Effect of exogenous application of free polyamines on physiological disorders and yield of ‘Kaleh-Ghoochi’ pistachio shoots (Pistacia vera L.)

Pistachio trees exhibit some physiological disorders such as abscission of inflorescence buds, fruit abscission, the production of blank, non-split, early-split and deformed nuts. Since the occurrence of these disorders is closely related to the yield, the effect of free polyamine treatments on these disorders and the yield was investigated in two consecutive years (“on” and “off” years). Free polyamine treatments were applied one week before and also two weeks after full bloom. Results showed that Spermine (Spm), unlike Putrescine (Put), decreased the physiological disorders of pistachio and also increased the yield. Free polyamine treatments did not affect the percentage of early-split nuts. Spermidine (Spd) decreased the percentage of both fruit abscission and deformed nuts but did not affect the yield. In both the “on” and “off” years the effect of Spm and Spd was greatly dependent on both the time of application and the concentrations used. Results of free polyamine analysis showed that exogenous application of these compounds, especially two weeks after full bloom, increased the free polyamine contents of shoots in both “on” and “off” years confirming the absorption of free polyamines via spray application in pistachio crop. Exogenous application of Spm two weeks after full bloom decreased the abscission of inflorescence buds in “on” year supporting the idea that free polyamines could trigger the abscission process of inflorescence buds. Since Spm decreased the percentage of blank, non-split and deformed nuts, it seems that Spm dominantly plays a key role in the growth and development of pistachio nuts.     

Effect of harvesting time on nut quality of pistachio (Pistacia vera L.) cultivars

The appropriate time of harvest is one of the most important factors affecting the quality of pistachio. Cultivars ‘Ahmad-Aghaii’, ‘Kaleh-Ghoochi’, ‘Ohadi’ and ‘Badami-Zarand’ were evaluated for qualitative indices of nut over a period of four years from 2001 to 2004. Nut samples were collected during eight successive weeks from 23 August to 11 October. Splitting, early splitting, hull cracking and hulling percentage continually increased toward the last harvest week while non-splitting, immaturity, number of nuts per ounce and moisture content decreased during the harvest weeks. The increment of splitting and the number of nuts per ounce was not significant from 20 September to the last week of harvest. Early splitting, hull cracking and aflatoxin contamination of kernel progressively increased from 13 September. Total crude fat and sugar contents showed a peak in the middle of September. The concentration of aflatoxins prior or at maturity stage of selected cultivars was lower than the critical level. In general, the appropriate time of harvest for the cultivars studied is the middle of September to avoid contamination of nuts to aflatoxin and to ensure the nut quality. This study emphasizes different quality indices for determining the optimum harvest time of pistachio crop.     

Water relations of pistachio (Pistacia vera L.) as affected by phenological stages and water regimes

Pistachio is a drought tolerant fruit tree that can be cultivated in rainfed and irrigated conditions. The water requirements of the tree, however, are considerable so in most of the commercial orchards deficit irrigation is a common practice. Regulated deficit irrigation in pistachio trees has been described in several works, which reported that the phenological stage of shell hardening, so called stage II, is the most drought tolerant. This paper proposes that such drought resistance is related to changes in water relations linked to the phenological stages, even in conditions of no water stress. In order to evaluate such changes, the daily pattern of stem water potential and gas exchange (net photosynthesis, P_n, and leaf conductance, g_s) was measured, determining also the pressure–volume curves, in three different phenological stages of mature pistachio trees (Pistacia vera cv Kerman on P. terebinthus L. rootstock.). The daily pattern of stem water potential and gas exchange were performed in three different irrigation treatments: control, regulated deficit irrigation and rainfed. The pressure–volume curves were made only in the control and rainfed treatments. Significant differences were found in the daily pattern of stem water potential in all the phenological stages considered, while only in the last one the net photosynthesis was affected by water stress. The daily pattern of gas exchange at the beginning of the season was not affected by the evaporative demand, with a constant value when radiation was not limiting. Moderate levels of water stress during the last measurement date reduced the maximum values of g_s and P_n resulting also in a clear change in the pattern of the daily curve, with maximum values only at the beginning of the day. The relationships between stem water potential and gas exchange parameters were different during stage II and almost the same in stages I and III. The parameters drawn from the pressure–volume curves also indicated a change in the elastic modulus of the leaf cells in stage II. In addition, differences in the osmotic adjustment (OA) index suggested different degree of osmotic adjustment of the phenological stages in the response to water stress. The results showed that different mechanisms of drought resistance are operating in the different phenological stages in pistachio trees.     

