Growth Of Fruit Trees Research Articles

Genome-wide identification of vegetative phase transition-associated microRNAs and target predictions using degradome sequencing in Malus hupehensis.

BackgroundA long juvenile period between germination and flowering is a common characteristic among fruit trees, including Malus hupehensis (Pamp.) Rehd., which is an apple rootstock widely used in China. microRNAs (miRNAs) play an important role in the regulation of phase transition and reproductive growth processes.ResultsM. hupehensis RNA libraries, one adult and one juvenile phase, were constructed using tree leaves and underwent high-throughput sequencing. We identified 42 known miRNA families and 172 novel miRNAs. We also identified 127 targets for 25 known miRNA families and 168 targets for 35 unique novel miRNAs using degradome sequencing. The identified miRNA targets were categorized into 58 biological processes, and the 123 targets of known miRNAs were associated with phase transition processes. The KEGG analysis revealed that these targets were involved in starch and sucrose metabolism, and plant hormone signal transduction. Expression profiling of miRNAs and their targets indicated multiple regulatory functions in the phase transition. The higher expression level of mdm-miR156 and lower expression level of mdm-miR172 in the juvenile phase leaves implied that these two small miRNAs regulated the phase transition. mdm-miR160 and miRNA393, which regulate genes involved in auxin signal transduction, could also be involved in controlling this process. The identification of known and novel miRNAs and their targets provides new information on this regulatory process in M. hupehensis, which will contribute to the understanding of miRNA functions during growth, phase transition and reproduction in woody fruit trees.ConclusionsThe combination of sRNA and degradome sequencing can be used to better illustrate the profiling of hormone-regulated miRNAs and miRNA targets involving complex regulatory networks, which will contribute to the understanding of miRNA functions during growth, phase transition and reproductive growth in perennial woody fruit trees.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-1125) contains supplementary material, which is available to authorized users.

Desenvolvimento inicial de maracujazeiros (Passiflora edulis f. flavicarpa, P. edulis f. edulis e P. alata) enxertados sobre Passiflora cincinnata

The present work aimed to evaluate the initial growth and leaf mineral levels in passion fruit trees ( Passiflora edulis f. flavicarpa Deg., P. edulis f. edulis Sims. and P. alata Dryander) grafted onto Passiflora cincinnata . To obtain seedlings, seeds were sown in plastic bags (500 mL) and hypocotyl grafting was performed when seedlings reached the stage of two fully expanded leaves. Fifteen days after grafting, plants were transplanted to 10L pots filled with previously limed and fertilized soil. Each pot contained two plants and corresponded to one plot. For each commercial species studied as rootstock, experimental design was completely randomized, in 3x5 (plant type x time of harvest) factorial arrangement, with four replicates of two plants per plot and five destructive harvests. Plant types were ungrafted P. cincinnata , ungrafted commercial passion fruit tree and commercial passion fruit tree grafted onto P. cincinnata . The first harvest was performed at 15 days after transplanting and the remaining ones at 14-day intervals (60, 74, 88, 102 and 116 DAS). At each harvest, the number of leaves per plant was counted, and leaf area, stem length, and stem, root, leaf and total dry matter were estimated. At the last harvest, the mineral composition (macro and micronutrients) of plants was analyzed. In general, it was observed that grafting onto P. cincinnata did not interfere negatively with the initial development and mineral levels of commercial passion fruit trees, and this interference varied according to the used canopy.

Intelligent data acquisition and cloud services for apple orchard

An intelligent data acquisition and service system for orchard was developed for acquiring apple tree growth information in time and managing orchard production remotely. The data of fruit tree growth environment were collected by PDA (Portable Digital Assistant) through the ZigBee WSN (wireless sensors network) deployed in the apple orchard. The collected data were packaged and uploaded following the transportation protocol through the web service interface provided by the orchard server. After that the orchard data were parsed and stored using distributed mechanism. Finally, the data could be processed, analyzed and visualized by the cloud orchard server, and the orchard production decisions based on WebGIS technology could be made as well. Hence the users could access the services provided by the network platform via remote movable or fixed terminals. The system test run showed that the whole process was stable and reliable, during which intelligent data collection, storage, and cloud data processing and services were achieved. Keywords: orchard, PDA, WSN, WebGIS, distributed storage, web service DOI: 10.3965/j.ijabe.20140702.018 Citation: Guo X, Zheng L H, Li M Z, Zhang Y. Intelligent data acquisition and cloud services for apple orchard. Int J Agric & Biol Eng, 2014; 7(2): 146－153.

