Young Orchards Research Articles

Contribution of understorey vegetation to evapotranspiration partitioning in apple orchards under Mediterranean climatic conditions in South Africa

Orchard evapotranspiration (ET) is a complex flux which has been the subject of many studies. It often includes transpiration from the trees, cover crops and weeds, evaporation from the soil, mulches and other orchard artefacts. In this study we investigated the contribution of the orchard floor evaporative fluxes to whole orchard ET focusing on the transpiration dynamics of understorey vegetation which is currently not well known. Data on the partitioning of ET into its constituent components were collected in apple (Malus Domestica Bork) orchards with varying fractional canopy cover. The study orchards were in the prime apple growing regions in South Africa. The orchards were planted to the Golden Delicious/Reinders and the red cultivars (i.e. Cripps’ Pink/ Royal Gala/Fuji). Tree transpiration was quantified using the heat ratio method and the thermal dissipation sap flow techniques. Understorey transpiration was measured at selected intervals using micro stem heat balance sap flow gauges calibrated against infrared gas analyser readings. Orchard ET was measured using an open path eddy covariance system while the microclimate, radiation interception, and soil evaporation were also monitored. Orchard floor evaporative fluxes accounted for as much as 80% of the measured ET in young orchards with dense understorey vegetation that covered most of the orchard floor. In these orchards the understorey transpiration was of the same order of magnitude as the bare moist soil evaporation suggesting that water use by the understorey vegetation was substantial. However, in mature orchards with a high canopy cover (>55% fractional cover), orchard floor water losses were less than 30% of the measured ET. Understorey transpiration rates were much lower, contributing less than 10% of the whole orchard ET. Significant volumes of water can be saved, especially in young orchards, by keeping the orchard floor vegetation short, reducing the area occupied by understorey vegetation, and by reducing the wetted ground surface area.

Biological potential of the Carmen apple variety in the South of Dagestan

The article provides a pomological estimation of the Carmen apple variety cultivated in the southeastern foothill sub-province of Dagestan. The purpose of the research is to study the biological potential of the variety and to reveal the best in productivity apple scion/stock combinations that combine high adaptive capabilities for constructing intensive-type orchards in the commercial horticultural zone. The establishment of such orchards is associated with high material costs; therefore, improving the technology plays a crucial role. Especially important is the selection of scion/stock combinations in the production of apple planting material, which in the intensive horticulture should be characterized by precocity, stable productivity, high fruit quality and environmental sustainability. In Dagestan, fruit zones are sharply heterogeneous in terms of soil and climate conditions, which prevents the unification of the technology of intensive apple plantations. The most promising for the development of commercial horticulture is the South-Eastern foothill sub-province. Among the unfavorable environmental factors that negatively affect the vital activity of fruit crops in Dagestan, the first place is occupied by recurrent cold in spring and early frosts in autumn. In accordance with the Program of scientific research of the Federal Agrarian Scientific Center of the Republic of Dagestan, it is planned to study the influence of different stocks – dwarf M9, SK7 and medium-tall SK2, MM106 on the productivity of the Carmen variety. Based on the research results, biometric parameters of tree growth in a young orchard were studied depending on the design of the plantings. It is noted that at the three-year-old, the condition of the trees estimated on a 5-point scale is good. The height of the trees, depending on the stock, reached an average of 1.9 to 2.6 m. On dwarf rootstocks M9 and SK7, the diameter of the tree stem in the Carmen variety was 3.0-3.3 cm; on stocks SK2 and MM106, respectively 3.6-4.0 cm. The most prominent growth activity of trees of various scion/stock combinations reflects the total length of shoots. The smallest shoot length was observed in stands with dwarf rootstocks M-9 and SK-7, the largest – on medium-sized rootstocks MM-106. The largest number of fruit formations was on the dwarf rootstock SK7 (24.7 PCs.), with a planting scheme of 3.0×1.5 m; per square meter of food area, the number of fruit formations was 4.3-5.4 PCs./m2, and on stocks SK-2 and MM-106 with a planting scheme of 5.0×2.0 m their number was 2.1-2.2 PCs./m2.