Direct plant regeneration from mature leaf explants of pistachio, Pistacia vera L.

A protocol was developed for direct shoot and plantlet regeneration from in vitro regenerated leaf explants of male Pistacia vera L. cv. ‘Atl?’. Leaves excised from axenic shoot cultures of pistachio were used to induce organogenesis on a Murashige and Skoog (MS) medium with Gamborg vitamins supplemented with combinations of different concentrations of BAP and IAA. The highest adventitious shoot regeneration in 35% of the explants, with the number of shoots ranging from 2 to 3 per explant, occurred in the explants cultured during the establishment phase in the medium with 1 mg l⁻¹ IAA and 2 mg l⁻¹ BAP. For shoot multiplication, the highest number of new microshoot/explants (5.76) was obtained in a culture medium supplemented with 1 mg l⁻¹ BAP, but it was not significantly different from the number obtained at 2 mg l⁻¹ BAP. A high rooting frequency (84%) for microshoots was recorded on a medium supplemented with 2 mg l⁻¹ IBA. In vitro rooted plantlets were transferred to pots filled with a mixture of soil, sand and peat (1:1:1). They were weaned in a growth room and finally moved to a greenhouse. This protocol could be utilized for in vitro clonal propagation of this economically important plant.     

Rootstock influences the response of pistachio (Pistacia vera L. cv. Kerman) to water stress and rehydration

Pistachio cultivation requires the use of rootstock because grafting is the only form of vegetative propagation. The main commercial rootstocks are Pistacia integerrima L., Pistacia atlantica Desf., Pistacia terebinthus L. and Pistacia vera L. Pistachio is considered to be a drought and saline-resistant crop; however, there is little information describing varietal responses of rootstocks to water stress. Some studies have suggested that P. terebinthus L. is the most drought and cold resistant rootstock. The effect of the rootstock on the water relations of the grafted plant is crucial for improving crop performance under water stress conditions and for developing the best irrigation strategy. This work studied the physiological response to water stress of pistachio plants (P. vera L. cv. Kerman) grafted onto three different rootstocks P. terebinthus L., P. atlantica Desf. and a hybrid from crossbreeding P. atlantica Desf. × P. vera L. Plant physiological responses were evaluated during a cycle of drought and subsequent recovery in potted plants. Parameters measured were soil moisture, trunk diameter, leaf area, leaf number, leaf and stem dry weight, stem water potential, leaf stomatal conductance. The results showed different responses of cv. Kerman depending on the rootstock onto which it had been grafted. The hybrid rootstock was associated with a higher degree of stomatal control and reduced leaf senescence compared to P. atlantica and P. terebinthus, despite being associated with the most vigorous shoot growth. P. terebinthus enabled very effective stomatal control but was also associated with the most rapid leaf senescence. P. atlantica was associated with less vigorous shoot growth and similar levels of water stress as occurred with the others rootstocks under conditions of high evaporative demand, which was associated with lower stomatal control. The selection of the most effective rootstock choice for different environmental conditions is discussed.     

Growth,yield and fruit quality of ‘Marisol’ clementine grown on four rootstocks in Egypt

To evaluate the most appropriate rootstocks for mandarin production in Egypt, vegetative growth, yield and fruit quality of ‘Marisol’ clementine (as newly introduced cultivar in Egypt) grafted on Sour orange (the common rootstock), Cleopatra mandarin, Carrizo citrange and ‘Swingle’ citrumelo were evaluated under the Egyptian conditions during 2004/2005 and 2005/2006 seasons. Trees were grown in a private farm at ‘Wady El-Mullak’ region, Ismailia Governorate (Latitude, 30°36′ N; longitude, 32°14′ E; Altitude, 10 m above sea level).     