The Diversity in Performance of Commercial Olive Clones Selected from the Autochthonous cv. Souri Population for Intensive Irrigated Cultivation

The performance of five cv. Souri selections designated as “clones” were compared in two consecutive plots for ≈20 years each and three additional ones for 18 years. Fruit morphology, yield, oil production, and tree growth were monitored. The major results are presented as mean values of five sequential “on” years as well as the characteristic production of young and mature trees. The DNA identity was determined using both simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs). The performance of two “clones,” SLO and SBU, showed stable diverse production characteristics and could be designated as defined clones, although no clear differences of the DNA between them or the other “clones” were apparent. Another “clone,” SGS, was also designated as a true clone as a result of both unique fruit morphology and DNA markers. The differences between the other “clones” were minute in fruit production morphology and oil production as well as on a DNA basis and their designation as being true clones is doubtful.

Custom Microarray Analysis for Transcript Profiling of Dormant Vegetative Buds of Japanese Apricot during Prolonged Chilling Exposure

Bud dormancy is a critical developmental process for perennial plant survival, and also an important physiological phase that affects the next season’s growth of temperate fruit trees. Bud dormancy is regulated by multiple genetic factors, and affected by various environmental factors, tree age and vigor. To understand the molecular mechanism of bud dormancy in Japanese apricot (Prunus mume Sieb. et Zucc.), we constructed a custom oligo DNA microarray covering the Japanese apricot dormant bud ESTs referring to the peach (P. persica) genome sequence. Because endodormancy release is a chilling temperature-dependent physiological event, genes showing chilling-mediated differential expression patterns are candidates to control endodormancy release. Using the microarray constructed in this study, we monitored gene expression changes of dormant vegetative buds of Japanese apricot during prolonged artificial chilling exposure. In addition, we analyzed seasonal gene expression changes. Among the 58539 different unigene probes, 2345 and 1059 genes were identified as being more than twofold up-regulated and down-regulated, respectively, following chilling exposure for 60 days (P < 0.05). Cluster analysis suggested that the expression of the genes showing expression changes by artificial chilling exposure were coordinately regulated by seasonal changes. The down-regulated genes included P. mume DORMANCY-ASSOCIATED MADS-box genes, which supported previous quantitative RT-PCR and EST analyses showing that these genes are repressed by prolonged chilling exposure. The genes encoding lipoxygenase were markedly up-regulated by prolonged chilling. Our parametric analysis of gene-set enrichment suggested that genes related to jasmonic acid (JA) and oxylipin biosynthesis and metabolic processes were significantly up-regulated by prolonged chilling, whereas genes related to circadian rhythm were significantly down-regulated. The results obtained from microarray analyses were verified by quantitative RT-PCR analysis of selected genes. Taken together, we have concluded that the microarray platform constructed in this study is applicable for deeper understanding of the molecular network related to agronomically important bud physiology, including dormancy release.

