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This study was conducted to investigate the effects of salicylic acid and harvest date on the yield and biochemical and physiological characteristics of peanuts in different humidity conditions, which is the novelty of this research. For this purpose, a split-plot factorial design during the 2018 and 2019 cropping seasons was conducted based on a randomized complete block design with three replications at the experimental field of the Agricultural and Natural Resources Research and Education Center of Guilan Province, Astara, Iran. Humidity regimes included rain-fed conditions (no irrigation), irrigation at the 10% flowering stage, 10% pod formation stage, and 10% flowering stage +10% pod formation stage in the main plots, and three salicylic acid levels (100, 200, and 300 µmol/l), and harvest dates (August 22, September 6, and September 21), were placed in subplots. Drought stress reduced the Chlorophyll Index, relative water content, seed, and pod yield but increased proline, Antioxidant enzyme activity, soluble sugar content, and H2O2 content. Conversely, Supplementary irrigation decreased proline, antioxidant enzyme activity, soluble sugar content, and H2O2 content, which increased the Chlorophyll Index, relative water content, seed, and pod yield. Also, salicylic acid foliar application enhanced guaiacol peroxidase, polyphenol oxidase, and ascorbate peroxidase antioxidant enzyme activity, mitigating the undesirable impacts of water deficiency. The maximum pod and seed production was obtained in all humidity conditions with 300 µmol/l salicylic acid. Under Humidity stress conditions, if water resources are available, two supplementary irrigations at 10% flowering and 10% pod formation stage are recommended. Also, for humid climates such as Astara and similar regions, in terms of climate, with limited rainfall in June and July (rainfall less than 10 mm during flowering and podding stages), one supplementary irrigation at 10% pod formation stage is recommended.

Safflower (Carthamus tinctorius L.), adapted to arid and semiarid regions, is grown for seed and petal production, but the present study aimed to evaluate the possibility of simultaneous forage and seed production in the autumn and middle types of safflower varieties in dual-purpose cultivation in semiarid areas in the shortfall forage period. An experiment was done based on a randomized complete block design with nine treatments and three replications at the Seed and Plant Improvement Institute, Agriculture Research, Education and Extension Organization, Karaj, Iran. The treatments included the cultivation of Parnian, Goldasht, and Golmehr varieties with the purpose of seed harvesting as control treatments; the same varieties (Parnian, Goldasht, and Golmehr), once with the aim of forage harvesting at 50% stem elongation stage and seed harvesting; and again with the aim of forage harvesting at 50% branching stage and seed harvesting. The results showed that forage harvesting at the 50% branching stage significantly increased the dry and fresh forage yield compared to the 50% stem elongation stage. The highest fresh and dry forage yields (DFY) (42,229 and 11,266 kg/ha) were related to the Golmehr variety at the 50% branching stage. Forage harvesting at the stem elongation stage decreased the crude protein, protein content, and digestibility compared to the branching stage in three safflower varieties. Parnian variety had the maximum seed yield (2,226 kg/ha) without forage harvesting. The highest seed yield in the second year (2018–2019) of the experiment belonged to the Golmehr variety (1,310 kg/ha) to harvest forage at 50% stem elongation (rapid stem growth) and seed harvest treatment, which compared to the first year (2017–2018), showed an increase of 25%. Finally, the forage harvested amount of all three varieties studied was higher in the branching stage than in the stem elongation stage. These results implied that the Golmehr variety (11,266 kg/ha DFY and 520 kg/ha seed yield) is for dual-purpose cultivation, and the Parnian variety (2,226 kg/ha seed yield) is suitable for only seed production for the semiarid region of Karaj in Iran and similar areas in terms of climate.

The aim of this study was to examine the effect of the foliar application of B, Zn, and Mn nano-chelates in separate and combined forms and determine what level of nano-chelates fertilizer treatment most significantly enhances the grain yield of wheat (Azar-2 cultivar) under rainfed and supplementary irrigation conditions. The experiment was performed as a split-plot experiment with three replications in two crop years (2014–2015). The main plot included two irrigation regimes ((I1) rainfed irrigation and (I2) supplementary irrigation) during two stages of development (spike emergence and grain filling). The sub-plot had eight foliar application levels: B, Zn, Mn, B + Zn, B + Mn, Zn + Mn, B + Zn + Mn, and distilled water (control). The foliar application of B, Zn, and Mn nano-chelates combined with supplementary irrigation or its sole application dramatically increased wheat's resistance to drought stress. Thousand kernel weight and the number of kernels per spike play a decisive role in grain yield. Therefore, the foliar application of nano-fertilizers can increase grain yield by improving these components. The highest grain yield (2528.33 kg/ha−1) was obtained in the supplementary irrigation condition after the combined foliar application of B + Mn + Zn nano-chelates. This condition led to a 41% increase compared to the highest grain yield obtained under rainfed conditions after the foliar application of Zn nano-chelates (1490 kg/ha−1). [ABSTRACT FROM AUTHOR]

The present study was conducted in order to investigate the effect of salicylic acid on growth, yield and macroelements absorption of fennel in split-plot as base on randomized complete block design (RCBD) with three replications in Tehran, Iran. Irrigation regime as main plot was undergone in 5 levels that included: I1: full irrigation, I2: cut off irrigation at stem elongation stage, I3: cut off at budding stage, I4: cut off irrigation at 50% flowering stage and I5: cut off irrigation at grain filling stage. Foliar application of SA (0, 3, 6, and 8 mM) as sub plot was applied at stem elongation, budding and 50% flowering stages. Result indicated application of SA was resulted to increase biological yield in all irrigation regimes. However, application of 6 mM SA had the most biomass under water stress at grain filling stage. Interaction of water stress and SA demonstrated that application of 3 mM SA had the most grain yield under full irrigation, water stress at stemming and water stress at grain filling stages, while application of 9 mM SA had the highest grain yield under water stress at budding and 50% flowering stages. [ABSTRACT FROM AUTHOR]