Palm Orchards Research Articles

Evaluation of the Trace Metal Bioremediation Activity of some Aquatic Plants in Date Palm Orchards

Evaluation of the Trace Metal Bioremediation Activity of some Aquatic Plants in Date Palm Orchards

How Far Can the Red Palm Weevil (Coleoptera: Curculionidae) Fly?: Computerized Flight Mill Studies With Field-Captured Weevils.

Adult Rhynchophorus ferrugineus (Olivier) captured in pheromone-baited traps in commercial date palm orchards in the Al Ahsaa Directorate, Kingdom of Saudi Arabia, were used in computerized flight mill studies to determine the flight characteristics of this highly invasive and destructive palm pest. Flight mill studies were run at three different time periods, winter (December), spring (March), and summer (May). Of the 192 weevils tethered to flight mills ∼30% failed to fly > 1 km. Of those weevils flying > 1 km (n = 139), 55% flew > 10 km, and of these flyers 5% flew > 50 km in 24 h. Flying weevils exhibited an average weight loss of 20-30% and nonflying control weevils lost ∼9-13% body weight in 24 h. Male and female weevils flying in summer (average laboratory temperature was ∼27°C) flew the longest average distances (∼25-35 km), exhibited highest weight reductions (∼30%), and greatest mortality rates (∼80%). Consequently, time of year not weevil sex or color morph had a consistent and significant effect on flight activity, weight loss, and survivorship rates. Flight activity was predominantly diurnal commencing around 5:00 a.m. and peaking between 9-11:00 a.m. before tapering off. The distribution of flight distances combined across season and sex was mesokurtic (i.e., normally distributed).

Improving Fruit Set, Yield and Fruit Quality of Date Palm (Phoenix dactylifera, L. cv. Mnifi) Through Bunch Spray With Boron and Zinc

Abstract Fertilization is one of the most important cultural practices in date palm orchards. Spraying micro-nutrients has an important role in fruit set, fruit retention, development, improved total yield, and fruit characteristics. The present study was conducted during the two successive seasons, 2011 and 2012, in order to investigate the effect of bunches sprayed with boron and/or zinc on fruit set, yield, and fruit quality of 10-year-old “Mnifi” date palm. Bunches were pollinated by placing 10 “Meghal” fresh male strands among female clusters during both seasons. Nine spraying treatments were performed twice; 2 h before pollination and 4 weeks after pollination. Results of the two seasons indicated that application of 1500 ppm boron +300 ppm zinc (B1 + Zn1) increased total yield/palm, fruit weight and volume, flesh weight, soluble solids content (SSC), and total and reducing sugars. Fruit set and titratable acidity were improved with spraying of 1500 ppm boron (B1). Fruit dimensions and moisture content increased with B1 treatment in the first season and B1 + Zn1 treatment in the second season. Application of boric acid alone (1500 ppm) or combined with zinc sulphate (300 ppm) to get a positive effect on fruit set, total yield, and fruit quality of “Mnifi” date palm could be recommended.

English

In present investigation, an efficient Agrobacterium - mediated genetic transformation was successfully carried out for a well known date palm ( Phoenix dactylifera L.) cultivar “Khalasah” using matured somatic embryos. Somatic embryogenesis was initiated from offshoot’s shoot tips of date palm cultivar. For genetic transformation, morphologically advanced matured somatic embryos developed on MS medium fortified with TDZ (1.0 mg/l) were co-cultured with A. tumefaciens strain LBA 4404 harboring binary vector pBI 121, containing uidA ( GUS ) and npt II genes and incubated for 4 days and later it was (somatic embryos) inoculated on germinating and plantlet conversion MS medium supplemented with BAP (0.75 mg/l) + kanamycin (100 mg/l). Prolific shoots developed from putatively transformed matured embryos showed 47.5 % transformation efficiency. A large number of transgenic plants were obtained and later established in black hard plastic bags. A strong GUS activity was detected in the putatively transformed plant leaves by histochemical assay and, the integration of uidA ( GUS) and npt II genes into transgenic plants was confirmed by polymerase chain reaction ( PCR ) and Southern hybridization analysis. The established transformation protocol allows effective and quick regeneration via somatic embryogenesis, and it would be highly valuable for existing date palm orchards and improving their productivity.