Improving Growth and Productivity of Pomegranate Fruit Trees Planted On Sandy Dunes Slopes at Baloza District (N. Sinai) Using Different Methods of Drip Irrigation, Organic Fertilization, and Soil Mulching

This study was carried out during the two successive seasons of 2012 and 2013 at Baloza Experimental Station, Desert Research Center, North Sinai Governorate, Egypt, on Manfalouty pomegranate (cv.) shrubs planted on the slops of sandy dune. All the area subjected to the same agriculture practice. The study aimed to plan such model of farm management for planting the sand dune slops. The experimental work depended on modifying some traditional methods of irrigation, fertilization and protecting soil surface from erosion and water loss. Two irrigation systems (surface and sub surface drip irrigation) with organic fertilization (control 1 (without), compost and goat manure) and soil mulching (control 2 (without), plastic sheets and rice straw) were the main treatments applied to achieve the aim of the work and evaluate the improvement or that highly economic value fruit. The obtained results cleared that, sub surface drip irrigation was better than surface drip irrigation system. In addition, using plastic sheet as a mulching and compost as organic fertilization under sub surface drip irrigation gave the high leaf area, leaf chlorophyll, number of leaves/shoot, shoot length, number of followers / shoot, fruit set %, total yield, fruit length, fruit diameter, fruit weight, grains weight, TSS , total sugar content and vitamin C in both seasons. On the other side, surface drip

Impacts of Water logging on Biodiversity – Study on Southwestern Region of Bangladesh

Water logging significantly affects existing biodiversity in South-western region, which has important implication for lives and livelihoods of the people. Collecting primary data through FGD, key informant interview and questionnaire survey from three water logged villages of two Unions of Dumuria and Keshabpur Upazila of South-western region, the study reaches to the conclusion that duration of water logging and peoples' response to that situation are two important factors that determine the effects of water logging in the study area. Impacts of water logging on biodiversity in the study area are visible in reduced number of birds, livestock, fisheries, as well as restrained growth of plants and vegetations. The study also finds that water logging affects peoples' well being by narrowing down the livelihood options of the people. Water logging squeezes the scope for maintaining household economy by reducing the number of livestock, fisheries, and restraining the growth of vegetation, fruit trees and timber trees.

INFLUENCE OF ROOTSTOCK ON MINERAL UPTAKE AND SCION GROWTH OF ‘GOLDEN DELICIOUS’ AND ‘ROYAL GALA’ APPLES

Influence of four rootstocks (M.9, MM.106, MM.111, and local seedling) on the scion leaf and fruit mineral concentrations, tree growth, yield and fruit quality attributes of ‘Golden Delicious’ and ‘Royal Gala’ apples during four seasons (2008–2011) were significant. The mechanisms behind the influence of rootstock on scion vigor and yield was that the rootstock brought about its effects upon the scion by influencing the amounts of minerals taken up and translocated to the scion. ‘Royal Gala’ and ‘Golden Delicious’ trees on seedling had the highest efficiency in calcium (Ca) and potassium (K) uptake. Whereas, trees of these cultivars on M.9 were more efficient in nitrogen (N), manganese (Mn) and iron (Fe) uptake. MM.106 had the highest efficiency in phosphorous (P) uptake, and M.9 had the lowest K and Ca uptake. The highest N- fruit concentration and the lowest Ca-fruit concentration were observed in cultivars on M.9.

Effects of soil water and nitrogen availability on photosynthesis and water use efficiency of Robinia pseudoacacia seedlings

The efficient use of water and nitrogen (N) to promote growth and increase yield of fruit trees and crops is well studied. However, little is known about their effects on woody plants growing in arid and semiarid areas with limited water and N availability. To examine the effects of water and N supply on early growth and water use efficiency (WUE) of trees on dry soils, one-year-old seedlings of Robinia pseudoacacia were exposed to three soil water contents (non-limiting, medium drought, and severe drought) as well as to low and high N levels, for four months. Photosynthetic parameters, leaf instantaneous WUE (WUEi) and whole tree WUE (WUEb) were determined. Results showed that, independent of N levels, increasing soil water content enhanced the tree transpiration rate (Tr), stomatal conductance (Gs), intercellular CO2 concentration (Ci), maximum net assimilation rate (Amax), apparent quantum yield (AQY), the range of photosynthetically active radiation (PAR) due to both reduced light compensation point and enhanced light saturation point, and dark respiration rate (Rd), resulting in a higher net photosynthetic rate (Pn) and a significantly increased whole tree biomass. Consequently, WUEi and WUEb were reduced at low N, whereas WUEi was enhanced at high N levels. Irrespective of soil water availability, N supply enhanced Pn in association with an increase of Gs and Ci and a decrease of the stomatal limitation value (Ls), while Tr remained unchanged. Biomass and WUEi increased under non-limiting water conditions and medium drought, as well as WUEb under all water conditions; but under severe drought, WUEi and biomass were not affected by N application. In conclusion, increasing soil water availability improves photosynthetic capacity and biomass accumulation under low and high N levels, but its effects on WUE vary with soil N levels. N supply increased Pn and WUE, but under severe drought, N supply did not enhance WUEi and biomass.

