abbas mirsoleimani

It is believed that wood vinegar (WV) can improve soil nutrient availability and uptake, thereby improving plant growth and development. In this study we investigate the effect of WV on the availability of macro- and micro elements in the soil and the uptake, translocation and efficiency of these elements in seedlings of sour orange (SO) and Mexican lime (ML) as well as on plant growth.

The applied WV (1 and 2%) (v/v) was added to the irrigation water at intervals of 3, 6, 9 and 12 weeks after planting.

The results showed that the use of WV at both concentrations reduced the phosphorous (P) and potassium (K) concentration in the leaves of ML, reduced the percentage of calcium (Ca) uptake and efficiency of copper (Cu) in SO and increased the iron (Fe) in ML root (1150 to 1320 mg kg-1 DW). Although 1% WV increased soil availability of Ca, sodium (Na), zinc (Zn) and manganese (Mn) and thus decreased root K/Na and Ca/Na, WV 2% improved Mn and K availability but decreased Ca in the soil solution. Application of 1 and 2% WV reduced root dry weight by 16.1 and 12.9% in SO seedling, respectively and in ML seedlings 2% WV reduced total chlorophyll and leaf greenness.

Research limitations: 

No limitations were found.

Originality/Value:

 The results showed that although the addition of WV to the soil can reduce the pH and thereby increase the availability of some elements such as K and Mn, the increase in EC prevents the effective absorption and translocation of elements and thus plant growth such as root dry weight and greenness.

In order to investigate the effect of palm leaf biochar on some characteristics of Cucumis melo L. under drought stress, a split plot experiment was conducted in a completely randomized block design with three replications for two consecutive years. The main plot was irrigation level (60, 85, and 100% water requirement) and subplot was biochar in four levels (0, 0.18, 0.24, and 0.36 kg/m2). Results showed that treatment of 0.24 kg/m2 biochar and 100% water requirement increased the characteristics of  shoot fresh weight as 77%, shoot dry weight as 32%, root fresh weight as 100%, root dry weight as 84%, root length as 54%, and average fruit weight 84%, water use efficiency as 88%, compared to treatment without biochar and 60% water requirement.  The biocharfree treatment with 60% water requirement accounted for the highest amount of proline due to high stress, and the proline content reduced with increasing biochar and decreasing stress in treatments. The highest level of leaf N, Mn and K, shoot length, leaf area, leaf number, fruit diameter and fruit flesh thickness in the treatment of 0.36 kg/m2 biochar and 100% water requirement were higher 58%, 48%, 65%, 18%, 50%, 95%, 43% and 55%, than to of treatment without biochar and 60% water requirement respectively and had no significant difference with the treatment of 0.24 kg/m2 biochar and 85% water requirement. The highest rates of Fe, Zn and Cu were related to 0.36 kg/m2 biochar and 60% water requirement as 60, 44 and 66% respectively compared to treatment without biochar and 100% water requirement. Generally, the treatments of 0.24 and 0.36 kg/m2 of biochar increased most of the characteristics, however no significant difference was observed between these treatments. Moreover, in 85% water requirement the drought stress conditions could compensate with the application of biochar. Thus, using 0.24 kg/m2 of biochar and 85% of water requirement, recommended for the best result.

Yaghooti is the earliest-maturing grape cultivar in Iran that is mostly grow in warm regions. In these regions berries do not have complete pigmentation and uniform color and this reduces marketability of fruits. The aim of this study was to investigate the effects of Ethephon (150 and 300 mgl-1), Ethanol (5 and 10%), Brassinosteroid (0.5 and 1 mgl-1) and defoliation (5 to 6 leaves around the clusters) on pigmentation and some quantitative and qualitative characteristics of Yaghooti Siyah grape berries. The experiment was carried out in a randomized complete block design with four replications and a 7-years-old vine in each replication during two consecutive years and two regions (Jannatshahr and Fasarood) of Darad. Based on the results, treatments had no effect on the chemical properties of fruit juices such as TSS, TA and TSS/TA. Although ethephon (300 mgl-1) significantly increased cluster weight compared to the control, other physical properties of berries and clusters were not affected by treatments. Treatments had not also effect on the color indicators such as CIRG, chroma, and Hunter components (L *, a * and b *). Anthocyanin and total phenolics concentration and antioxidant activity of fruit juice were not significantly different from those of the control. The results of the present study showed that the use of ethephon, ethanol and brassinosteroid in conventional concentrations can not improve the quantitative and qualitative properties and improvement of berries color, and it seems that in areas like Darab, high temperature during berry ripening and coloration period can be an important factor in color development and ripening process of fruit in Yaghooti Siyah grape.