Timing of fruit removal affects concurrent vegetative growth and subsequent return bloom and yield in olive (Olea europaea L.)

Olive (Olea europaea) demonstrates a high tendency toward alternate fruit production, with significant negative consequences on the industry. Fruit load is one of the main cause-and-effect factors in the phenomenon of biennial bearing, often disrupting the balance between reproductive and vegetative processes. The objectives of the present study were to identify the time range during which heavy fruit load reversibly interrupts the reproductive processes of the following year. The linkage between timing of fruit removal, vegetative growth, return bloom, and fruit yield was studied. Complete fruit removal in cv. Coratina until about 120 days after full bloom (August 15) caused an immediate resumption of vegetative growth. The new shoots grew to twice the length of those on trees that underwent later fruit removal. Moreover, a full return bloom, corresponding with high subsequent yields, was obtained by early fruit removal, while poor or no bloom developed on late-defruited or control trees. Thus, the critical time to affect flowering and subsequent fruiting in the following year by fruit thinning occurs in olive trees even weeks after pit hardening—much later than previously suggested. Furthermore, the data indicate that flowering-site limitation, due to insufficient or immature vegetative growth during the On-year, is a primary factor inducing alternate bearing in olive.     

Physical,compositional and sensory differences in nuts among pistachio (Pistachia vera L.) varieties

Differences in some physical, compositional and sensory characteristics among eight varieties of pistachio nuts (Aegina, Pontikis, Bronte, Cerasola, Joley, Kerman, Mumtaz and Sirora) from different origins were studied. The evaluated varieties were cultivated under the same field conditions and the dried nuts were utilised. The percentage of split nuts ranged from 93.8% (Sirora) to 80.2% (Aegina), the 10-nut weight from 15.23 g (Kerman) to 9.7 g (Cerasola), the kernel/nut percentage from 57.24% (w/w) (Pontikis) to 47.08% (w/w) (Kerman) and the ratio of length/width of nut from 1.81 (Aegina and Joley) to 1.56 (Mumtaz). Colour measurements showed the highest shell L* (80.26) for Kerman, the lowest shell h° (81.19) for Mumtaz, the lowest kernel membrane h° (24.43) for Cerasola, and the highest h° (107.23) on the inner kernel of Aegina. Crude protein content varied between 21.87 (Cerasola) and 18.99% d.w. (Joley), and the fat between 57.62 (Joley) and 49.79% d.w. (Cerasola). Among the major fatty acids in kernel oil, oleic ranged from 67.86% in Cerasola to 51.6% in Kerman, linoleic from 27.03% in Kerman to 11.56% in Pontikis and palmitic from 10.24% in Kerman to 8.54% in Cerasola. Linolenic acid was highest in Kerman (0.5%). Myristic, palmitoleic, stearic, vaccenic, arachidic and gondoic acids were also found in all samples. Negative and significant linear correlations were found between oleic and linoleic, and between mono- and poly-unsaturated fatty acids. Most of the physical and compositional characteristics measured were affected significantly by variety. Panelists preferred nuts of big size with a naturally yellowish shell colour. Visual differences in kernels were not significant, whereas Kerman, Sirora and Cerasola gained the panelists’ overall flavour preference among the varieties evaluated.     

Potential of ethephon,NAA, NAD and urea for thinning pistachio fruitlets

Alternate bearing, the occurrence of high yield ‘on’ year followed by low yield ‘off’ year, is striking in pistachio (Pistacia vera L.). Floral buds of pistachio are formed a year before bloom, but abscise during the years with heavy crop (‘on’ year). Abscission of floral buds is due to competition between growing seeds on 1-year-old shoots and developing buds on current season growth. We studied the effects of chemical fruit thinning on alternate bearing and nut characteristics in a commercial orchard of ‘Owhadi’ pistachio cultivar during 2003–2004 in Rafsanjan, Iran. In both years, ethephon (100 and 200 mg l⁻¹), naphthaleneacetic acid (NAA) (125 and 250 mg l⁻¹) and urea (2.5 and 5%) were applied to the branch units of each individual ‘on’-year trees. The results showed that ethephon at both concentrations significantly increased fruit thinning and floral bud retention for the subsequent year. Other treatments also increased fruit thinning and floral bud retention but were inferior to ethephon.     