Uso de fungos micorrízicos arbusculares (FMA) na promoção do crescimento de mudas de pinheira (Annona squamosa L., Annonaceae)

Os fungos micorrízicos arbusculares (FMA) podem ser usados na formação de mudas frutíferas, porém o seu efeito na pinheira não é conhecido. Foi investigado o papel de dois isolados de FMA (Acaulospora longula e Gigaspora albida) na promoção do crescimento de mudas de pinheira. O delineamento experimental foi tipo inteiramente casualizado em seis tratamentos: 1) Controle não inoculado em solo; 2) Controle não inoculado em solo adubado; 3) Inoculado com A. longula em solo; 4) Inoculado com A. longula em solo adubado; 5) Inoculado com G. albida em solo; 6) Inoculado com G. albida em solo adubado, em quatro repetições, totalizando 24 unidades. Plântulas com duas folhas foram inoculadas na região das raízes com solo-inóculo fornecendo 200 esporos de G. albida ou de A. longula. Após 140 dias em casa de vegetação avaliou-se: altura, número de folhas, diâmetro do caule, área foliar, massa fresca e seca da parte aérea e radicular, colonização micorrízica e produção de esporos de FMA. Em solo não adubado, os benefícios da micorrização foram evidenciados nas mudas formando simbiose com G. albida. Em solo com vermicomposto, a micorrização não incrementou o crescimento da mudas. A micorrização com G. albida pode ser alternativa para produção de mudas de pinheira, dispensando a fertilização.

Impact of rootstock and interstems on fine root survivorship and seasonal variation in apple

Both the production and longevity of fine roots have great impacts on the growth and development of fruit trees. To determine whether different dwarfing rootstocks and interstems could affect fine root longevity, root diameter, and peak-production season, minirhizotrons were used to examine root production, senescence, and mortality over two years in six apple (Malus domestica Borkh.) rootstock/interstem combinations. Fine root longevity was significantly affected by diameter, season of born and rootstock/interstem combinations. Fine roots on three dwarfing rootstock combinations, Dwarfing-Red Fuji/M9, Dwarfing-Red Fuji/SH40, and Dwarfing-Red Fuji/Malus xiaojinensis, had smaller diameters and shorter lifespans than the Vigorous-Red Fuji/Baleng Crab combination. Insertion of a dwarfing interstem in the Red Fuji/M9/Baleng Crab and Red Fuji/SH40/Baleng Crab combinations did not significantly change the diameter or longevity of fine roots. The dwarfing rootstock combination Dwarfing-Red Fuji/SH40 did not have an autumn peak like others. The lifespan of fine roots differed significantly among seasons. Fine roots produced in autumn had longer lifespans regardless of rootstock/interstem combination.

Efficiency of a new strategy involving a new class of natural hetero‐ligand iron(III) chelates (Fe(III)‐NHL) to improve fruit tree growth in alkaline/calcareous soils

