جستجوی مقالات مرتبط با کلیدواژه « وزن میوه » در نشریات گروه « زراعت »

Date palm is one of the important crops mainly grown in the arid regions of the Middle East and North Africa as well as in the southern warm and dry areas in Iran. One of the most important factors that reduces the quality and commercial value of date fruit is sunburn disorder during fruit growth and development. Therefore, this research was carried out to evaluate the effect of kraft paper, black, white, and blue cloth, green greenhouse netting, straw bag, and without bag (control) at the khalal stage on the ripening rate and sunburn incidence of cv. Medjool using randomized complete block design with eight replication in in Umm al Tameir research station, date palm and tropical fruits research, Ahvaz, in 2020 and 2021. The bags' ends were open and remained on the trees until harvest. The results showed that the bunch weight, the kimiri, khalal and date fruits proportions were affected by year. In 2021, average bunch weight (5.83 kg), kimiri percentage (8.6%) and khalal percentage (28%) were more than 2020, while in 2020 the percentage of date fruits (10.48%) was more than 2021. The rate of kimiri at harvest was lower in black cloth than in others bags. In 2020, bunch bagging with green greenhouse netting, white cloth, and kraft paper increased rutab rate by 9.81%, 12.99% and 11.37%, respectively, as compared to control. Bagging did not affect fruit size and weight. All kind of bags decreased the incidence of sunburn disorder. Kraft paper bag significantly decreased the percentage of dried fruits to 6.78% as compared to control with 9.93%. The rate of fruit decay was not affected by bagging. Considering the results of this research, it was concluded that black and white cloth bags were more effective in reducing sunburn disorder and fruit decay rate of palm date fruit cv. Medjool.

Blackberry is a plant of the genus Rubus and family Rosaceae, which due to its nutritional properties has role in human health. One way to increase nutritional properties is to use bio-organic fertilizers such as vermicompost and nitroxin. These fertilizers not only reduce the negative effects of chemical fertilizers, but also improve the growth and reproductive characteristics of blackberries.

To investigate the effect of nitroxin and vermicompost on the vegetative and reproductive characteristics of blackberry, a factorial study was performed in a completely randomized design at 5 levels of vermicompost (0, 10, 20, 30 and 40) and two levels of inoculation and non-inoculation of nitroxin in pots in Noor city. For this experiment, culture media were prepared by mixing different levels of vermicompost with the base soil in the pot. Then, the rooted and uniform seedlings were prepared and selected for use in the experiment and the roots of the plants were placed in nitroxin solution (ratio of 1 to 10 with water) for 10 minutes and then planted in pots.

The results showed that the highest number of buds (42.5 per plant), the number of clusters (5.5 per plant), fruit weight (3.37 grams per plant) and the shortest ripening period were produced in 20% volume of vermicompost. The highest weight of drupelets (0.10 grams) was obtained in 30% volume of vermicompost. In addition, the largest flower diameter (3.77 cm) was seen in nitroxin treatment with 30% vermicompost by volume. The highest internode length (5.65 cm), branch length (2.55 m) produced in nitroxin treatment alone. The highest internode length (5.65 cm), branch length (2.55 m) produced in nitroxin treatment alone. The largest number of nodes (67 per plant) belonged to nitroxin in combination with 20% vermicompost by volume treatment and the largest vegetative branch diameter (2.8 cm) and leaf surface (25.83 cm2) was obtained in vermicompost treatments of 20% and 10% by volume, respectively. The use of vermicompost at the level of 20 to 30 percent by volume can show the greatest effect on fruiting branches, while nitroxin alone or in combination with vermicompost had a greater effect on vegetative branches. Vermicompost improves the growing medium conditions by stimulating beneficial soil microorganisms and the stable supply of mineral elements, especially nitrogen and phosphorus. The physical and chemical properties of humic acid in vermicompost increase plant nitrogen accumulation by increasing nutrient storage capacity and growth regulatory hormones, and plant growth factors such as height, number of nodes, internode distance and leaf area will increase with increasing nitrogen. However, increasing the level of vermicompost increases the concentration of soluble salt, toxicity due to increasing the concentration of heavy elements and the presence of toxic compounds in the plant, which leads to reduced growth and yield. Under these conditions, the use of nitroxin modulates or neutralizes the harmful effects of abiotic stresses. Bio fertilizers that contain growth-promoting bacteria, in addition to providing part of the nutrients and their balanced absorption, increase the nutritional value of the fruit by preventing the imbalance between the plant's internal components.

The use of vermicompost at the level of 20 to 30 percent by volume can show the effect on fruiting branches, while nitroxin alone and together with vermicompost has a greater effect on vegetative branches.