Rainfall partitioning and its effects on regional water balances: Evidence from the conversion of traditional cropland to apple orchards in a semi‐humid region

AbstractRainfall partitioning by vegetation cover plays an important role in local and regional water balances. Large areas of traditional cropland have been converted to apple orchards on the Loess Plateau, China, so the effect of the conversion of traditional cropland to these orchards on rainfall partitioning cannot be ignored. In this study, we measured precipitation, throughfall (TF), and stemflow (SF) and calculated canopy interception (I) and canopy storage capacity (S) in two neighbouring apple orchards (8 and 18 years old in 2013) on the plateau during the four growing seasons of 2013, 2014, 2015, and 2016. Besides, we also summarized the percentage of rainfall partitioning of various crops and tree species and assessed the effect of land use change on regional water balances. The results showed that the percentage of rainfall partitioning and S differed between the two orchards. Mean annual I, TF, and SF for the young and mature orchards during the 4 years accounted for 7.9, 89.8, and 2.6% and for 10.3, 87.5, and 2.3%, respectively, of the rainfall partitioning. The percentage accounted for by mean annual I and TF differed significantly between the two orchards, but the percentage of mean annual SF did not differ significantly between the two orchards. Mean annual S for 2013–2016 was significantly higher for the mature than the young orchard. Although the conversion of traditional cropland to apple orchards led to a more serious soil desiccation in this region, the I loss percentage was higher in maize (12.5%) than the apple orchards. Therefore, we inferred that the effect of the conversion of traditional cropland to apple orchards on regional water balances was likely not caused by differences in rainfall partitioning. Differences in tree morphology due to tree age accounted for the differences in rainfall partitioning and S between the two orchards. Thus, tree age should be taken into account when assessing the effect of apple orchards on rainfall partitioning in this or similar regions.

THE STATE SUPPORT FOR DEVELOPMENT OF THE AGRICULTURAL SECTOR OF ECONOMY OF UKRAINE

The article reviews problems in the field of state support for the development of the agricultural sector of Ukrainian economy. The main forms of financial support of the domestic agricultural sector, in particular, direct state support (budget allocations, budget positions) are considered. Legislative initiatives of budget financing of agricultural sector development are highlighted. An assessment of financial support for the development of the agricultural sector of Ukraine’s economy for 2015-2019 is done. It is argued that in recent years, state support for the functioning and development of the agricultural sector of Ukraine’s economy has been aimed at increasing budget support, funding program to support farms, farms, hop development, creation of young orchards, vineyards and berries and review them, as numerous enterprises who receive loans, and assistance in obtaining credit financing. The study noted that the available financial support for the development of the domestic agricultural sector still remains insufficient and does not significantly meet the real needs, as in most cases financial resources are not available to businesses. The main measures to improve the current mechanism of state support for the agricultural sector of economy, which are to restructure existing approaches to financing the development of this sector by improving state support for its industries. The main ones are: reduction of corruption and bureaucracy in the process of budget allocation, transition to financial support for projects of innovative development of the agricultural sector on a competitive basis, promoting the implementation of mechanisms of public control over the use of funds. It is argued that the comprehensive implementation of the proposed measures will formalize the tools for modernization of state support for the development of the agricultural sector, which in the long run is transformed into improving the efficiency and competitiveness of the world food market. Keywords: agricultural sector, budget expenditures, state support for development of the agricultural sector, financial support, budget financing.

Soil biota from newly established orchards are more beneficial to early growth of cherry trees than biota from older orchards

Growth of young fruit trees replanted into old orchard soil is often poor relative to growth in soil that has not previously been planted with fruit trees. There is evidence that a consortium of deleterious soil biota, commonly referred to as the replant disease complex, are responsible for this poor early growth. We used a bioassay, comparing cherry plant growth in sterilized and non-sterilized subsamples of soil, to assess the net effect of soil biota from 18 orchards in the Okanagan Valley of British Columbia, Canada with differing histories of fruit tree production (previously cropped ‘old’ orchards, and not previously cropped ‘young’ orchards). Generally, shoot height increment was larger in non-sterile soil from young orchards than from old orchards (two-factor ANOVA; P < .001). When soil from young orchards was sterilized plant weight was lower, compared to the non-sterilized counterpart (two-factor ANOVA; P = .006). Pratylenchus populations in root tissue were greater in plants grown in old orchard soils than in young orchard soils (one-factor ANOVA; P < .001). Multiple regression analyses showed that FDA hydrolysis, an indicator of microbial activity, was the only variable that significantly predicted plant growth response to sterilization for the variables shoot height increment (R2 = 0.6; P = .001) and plant weight (R2 = 0.5; P = .002). Overall, results from this study suggest that management practices that stimulate microbial activity will benefit growth of cherry trees in previously cropped ‘old’ orchards, and not previously cropped ‘young’ orchards.