Iron (Fe) chlorosis is a serious problem affecting the yield and quality of numerous crops and fruit trees cultivated in alkaline/calcareous soils. This paper describes the efficiency of a new class of natural hetero-ligand Fe(III) chelates (Fe-NHL) to provide available Fe for chlorotic lemon trees grown in alkaline/calcareous soils. These chelates involve the participation in the reaction system of a partially humified lignin-based natural polymer and citric acid. First results showed that Fe-NHL was adsorbed on the soil matrix while maintaining available Fe for plants in alkaline/calcareous solution. The effects of using three different sources as Fe fertilisers were also compared: two Fe-NHL formulations (NHL1, containing 100% of Fe as Fe-NHL, and NHL2, containing 80% of Fe as Fe-NHL and 20% of Fe as Fe-ethylenediamine-N,N'-bis-(o-hydroxyphenylacetic) acid (Fe-EDDHA)) and Fe-EDDHA. Both Fe-NHL formulations increased fruit yield without negative effects on fruit quality in comparison with Fe-EDDHA. In the absence of the Fe-starter fraction (NHL1), trees seemed to optimise Fe assimilation and translocation from Fe-NHL, directing it to those parts of the plant more involved in development. The field assays confirmed that Fe-NHL-based fertilisers are able to provide Fe to chlorotic trees, with results comparable to Fe-EDDHA. Besides, this would imply a more sustainable and less expensive remediation than synthetic chelates.

Differential expression of proteins associated with seasonal bud dormancy at four critical stages in Japanese apricot

Dormancy is of great significance in the growth and development of deciduous fruit trees. We used a combination of two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation time of flight/time of flight mass spectrometry (MALDI-TOF/TOF MS) to identify the differentially expressed proteome of Japanese apricot flower buds at four critical stages, from paradormancy before leaf fall to dormancy release. More than 400 highly reproducible protein spots (P < 0.05) were detected: 34 protein spots showed a greater than twofold difference in expression values, of which 32 protein spots were confidently identified from databases. Identified proteins were classified into six functional categories: stress response and defence (11), energy metabolism (ten), protein metabolism (five), cell structure (three), transcription (one) and unclassified (two). The glyoxalase I homologue could help Japanese apricot survival under various abiotic and biotic stresses, greatly contributing to its dormancy. Enolase, thioredoxin family proteins and triose phosphate isomerase provide adequate energy to complete consecutive dormancy release and bud break in Japanese apricot. Cinnamyl alcohol dehydrogenase 9 and arginase enhance the resilience of plants, enabling them to complete dormancy safely. Analysis of functions of identified proteins and related metabolic pathways will increase our knowledge of dormancy in woody plants.

Irrigation management of a peach orchard

The research field was at Siófok, in Hungary, which is situated in the South East side of Lake Balaton. The physical characteristic of the soil is sandy loam and loam and the peach orchard is irrigated. Mainly Sweet Lady (early ripening), Red Heaven (medium ripening) and Weinberger (early ripening) species were installed. In order to achieve the optimal developement level of trees and maximal yield amount and fruit diameter (Sweet Lady 60–75 mm, Red Heaven 60–70 mm, Veinberger 50–60 mm) continous water and nutrient supply is required. The irrigation modeling was set by CROPWAT 8.0 based on the climatic, crop and soil data inputs of the last 10 years. Based on the results, large amount of water is needed for optimal growth of fruit trees, particularly in the summer months, in case of active ground cover (+) and bare soil (–) as well. The irrigation requirement of a tree was found maximum 4 l/hour in certain cases. This irrigation intensity can be achieved – calculated with 12-hour operating time – by using continuous water NAAN Tif drip tube with 2 l/h flux on 3 atm pressure with 16 mm pipe diameter. If lower irrigation intensity is required irrigation can be controlled by the decreased the operation time.