To select the high yielding and adapted pecan genotypes for Dezful climatic conditions in Iran, 50 seedling trees were evaluated in 2019-2021 in Dezful in southwest of Iran. The results showed that P200-7 and P200-8 genotypes had the largest and smallest nuts with 14.3 and 4.2 grams, respectively. P220-2-1 genotype had the highest and P200-9, and P220-2-5 genotypes had the lowest percentage of blank nuts. Kernel removal was easy in P200-1 and P200-10 genotypes, while it was very difficult in P200-3 and P200-31 genotypes. Fruit ripening time was the earliest in P200-1 and P220-2-5 genotypes and the latest in P200-23. P200-23, P220-1-1 and P200-9 genotypes had the highest yield index with 65, 49 and 39 g cm-2 of tree trunk, respectively. The results of evaluation for heat stress tolerance in pecan genotypes showed that 40 to 70% of the branches of all genotypes were damaged by hot temperatures in the summer of 2021 with 430 hours of temperatures above 45 oC, while the branches of P200- 23 genotype were not damaged. In addition, the results indicated that heat stress damage had significant correlation with yield index (r = 0.311*) and kernel color (r = 0.323*). There was highly significant (r = -0.597**) correlation between shell thickness and kernel removal. The relationship between mean fruit weight and nut length (r = 0.386**) and nut width (r = 0.440**) were also highly significant. Factor analysis showed that nut length, shell thickness, blank nuts percentage, nut weight, yield index and heat stress damage accounted for 67% of the total variance. Finally, P200-23 genotype with high yield index, golden bright kernel color and very high heat stress tolerance, and P220-1-1 genotype with high yield and low percentage of blank nuts were identified as promising genotypes for future supplemental research.

Pre-harvest citrus fruit splitting is a physiological disorder that causes significant damage to producers of susceptible cultivars by reducing the amount of crop available on the market. Proper management of tree nutrition and paying special attention to the three key elements of potassium, calcium, and boron, which are involved in the strength of cell walls and fruit peel flexibility, can be effective in reducing the fruit splitting severity. Therefore, an experiment has been carried out in the Ramsar (Citrus and Subtropical Fruits Research Center) during 2018 and 2019 to investigate the effects of foliar application of 1.0% potassium nitrate, 1.0% calcium nitrate, and 0.5% boric acid at the end of June drop on reducing the severity of splitting and some fruit traits of Page mandarin. This study is performed according to a combined analysis in time with two factors including years of experimentation and different treatments of foliar application of nutrients, based on randomized complete block design with three replications. The results show that the treatments especially 1.0% potassium nitrate have reduced pre-harvest fruit splitting, increased the yield, and improved the quantitative and qualitative fruit traits. However, they have had no significant effect on the activity of polygalacturonase enzyme, cell density of blossom-end, and navel diameter. Overall, foliar application of nutrients, especially 1.0% potassium nitrate, could be suggested as an effective approach to control pre-harvest fruit splitting and boost the quantity and quality of page mandarin fruit.

The most regions of Iran are arid and semi-arid and electrical conductivity of irrigation water in these regions is high and often is salty. The improvement of saline water and soils is costly and time-consuming and it is practically impossible. Therefore, it is necessary to evaluate the tolerance of various plant species and cultivars to salinity for cultivation in these areas. Strawberry is one of the small fruits which has a high demand in the market due to high nutritional value and favorable taste. Strawberry has various cultivars with different yield and sensitivity to stress. Therefore, this research evaluated the sensitivity of "Aromas" cultivar to different levels of electrical conductivity of the nutrient solution.

In order to evaluate the effect of different levels of electrical conductivity of nutrient solution on morphological, yield, physiological and biochemical characteristics of "Aromas" cultivar of strawberry, an experiment was performed as pot based on the completely randomized design in the Research Center of Strawberry Breeding and Improvement of the University of Kurdistan. The culture media was cocopeat perlite with equal ratio and the nutrient solution was modified Hoagland. Different levels of electrical conductivity of a nutrient solution (0.7, 2, 3, 4 and 5 dS/m) were prepared by adding sodium chloride. Frozen leaf samples were used for physiological and biochemical evaluations. Then, at the end of the experiment period, the functional characteristics of plants were measured and the obtained data were analyzed by SAS software and mean comparison was done by the LSD method.

The results of variance analysis showed that the electrical conductivity of the nutrient solution had a significant effect on all of the measured traits. The highest mean number of leaf, leaf area, leaf dry weight, root volume, root dry weight, number of crown, crown dry weight, dry weight of whole plant, number of fruit, single fruit weight and total fruit yield belonged to control plants (irrigated with nutrient solution with electrical conductivity of 0.7 dS/m) and with increasing electrical conductivity of nutrient solution, the amount of mentioned factors decreased. Moreover, the highest relative water content of leaf, membrane stability index, total soluble proteins, chlorophyll, carotenoids and potassium of leaf belonged to 0.7 dS/m treatment. While the highest total soluble carbohydrates, proline, hydrogen peroxide, the activity of peroxidase and superoxide dismutase enzymes, malondialdehyde and sodium of leaf were observed in plants that received a nutrient solution with electrical conductivity of 5 dS/m. The slope of yield loss was 49.02 for each unit of electrical conductivity of nutrient solution and the salt tolerance threshold of this cultivar was less than 2 dS/m based on total fruit yield and biomass.

Overall, based on the findings of this research, the "Aromas" cultivar was strongly influenced by the electrical conductivity of the nutrient solution and its morphological, physiological, biochemical and yield properties changed significantly. Based on the observations, it seems that Aromas cultivar is not able to withstand high electrical conductivity of the nutrient solution and to achieve optimal performance of this cultivar, nutrient solutions with electrical conductivity of less than 2 dS/m should be used.