Using sap flow data to assess variations in water use and water status of apple orchards of varying age groups in the Western Cape Province of South Africa

No accurate quantitative information currently exists on how water use of apple (Malus domestica) orchards varies from planting to full-bearing age, leading to poor irrigation and water allocation decision making. This study sought to address this knowledge gap by investigating how the water use and tree water status vary with canopy cover, cultivar, and climatic conditions in 12 orchards growing in prime apple-producing regions in South Africa. The orchards were planted to the Golden Delicious/Golden Delicious Reinders cultivars which are widely planted in South Africa and the Cripps’ Pink/Cripps’ Red/Rosy Glow which are high-value late-season cultivars. The performance of two transpiration reduction coefficients, one based on sap flow (Ksf) and the other based on soil water depletion (Ks) (FAO approach) were evaluated against the midday stem water potential (MSWP) in all the orchards. While canopy cover had a clear effect on the whole-tree sap flow rates, there were no significant differences in the transpiration per unit leaf area among the cultivars. The daily average sap flux density under unstressed conditions was highest (~284 cm3∙cm-2) in the medium canopy cover orchards (30–44% fractional cover), followed by the mature orchards (~226 cm3∙cm-2), and was lowest in the young orchards (~137 cm3∙cm-2). Canopy cover rather than growing season length had a greater effect on seasonal total water use. Peak daily orchard transpiration ranged from 1.7 mm for young Golden Delicious Reinders trees to 5.0 mm in mature Golden Delicious trees that were maintained with large canopies to reduce sunburn damage to the fruit. For the red cultivars, the peak daily transpiration ranged from 2.0 to 3.9 mm, and the mature trees were maintained with less dense canopies to facilitate the development of the red fruit colour. The less dense canopies on the red cultivars had water-saving benefits since the seasonal total transpiration was lower relative to the Golden Delicious cultivar. The sap flow derived stress coefficient was strongly correlated to the MSWP (R2 ~ 0.60–0.97) in all the orchards while Ks was not able to detect plant stress due to over-irrigation.

Using sap flow data to assess variations in water use and water status of apple orchards of varying age groups in the Western Cape Province of South Africa

No accurate quantitative information currently exists on how water use of apple (Malus domestica) orchards varies from planting to full-bearing age, leading to poor irrigation and water allocation decision making. This study sought to address this knowledge gap by investigating how the water use and tree water status vary with canopy cover, cultivar, and climatic conditions in 12 orchards growing in prime apple-producing regions in South Africa. The orchards were planted to the Golden Delicious/Golden Delicious Reinders cultivars which are widely planted in South Africa and the Cripps’ Pink/Cripps’ Red/Rosy Glow which are high-value late-season cultivars. The performance of two transpiration reduction coefficients, one based on sap flow (Ksf) and the other based on soil water depletion (Ks) (FAO approach) were evaluated against the midday stem water potential (MSWP) in all the orchards. While canopy cover had a clear effect on the whole-tree sap flow rates, there were no significant differences in the transpiration per unit leaf area among the cultivars. The daily average sap flux density under unstressed conditions was highest (~284 cm3∙cm-2) in the medium canopy cover orchards (30–44% fractional cover), followed by the mature orchards (~226 cm3∙cm-2), and was lowest in the young orchards (~137 cm3∙cm-2). Canopy cover rather than growing season length had a greater effect on seasonal total water use. Peak daily orchard transpiration ranged from 1.7 mm for young Golden Delicious Reinders trees to 5.0 mm in mature Golden Delicious trees that were maintained with large canopies to reduce sunburn damage to the fruit. For the red cultivars, the peak daily transpiration ranged from 2.0 to 3.9 mm, and the mature trees were maintained with less dense canopies to facilitate the development of the red fruit colour. The less dense canopies on the red cultivars had water-saving benefits since the seasonal total transpiration was lower relative to the Golden Delicious cultivar. The sap flow derived stress coefficient was strongly correlated to the MSWP (R2 ~ 0.60–0.97) in all the orchards while Ks was not able to detect plant stress due to over-irrigation.

Influence of planting distances on biological-commercial characteristics of mature cultivar ‘Auksis’ fruit trees on rootstock P60

Investigations of the planting distance effect on the growth, productivity and fruit quality of dwarf apples in 14–15-yearold orchard were carried out at the Experimental Orchard of the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, in 2014–2015. The aim of the study was to evaluate the influence of planting distances on the growth, productivity and fruit quality of ‘Auksis’ apple trees on rootstock P60 in the mature 14–15 year old orchard. Fruit trees were spaced at the following distances: 3 × 1.5 m, 3 × 1.2 m, 3 × 1 m and 3 × 0.75 m. Based on the obtained results apple trees spaced at 3 × 1.25 m (2667 trees/ha) could be recommended for achieving high yields and good-quality fruits. If cultivated apple cultivars are not winter hardy or not resistant to bark diseases, apple trees on P60 rootstock could be planted at the distance 3 × 1 m or even more densely in order to achieve as high as possible yield in the young orchard.