Soil Carbon Pools, Nitrogen Supply, and Tree Performance under Several Groundcovers and Compost Rates in a Newly Planted Apple Orchard

This study evaluated the effects of in-row groundcovers (bare ground, brassica seed meal, cultivation, wood chip mulch, legume cover crop, and non-legume cover crop) and three compost rates (48, 101, and 152 kg available nitrogen (N)/ha/year) on soil carbon (C) pools, biological activity, N supply, fruit yield, and tree growth in a newly planted apple (Malus domestica Borkh.) orchard. We used nonlinear regression analysis of C mineralization curves to differentiate C into active and slow soil C pools. Bare ground and cultivation had large active soil C pools, 1.07 and 0.89 g C/kg soil, respectively, but showed little stabilization of C into the slow soil C pool. The use of brassica seed meal resulted in increased soil N supply, the slow soil C pool, and earthworm activity but not total soil C and N, fruit yield, or tree growth. Legume and non-legume cover crops had increased microbial biomass and the slow soil C pool but had lower fruit yield and tree growth than all other groundcovers regardless of compost rate. Soils under wood chip mulch had elevated earthworm activity, total soil C and N, and the slow soil C pool. Wood chip mulch also had the greatest cumulative C mineralization and a high C:N ratio, which resulted in slight N immobilization. Nevertheless, trees in the two wood chip treatments ranked in the top four of the 13 treatments in both fruit yield and tree growth. Wood chip mulch offered the best balance of tree performance and soil quality of all treatments.

Early growth habit and vigour parameters in olive seedlings

Fruit tree growth habit and vigour are important traits for orchard management and production, yet are difficult to select for in breeding programs because the parameters for their evaluation are complex, and their expression often requires sufficient plant size and development, entailing valuable time. Thus, in olive ( Olea europaea L.) breeding, as for other fruit crops, it is critical to define growth habit and vigour parameters with selection potential, and to determine the earliest age at which they can be measured. Furthermore seedling growth habit traits are important in themselves, particularly in their relation to juvenile period length and management. To explore these issues we evaluated a series of new and standard growth habit parameters during the first year of growth in a population of unpruned olive seedlings originating from six different crosses. The influence of plant age on growth habit traits was determined by comparing measurements at two or three different times. Both parent genotype and plant age significantly affected the vigour and growth habit of the olive seedlings, and 9 months was the most appropriate age for evaluating seedling growth parameters. ‘Picual’, ‘Arbosana’ and ‘Sikitita’ were shown to be promising cultivars for use as genitors, because of their tendency to produce offspring with desirable growth habit traits such as high vigour, weeping habit and low lateral shoot number. From among the 17 parameters studied, based on parent influence and the absence of correlation among parameters, five were identified which best described olive seedling growth habit: Primary Shoot Top Diameter, Primary Shoot Conicity, Secondary Shoot Number, Secondary Shoot Insertion Angle and Longest Secondary Shoot Internode Length.

Dual effect of fruit tree cultivation on soil physical characteristics

Soil bulk density, hardness, moisture and surface soil aggregation composition were measured in 10-, 10~20and 20-year-old orchards in Weibei Region. The results showed that soil bulk density in the 0~30 cm soil layer decreased with increasing orchard age. However, bulk density below the 30 cm layer increased with increasing orchard age, exceeding the 1.30 g?cm?3 upper limit for healthy garden soils. Soil bulk density in the 10~30 cm soil layer was lower in orchards than in croplands. Soil hardness increased sharply below the 30 cm soil layer, almost reaching the 1 000 kPa upper limit of soil quality standard for healthy root growth. Soil hardness in the 17.5~27.5 cm soil layer is lower in orchards than in croplands. Soil aggregation status was poor in surface soil of orchards. Most water-stable aggregates in the orchard soils were in 0.5~0.25 mm range class. Contents of water-stable soil aggregates 0.25 mm increased with increasing age of orchards. Water-stable soil aggregates contents in 20-year-old orchards were two times higher than those in 10-year-old orchards. Fruit trees have a dual effect on soil physical characteristics. Soil physical conditions was generally improved in topsoil (0~30 cm), but worsen in subsoil (30 cm) with increasing orchard age. As latent degradation of subsoil in orchards affected the healthy growth of fruit trees, any such degradation should be carefully monitored.