Diversity and phylogenetic analysis of endosymbiotic bacteria of the date palm root borer Oryctes agamemnon (Coleoptera: Scarabaeidae).

BackgroundThe date palm root borer Oryctes agamemnon (Coleoptera: Scarabaeidae) is one of the major pests of palms. In Saudi Arabia, both larvae and adults of Oryctes are particularly troublesome, especially during the establishment of young date palm orchards. Endosymbiotic bacteria are known to have a key role in food digestion and insecticide resistance mechanisms, and therefore are essential to their host insect. Identification of these bacteria in their insect host can lead to development of new insect pest control strategies.ResultsMetagenomic DNA from larval midgut of the date palm root borer, O. agamemnon, was analyzed for endosymbiotic bacterial communities using denatured gradient gel electrophoresis (DGGE) utilizing 16S rRNA genes. The DGGE fingerprints with metagenomic DNA showed predominance of eleven major operational taxonomic units (OTUs) identified as members of Photobacterium, Vibrio, Allomonas, Shewanella, Cellulomonas, and Citrobacter, as well as uncultured bacteria, including some uncultured Vibrio members. DGGE profiles also showed shifts in the dominant bacterial populations of the original soil compared with those that existed in the larval midguts. The endosymbiotic bacterial community was dominated by members of the family Vibrionaceae (54.5%), followed by uncultured bacteria (18.2%), Enterobacteriaceae (9.1%), Shewanellaceae (9.1%), and Cellulomonadaceae (9.1%). Phylogenetic studies confirmed the affiliation of the dominant OTUs into specified families revealed by clustering of each phylotype to its corresponding clade. Relative frequency of each phylotype in larval midguts revealed predominance of Vibrio furnisii and Vibrio navarrensis, followed by uncultured bacterial spp., then Cellulomonas hominis, Shewanella algae, and Citrobacter freundii.ConclusionAnalysis of metagenomic DNA for endosymbiotic bacterial communities from the midgut of Oryctes larvae showed strong selection of specific bacterial populations that may have a key role in digestion, as well as other benefits to the larvae of O. agamemnon. Determination of the distinct endosymbiotic community structure and its possible biological functions within the insect could provide us with basic information for future pest control research.

DoesOryctes elegans(Coleoptera: Scarabaeidae) Abundance Determine Future Abundance ofRhynchophorus ferrugineus(Coleoptera: Rhynchophoridae) in the Date Palms of Saudi Arabia?

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) is known to be the most serious pest of coconut palms and other cultivated palms in India, South Asia, North Africa, Europe, the United States and the Middle East. The larval feeding sites of the date fruit-stalk borer (FSB), Oryctes elegans Prell, may be attractive to RPW to lay eggs. Understanding the correlation between the RPW and FSB might help in predicting RPW infestations. The relative abundances of both species were followed in 16 date-palm production orchards in the Kingdom of Saudi Arabia from June 2007 to May 2008. A specifically designed light trap was used to monitor FSB, and pheromone traps (ferrugineol (4-methyl-5-nonanol)) were used to monitor RPWs. There was a weak correlation between FSB abundance and subsequent RPW infestation in date palms (R2 = 0.0039). The relative abundances of both species were well synchronized in the date palm orchards that were sampled.

Survey and Relative Abundance of Insects (Insecta) Excluding Lepidoptera from Sixteen Commercial Date Palm Orchards using Light Traps at Riyadh Province, Saudi Arabia

