جستجوی مقالات مرتبط با کلیدواژه « وزن تر و خشک » در نشریات گروه « زراعت »

Environmental conditions such as soil moisture have a significant effect on herbicides efficacy. In order to evaluate the effect of Othello herbicide in different soil moisture conditions on wild mustard and wheat, a greenhouse experiment was conducted as split plot based on randomized complete block design with three replications. Three levels of soil moisture including field capacity, 75% field capacity and 50% field capacity, and 0, 33, 66, 99, 132 and 165 grams of active ingredient of Mesosulfuron + Iodosulfuron + Diflufenican per hectare were the experimental treatments. Results showed that the concentration required to reduce the dry matter content of wild mustard by 50% in the field capacity was 71. 57 g. a. i /ha of herbicide, while in 75% and 50% of the field capacity, it was increased to 88. 69 and 112. 11 g of active ingredient per hectare, respectively. The required concentration to reduce 50% of dry weight of wheat in the field capacity was 86. 85 g. a. i / ha, while it reached to 102. 5 and 73. 95 g. a. i /ha at75% and 50% moisture content, , respectively. The results of the data showed that at 50% moisture content of the field capacity, lower concentrations of this herbicide would also have adverse effects on wheat.

In order to select drought resistant or tolerant local olive genotypes an experiment were conducted in field conditions. Seven olive genotypes (D1, Dd1, GW, Ps1, Bn3, Bn6 and Ds17) used as plant materials. A split plot experiment in time was used based on a completely randomized block design with three replications and three irrigation regimes for field experiment. Irrigation treatments period for field experiment were 6, 9 and 12 days interval and 6 days period was as control. Some vegetative characteristics such as plant height, trunk diameter, leaf number, leaf, shoot, and root fresh and dry weight were recorded. Result in field experiments show that Ds17 genotype had the highest trunk diameter and Dd1 genotype had the lowest trunk diameter. Bn3 genotype had the highest number of leaf and D1 had the lowest but D1, Dd1 and GW were in a statistic class. Genotypes show significant differences in leaf fresh and dry weight so that Bn3 genotype had the highest leaf fresh and dry weight and D1 had the lowest. Genotypes show significant differences in shoot and root fresh and dry weight so that Ds17 genotype had the lowest shoot fresh and dry weight and GW had the lowest root fresh and dry weight. The results indicated that olive genotypes had different resistance to drought and vegetative growth status of Bn3 and Ds17 genotypes were better in drought stress conditions.

Background and Objectives Olive (Olea europaea L.) trees are traditionally grown in relatively infertile lands being adapted to poor soils and irrigation. New olive orchards are usually established using mist-propagated plants derived from semi-hardwood cuttings. Although this propagation system is very efficient, from the economic point of view, shortening the juvenile period of plantlets is very important. Root colonization with mycorrhizal fungi can shorten the length of the juvenile period in olive plantlets, as inoculated plants can absorb the essential nutrient elements much better resulting in growth enhancement and faster development.
Materials and Methods In this study, symbiosis effect of three mycorrhizal fungi on growth, chlorophyll content and the absorption of some nutrient elements in rooted cuttings of three olive (Olea europeae L.) cultivars was investigated. The study was conducted through a factorial experiment based on a completely randomized design with three replications in the Research Greenhouse of the Department of Horticultural Sciences, Bu-Ali Sina University. The first factor included olive cultivars at three levels (Arbekin “R1”, Conservalia “R2” and Moharam “R3”), and the second factor consisted of mycorrhizal fungi inoculation at five levels (G.mosseae.intraradices) “D1”, )G.hoi.mosseae( “D2”, (G.hoi.intraradices) “D3”, (Mixed three species) “D4” and the control (non-­inoculation) (D5).
Results The results showed that almost all measured characteristics were affected by the treatments. The highest symbiosis percentage was observed in R2D2 and the least belonged to D5. Based on the result, symbiotic fungi made a significant increase in some growth indices including the height and diameter of the plants, leaf area and diameter and length of the branch. The inoculation also caused an increase in the fresh and dry weight of the root and aerial parts of the plants compared to the controls. Mycorrhizal fungal inoculation resulted in increasing the total, a and b chlorophyll contents in all treatments. This symbiosis caused a significant increase in the absorption of some nutrient elements such as K, Zn, Fe and P compared to the controls.
Discussion The results of the present study showed that, mycorrhizal fungi colonization enhanced the uptake of essential nutrients by plants, leading to a greater root surface area and biomass. Both the growth and nutrient content of the mycorrhizal fungi colonized olive plants were increased. It seems that mycorrhiza increases the absorption of water and nutrient elements from the soil through the further development that results in increasing leaf photosynthesis and ultimately increasing the plant growth.

To study intermittence of duration of exposure to magnetic field or MF (0.9 mT) on direct organogenesis of African violet explant in medium with and without PGRs these experiments performed. First experiment performed as completely randomized design (CRD) with three level of MF exposure (control, 5 day continuous and 5 day discontinuous) in PGR- free medium included via 6 repeat. The second experiment performed as factorial in CRD. Factors included auxin and cytokenin as two PGRs in 1mg Lit and 3mg Lit IBA and BAP levels and 3 levels of MF exposure as well as first experiment with 6 repeat. The results showed that explants exposed to a discontinuous MF with and without PGRs produced the highest shoot number (7.08) and the lowest number was produced in the control (2.35). Plantlets length was not affected by the MF but it was affected inside of PGRs. The leaf number in the continuous (4.4) and discontinuous (4.7) magnetic field was approximately doubled in comparison with control (2.77). The fresh and dry weight revealed better values in the MF discontinuous (0.49 and 0.03 mg) than continuous (0.35 and 0.02 mg) in PGRs-free medium. Results showed the fresh weight of plantlets was significantly higher for 1mgl-1 PGRs than 3 mgl-1 PGRs, when exposed to 0.9 mT MF for 5 days continuously, as well as for dry weight. It seems that the MF as a light abiotic stress can simulate the cell division and elongation and eventually the plant growth.