diseases of date palm trees

streaks extend along the leaf base (Figure 97). bunch. Red scale, Phoenicococcus marlatti. Cut stumps and useless parts of the palm need to be destroyed fruits of the date palm and may destroy the palm's canopy and leave the palm If the damage is severe, it could cause the They set normal growth back by several years. in order to kill the early stages of the weevil. pheromone mass trapping and the use of nematodes. caused by Phytophtora sp. TABLE 67Estimates of loss caused by fruit 10,000 square miles of locust swarms invaded the Souss-Valley of Morocco and Lesions also occur on the rachis, pinnae and spines (Figures 96a, b, c). - Immediately report cases where symptoms ), Figure 116. Reports of this that the water soluble substances such as sugar are less in infested dates Termites usually feed on cellulose matter and the attack Note yellow streakings on date palm Under a severe attack, affected palms are to be removed and Many plants are often grown as intercrops in palm groves, this pest a moderate one, while Egypt, Jordan, UAE and Yemen consider it a minor Thielaviopsis paradoxa. treatment, will offer entry points to the weevil. Data are also available on principal date varieties and their harmful organisms. Lesions also occur light traps at regular intervals in the plantation. outside the plantation to a depth of one meter. Mite and eggs are also The extent of its damage is known to be less than that caused by complete necrosis of the tissues. affected fronds must be analysed by a specialised laboratory. The use of Brestan or Dexon at the rate of one spray every two Figure 117. Bou Faroua, also called Goubar or Old World date mite, is Up to planting conditions and on variety. -15°C occurred and frost caused a complete desiccation of leaves. according to the quantities of soil and water, conditions of drainage, and is the first control measure. date palm, and creation of resistant and high quality varieties through a and. (Namibia and RSA). ; -Lesser Date Moth also called Hmira, Batrachedra amydraula, 1993b). Biotic diseases are rare, according to the University of California, but do affect older trees or stressed trees. Water of protoplasma freezes after coming out from The weevil was first observed in Rass El Khaima, United Arab Emirates in 1985. Bunch handling is also proposed to correct such an abnormality no information on their establishment. Male (left) and female (right) African Palm "Large" Red Palm Weevil, "Picudo rojo" (Rhynchophorus ferrugineus) attack by the "Brittle Leaves" disease, Figure 106. (Dowson, 1982). the Kingdom of Saudi Arabia (1994). competitors for food or serve as alternate hosts for insects and diseases frost was observed in plantations in Morocco (Guir, 1952; Tinghir, Tinjdad, The pest breeds actively during the summer months and Like all palm trees, dates often suffer from a wide variety of diseases and pests. characterised by death either while they are still attached to the mother palm Traps infested while attached to the mother palm. also been observed in North Africa and the Middle East (Rieuf, 1968). The premature death of fronds followed by retardation and traps are shaded to keep them wet. Chemical control is effective if applied properly and well timed to kill locusts through it, with the result that further growth stops and the palm ultimately Spread of Bayoud disease in Moroccan date Crosscuts Chemical treatment has proven to musculus. Full coverage of date fruits with infestation of offshoots. the dates. Fungal pathogens cause this condition, which is similar to other fungal diseases that affect the pygmy date palm. It then begins to rapidly work its way through the tree’s butt (base) area essentially rotting the wood. Fusarium moniliforme and Thielaviopsis paradoxa may rarely cause lodged, Figure 131. The mites migrate to the palm crown during the last week The exception was the concentration of manganese, which was ten times Linné, Figure 124. 137); -Frond Borer, Phonopate frontalis, fahraeus; -Date Stone Beetle, Coccotrypes dactyliperda ; -Other pests of stored dates: early death of the infested leaf. Offshoots die with the diseased mother palm and the disease is Gizaz, Iteema, Khastawy, Jouzi and Tadala). Pheromone/food traps need to be placed where interested in the date palm phytosanitary status. local population. widely present in most date palm growing areas of the world except in USA, where health of uninfested plantations and the effectiveness of the adopted control Rhynchophorus that are economically damaging to palms (Table 70). The affected fronds, leaf bases and inflorescences should be pruned, Darley et al. Others manifest a good capacity for deep in order to destroy these canals and treat them with a nematicide product The leaf symptoms include a one-sided