PROGRESS OF FRUIT PLANTS IN SELENIUM-ENRICHED RESEARCH IN CHINA

Selenium (Se) affects the development of fruit plants as a necessary element. It is effective in the prevention and treatment of some diseases in a health protection element. There are many of areas with low selenium, which could be called Selenium-poor zones in China, except for individual zones. Therefore, plenty of researches have been carried out to find the effect of Se on the growth of fruit plants by artificial cultural methods. The main objectives include: the ability to Se-enrich fruits and the physiological effects on growth and development of Se-enriched fruit trees. The fertilizers containing Se have been widely used to produce Se-enriched fruits. The main fruit species were as follow: apple, pear, jujube, kiwifruits, grape, oranges and watermelon.

Leaf area estimation in some species of fruit tree by using models as a non-destructive method

Introduction. Leaf area measurements are used commonly in the study of growth and development of fruit trees. These measurements can be made destructively by using a variety of sen- sitive instruments and/or non-destructively by using models of leaf area estimation. For models of leaf area estimation, some leaf parameters such as the length and width of leaves are usually used in the measurements. Construction of a model of leaf area estimation. Computer programs such as Excel, SAS and SPSS may be used in this process. In brief, after a leaf has been placed on a sheet of paper and photocopied, a digital planimeter or suitable tool may be used to measure the actual leaf area. The leaf width (W) and length (L) of the leaves sampled can be measured by a simple ruler. After this, regression analysis of the data may be performed separately for each genotype, species or cultivar. The analysis can be conducted with various subsets of the independent variables; for ins- tance, leaf length (L), leaf width (W), L 2 , W 2 and (L 2 /W 2 ) to develop the best model for predicting leaf area. Regression analyses should be carried out until the deviation sum of squares is minimized. Models of leaf area estimation for specific crops. In our study, prediction models of leaf area were developed by referring to the relevant current literature that studied such fruits as avocado, banana, blackberry, cacao, cherry, chestnut, grape, guava, kiwifruit, lotus plum, peach, pistachio, rabbiteye blueberry, red currant, red raspberry, sour orange, strawberry, pecan and white mulberry. Advan- tages and disadvantage of the models of leaf area estimation. Some advantages and a disad- vantage of models of leaf area estimation are presented. Conclusion. Our mini-review has shown that the models which have been formulated and which will develop in the future for some fruit spe- cies can be reliably used. Turkey / fruit-growing / models / forecasting / leaf area / methods / measurement / evaluation

Overcoming Fe deficiency in guava (Psidium guajava L.) by co-situs application of controlled release fertilizers

Among micronutrient deficiencies, Fe deficiency is the most difficult nutritional disorder to prevent in the fruits of trees growing on calcareous soils. In this study, a pot experiment was carried out to evaluate the potential of co-situs application of controlled release fertilizers (CRF) in alleviating Fe deficiency and improving the growth of fruit trees growing on calcareous soil (pH 9.3). Guava (Psidium guajava L.) seedlings were used as test plants because of their sensitivity to Fe deficiency. Treatments consisted of the following: (1) broadcast application of readily soluble Fe, Zn, Cu, B and Mn fertilizers (Control) or (2) co-situs application of CRF containing N, P, K, Mg, Fe, Zn, B, Cu and Mn (Co-situs). For the Control treatment, CRF containing only N, P and K was used. Both treatments received the same amount of all nutrients. Plants were more chlorotic in young leaves under the Control treatment and the Fe content of young leaves was significantly (least significant difference [LSD0.05]) higher under the Co-situs treatment. Dry matter production of shoots under the Co-situs treatment was 5.2-fold higher than under the Control treatment, and the total accumulations of macro and micronutrients were much higher under the Co-situs treatment than the Control treatment. Total accumulations of N, P, K, Ca and Mg were 5.0, 4.1, 9.6, 3.2 and 2.2-fold higher, respectively, under the Co-situs treatment compared with the Control treatment, and Fe, Zn, Cu and Mn accumulations were 3.2, 4.1, 6.0 and 3.7-fold higher, respectively. Iron deficiency in guava seedlings was successfully alleviated by the co-situs application of controlled fertilizer, proving the high potential of this method in alleviating Fe deficiency in fruit trees growing on calcareous soils.