Date palm (Phoenix dactylifera L.) is one of the oldest fruit crops of the world having been cultivated for many centuries in North Africa and the Middle East. In Saudi Arabia commercial date palm production is an important industry. Insects, excluding the Lepidoptera, were sampled with Robinson-type light traps placed in 16 date palm commercial orchards in the Al-Kharj region, Riyadh Province, Saudi Arabia, for 12 months from June 2007 to May 2008. No insecticide treatments or manure fertilizer applications were made in the orchards during operation of the traps. A total of 44 485 insects representing nine orders (Orthoptera, Blattodea, Dermaptera, Hemiptera, Mantodea, Neuroptera, Coleoptera, Hymenoptera and Diptera) and at least 50 different taxa were counted and identified. Most of the insects were trapped during a period extending from mid-Spring (April) to early autumn (September). The highest numbers were trapped during July and August (87 % of the total). Two orders, Coleoptera and Diptera represented 97 % of all insects trapped. Beetles comprised 87.83 % of the total insects trapped with scarabs composing 73 % of this percentage. The fruit stalk borer Oryctes elegans comprised 58 % of that total. This species was exceptionally abundant in one of the orchards in August. Dipterans comprising 10 % of the total (4 701 individuals), was the only other order attracted in relatively large numbers to the light traps. Most of these flies were trapped during August. The sericine scarab Maladera insanabilis previously not known from date palm orchards of Saudi Arabia may be a potential new pest.

Biology, predation, and life table of Cydnoseius negevi and Neoseiulus barkeri (Acari: Phytoseiidae) on the old world date mite, Oligonychus afrasiaticus (Acari: Tetranychidae).

The old world date mite, Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) is a severe spider mite pest of date palm in most of the Middle East and North Africa. Considering that nothing is known about the performance of phytoseiid predators against O. afrasiaticus , biology, predation, and life table parameters of Cydnoseius negevi (Swirski and Amitai) and Neoseiulus barkeri Hughes (Acari: Phytoseiidae), collected from date palm orchards, were studied under laboratory conditions (25, 35°C and 35 ± 10% RH) as a first step to understand their effectiveness against all mobile life stages of O. afrasiaticus . For both predators, oviposition period was significantly shorter at 35°C than at 25°C. The following parameters were obtained for C. negevi and N. barkeri at 25 and 35°C, respectively: female longevity, 31.8, 20.1, 35.7, 27.4 d; fecundity, 21.6, 38.0, 18.8, 34.8 eggs per female; oviposition period, 23.9, 13.7, 25.9, 18.1 d. Total predation of C. negevi and N. barkeri female was 246.0, 270.0, 227.6, 205.3 prey at 25 and 35°C, respectively. Rectal plugs were observed attached to the opisthosoma of some adult females of N. barkeri , which often cause the mite to stick to the surface. Life table parameters were estimated as net reproductive rate ( R0 ) 10.44, 17.35, 10.19, 13.84, intrinsic rate of increase ( rm ) 0.14, 0.19, 0.13, 0.16 d −1 , finite rate of increase (λ) 1.15, 1.21, 1.12, 1.17 d −1 , generation time ( T ) 17.03, 15.17, 17.83, 16.61 d, doubling time (DT) 04.95, 03.64, 05.33, 04.33 d for C. negevi and N. barkeri at 25 and 35°C, respectively. The values of intrinsic rate of increase and net reproductive rate were higher in C. negevi than N. barkeri at both temperature regimes. Therefore, it could be concluded that C. negevi performance was better than N. barkeri against O. afrasiaticus and can be considered as a valuable addition to the existing methods for spider mites control.

First record of Arabian Rhinoceros Bettle, Oryctes agamemnon arabicus Fairmaire on date palm trees in Iraq

Field surveys were conducted in date palm orchards of five Iraqi provinces to study patterns of borers infestation on identity species presence during season of 2008-2013. Results indicated that larvae infest different parts of palm trees: Rizospherre, Turnk and Crown area. Identification of specimens done by specialist depicted first record of Arabian Rhinoceros Bettle, Orycetes Agamemnon arabicus Fairmaire infested date palm trees in Iraq.

