ebrahim abedi gheshlaghi

The application of natural organic compounds without harmful environmental effects in the production of horticultural and agricultural products is considered as a new method to reduce waste before and after harvesting, increase the storage life and maintain antioxidant activity in developed agriculture. As regards, this study investigated the impact of foliar applications of brown macroalga extract on antioxidant enzyme activity and mineral uptake in 'Hayward' kiwifruits.

Four treatment levels of brown macroalga extract (0, 1, 2, and 3 g/L) were applied at three distinct phases, occurring 110, 125, and 140 days after full bloom. Fruit samples were stored at 1±0.5°C with 95% relative humidity for 90 days, with measurements taken every 30 days.

Results revealed that the 3 g/L extract treatment significantly increased the uptake of calcium (47.82 %), nitrogen (20.52 %), potassium (12.06 %), phosphorus (19.81 %), and iron (25.77 %) compared to the control. The extract demonstrated a substantial effect on all recorded traits. Among the applied treatments, 3 g/L of brown macroalga extract concentration had the best effect in reducing electrolyte leakage (25.10%), malondialdehyde accumulation (96.73%), hydrogen peroxide content (54.54%) and increasing activities of antioxidant enzymes including superoxide dismutase (50.42%), catalase (84.90%), ascorbate peroxidase (79.02%), and peroxidase (49.40%) compared to the control in 90 days of storage.

Research limitations: 

No limitations were found.

Originality/Value: 

The results suggest that the 3 g/L brown macroalga extract concentration holds promise for enhancing the quality of 'Hayward' kiwifruits.

Xenia plays an important role in increasing yield and improving the quantitative and qualitative traits of nut fruits and is widely used in breeding programs. This study was conducted as factorial based on completely randomized block design. The first factor is pollen in four level, and the second factor is cultivar in four level with three replications. In this study, Ronde, Atrak, Ganjeh and Nemsa cultivars were used as the maternal and the Gerde- Eshkvarat, Ryasnet, Daviana and Negrate cultivars were used as pollinizers; Self-pollination of main cultivars was also used as a control. The aim of this study was to investigate the effect of different pollen grain sources on some chemical and biochemical compounds of hazelnut kernel. The results showed that the interaction of pollen grains and cultivar on hazelnut kernel compounds was significant. The highest percentage of oil in Daviana × Ganjeh (65.93%), protein in Ronde × Daviana (17.75%), potassium in Ryasnet × Ronde (366.68 mg.100g-1), calcium in the Ryasnet × Ronde (336.53 mg.100gr-1) and phosphorus in Daviana× Ronde (370.87 mg.100g-1), phenol in Riacent×  Atrak (3.45 mg .g-1), total unsaturated fatty acid in Atrak × Daviana (91.56%), total saturated fatty acid in Gerde- Eshkavarat× Atrak (12.34%) were observed. The results showed that Daviana and Ryasnet pollen grains were suitable for pollination of the studied cultivars and they could be used as suitable pollinizer.

The present study was conducted as a factorial study in a randomized complete block design on Hayward cultivar kiwifruit vines for two years. The first factor included the intensity of summer pruning in four levels, and the second factor included pruning time at two levels. The results showed that fruit yield and size were affected by the interaction of pruning intensity and pruning time, and the leaf-to-fruit ratio, light transmission through the canopy, and fruit firmness were affected by pruning intensity. The highest yield, with 126.2 kg/vine, was observed in zero leaf pruning one month after fruit set. Pruning after 3-4 leaves after the last fruit and pruning after the last fruit reduced the leaf-to-fruit ratio and increased light transmission from the canopy of kiwifruit vines. Different pruning treatments increased the firmness of the fruit by about one unit compared to the control, but had no significant effect on the amount of soluble solids, vitamin C, and dry matter. According to the results of this experiment, zero leaf pruning within four weeks after fruit set and pruning after 3-4 leaves after the last fruit within a week after fruit set showed better effects on vine growth, yield, and some quantitative and qualitative traits of the fruit.