In vitro embryo germination and proliferation of pistachio (Pistacia vera L.)

In vitro development of isolated embryos and axillary bud proliferation were studied in Pistacia vera L. Different regulator-free nutrient media were compared to determine the effects of the mineral solution, agar and sucrose concentrations on seedling development from mature embryos. Nutrient-rich MS [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tabacco tissue cultures. Physiol. Plant. 15, 473–479] and DKW [Driver, J.A., Kuniyuki, A.M., 1984. In vitro propagation of Paradox walnut rootstock. HortScience 19, 507–509] mineral solutions were more efficient for the development of aerial parts than nutrient-poor KN [Knop, W., 1884. Bereitung einer concentrierten nährstofflosung für pflanzen. Landwersuhssat 30, 292–294] and WT [Withe, P.R., 1936. Plant tissue cultures. Bot. Rev. 2, 419–437] solutions. Reducing the agar concentration enhanced fresh matter production and balanced seedling development. When tested at different concentrations, sucrose was found to orient mature embryo development, with the best results obtained at concentrations of 2–4%, whereas high concentrations (6 and 12%) mainly inhibited elongation of the aerial parts. Plantlets obtained previously from in vitro cultured embryos were propagated by axillary budding. High bud proliferation (six shoots per explant) was achieved when using 17.8 μM benzyladenine (BA) combined with 0.5 μM indole-3-butyric acid (IBA). The addition of 2.9 μM gibberellic acid (GA₃) to the propagation medium did not improve axillary shoot yields and on average, media with GA₃ produced 2.3–2.6 elongated stems per cultured explant. Shoots were rooted in vitro in half-strength MS medium containing 12.3 μM IBA.     

Total phenolics and flavonoids and total antioxidant capacity in pistachio (Pistachia vera L.) nuts in relation to cultivars and storage conditions

The effects of cultivar, drying and storage conditions on total phenolics (TP), total flavonoids (TF) and total antioxidant capacity (TAC), measured with ferric reducing antioxidant power (FRAP) and radical scavenging capacity (2,2-diphenyl-1-picrylhydrazyl or DPPH) assays, of in-shell and unpeeled kernels of ripe pistachios were investigated. Drying was carried out at 45 °C for 34 h to approximately 5% moisture in kernels and storage of dried nuts in packaging atmosphere of dry air or N₂ at 1 °C or 20 °C for 6 or 12 months. At harvest, each cultivar showed its highest values for each measured variable and TP ranged from 16.2 to 7.9 mg gallic acid equiv. g⁻¹ d.w., TF from 7.2 to 3 mg catechin equiv. g⁻¹ d.w., FRAP from 132.5 to 58.8 μmol Trolox equiv. g⁻¹ d.w., and DPPH from 122.6 to 45.7 μmol Trolox equiv. g⁻¹ d.w. Drying resulted in losses in all cultivars that averaged approximately 14.2%, 14.1%, 11.9% and 12.2% for TP, TF, FRAP and DPPH, respectively, while during 12-month storage the corresponding losses in dried kernels averaged approximately 24.7%, 21.8%, 30.3% and 32.4%. Decreases in all measured variables were advanced by storage time, but prevented by low temperature and packaging in N₂ atmosphere. Among the studied cultivars, Pontikis, Aegina, Bronte and Cerasola showed higher values of TP, TF and TAC than Sirora, Kerman, Joley and Mumtaz in all cases, while Pontikis the highest in most cases. The effects of cultivar, time, temperature and packaging atmosphere during storage were all significant on TP, TF, FRAP and DPPH. Strong correlations were also found among the measured variables.     