DATE PALM FRUITS AS A POTENTIAL HOST OF THE PEACH AND MEDITERRANEAN FRUIT FLIES IN FAYOUM GOVERNORATE

The peach fruit fly, Bactrocera zonata (Saunders) and the Mediterranean fruit fly Ceratitis capitata (Wiedmann) are two of the most destructive fruit flies that attack commercial fruits causing significant damages. This study was contributed for monitoring the relative abundance and infestation percentage of B. zonata and C. capitata during two successive seasons, 2010 and 2011 in Fayoum governorate. The experimental locations included various types of date palm cultivation including, firstly, the mixed fruit orchards that containing mango and citrus beside date palm trees, secondly, the orchards containing field crop and vegetables bedside fruit and date palm trees, thirdly, an aggregated date palm orchards only. During The 1st season, the means of CTD (captured flies per trap per day) of B. zonata were 7.68 , 4.55,and 1.65 flies, for the forementioned types, respectively, while during the 2nd season, the means of CTD were 15.31, 6.55 and 0.47 flies for the same cultivations, respectively. The highest CTD values of B. zonata were 11.95 and 26.71 flies / trap/ day observing on 3rd week of October and 3rd week of September during the two seasons, 2010 and 2011, respectively, recorded on the mixed orchard cultivations. Population of C. capitata was low in mixed-cultivation orchards, whereas the means of CTD were 0.16 and 0.48 fly during the 1st and 2nd seasons, respectively, while, there weren't captured flies of C. capitata on the other two types of mentioned date palm cultivations.The samples of fallen date fruit were free of infestation by either of B. zonata or C. capitata in the mature stage for the four tested varieties (Siwi, Amhat, Zaghloul and Balady) of date palm. Percentages of infestation of B. zonata in the fallen palm fruits for the half-ripe and ripe stages during the 1st season in Siwi, Amhat, Zaghloul and Balady varieties were 18.29, 6.31, 6.36, 4.37, 16.29, 5.50 and 20.51, 5.66%, respectively, and during the 2nd season, the percentages of infestation were 34.40, 17.00, 9.42, 3.10, 25.00, 11.76 and 28.96, 6.15%. The obtained data suggests that the earlier control of the fly on the former crop, removal of the infested date fruits that are shelter of immature stages of B. zonata and C. capitata, also, the early harvesting of some date varieties that could be marketing on mature stage results in reducing the population and percentages of infestation of the two flies. Also, avoidance of mixed fruit host cultivation and removing the secondary hosts support such procedures.

MODFLOW Modeling to Solve Drainage Problems in the Argaman Date Palm Orchard, Jordan Valley, Israel

Overwetting and soil salinization processes are common in irrigated date palm orchards in Israel. Subsurface drainage systems are generally used to overcome soil salinity. Subsurface drainage models can contribute to the selection of a proper drainage system and its proper placement in the field. In this paper, the groundwater flow modeling program MODFLOW was used to simulate groundwater levels in a date palm orchard in Argaman, in the Jordan Valley, Israel. Using a three-layer groundwater flow model, the most efficient drainage system was a combination of 4.5-m depth primary drains and 3-m depth drains of different lengths installed at a different spacing between drains. Installation of this drainage system would cost approximately NIS$2.6 million, i.e., 30% less than the initially proposed project. Given certain input, a spatially distributed groundwater flow model such as MODFLOW can provide more reliable information than different analytical solutions for planning an effective subsurface drainage system.

Applying boron to coconut palm plants: effects on the soil, on the plant nutritional status and on productivity boron to coconut palm trees

Boron, one of the micronutrients frequently found in low levels in tropical soils affects nutrition and productivity of coconut palm trees essentially cultivated in tropical climates. The objective of this research study was to evaluate the effect of boron on the nutritional status of the plant and its productivity when artificially applied to the culture soil. The experiment was carried out in a four year old, artificially irrigated, dwarf coconut palm orchard in Brazil, between January, 2005 and October, 2006. The soil was a red yellow Latosol (B: 0.18 mg dm -3 ). The treatments consisted in the application of five boron dosages: zero, 1, 2, 4, and 6 kg ha -1 . In the field, the treatments were arranged according to a completely randomized block design, with four replications. Boron (borax) dosages were applied in equal halves directly into the soil in the months of January and February of 2005. Boron concentration in the soil and plant and plant productivity were evaluated. The higher palm tree production was associated to levels of 0.6mg dm-3 of B in the soil and 23.5mg kg -1 in leaves. Ninety five percent of palm trees maximum production was obtained with the use of a boron dosage of 2,1kg ha-1.