The present research was conducted to investigate the efficacy of preharvest NaHS application as foliar spraying on the quality and antioxidant capacity of kiwifruits cv. Hayward during cold storage. In the present investigation, the effects of a preharvest treatment with H2S donor NaHS in four levels (0, 0.5, 1 and 1.5 mM) at 110, 125, and 140 days after full bloom on nutritional quality and antioxidant capacity of kiwifruit (Actinidia deliciosa 'Hayward') were evaluated during 90 days of storage at 1 °C and 90% relative humidity. Sampling was done to measure the desired traits during four periods of 0, 30, 60 and 90 days after storage. The results showed that NaHS treatment had a significant effect on the evaluated traits. At the end of 90 days of storage, NaHS treatment prevented fruit weight loss and maintained fruit firmness in comparison to the control. The percentage of electrolyte leakage and the amount of accumulated malondialdehyde (MAD) in all concentrations of NaHS was lower in comparison to the control. Preserving ascorbic acid content and increasing the activity of phenylalanine ammonialyase (PAL) lead to higher production of total phenol and flavonoids and improve the antioxidant capacity of fruits. NaHS treatment decreased the activity of polyphenol oxidase in comparison to the control. NaHS at 1.5 mM showed the best effect among the applied treatments. According to the obtained results, this concentration can be recommended as a suitable treatment to maintain the quality of kiwifruit cv. Hayward.

Pollination is one of the most critical stages for kernel formation in nut fruits, and without pollination, most fruit will be blanks, so that, to commercial production of hazelnut orchards, should be used two or more cultivars as pollinizer. The aim of this study was to investigate the phenology of flowers, xenia and metaxenia in four commercial hazelnut cultivars and select a suitable and compatible pollinizer for four commercial hazelnut cultivars.

This study was conducted as a two-factor factorial in a completely randomized design. The first factor is pollen, and the second factor is four cultivars having three replications in the period of 2019-2020 in Astara Horticultural Research Station. Gerde Eshkvarat, Riasnet, Daviana and Negret were used as pollinizer cultivars and Ronde, Nemsa, Ganjeh and Atrak cultivars were selected as maternal cultivars. In addition to open pollination (control), self-pollination of maternal cultivars was performed. At the time of fruit ripening, 100 nuts were harvested from each treatment, the variables related to the quantitative characteristics of the fruit, and the nut kernel were determined.

The results of phenology showed that the cultivars were protanderious and the opening time of male flowers (catkins) and shedding of pollen grains were from mid-January to March 24. The opening time of female flower clusters and stigma ready to accept pollen grains varied from January 19 to March 31. The study of xenia and metaxenia in this study showed that the quantitative traits of nut and kernel were strongly influenced by the sources of pollen grains. Increased fruit set and kernel percentage by 87% and 49.84% and the percentage of fruit drop decreased to 31.65% and blank nut by 10.86%. However, when pollen grains of Gerde Eshkorat cultivar were used, the percentage of fruit set, nut and kernel weight and percentage of kernel decreased to 75.86%, 2.48 g and 46.64%, respectively, and the percentage of blank nut with 15.60% and dropping fruit increased by 41.6. In the case of self-pollination, the percentage of fruit drop and the amount of blank nut increased, and the percentage of fruit set, nut, kernel weight, and kernel percentage decreased.

Based on the results, the source of pollen grains affected nut and kernel characteristics of hazelnuts through xenia and metaxenia effects. The effects of treatments on important components of hazelnut yield (nut and kernel weight, kernel and fruit set percentage, fruit drop and blank percentage) were remarkable and it was statistically significant at the 5% probability level. Therefore, for the economic production of hazelnut orchards, pollinizer cultivars should be used that overlap with the main cultivars in terms of pollination period and genetic compatibility.

Fruit size is an important attribute of all fruit crops and harvest fruit weight has a major influence on market acceptance and returns for many fruit crops like kiwifruit (Actinidia deliciosa 'Hayward'. The purpose of this study was to develop a non-destructive technique by measuring fruit dimensions and fruit volume by water displacement to measure fruit growth and using this information to develop a method for predicting fruit weight at different stages of its development.

This experiment was conducted using the mature vines of ‘Hayward’ kiwifruit. The kiwifruit vines were grown in an orchard located in Astara, Guilan province, Iran (latitude 38.22°N and longitude 48.51°E), trained to a T-bar system with plants spaced of 4×5 m. Fruits were destructively harvested at one-two weeks after fruit set during the season to obtain measurements of individual fruit volume by water displacement, fruit fresh weight, circumference of fruit and three linear measurements of fruit size, from which a correlation relation was derived to enable estimation of fruit volume, fruit fresh weight from the fruit measurements (r> 0.995). This enabled the growth of tagged fruit on the vine to be followed by non destructive measurements of the fruit dimensions and the growth curves of each mean were estimated at each measurement step.