Performance of ‘Coscia’ pear (Pyrus communis) on nine rootstocks in the north of Israel

The vegetative and reproductive performances of ‘Coscia’ pear (Pyrus communis L.) grown on nine rootstocks [OHF 69, OHF 97, OHF 217, OHF 333, OHF 513 and BP 1 (P. communis), clonal seedling (Davis AxB) of Pyrus betulifolia and quince BA 29 and EMA (Cydonia oblonga)] were compared during a 9-year period. The trial was conducted at the Experimental Station ‘Avnei Eitan’ in northern Israel (elevation 400 m above sea level, a.s.l.), on a well-drained soil with pH 7.1. Trees were planted in December 1998, spaced at 4.0 m × 2.0 m and trained with a central axis. The most vigorous trees were on P. betulifolia seedlings, followed by the four OHF rootstock (69, 97, 333, 513) and BP 1 (with no significant difference between them). All the above rootstocks demonstrated greater vigor than OHF 217 and quince BA 29 or EMA. The highest cumulative yields per tree were harvested from trees on the four OHF rootstocks (69, 97, 333, 513) and P. betulifolia followed by the BP 1. The two quince rootstocks, as well as OHF 217, had the lowest cumulative yield and the lowest yield of large fruit. A positive correlation was found between the vigor of the tree, as affected by the rootstock, and both the total yield and the fruit size. We conclude that in a warm climate, yield efficiency is not the only parameter that should be taken into account, and building a strong tree for a weak cultivar is the first requirement for establishing an orchard.     

The effect of predetermined deficit irrigation on the performance of cv. Muhasan olives (Oleaeuropaea L.) in the eastern coastal plain of Israel

The response of cv. Muhasan trees and its fruit characteristics to a 50% regulated deficit irrigation (RDI) was studied. The general response to the reduced irrigation was relatively small. However, the schedule of water application was very significant for various fruit characteristics. In the best schedule the 50% reduction in annual irrigation water reduced the oil yield over 4 years by only 12.2% and that of the fruit yield by 18.5%. The most efficient schedule was based on applying all the irrigation water after stone hardening. In lighter soils however, with lower water holding capacity or in regions with a lower rainfall diverting some of the water to the pre-bloom and fruit set period might be needed. The fruit mesocarp/endocarp (flesh/pit) ratio was dependent on the water availability during the stone hardening period. This ratio was significantly improved when water availability during the stone hardening period was reduced. The rate of oil accumulation was also affected by the irrigation schedule but was about the same in ‘on’ and ‘off’ years. Fruit growth was less affected by the irrigation schedule but most significantly by the yield load. All the affects of the irrigation schedules were more expressed in the ‘on’ years than in the ‘off’ years. No clear cut differences or consistent effects of the irrigation schedule were found on the degree of alternant bearing and mineral content of the leaves.     

Rhizobacteria as bioenhancer and biofertilizer for growth and yield of banana (Musa spp. cv. ‘Berangan’)

Banana, an important fruit crop, requires high amounts of fertilizers for commercial cultivation, which is costly and can be hazardous to the environment when used excessively. Inoculations of plant growth promoting rhizobacteria (PGPR) have been shown to produce beneficial effects through growth stimulation in legumes and cereals, and an attempt has been made to use rhizobacteria in bananas. Three experiments were conducted to observe the effects of plant growth promoting rhizobacteria (PGPR) inoculation on root stimulation and colonization, nutrient absorption, growth and yield of bananas (Musa spp. cv. ‘Berangan’, AA type). The results showed that inoculation together with 33% N improved the bioenhancing activity by increasing root and shoot growth, and photosynthetic rate. The PGPR inoculation with 33% N-fertilizer also increased the Ca uptake capacity resulting in higher Ca concentration in root, corm and pulp but increased the Mg concentration in the root only. In addition, the total accumulation of nutrients was heavily influenced by PGPR inoculation due to enhanced root proliferation. The PGPR inoculation greatly increased the bunch yield (35–51%). The strains Sp7 and UPMB10 were evaluated for their N₂ fixing capacities in association with banana roots by ¹⁵N isotopic dilution technique and acetylene reduction assay (ARA). The results conclusively showed that roots of PGPR-inoculated plants fixed N₂ and produced higher ARA values and inoculated plants together with the least N-fertilizer supply showed the highest amount of nitrogen derived from atmosphere (Ndfa). The findings from the above studies demonstrated that PGPR strains (Sp7 and UPMB 10) inoculation with minimal N-fertilizer supply are effective as a bioenhancer for increasing plant growth, nutrient uptake and yield of bananas.     