Incidence of predatory phytoseiid mites in Saudi Arabia: new records and a key to the Saudi Arabian species (Acari: Mesostigmata: Gamasina)

Cydnoseius negevi (Swirski & Amitai, 1961), Neoseiulus paspalivorus (De Leon, 1957) and Proprioseiopsis beatus (Chaudhri, 1968) are reported for the first time from Saudi Arabia. The mite genus Cydnoseius Muma, 1967 is also new to the Saudi Arabian fauna. Cydnoseius negevi was collected from various host plants in three different regions (Riyadh, Hail, Eastern region) while N. paspalivorus and P. beatus were collected from Cynodon dactylon L. (Poaceae) in date palm orchards in Riyadh and Eastern region respectively. A key is provided to the adult females of the known species of Phytoseiidae of Saudi Arabia.

A new species of Neoseiulus Hughes, with records of seven species of predatory mites associated with date palm in Saudi Arabia (Acari: Phytoseiidae)

Eight species of phytoseiid mites are reported from date palm orchards in Saudi Arabia. Seven of them were first records forthis country: Neoseiulus bicaudus (Wainstein), N. conterminus (Kolodochka), N. makuwa (Ehara), N. rambami (Swirski &Amitai), Proprioseiopsis asetus (Chant), P. messor (Wainstein), P. ovatus (Garman). Neoseiulus makuwa and P. asetus arerecorded from the Middle East and North Africa for the first time. One new species is described from Bermuda grass, Neoseiu-lus saudiensis n. sp. The new species is most similar to Neoseiulus alpinus (Schweizer) and N. marginatus (Wainstein). A key for identification of the included species is provided.

Activity of Insect Fauna during the Night in the Palm Orchards of Central Iraq

The study was carried out at three palm orchards, each of 2.5 hectare in Al-Madain palm orchards (30 km, South Baghdad) contains the palm varieties (Prem, Osta omran, Zahdi, Berhee, Khadrawi, Khastawi, Oueedi and Tebarzel) in 2010 season aiming to determine the population density of palm borers and to know other insect occurring in date palm orchards. Three light traps with solar energy (Magna Traps with lamps of 320-420 nm wavelength are produced by Russell IPM) were used as one trap in each orchard. The number of fruit stalk borer, Oryctes elegans and frond borer, Phonapate frontalis adults were calculated per week in each trap aiming to determine the population density of adults in the three orchards under this study. Results of using light traps (Magna Traps) indicated that the number of O. elegans adults catch per trap during the period from April to December 2010 were 254, 217 and 240 adult/trap in orchards No. 1, 2 and 3, respectively, the higher population densities were 87 ,79 and 81 adult/trap per month, respectively reported in July. Also, the study indicated that the population density of frond borer, Phonapate frontalis catch per trap during the period from April to December 2010 were 34, 58 and 54 adult/trap for orchards No. 1, 2 and 3, respectively, the higher population densities were 10, 21 and 15 adult/trap per month, respectively reported in June. Many insect groups were caught in light traps, the insect fauna composed of nineteen insect groups, 12 are coleoptera, 1 hemiptera, 1 hymenoptera, 1 homoptera, 2 dermaptera, and 2 orthoptera, the numbers of this insect were recorded per month a year round in palm orchards.

Composition and diversity of weed communities in Al-Jouf province, northern Saudi Arabia

The aim of this study was to identify the main weed communities in Al-Jouf province in northern Saudi Arabia. Moreover, the composition and diversity of these communities were studied in relation to soil variables and crop type. Some 54 stands representing olive orchards, date palm orchards, wheat crop and watermelon crop were studied, using ten quadrats (1×1m) per stand. A total of 71 species belonging to 22 families and 61 genera were observed. The classification of vegetation using the Two Way Indicator Species Analysis (TWINSPAN) resulted in the recognition of four vegetation groups representing wheat crop, orchards in winter season, orchards in summer season and watermelon crop. These results suggested the importance of both crop and season for the formation of weed community. Detrended Correspondence Analysis (DCA) showed that these groups are clearly distinguished by the first two DCA axes. The species richness was higher in both olive and date palm orchards than in wheat and watermelon crops. This pattern of species richness could be related to farm management practices and habitat micro-heterogeneity. Soil electrical conductivity, organic carbon and soil texture showed significant correlations with species richness and the cover values of some dominant species, suggesting the significant role of soil characteristics in weed community structure and diversity.