The increase in the fresh weight or volume of 'Hayward' fruit over the season was a double sigmoid in shape. The fruit density was less than one in about three months after the fruit set and then increased to more than one unit. Correlation analysis between the data of different stages of measurement with fruit harvesting data showed that with the progress of fruit growth, the correlation between fruit size and its final size increased, and about 55 days after fruit set reached to more than 0.95. The standard deviation of fruit size at this stage was 11.55 cm3. The correlation coefficient above 0.95 between fruit weight and its length with fruit weight and length at harvest time was calculated 72 and 89 days after fruit set, respectively. Fruit size in kiwifruit is affected by various factors and the final size and weight of the fruit is likely to be determined by the rapid fruit growth period. This period that results from cell division and cell size enlargement took about 50-60 days after fruit set for Hayward cultivar when the fruit reaches approximately half of its volume in this period. Applying any stress at the cell division stage will affect the final fruit size. Given the high correlation between the dimensions of the fruit with the final fruit size at the end of the rapid growth period, it is possible to predict the final fruit size at the end of this period with great accuracy. Therefore, using the obtained mathematical equations, the final size of the fruit can be estimated by the measurement of the length and circumference of fruit in one and a half months to two after the fruit set.

Based on the results of this study, with a simple and practical method and with a high and significant correlation coefficient, by measuring the length and circumference of the fruit about one and a half months to two after fruit formation, the final fruit size at harvest can be predicted in order to take the necessary measures to export, sell and/or store the fruit.

Pollination is very important for achieving an economical production in hazelnuts. This study was conducted as a factorial randomized complete block design with three replications. In this study, the effects of three pollinizers (Pashmineh, Gercheh and Shastak) on nut and kernel characteristics of some hazelnut cultivars (Rounde, Fertilede coutard and Gerdeshkvarat) were investigated. The results of the flowering phenology showed that all cultivars were protanderious. The time of the male flowers opening in Ronde and Fertilede coutard was from early January to late January and in Gerd Eshkvarat was from mid-January to late January. The opening time of the female flower was variable from mid-January in Ronde to late February in Fertilede coutard. The results showed that the quantitative traits of nut and kernel were strongly influenced by pollen sources. Using stronger and more viable pollen grains of Gercheh pollinizer, the heaviest nut and kernels, the highest percentage of kernel production, and the lowest percentage of blankness kernels were 3.64, 1.48, 48.69, and 13.94, respectively. However, using Shastak pollen grains, the weight of the nut and kernel was decreased by 2.44 % and 1.22 %, respectively, and the blankness percentage of kernel was increased by 26.48 %. The amount of blankness increased dramatically to 87.51 % in self-pollination and nut and kernel weight significantly reduced to 1.27 and 0.22 g, respectively. In general, pollen grain had effects on some fruit characteristics such as nut and kernel weight, percentage of blankness and kernel production, and pollen grain had no significant effect on nut and kernel shape. The highest overlap of male flowers opening in pollenizer genotypes with female flowers of Rounde, Fertilede coutard, and Gerdeshkvarat was observed in Gercheh.

Understanding of flower induction and its related physiological events are very important in regulating of the kiwifruit fruiting. In this research, kiwifruit flower induction was investigated using defoliation without girdling and with girdling on current shoots, 4-6 months after bud swollen, in eight treatments for two years. Based on the results, the year alone was not statistically significant for measuring traits, but its interaction with the variety and treatment affected significantly some of the measured traits. Defoliation without girdling of female Hayward and male Tomuri cultivars current shoots did not have a significant effect on the percentage of budbreak and percentage of fertile shoots, but the number of flowers per cane and means flower per new shoots of Tomuri cultivar was significantly greater than those of Hayward. The effects of defoliation with girdling treatment on the budbreak percent, fertile shoot percent, the number of flowers per cane and the mean flowers per new shoot were 32.92%, 4.00%, 4.00 and 1.29 flowers for Hayward and 47.08%, 52.5%%, 53.53 and 11.72 flowers for Tomuri respectively. Flower induction in Tomuri cultivar started two weeks earlier than Hayward about five months from bud swelling and peaked in mid-September. Flower induction in the Hayward cultivar began about five and a half months from bud swelling and lasted until the end of it’s when about 88% of the broken buds were fruitful.