Estimating crop coefficients for apple orchards with varying canopy cover using measured data from twelve orchards in the Western Cape Province, South Africa

The FAO-56 crop coefficient (Kc) approach is widely used for making irrigation decisions. Allen and Pereira (2009) extended this approach by developing a method for estimating Kc using a density coefficient (Kd), which is estimated from the fraction of ground covered by vegetation and plant height. In this study we evaluated this method using detailed measurements of transpiration (T), evapotranspiration (ET), soil attributes, weather, and tree physiological variables in 12 apple (Malus domestica Borkh.) orchards in the Western Cape Province of South Africa. Mid-summer canopy cover of the orchards was less than 20 % in young non-bearing and exceeded 60 % in mature full-bearing orchards. Data were collected over three growing seasons (October 2014 to May 2017) in orchards planted to the Golden Delicious/Reinders®, Cripps Pink, Cripps Red, and Rosy Glow apple cultivars. The original Allen and Pereira (A&P) method significantly overestimated the basal crop coefficients (Kcb) by on average 47 % in mature and 103 % in young orchards, respectively. However, improved Kcb estimates were obtained by adjusting the ratio of the resistances (i.e. rl /100) in the A&P method, where rl is the mean leaf resistance and 100 s/m is the typical resistance for annual crops. We defined a resistance parameter “α” for apple orchards which is equivalent to the bulk canopy resistance of a well-watered tree. Replacing rl /100 with rl /α, and using the measured mean rl and other biophysical measurements to solve the A&P equation for α gave a value ∼ 37 s/m. The improved Kcb values were used to derive the orchard Kc taking into account the contribution of cover crops whose transpiration was measured using miniature stem heat balance sap flow gauges. The seasonal total transpiration (T) estimated as T = Kcb x ETo, where ETo is the reference ET closely matched the measured values with a RMSE (root of the mean square error) of ∼ ±16 mm. Therefore, using the mean canopy resistance which is representative of apple trees in the A&P method has the potential to accurately predict both the crop coefficients and water use of apple orchards from planting until full bearing age.

To What Extent do Mango Agrosystems (Mangifera indica, Anacardiaceae) Contribute to the Restoration of Hypogenous Termites (Insecta: Isoptera) in Korhogo Region (Northern Côte d'Ivoire)?

The conversion of natural ecosystems to agriculture is recognized as the current major cause of biodiversity loss. Given large expanses of land that is under agriculture worldwide, this study, carried out in 2013, aimed to examine the contribution of mango orchards to the restoration of hypogenous termite in northern Côte d'Ivoire. Using the TSBF (Tropical Soil Biology and Fertility) monolith method of soil macrofauna estimation, termites were collected in seven age classes of mango tree orchards (class 1: &lt;5 years; class 2: 5–9 years; class 3: 10–14 years; class 4: 15–19 years; class 5: 20–24 years; class 6: 25–29 years; class 7: 30 years and over) and compared with termites collected from the savannah. A total of 16 species of termite were collected in all the study plots. The species richness, low in young orchards of classes 1 and 2 (05 species), increases to reach its maximum in old orchards of more than 30 years (13 species). These old orchards would be even richer and more diversified in termite species than savannah (10 species). Termites were less abundant in young orchard of class 1 (151.33±87.35 Individuals/m2) and more abundant in the old orchards of class 7 (344.88±119.90 ind./ m2). In the young orchards of class 1, termites were more prevalent in the 20-30 cm depth (7.92%) and in the old orchards of class 7, termites were found more at the surface between 0-10 cm depth (67.26%). Soil-feeders were absent in the young orchards but were abundant in the old orchard of class 7 (519 individuals). This study showed that in this highly disturbed region, mango orchards are re-colonized by termite communities. These results encourage the establishment of mango orchards to allow natural regeneration after agricultural disturbances.

Management of Fire Blight Using Pre-bloom Application of Prohexadione-Calcium.