Evaluation of ‘Tonda di Giffoni’ hazelnut (Corylus avellana L.) clones

‘Tonda di Giffoni’ is among the most highly appreciated Italian hazelnut (Corylus avellana L.) cultivars. Due to its round kernels and excellent processing quality, it was awarded a Protected Geographical Indication (PGI) from the European Union. To identify clones expressing improved nut and production qualities, a ‘Tonda di Giffoni’ clonal selection programme was conducted across hazelnut orchards in the Irno valley of Italy from 1995 to 2006. One hundred different clones were selected and propagated in a replicated trial under similar climate, soil, and cultural conditions. From this work, the 29 best clones were identified and from 2006 to 2008 their agronomic and pomological characteristics were observed. Microsatellite or simple sequence repeat (SSR) markers were used to successfully confirm true-to-type identity of the clones. Traits evaluated included flowering time (anthesis), bud break, suckering, trunk diameter, nut and kernel characteristics and productivity (yield). Best linear unbiased predictions for clone means and estimates of intraclass correlation coefficient were obtained using R environment, lme4 and ggplot2 packages. Five clones superior to that of the standard of ‘Tonda di Giffoni’ were identified in this study. Furthermore, yield and number of suckers produced showed sufficient variability to likely be exploited for breeding. The selected clones express features useful for both growers and the processing industry and will be propagated and planted in hazelnut orchards for further study and commercial production.     

Water spray as a potential thinning agent for date palm flowers (Phoenix dactylifera L.) c.v. ‘Lulu’

Flower or fruit thinning is a critical cultural practice in the date palm production chain that affects fruit development, quality and yield and regulates tree yearly bearing. Development of a save and economic thinning agent for date palm is critically required especially under harsh conditions. During 2004 and 2005 seasons, water spray for 3 min was applied at different times following mechanical pollination on ‘Lulu’ date palm cultivar growing under Al-Ain oasis conditions. The results showed that water spray following pollination generally decreased fruit set percentage to different extent depending of the time of application. In this respect, the most effective treatment was water spray after 4 h following pollination. This treatment significantly decreased fruit set percentage (48%) compared to the control (79%), as the mean of both seasons. However, the other treatments including water spray 1 h before pollination also decreased fruit set percentage but to a lesser extent. Fruit quality characteristics especially fruit and flesh weight, length and diameter were significantly increased by water spray treatments during the 2004 season, in contrast to the 2005 season. Thinning with water significantly decreased both bunch weight and total yield per tree at the Tamr stage especially when applied after 4 h following pollination. To the best of our knowledge, this is a pioneer study investigating the role of water as a potential thinning agent for date palm flowers. The use of water spray as a save and economic thinner needs, however, more research work to justify the time following pollination and duration of application which may vary upon cultivar, method of pollination and district.     

Effect of synthetic auxins on fruit development of ‘Bing’ cherry (Prunus avium L.)

The main cherry cultivar grown in the warm climate of Israel, ‘Bing’, produces relatively small fruit. Over three consecutive years (2003–2005), application of 50 mg l⁻¹ 2,4-dichlorophenoxypropionic acid [2,4-DP; as its butoxyethyl ester (Power™)], 10 mg l⁻¹ 3,5,6-trichloro-2-pyridyloxyacetic acid [3,5,6-TPA; as the free acid (Maxim^®)], or 25 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) plus 30 mg l⁻¹ naphthaleneacetic acid (NAA; 0.3% Amigo™), at the beginning of pit-hardening when fruitlet diameter was ca. 13 mm caused appreciable and significant increases in fruit size and total yield, except when the crop load was heavy. Anatomical studies revealed that the main effect of these synthetic auxins was via direct stimulation of fruit cell enlargement. The above auxins had no negative effect on fruit quality, either at harvest or after 1 month of storage at 0 °C, or on return yield in the following year.     