Kiwifruit is a dioecious plant species, requiring cross pollination for fruit production. The objective of this study was to evaluate effects of temperature and duration storage on viability of ‘Tomuri’ pollen grains. Collected pollen grains were stored for 1, 2, 3 and 15 days in room temperature; 3, 15, 30, 45 and 60 days in 4°C and 3, 30, 60 and 180 days in -20°C. This research was carried out using completely randomized design with 12 treatments and three replications. Germination percentage and length of pollen tube decreased with increasing temperature and pollen storage period and an inverse relationship between germination percentage and pollen length with storage period was observed. The pollen tube growth was more affected by duration and temperature of the pollen storage compared to germination percentages. At room temperature, the germination percentage of pollen reached zero after 15 days. After one month of pollen storage at 4°C, growth of pollen tubes declined sharply and reached to the lowest levels among treatments. After six months months of pollen storage at -20 °C, percentage of germination was 65% and length of pollen tube was 380 μ. According to the results, the Tomuri pollen grains can be stored for up to three days at room temperature and for a long time at -20 °C after drying.

Kiwifruit is a fast-growing deciduous woody vine that can be propagated in several ways. Nevertheless, seedlings have a strong and widespread system of roots than cuttings. The aim of this study was to find a simple and practical method for farmers to increase the germination percentage of kiwifruit seeds. This study was performed in a completely randomized design with five treatments of Cold Stratification (2, 3, 4, 5, and 6 weeks) at 4 ° C with three replications in the Citrus and Subtropical Fruit Research Center. The results showed that vegetative traits of seedlings such as stem length, seedling length, and number of seedlings with one true leaf were significantly different among stratification treatments. In the tetrazolium test, the average percentage of viable seeds was 72.22%. In non-stratified seeds, no germination was observed until the end of the experimental period, but the chilling stratified seeds showed 16.00 to 39.78% germination in different treatments. The highest germination rate (2.67%), seed germination index (18.96), seed vigor index (1935.52), mean daily germination (1.17 Seed per day), germination value (1.58), and peak value (1.13) were observed in 4 weeks Cold Stratification at 4±0.5 ˚C. Therefore, Hayward kiwifruit seeds need 4 weeks of Cold Stratification at 4±0.5 ˚C to break the dormancy and reach maximum germination.