Fire blight, a bacterial disease of rosaceous plants caused by Erwinia amylovora, is one of the most important diseases affecting commercial apple production worldwide. Antibiotics, applied at bloom to protect against blossom infection, are the most effective means of management but raise concern due to the potential for antibiotic resistance in both the pathogen population and nontarget organisms. In addition, most fire blight outbreaks in New York State often emerge in late June to July as shoot blight, calling into question the role of blossom infections and the antibiotic applications made to manage them. Prohexadione-calcium (PhCa) is a gibberellic acid inhibitor used post-bloom to control shoot vigor and to manage shoot blight. However, the magnitude of shoot blight management is directly related to the suppression of shoot growth, which is undesirable, especially in young orchards during establishment years. PhCa is believed to control shoot blight by thickening cell walls in cortical parenchyma, preventing invasion of host tissues by E. amylovora. We hypothesize that PhCa applied pre-bloom could similarly prevent invasion of blossom pedicels following infection, leading to reduced disease incidence. We evaluated novel pre-bloom PhCa programs for their effects on disease management (blossom and shoot blight) as well as their impact on shoot growth for three years in a mature 'Gala' orchard in New York. In all three years of the study, all PhCa programs resulted in less than 27% incidence (71% control) of blossom blight and less than 13% incidence (77% control) of shoot blight with minimal effect on tree growth. Inclusion of a biopesticide during bloom further reduced the incidence of blossom blight in one year of three. Using light microscopy, we found that cell walls in the cortical parenchyma of fruitlet pedicels on trees receiving pre-bloom PhCa applications were significantly thicker than those of untreated trees 40 days after full bloom and inoculation. Overall, we found that pre-bloom applications of PhCa had utility in reducing blossom blight and shoot blight with minimal impacts on tree growth. These pre-bloom programs would fit with standard production practices and may contribute toward the development of fire blight management programs without the use of antibiotics.

Pathocomplex of root rot of apple tree in nurseries and young orchards of the South of Russia

Root rot poses a serious threat to the main fruit crop domestic apple in nurseries and young orchards. Obtaining healthy planting material, free from root pathogens and root rot, is an especially priority task in conditions of intensive production. In the process of analyzing the affected plants from nurseries and young orchards at four sampling points, pathogens of apple root rot from 11 genera were identified and 431 isolates were extracted. The most common causative agents of apple root rot seedlings in the entire studied sample were species of the genus Fusarium spp. Soil micromycetes such as Rhizoctonia spp., Cladosporium spp., Cylinrocarpon spp., and oomycetes from the genus Pythium were rare. The composition and occurrence of species were heterogeneous at different points in the studied region. Phomopsis mali (Schulzer &amp; Sacc.) Died., Cytospora spp., Alternaria alternate (Fr.) Keissl., and Aspergillus niger Tiegh. have been associated with root rot of seedlings and young apple trees.

First Report of Lasiodiplodia pseudotheobromae Causing Canker and Shoot Dieback on Apple in China

In July 2017, apple trees (Malus pumila Mill.) with canker and shoot dieback symptoms on side branches were observed in several young orchards in Yantai, Shandong Province, China. Symptoms included shoot dieback, discoloration of xylem tissues, cankers, and sunken necrotic bark lesions, which surrounded the branches and resulted in the death of the branches. The disease is symptomatically different from canker diseases of apple earlier described. Small pieces (4 to 5 mm) of necrotic tissues from the shoot cankers were disinfected for 1 min in 75% ethanol, rinsed thrice with sterile distilled water, and plated onto potato dextrose agar (PDA) with 0.05% lactic acid. White colonies developed from symptomatic tissues but became dark gray mycelia with age. Pycnidia were produced on sterilized apple twigs on 2% water agar after incubation for 3 weeks at 25°C. Conidia were unicellular, ellipsoidal, initially hyaline, and became dark brown and developed a central septum with age. Conidia measured 21.3 to 31.9 × 12.4 to 16.9 µm (n = 50). On the basis of morphological characteristics, the isolates were identified as Lasiodiplodia sp., a member of the Botryosphaeriaceae family (Alves et al. 2008; Phillips et al. 2013). For further identification, total DNA was extracted from the mycelium of three monoconidial isolates (La1, La2, and La3). The rDNA internal transcribed spacer (ITS), a partial sequence of β-tubulin gene (TUB), and translation elongation factor 1-α gene (TEF1) were amplified and sequenced using primers ITS1/ITS4, Bt2a/Bt2b, and EF1-688F/EF1-1251R, respectively (Alves et al. 2008; Glass and Donaldson 1995; White et al. 1990). The sequences (GenBank accession nos. MK408640 to MK408642 for ITS, MK446722 to MK446724 for TUB, and MH829861 to MH829863 for TEF1) were aligned using BLASTn in GenBank, showing 99 to 100% homology with the sequences of ITS (EF622077), TUB (EU673111), and TEF1 (EF622057) from L. pseudotheobromae isolate CBS 116459 (Alves et al. 2008). The pathogenicity testing of three isolates was conducted using the wound inoculation method both on living apple trees and detached twigs. Thirty 2-year-old twigs were wounded with a scalpel on the phloem tissues and inoculated by placing 5-mm² agar plugs containing 2-day-old cultured hyphae or 10 μl of an inoculum suspension (10⁵ conidia/ml), which were then sealed with Parafilm. The same number of wounded twigs was inoculated with uncolonized PDA plugs or sterile water as controls. After 7 days, necrotic lesions (35 to 60 mm in diameter) developed around the inoculation points, which resembled the symptoms on infected apple shoots in the field. No symptoms were observed on the control twigs, and the pathogenicity test was conducted thrice. The pathogen was reisolated from symptomatic twigs and was reidentified as L. pseudotheobromae on morphological and molecular analysis. Although L. pseudotheobromae was previously reported on several forest and fruit trees (Alves et al. 2008; Awan et al. 2016), to our knowledge, this is the first report of the pathogen causing canker and shoot dieback on apple in China. This report is important for the new research aiming at management of apple canker disease.