Nutrient deficiency disorders in Pistacia vera seedling rootstock in relation to eco-physiological,biochemical characteristics and uptake pattern of nutrients

This study examines the effects of nitrogen (N), iron (Fe), magnesium (Mg), manganese (Mn) and molybdenum (Mo) deficiencies on the eco-physiological, biochemical and growth characteristics of pistachio seedlings (Pistacia vera) in sand culture situation. This experiment, which was carried out in Iran's Pistachio Research Institute (IPRI), seedlings of ‘Badami-e-Zarand’ were used as common rootstock. The following treatments were employed: (1) complete Hoagland's nutrient solution; nutrient solution lacking either: (2) N, (3) Fe, (4) Mg, (5) Mn, (6) Mo, (7) distilled water without Hoagland's solution (Control), (8) Fe–N, (9) Fe–Mn and (10) Fe–Mo. The main deficiency symptoms observed after 7 months of planting were; leaf discoloration, necrosis, scorching, defoliation and stunted growth. Seedlings that received complete nutrient solution were healthy with dark green foliage. Visual symptoms of N-deficient seedlings also coincided with the reduction in foliar levels of the concerned element. Shoot and root growth of the seedlings deficient in nutrients were also affected. Changes in shoot and root biomasses production due to treatments were statistically significant at 1% level. A reduction in height, leaf area and leaf number was noticed for various levels of nutrient element deficiencies. Analysis of some biochemical indices (chlorophyll content) and eco-physiological indices such as primary florescence chlorophyll (Fo), ratio of variable chlorophyll to maximum (Fv/Fm), leaf temperature, transpiration, stomata conduction and resistance of stomata, showed that fractions of chlorophyll, transpiration, stomata conduction and resistant of stomata in treated seedlings, particularly N-deficient seedlings, declined significantly. Chlorophyll (Fo) and ratio of variable chlorophyll to maximum (Fv/Fm) were significant at 5% level. The effects of Fe, Mn, Mg and Mo on dry matter production were statistically significant at 1% level. Synergic effects of certain elements were also evident in the present study. The typical symptoms of deficiencies of various nutrient elements can be used as a guideline for diagnosing nutrient deficiencies of pistachio in commercial nurseries and plantations. The present study also showed multi-deficiency of nutrients, produces new symptom in leaves, which differs from single deficiencies.     

A strain of Bacillus subtilis stimulates sunflower growth (Helianthus annuus L.) temporarily

Preliminary studies showed that a Bacillus subtilis strain stimulates plant growth. We investigated how inoculating seeds of a sunflower cultivar (Helianthus annuus L.) with this strain stimulated plant growth, soil properties and emissions of greenhouse gasses, i.e. carbon dioxide (CO₂) and nitrous oxide (N₂O), when cultivated in a greenhouse. Unfertilized sunflowers or fertilized with urea served as controls. After one month, root length and fresh and dry root weight of the sunflower was significantly higher in the bacteria amended plant than in the urea and unfertilized plants. However, at harvest, no positive effect was observed. The number of seeds per plant and seed weight was not significantly different between the treatments, but total plant N was significantly higher in urea-amended plants than in unfertilized plants. The CO₂ production rate was not affected by treatment, but the N₂O emission rate was significantly higher in soil amended with urea plus bacteria soil compared to the unfertilized treatments. It was found that the B. subtilis strain used in this study had a positive, but only temporarily effect on growth of the sunflower cultivar used.     

不同砧木对黄瓜产量、品质及南方根结线虫防治效果的影响

以7个南瓜砧木为试材,研究了砧木嫁接对黄瓜产量、品质和南方根结线虫防治效果的影响。结果表明：采用南瓜砧木嫁接,黄瓜春季增产4.1%～10.7%,秋季增产15.0%～104.2%,其中新动力嫁接的黄瓜产量最高,其次是黄砧3号。砧木嫁接对黄瓜果实中的可溶性蛋白含量没有显著影响|不同砧木品种和不同接穗品种嫁接黄瓜果实中可溶性糖、VC和硝酸盐含量比自根黄瓜有的增加,有的减少。砧木嫁接对黄瓜南方根结线虫具有较好的防治效果,春季为67.8%～79.7%,秋季12.7%～44.7%。综合来看,采用南瓜砧木新动力和黄砧3号嫁接的黄瓜,其产量较高,品质较好,对南方根结线虫的防治效果较好。