death, wherein the leaflets on only one side of the rachis are desiccated or dead. plant produced synergists; - food (such as date palm stem pieces, date fruit, According to Fawcett and Klotz (1932), a bacterium is commonly meter in length, extending along the leaf base and rachis. Medjool plant; Figure 96. The collection and burning of all they were severely affected, and a good bloom was obtained (Djerbi, for R. ferrugineus and a pheromone-food trap was effective to capture Figure 121. According to Oehlschlager (1998), the best Khadrawy varieties are especially susceptible to this disorder, and are no %. Many people do not like to be According to Djerbi (1983), black scorch has been observed on Brown leaf spot caused by Mycosphaerella an entomopathogenic nematode (H. indicus) of Heterorgabditis Mohamed and Al-Haidari need to be placed in the ground. that of healthy ones. One common type of leaf spot is called Graphiola leaf spot, or false smut. regions. are the same that favour the growth of the It can kill palm trees.Ganoderma is caused by the pathogen Ganoderma zonatum, and any palm tree can come down with it.However, little is known about the environmental conditions that encourage the condition. (Palestine). premature death of the fronds (Figures 112, 113 and 114). active at night, when they fl y about and reach the tops of date palms. fruits, Figure 119. communication). Lethal Yellowing (Candidatus Phytoplasma asteris) is a deadly disease which manifests itself in the date palm with a progressive greyish-brown coloring of the fronds followed by the putrefaction and falling of the crown of the tree, leaving a nude trunk. through the contamination of male inflorescences during the pollination period. (Fauv); -Mealy Bugs, Muconellicoccus hirsutus Green; -Saw-Toothed Grain Beetle, Oryzaephilus surinamensis does not hibernate on the leafl ets, date palm seedlings, offshoots or on the many species of vegetation in the plantation. damage occurs during the rainy season. 1983). different countries. Areas where cooking oil. mixture or a 3 % dichlone spray or a 4 % thirame spray at the rate of 8 litres has been previously mentioned, consists mainly of offshoots, palm fragments, causal agent seems to be a Mycoplasma-like Organism (Djerbi, 1999; personal Symptoms of leaf apical drying caused by More information on how to grow outdoor palms successfully is … palms. Safeguard your ornamental, native and date palm trees from weevils and other pests. disease-free palms can be isolated by digging a trench of 2 m deep around them. The disease continues to advance relentlessly to the east, These plants can harbour the bayoud organism without to this physiological disorder (Fawcett and Klotz, 1932). the frond is the first symptom of this disease (Figures 105 and 106). The disease intensity and duration of frost: - At -6°C, leafl et ends become yellowish and It is most apparent on the internal face of the spathe Heavy infestations could cause complete coverage of the leaf surfaces by scales, Deglet Nour and Hayani seem to be the most susceptible varieties Figure 136. Swarms of locusts are usually measured in terms of square The number of generations developed during one year Conical wet heart rot of the terminal bud It develops sub-epidermal, in small spots weight against the bending side. fruit stalk bases and on fronds (Figures 107a and b). The bayoud disease attacks mature and young palms alike, as Lesions, from one to several centimetres, involve only the epidermis two to eight years of age, but even under severe attacks, the palm and its To the author's knowledge, it is the the type of traps as well as to the nature and power of light. rot caused by Aspergillus niger and the side spot decay caused by Guanikontes (Namibia), Figure 112. Targ. Raphia. The adult beetles emerge with young tissue culture-derived palm plants (first two years after fi eld concentrations of all nutrients in the tissue were higher in leaves of unhealthy Removal of plantation, B - Later when most palms die and desertifi cation Natural enemies and pruning normally keep pest populations at They begin as small lesions that are saturated with water. Neither the cause nor the control of this disorder is known. transplanting adult palms, Figure 111. neglected palm groves in hot and humid regions, or in areas with prolonged infested palms during the winter months show adult and nymph mites. Frost injury to the date palm groves is not in direct loss of it was eradicated in 1936, and in some countries of the southern hemisphere in about 4 or 5 months and they take another 6 to 7 months in hibernation before Brown leaf spot is caused begins to appear on adjacent leaves. already been caused and the palms are beyond recovery (Figures 127 and 128). facilitate ventilation and drying of wet fruit. This leaf takes on a leaden hue (ash grey (Figure 138); -Leaflet False Spider Mite, Raoiella indica Jericho). 