CROP INVENTORY OF ORCHARD CROPS IN INDIA USING REMOTELY SENSED DATA

Abstract. The use of satellite remote sensing (RS) technologies for purpose of crop discrimination, mapping, area estimation, condition and yield assessment has been proved to be effective and efficient in terms of time and cost, having better consistency implemented with scientific approaches. However, application of satellite RS technology for horticultural crops in India has certain challenges due to scattered and small field sizes, comparatively short duration such as vegetable crops and mixed cropping. Hence the study was taken for developing research methodology for area assessment of three major fruit crops such as Banana, Mango and Citrus over 20 districts in four states viz. Gujarat, Madhya Pradesh, Uttar Pradesh and Bihar. Appropriate bio-window for analysing different crop types was selected and mapping of crops were done using pixel based hybrid classification i.e. un-supervised ISODATA clustering plus supervised MXL classification as well as object based classification of high resolution remote sensing data (Resourcesat LISS III and/or LISS IV, Cartosat – 1 PAN) followed by their accuracy assessment and their comparison with departmental reported statistics. Overall, the classification accuracy was more than 80% for all the crops. Deviation from statistics were in the range of 3 to 38%. Higher deviations from statistics were mostly due to use of lower resolution satellite data or mixing of crops having similar spectral signatures e.g. mango and sapota in Navsari and Valsad districts of Gujarat. It was very difficult to discriminate the young orchards of 2–3 years from other field crops due to mixed / inter cropping practices. The maps were checked and certified by respective State Horticulture Departments and were archived in VEADS, SAC and BHUVAN, NRSC geoportals of ISRO. RISAT – 1 (microwave) data were explored for the estimation of banana orchards in order to detect banana plantation at early stage and under cloudy sky conditions. There is huge potential of application in this sector using advanced observations from hyperspectral, thermal infrared sensors and advanced radars or LIDAR’s on-board upcoming satellites.

Subsoiling and Planting Method on the Initial Growth of ‘Pera’ Sweet Orange (Citrus sinensis (L.) Osbeck)

The objective of this work was to evaluate the vegetative vigor and root architecture of &amp;lsquo;Pera CNPMF D-6&amp;rsquo; sweet orange grafted on Rangpur lime at early stage of development, submitted to different planting methods (planting of nursery trees produced in a protected environment-PNT and planting of seeds at the definitive place-PS) and soil preparation with and without subsoiling. The experiment was carried out at the Lagoa do Coco Farm, Rio Real, Bahia, Brazil. Biometric evaluations were performed to estimate the variables: canopy volume (CV), vegetative vigor index (VVI) and canopy cover rates in the planting row (CCR-R) and interrow (CCR-I). Root samples were also collected up to a depth of 1.45 m at five points in the planting row. The roots were digitized and processed to obtain total root length (TRL), root length density (RLD), average root diameter (RD) and root length for the diameter classes. Plants produced in protected environment exhibit greater shoot vegetative and root development compared to those produced by sowing at the definitive place, at least for the young orchard and under rainfed conditions. Subsoiling did not affect root system distribution and PNT favored the increase in TRL along the soil profile compared to PS, for all diameter classes evaluated, contributing to the increase in vegetative vigor observed in the plants. Regardless of the management practices adopted, roots were concentrated in the first 0.35 m of the vertical soil profile, due to physical impediment caused by the presence of cohesive horizons.

