- Avena ludoviciana Duriu competition in response to nitrogen and Othello OD herbicide. A field experiment in 2018-19 was conducted as split plots in a randomized complete block design with four replications at Agricultural Sciences and Natural Resources University of Khuzestan. Nitrogen fertilizer in included five levels of 0, 80, 160, 240 and Unconventional consumption 320 kg ha-1 of Nitrogen fertilizer was considered as the main plot and the herbicide dose of Othello OD herbicide in five levels of 0, 0.25, 0.5, 0.75, and 1 times the recommended dose (The recommended dose of herbicide is 1.6 L ha-1) was considered as the sub plot. The results showed the dose required for 50% reduction of weed biomass in non-fertilized conditions, was equal to 75% of the recommended herbicide was used. That with increasing nitrogen fertilizer consumption led to lower herbicide dose. So that by consumption 320 kg N ha-1 reached 37% of the recommended dosage of this herbicide. Also, to achieve about 700 g m-2 of wheat biomass, using 185 kg ha-1 of nitrogen fertilizer plus 85% of the recommended herbicide dose, or applying 320 kg ha-1 of nitrogen fertilizer and 65% of the recommended dose of herbicide.

In order to investigate the effect of potassium nano chelate and ascorbic acid on acid yield and some qualitative characteristics of cowpea seed, a factorial experiment was conducted in a randomized complete block design with three replications was carried out at the Shahid Salemi Research Farm in Ahvaz. Factors included different amounts of potassium nano fertilizer at three levels (0, 2 and 4 liters per hectare), and levels of ascorbic acid (0, 15 and 30 mM). Results showed that there was significant difference at 1% probability level between potassium nano fertilizer and ascorbic acid in number of pods per plant, number of seeds per pod, 1000 seed weight, grain yield, biological yield, harvest index, protein percentage and potassium percentage. Among the measured traits, only interaction of potassium nano chelates and ascorbic acid on harvest index was significant at five percent. The highest harvest index was obtained with four liters per hectare potassium nano chelate and sprays application with 30 mM ascorbic acid with 39.68% and the lowest harvest index with 24.03% non-foliar treatment. The highest grain yield was obtained using 4 liters.ha-1 of potassium nano fertilizer and 30 mM ascorbic acid, respectively, with 3640 and 3183 kg.ha-1, and the lowest grain yield was obtained by control. The highest protein percentage was obtained by spraying with 4 liters.ha-1 of potassium nano fertilizer and 30 mM ascorbic acid, respectively, with 22.02 and 23.57 percent, respectively, and the lowest one was in control. In general, according to the results spraying with 4 liters.ha-1 of potassium nano fertilizer and 30 mM of ascorbic acid increases the quantitative and qualitative yields.

In order to investigate the effects of chemical and organic nutritional systems on yield, water utilization in rice cultivars under irrigation stress, a split Plot factorial experiment was conducted in a randomized complete block design with three replications at Dasht-e Naz Agricultural Company, located in the city of Sari in 2016 Irrigation stress treatments were performed in three levels: the stress at the time of the beginning of the tillering (15 days after the installation of the work), the developmental stage of the transfer (the end of flowering and grain filling start) and the lack of stress (controls) as the main factor, through irrigation cut and irrigation again after the appearance of surface cracks The type of feeding system was considered in four levels of Vermicompost and compost azolla (6 and 8 t.ha-1 respectively), humic acid (4.5 L.ha-1) and the common chemical fertilizers Nitrogen, Phosphor, Potassium and cultivars were considered on two levels (Shirodi and local Tarom) in factorial form as a subagent The results variance analysis showed that there was a significant difference between Shiroudi and Tarom cultivars in terms of rice paddy yield in different levels of irrigation stress and nutritional systems. Under common irrigation conditions, the most biological functions of Paddy yield in the varieties of Shirodi and local Tarom, was obtained 6577.9 and 3776.4, Kg.ha-1, Respectively. Low irrigation stressin the developmental stage of the beginning of the tilleringreduced the rice paddy yield by 6.87 and 1.67 andin the remobilization stage, reduced the rice paddy yield by 17.65% and 2.97%, compared to non-stressed conditions With application of humic acid nutrition system, improvement of rice yield was observed in Shiroudi (6563.1 Kg.ha-1) and local Tarom (3878.77 Kg.ha-1) in compared with other nutrition systems.by using the humic acid, azolla compost and Vermicompost in Shirodi variant, the rice paddy yield increased 16.12, 9.02 and 3.62 Percent and in local Tarom 7.85, 3.47 and 2.21 percent respectively, compared with the chemical fertilizer. The highest Water Use Efficiency in the cultivars was observed with the average of 0.1050 and 0.8016 Kg/m3No rainfall, outlet runoff and tillage water were observed under conditions of non-stress. Totally, the results showed highest yield of Paddy was obtained for both Shirodi and Tarom cultivars under non-stress conditions in the humic acid nutrition system.