In order to investigate the seasonal changes and the possible role of the free polyamines in the leaves and stems on the alternate bearing habit of the ‘Kinnow’ mandarin (Citrus reticulata Blanco) trees, a comparative study was conducted to analyze the levels of free polyamines (putrescine, spermidine and spermine) in the leaves and stems tissues of “on” and “off” trees during the flower bud formation period. Samples were taken from trees in one month interval period in a commercial orchard in the City of Darab, Fars Province from Nov. 2010 till Mar. 2011 according to the stages of flower bud phenology in citrus. The experiments were designed as a randomized complete block with three replications and two trees per each replication. The experiments were designed as a randomized complete block with three replications and two trees per each replication. Total polyamines (putrescine, spermidine and spermine) levels in leaves were higher in “off” trees than in “on” trees throughout the experimental period but only the differences of spermine contents were significant during the most of season. The contents of spermidine and spermine in the stems of “off” trees were significantly higher than in “on” trees most of the season. Putrescine levels and polyamine ratio (putrescine/spermidine늗ꮚ⧞) in the stems were significantly higher in “on” trees than in “off” ones. Time of sampling had no significant effect on the stem total polyamines, putrescine and polyamine ratio in “off” trees. Results could not show a relationship between polyamine fluctuations in stems and leaves with processes of flower bud formation in mandarin trees.

The relationships between rooting potential with endogenous phenolic compounds, nitrogen and soluble carbohydrates of cuttings for five olive cultivars (‘Rowghani’, ‘Dusti’, ‘Tokhmekabki’, ‘Konservalia’ and ‘Amigdalolia’) were investigated. Extracts of the leaves and the base of the cuttings were used for analysis of biochemical compounds. Results showed that there were significant differences in rooting potential among olive cultivars. There was no correlation between leaves and stems nitrogen contents and rooting ability of the cuttings. Moreover, leaf and stem soluble sugars, leaf total phenolics, stem caffeic acid, narengin and chlorogenic acid contents of the leaf and stem, did not affect the rooting potential of the cuttings. However, leaf catechin, stem total phenolics and vanillic acid had positive effects on rooting potential of the cuttings. There was a negative correlation between rooting percentage of the cuttings and leaf gallic acid and narengine contents.

Several fruit trees including some cultivars of citrus tend to develop irregular bearing. Fruit thinning has been used for hundreds of years to manipulate blooming and crop load to improve the alternate bearing process. Frequently, combination sprays of two or more chemical thinners are used in various fruit trees and the thinning responses were additive and more effective than individual compounds. In this study, we investigated the effects of Naphthalene acetic acid and carbaryl alone and in combination in thinning of ‘Kinnow’ mandarin (Citrus reticulata Blanco) trees. Some characteristics such as fruit weight, diameter and volume, total soluble solid (TSS), titrable acidity (TA), TSS/TA, vitamin C and peel thickness were measured prior to harvest for 2010 and 2011 as a complete randomized block design with 13 treatments and four replications. Results showed that the application of NAA and carbaryl alone in June drop stage of fruit growth increased fruit thinning percentage, TSS of fruit juice, fruit weight, volume, diameter and length. These chemical thinners improved fruit size significantly by increasing the leaf/fruit ratio. Combination sprays could not effectively thin fruits than individual chemicals and thus had no effect on fruit size. Fruit characteristics such as TA, ascorbic acid, TSS/TA ratio and peel thickness were not affected by our treatments.