Fresh date production in Kachchh (India): Challenges and future prospects

Date groves of Kachchh encompasses a unique date palm based agro ecosystem mainly developed through seeds hence exhibit great variability and diversity which also offers a rich gene pool. After endorsing the variety ‘Barhee’ for cultivation in Kachchh, its adaptability attained great momentum increasing the area to about 800 ha within a short period. Non availability and high cost of tissue culture planting material still remain a challenge. The great diversity which exists in the groves is also not fully exploited for the benefit of farmers. On set of monsoon coinciding with the harvest pose a great risk and covering with plastic coated material before monsoon offers some protection. The identification and characterization of good male palms to trap the metaxenia effect, collection and storage of pollen, standardization of pollination techniques etc. need improvement for enhancing the productivity. Many operations like pollination, harvesting etc. are time bound and labour intensive and hence need to be mechanized. The high water requirement of the crop is a matter of debate for its further expansion in the arid zones, where water is very scarce. No serious attempt has been made to explore the possibility for value addition and post harvest techniques especially for the low quality fruits, which need to be addressed on priority. Among the biotic stress, Red palm weevil, Rhynchophorus ferrugineus is a great threat especially in young orchards, for which a periodical scouting and monitoring through pheromones is useful. This crop is very hard and highly salt tolerant and can survive in harsh climatic conditions under problematic and degraded soil with issue related to salinity. There is a great potential for this crop to rejuvenate such vast degraded and problematic soil to productive.

Influence of rootstock on plum trees performance during the early years after grafting

Plum cultivars (×13) were grafted on Prunus cerasifera and on ‘Wangenheim Prune’ (P. domestica) seedlings and compared for 4 successive years after planting in the orchard. Several vegetative and reproductive traits were monitored including trunk diameter, flowering intensity, yield, fruit weight, soluble solids content (SSC) and the yield efficiency index was determined, too. Cultivar ‘Kubanskaya Kometa’ was the most precocious. It started to yield in the first year after the planting. Cultivars ‘Kubanskaya Kometa’, ‘Violeta’, ‘Valor’, ‘Stanley’ and ‘Oda’ showed the highest yield in the young orchard. Cultivars ‘Jubileum’, ‘Kijevas vēlā’ and ‘Cacanska Rana’ produced attractive large tasty fruit: their weight reached 55-59 g and taste was estimated at 4.4-4.6 points in 1-5 score scale. The ‘Wangenheim Prune’ rootstock reduced tree trunk diameter by 29% in comparison with P. cerasifera seedlings. Average fruit yield per plot was 34% higher from trees grafted on P. cerasifera rootstock. Only yield efficiency of ‘Kubanskaya Kometa’ and ‘Valor’ were influenced by rootstock being higher when grafted on P. cerasifera. Rootstock had no effect on average fruit weight and SSC.

The effect of water status on productive and flowering variables in young ‘Arbequina’ olive trees under limited irrigation water availability in a semiarid region of Chile

The intense drought affecting olive production in Northern Chile underscores the need to research non-traditional irrigation strategies to obtain the best crop performance. Accordingly, this study aimed to obtain preliminary data to guide future research on this topic. Different water replenishment levels on crop evapotranspiration (ETc; 13.5, 27.0, 40.5, and 54%) were established in a young orchard, cv. Arbequina, from the end of fruit drop (EFD) to full bloom in the next season. We evaluated the influence of plant water status (Ψstem) and crop load, considered as function of fruit number divided by trunk cross-sectional area, on reproductive and productive variables using multiple linear regressions. Our results show that crop load and Ψstem measured from EFD to harvest affected yield components. Nevertheless, Ψstem had the strongest influence on fruit size, pulp development, oil accumulation, and yield. Oil content and yield were reduced by 54% and 50% for each MPa, respectively, from Ψstem EFD-H − 1.8 MPa, an effect that intensified as crop load increased. During the period of flower development (September–November), the number of flowers per inflorescence and percentage of perfect flowers were reduced when Ψstem was less than − 2.0 MPa. These preliminary results showed that bud differentiation, inflorescence and flower formation are highly sensitive to water deficit.