Bacteria associated with the rhizosphere of manganese-deficient date palms affected by brittle leaf disease.

Brittle leaf disease or “Maladie des feuilles cassantes” (MFC) is a disorder affecting date palm (Phoenix dactylifera) orchards in oases of southern Tunisia. No causal pathogen has yet been identified, despite search for nematodes, fungi, bacteria, viruses and viroids. Although the soils of the oases in which affected palms grow have similar contents of total and exchangeable manganese (Mn) compared with oases with no disease, the leaflets of affected palms are deficient in this element. Here, we characterized the bacterial flora in the rhizosphere of three MFC-affected date palms and three non-affected controls. Our results show a high bacterial diversity in the date palm rhizosphere. From 201 clones corresponding to a 16S rDNA PCR fragment, we identified 177 different bacterial phylotypes. Some of them corresponded potentially to Mn-oxidizing bacteria that may be involved in soil Mn oxidation and, consequently, deplete this micronutrient in MFC-affected date palms. More detailed studies are necessary to establish the exact role of these bacteria in the disease syndrome.

Vegetation composition and floristical diversity in date palm orchards of Central Saudi Arabia

The present study deals with the floristical composition of date palm orchards in Central Saudi Arabia (Al-Qassim Area). Fifty-five species of vascular plants were recorded, including 29 perennials and 26 annuals. Fifteen date palm orchards (stands) in each of five studied locations were investigated. Fifteen soil parameters were used to assess the relationship between species distribution and their controlling soil factors. Three main vegetation groups (A, B and C) were identified, and their characteristic species were recognised. These groups were separated along the first two axes of the principal component analysis (PCA). None of the measured soil variables showed significant difference between the identified vegetation groups. The first RDA axis can be defined as coarse sand-silt gradient, while the second axis, can be defined as potassium-coarse-sand gradient.

Population density of Oryctes elegans Prell. (Coleoptera: Scarabaeidae) on some date palm varieties in South Baghdad Orchards

Laboratory and field studies were conducted to investigate the population density of Fruit stalk borer Oryctes elegans Prell in date palm orchards grown in Al-madain region about 30km south of Baghdad in 2009.The susceptibility of some date palm varieties, ( Braim, Ustaomran, Zahdi, Berhee, Khadhrawi, Khastawi, and Oueedi), to borer infestation was also tested. Results indicated that the mean density for borer larvae was 5.75 individual/tree. The Brim variety showed the highest susceptibility with an average of larvae population reached to 13 individual/tree. found in the part of the tree which was under annual management for bruning and removal of old fronds used to done during March and April. As for the adult density, results obtained by solar light trap showed that the mean number for adults catch was 29 insect /trap for the period of July to October while the highest trap catch was 37 adult /trap occurred during September. Results of the morphological studies had also indicated the presence of some differences in term of width, depth, weight of frond bases. Therefore, results of this study could be of benefit for orchards owners when applying an integrated program for controlling date palm pests.

Phytoseiidae from date palms in Israel with descriptions of two new taxa and a key to the species found on date palms worldwide (Acari: Mesostigmata)

The old world date mite Oligonychus afrasiaticus (McGregor) is an important spider mite pest of the date palms Phoenix dactylifera in most of North Africa and the Middle East. To identify potential predators of this key pest we monitored the phytoseiids in the date palm canopy and on the orchard floor for three consecutive years in the Southern Arava Valley of Israel. In this study we report on the phytoseiid species found. We describe two new species, Neoseiulus cozae and Typhlodromus shoshae, and redescribe seven species, Proprioseiopsis beatus, Neoseiulus marginatus, N. conterminus, N. rambami, N. bicaudus, Cydnoseius negevi and Typhlodromus athiasae, found on date palms or on the understorey Bermuda grass, Cynodon dactylon, gramineae in these orchards. A key to all species collected from date palm orchards worldwide is given. Proprioseiopsis beatus, N. marginatus and N. conterminus are recorded for the first time in Israel.