It is important to understand the structural events associated with flower morphogenesis in horticultural plants, because it has many aspects of practical horticultural significance. Information about different stages of flower initiation and development is important for better management of the vineyardsand fruit set. Knowledge of floral ontogeny in kiwifruit is also important for the establishment of breeding programs and for the understanding of the evolutionary processes involved in the development of the floral organs. The main objective of this study was documentation of the differentiation stages of flower buds for better understanding of morphological and external changes in (Actinidiadeliciosa[A. Chev.] C.F. Liang &A.R. Ferguson var.deliciosa) cvs.Hayward (female) and Tomuri (male).
The experiment was carried out over two years in a mature 'Hayward' and ‘Tomuri’ kiwifruit vineyard at the Citrus and Subtropical Research Center of Iran (Ramsar city). Pistillate and staminate flowers development was followed from the stage of undifferentiated primordia, present in the axils of leaf primordia in dormant buds since mid-March to early June 2015 and 2016. Equally buds in diameter and size from sixth to twentieth buds on one-year old cane of Hayward and Tomuri selected at 5 to 7 days intervals. They were sampled and fixed in a solution of formalin, ethanol 70%, glacial acetic acid (2:5:1 FAA) then stored in refrigerator. Fifteen buds of each sample dissected under a Nikon SMZ645 stereo zoom microscope. The very dense pubescence within the buds was removed manually without damaging the axillary flower primordia. The remaining pubescence was removed using dissecting needles. Various stages of flower differentiation were explained with principal growth stage 5 of BBCH scale.
The first signs of the flower on Tomuri were observed 2 days before bud swelling stage (01), on the March 12th, about one month before bud break in 2015. While in the Hayward variety the first signs of the flower primordia were observed on the March 21th of 2015 (9 days later). At the beginning of bud swelling (01), flower primordia begin to differentiation and at advanced bud swelling stage (03), bracts and sepals initiated. As development proceeded, different parts of flowers initiated acropetally. Lateral flowers were formed in the bud break (07), before initiation of petals. In advanced budburst stage (09) stamen primordia appear almost immediately after petal initiation, as two whorls in 'Hayward' and as three whorls in the Tomuri cultivar. Stigma initiated in the open cluster stage (10) in Hayward cultivar about 24-25 days after bud swell stage. The process of differentiation of buds and reproductive organs in the second year was the same as the first year with the exception that differentiation began earlier than that in the first year. Climatic conditions were affected flower development and in the second year primordia differentiation began earlier two days in Tomuri and six days in Hayward than those in the first year. The advanced budburst stage (09) in Tomuri 9 days and in the Hayward 10 days was occurred earlier than that in the first year. Unlike other tree fruits, flower induction in the kiwifruit occurred about 6 months before flower initiation. Flower primordia differentiation initiated shortly before bud break stage and approximately two months before full bloom. Flower initiation and differentiation time may be partly estimated with external changes of buds development. According to cultivar, chilling and heat requirements and climatic conditions during the research, flower initiation and differentiation period have fluctuation. A reason for the difference between the development stages and different varieties can be caused by the chilling and heat requirements. The more heat requirement, the longer reproductive meristem differentiation period.
An understanding of the flower initiation and development is very important for the research and management of fruit trees. A knowing of flower initiation and differentiation can be developed corrective vineyard management and practices in crisis period and prepared breeding programs. Tomuri initiated and developed their floral organs earlier than those in Hayward. Different external changes in the bud may be partly used to estimate of flower development status. The results showed that flower initiation and differentiation in buds coincided with the beginning of development and elongation of bud in the early of spring.

Kiwifruit as a new commercial crop in comparison with other crops that are grown in the similar climatic conditions has a high economic return. On the other hand, this fruit has better quality in Iran than that in other kiwifruit production countries. Management practices such as pruning, application of growth regulators, fertilizers, pesticides, mechanical natural and hand pollination, flower and fruit thinning, harvest time, etc. rely on the recognition of certain phenological stages. Therefore, the objective of this study was to describe the phonological growth stages of a Hayward kiwifruit cultivar growing under the west of Guilan using the BBCH code and to calculate the heat requirements that help predict the time to reach each phenological stage.
This experiment was conducted in a randomized complete block design with 3 replications of 4 trees. Fruiting branches on each 4 tree (2 on each side) were marked for assessed. Principal and secondary phenological growth stages of development using the BBCH scale for 2 years in the west of Guilan (Astara) on mature vines were determined. Fruit growth curve, with measuring dimensions and equivalent water, TSS changes with hand refrectometer and the effect of temperature changes on TSS and flowering and fruit development were studied. Heat requirements were calculated as GDD.
Eight Principal phenological growth stages on kiwifruit include: stage 0 (bud development), stage 1 (leaf development), stage 3 (shoot development), stage5 (inflorescence emergence), stage 6 (flowering), stage 7 (fruit development), stage 8 (maturity of the fruit) and stage 9 (Senescence, beginning of dormancy) that began with the beginning of bud swelling in the 17th of March and terminated on the 25Th of December. The time of secondary phenological growth stages and some management practices related to each of these stages of BBCH scale also mentioned. Broken of branch buds increased from the base to the top of the shoots, so that all dormant buds were in the base. The percentage of bud break, and the number of fruitful shoots were affected by the year. The curve of fruit growth was double sigmoid and increased fruit soluble solids of fruit was about 3 months later. After dormancy breaking and from beginning of bud swelling, Hayward kiwifruit cultivar required 429.275±10.67 GDD to reach full bloom, 1187.5±65.8 GDD to reach 50% of final fruit size and 2763.58±19.92 GDD before the fruit could be harvested.
Determine of heat requirements is important for predict of the management time, so that the temperature difference between days in different years affected the development stages. The index can be used to predict developmental stages and thus to apply administrative tasks such as flowers thinning, fruit thinning, green pruning, winter pruning, fertigation, pest and disease control and also be used to expecting of physiological fruit maturity.