Understanding band canker of almond caused byBotryosphaeriaceaefungi and attempts to control the disease in California

Band canker of almond caused by Botryosphaeriaceae species has been a sporadic disease on 6- to 8-year-old almond trees in California many years after its discovery in the mid-1970s. However, during the mid- to late-2000s, the disease appeared frequently in much younger orchards, 2-4-year-old trees, and especially on trees grafted to vigorous rootstocks (i.e., ‘Hansen’) and in the majority of almond-growing regions. In California, for example, orchards with band canker were recorded in Kern, Fresno, Madera, Merced, Stanislaus, San Joaquin, Sacramento, Yolo, Solano, Colusa, Yuba and Sutter, Butte, Glenn, and Tehama Counties. The aim of this study, financed by the Almond Board of California, was to determine the causal agents of the disease, the period of infection of young almond trees, the spread of the disease among orchards, and develop disease management practices. Seven species were isolated and identified causing cankers on almond trees as follows: Botryosphaeria dothidea, Neofusicoccum parvum, N. mediterraneum, N. nonquaesitum, Diplodia seriata, and Macrophomina phaseolina causing cankers on the trunk of the trees; and B. dothidea, N. mediterraneum, N. parvum, and Dothiorella sarmentorum causing canopy cankers. Inoculations of potted plants of the cultivar ‘Nonpareil’ with B. dothidea periodically for 2 years indicated that the inoculation conducted from March through May caused the largest cankers. The spread of the disease from inoculum sources into the almond orchards was studied in two orchards, one in Fresno Co. with the principal source of inoculum from riparian vegetation along an irrigation canal, and the second in Butte County with the main inoculum source being an old walnut orchard next to the almonds bearing pycnidia and pseudothecia of the pathogens. In both orchards, the spatial pattern showed that the severity and incidence of symptoms declined with distance from the external inoculum sources. However, we have recently detected spatial patterns of band canker severity in very young orchards (2-3 years old) that suggest other inoculum sources, such as early putative infection at nurseries, although this contention needs to be studied in the near future. To manage the disease various methods were attempted. None of the tried methods had significant effect on reducing band canker, except the installation of splitters in the sprinklers in a ‘Nonpareil’/‘Padre’ orchard. Specifically, the size of the band cankers was significantly reduced about 4 months after the alteration of the sprinklers. Also, during the next season, this control practice caused a decrease in both the size and the incidence of the band cankers by 50%. Future research plans on possible endophytic inoculum sources of Botryosphaeriaceae as they transition to become pathogens and new disease management strategies in newly planted orchards will be discussed.

Estimating the water requirements of high yielding and young apple orchards in the winter rainfall areas of South Africa using a dual source evapotranspiration model

Exceptionally high yielding (>100 t ha−1) apple orchards (Malus domestica Borkh.) are becoming common in South Africa and elsewhere in the world. However, no accurate quantitative information currently exists on the water requirements of these orchards. Information is also sparse on the water use of young apple orchards. This paucity of data may cause inaccurate irrigation scheduling and water allocation decisions, leading to inefficient use of often limited water resources. The aim of this study was therefore to investigate the dynamics of water use in eight apple orchards in South Africa planted to Golden Delicious and the red cultivars i.e. Cripps’ Pink, Cripps’ Red and Rosy Glow in order to understand how canopy cover and crop load influence orchard water use. Four of the orchards were young (3–4 years after planting) and non-bearing, while the other four were mature high yielding orchards. Transpiration was monitored using sap flow sensors while orchard evapotranspiration (ET) was measured during selected periods using eddy covariance systems. Scaling up of ET to seasonal water use was done using a modified Shuttleworth and Wallace model that incorporated variable canopy and soil surface resistances. This model provided reasonable estimates in both mature and young orchards. The average yield in the two mature ‘Cripps’ Pink’ was ∼110 t ha−1 compared to ∼88 t ha−1 in the ‘Golden Delicious’ orchards. However, average transpiration (Oct-Jun) was ∼638 mm for the ‘Cripps’ Pink’ and ∼778 mm in the ‘Golden Delicious’ orchards. The peak leaf area index was ∼2.6 and ∼ 3.3 for the mature ‘Cripps’ Pink and ‘Golden Delicious’ orchards. So, canopy cover rather than crop load was the main driver of orchard water use. Transpiration by the young orchards ranged from 130 to 270 mm. The predicted seasonal total ET varied from ∼900 to 1100 mm in the mature orchards and it was ∼500 mm in the young orchards. Orchard floor evaporation accounted for ∼18 to 36% of ET in mature orchards depending on canopy cover and this increased to more than 60% in young orchards.