جستجوی مقالات مرتبط با کلیدواژه « ریخت شناسی » در نشریات گروه « زراعت »

Guar or cluster bean (Cyamopsis tetragonoloba L.) is a drought-tolerant annual leguminous crop grown mostly in India and Pakistan. Each pod contains 5 to 12 seeds. Seeds vary from dull-white to pink to light gray or black. Like other legumes guar is an excellent soil-building crop with respect to available nitrogen. Guar is one of the unique beans which its large spherical endosperm contains a significant amount of galactomannans that is used in a wide range of food and industrial applications. Organic fertilizers have a positive effect on agricultural sustainability due to the fact that authentic and safe products are important. One of the most important compounds in soil structure is humic acid, which results from organic matter decomposition in the soil. Humic acid is one of the most organic substances that has been used today due to its advantages, such as improving drainage and soil air, causing the development of microorganisms, increasing plant yield and growth, and also reducing the consumption of other fertilizers. In general, humic substances are used as soil modifiers. One of the important factors in plant cultivation is to determine the most suitable planting density. Plant density is an important agronomic factor that manipulates micro environment of the field and affects growth, development and yield formation of crops. The optimum planting density of the plants results in a balance in the competition between the plants and the maximum yield. So, this research focuses on the reaction of vegetative and reproductive growth of guar (cluster bean) to humic acid application with irrigation water in different planting densities in Ahvaz region.
 

In order to evaluate the response of vegetative and reproductive growth of guar or Cluster bean (Cyamopsis tetragonoloba L.) to the humic acid application with irrigation water in different planting densities, an experiment carried out in summer of 2016. This experiment was performed by split plot design with three replications based on randomized complete block design in research farm of Agriculture Sciences and Natural Resources University, Khuzestan Ahwaz. The experimental factors were four levels of humic acid, control (H0), 5 Kg.ha-1 (H1), 10 Kg.ha-1 (H2) and 15 Kg.ha-1 (H3) as the main factor in main plots and plants spacing on the planting row with four densities, 35 plant.m-2 (D1), 55 plant.m-2 (D2), 75 plant.m-2 (D3) and 95 plant.m-2 (D4) as sub factor in sub plots. In this experiment, measured traits were plant height, number of branches in the plant, leaf number, grain yield, dry matter, number of pod and number of grain/m2, number of grain in pod and harvest index. Data were analyzed by SAS 9.4 and mean comparison performed by Duncan test in 5% probability level.
 

Analysis of variance of data results showed that the main effect of humic acid and plant density were significant at p≤0.01, for all the measured traits (except the number of grains in pod and harvest index). So that as humic acid level increased, the traits increased. Also with increasing in plant density; all studied traits increased significantly except the number of branches of the plant. The interaction effect between humic acid and plant density were significant (p≤0.01) on grain yield, dry matter, plant height and the number of plant.m-2. The results also showed that the effect of humic acid and plant density on leaf number was significant at 1% level. So that, the highest plant height and leaf number per m2 were obtained from density of 95 plants.m-1 and 15 Kg.ha-1 humic acid application. So, with increasing plant density, leaf number increased. Generally, the highest grain yield (4209.7 Kg.ha-1) and dry matter (17955.6 Kg.ha-1) was under 15 Kg.ha-1 application of humic acid and the density of 95 plant.m-2 and the lowest grain yield (1433.2 Kg.ha-1) and dry matter (4812.6 Kg.ha-1) was under zero humic acid level and density of 35 plant.m-2.
 

Generally, the results showed that humic acid solution has a positive effect on the plant, therefore, using humic acid, produced highest grain yield, dry matter and morphological traits. Also, with increasing plant density, traits such as plant height, leaf number, yield and yield components increased but the number of branches decreased. In general, 15 Kg.ha-1 application of humic acid and the density of 95 plants.m-2 produced the highest yield.

In order to investigate the contamination of cotton seeds with Fusarium fungi, samples of different classes of 10 cotton cultivars were obtained from Southern Khorasan, Razavi, Golestan and Fars provinces. Various sections of a seed such as full seed, coat, kernel (endosperm and embryo), endosperm and embryo were cultured on the nutrient medium of potato dextrose agar and water agar. Of the 23 cotton seed samples, 76 isolates of Fusarium was obtained. The contamination in fuzzy and delinted seeds were 98.7 and 1.3 percent respectively. The hightest percentage of purified Fusarium was from kernel. Identification based on morphological traits showed that the isolates with the frequency of 39, 23, 10, 2, 1 and 1 isolates belonging to the species Fusarium equiseti, F. proliferatum, F. semitectum, F. compactum, F. nygamai and F. solani. Species of F. compactum and F. nygamai are reported for the first time from Iran. The application of Polymerase chain reaction and the use of specific primers of F. equiseti and F. proliferatum dominant species have led to the production of proprietary DNA bands using the DNA of the relevant fungal species, as well as the seed DNA that naturally contaminated these species. In this way, the results of identification of these two species based on morphological traits were confirmed by the molecular method. This study revealed that Fusarium traces are detected in infected seeds using the PCR reaction.

Oilseed pumpkin is an introduced medicinal plant, the seeds as well as some other organs of which are being utilized in treating an array of human diseases in Iran. Considering the plant's significance in the health product's industry on the one hand, and the countrywide drought stresses and a lack of information on mineral nutrition of oilseed pumpkin, the study aimed to assess the effects irrigation interval and different levels of nitrogen fertilizer on same of morphological traits, yield components and seed yield of this medicinal plant of this useful medicinal plant.
This experiment was studied as split plot based on randomized complete block design with three replications at the Research Farm of Bu-Ali Sina University in during growing season of 2012-2013. Irrigation intervals (6, 9, 12 and 15 days) as main plots and nitrogen levels (0, 60, 120, 180 and 240 kg N ha-1) were considered as sub-plots. Furrow irrigation system was used for crop irrigation and irrigation treatments were applied after full establishment of plants. Nitrogen fertilizer was applied at three stages of planting, flowering and fruting. The evaluation traits included plant length, node number/plant, branch number/main stem, leaf number/plant, fruit number/plant, seed number/fruit, 100 seed weight, seed yield and chlorophyll meter reading.
Results showed that the effects of treatments were significant on plant length, nod and branch number/main stem, leaf and fruit number/plant, seed number/fruit, 100-seed weight, grain yield and chlorophyll index of pumpkin. Also, interaction of treatments had significant effect on all traits except branch number/main stem and seed number/fruit. Maximum and minimum traits as well as grain yield in averaging of 84.84 and 25.26 g m-2, were achieved at 180 kg N in 6 days irrigation interval and non supplying N in 15 days irrigation interval treatments, respectively. Treatment of 180 kg N in 6 days irrigation interval did not differ with treatment of 180 kg N in 9 days irrigation interval. Drought stress occurrence and nutrient deficiency, especially nitrogen during development stages especially reproductive stages caused decreasing in yield components and eventually seed yield through reduction in chlorophyll content, reduction in photosynthesis period and material translocation resulted from current photosynthesis and also reduction of proportion of supplied remobilization of materials.
Generally, results of this experiment showed that the highest grain yield was obtained in the treatment of irrigation interval of 6 days with accompanying consumption 180 kg N, but there was no significant difference between the mentioned treatment and the treatment of irrigation interval 9 days and 180 kg N. So, it can be concluded that irrigation interval of 9 days and application of 180 kg N ha-1 can produce satisfactory yield besides water saving and reduction in production cost particularly from to nitrogen fertilizers.