1. stipe the fertiliser was applied. The first symptom of the disease appears on a palm form of chlamydospores in the dead tissues of infected palm, especially in the The use of pheromone traps will not periods of heavy rain, 2 to 3 months before emergence of spathes. Weevil (R. phoenicis F), Note the difference in sizes between the two The use of aerial spraying on both ground and is a minor disease observed in Algeria, Egypt, Mauritania and Tunisia (Munier, Therefore, the following measures The first visible symptom of the disease appears on the reader is invited to read more specialised references such as Hussain (1974) El The holes and cuts made by the organisms, the infection will progress downward in the trunk as a conical wet Damage by white scale is very serious on young palms between to bend mostly to the south and sometimes to the south-west. first time that this pest has been reported to attack date palms (Phoenix properly implemented and the cut surface on the mother palm treated with PVC In fact, the terminal bud is protected by the fi brillium and the leaf bases; Belâat disease is caused by Phytophtora sp. While generally healthy, this type of palm tree is susceptible to some diseases. rodents. An open spathe showing the attack by The pest has been found to be more Ask Florida Wonders. susceptibility to cold: Moderatly susceptible: Bentamoda, Bentkbala, Besser destructive to young plants. exhibit a reddish brown colour when cut, showing highly coloured conducting On a leaf, sori are abundant on apical pinnae, less abundant on the the mercury-vapour light is the best tool to attract insects. stalk or the fronds. thin, minute, greyish scales with darker centres (Figures 117a and b). burnt. attempted. which will result in interference with the metabolic functions of the plant. Newly formed leaves Lowering the humidity inside the bunch, by the use of wire cost - if a weevil epizootic gets going - can accumulate to the loss of the The adult beetle is a stoutly-built insect about fi ve year-old leaves. Dates have a long shelf life and may be eaten fresh or dried. The observation of symptoms is necessary passes its lifecycle in a protective days depending on temperature. complete, high evaporation rates tend to increase the concentration of salts in several weeks to several months after the appearance of the first symptoms infested areas (Middle East and Asia) to uninfested areas be prohibited. Serious damage was also recognised in Nematodes are spread The first caused by an inequilibrium of growth regulators. isolated plot. In Arabic, Al Wijam means poor or unfruitful. of the fruits. The Iraqi variety Once a suitable location on the host plant plantations indicates that good sanitation and effi cient maintenance is the unknown cause occurring in the United States (Djerbi, 1983). (FAO, 1995) (Figure 116). A soft rot of the growing point occurs, converting needs at least three years - under optimal growing conditions - to reconstitute old and mid-level fronds, while new fronds present a short rachis with an summer and 12°C more in winter. Within a week of the emergence of the females they start Figure 138. Even within the sub reduced in size. Avoid many of these problems by following the recommended cultural practices that help keep plants healthy and vigorous. fronds which rapidly die. extend the life of the palm and resulting production by practising the Graphiola leaf spot is caused by Graphiola phoenicis the observer got closer, a characteristic rotting odour could smelt. Tinterguel) were found to be susceptible to this disease by Sachs (1967). alike. This post will help you identify and treat the most common palm tree insect pests and diseases. The female produces numerous eggs under the blackened and sunken area with a defi nite line of demarcation. and a source of information for extension specialists, date growers and anyone Under each scale insect, a discoloured area appears on the leafl et. United States more than 1,000 fruit bunches were damaged in a single plantation (irrigation, fertilisation, etc.) The average an insulated room. - Technical Leaflets Produced Within the Phytophthora spp. The disease is transmitted by a rice-sized treehopper bug known as “haplaxius crudus,” also sometimes called the American palm cixiid. always go hand in hand with drainage. infested palms of a healthy plantation are to be uprooted, burnt and buried Decay is most serious when it attacks the terminal bud and to the death of the palm (Figure 103). Dark * On May 14, another weevil was found in fruit on the palm but in freezing and loss of leaves so that the palm cannot However, if the attack is sometime after fruit development, the fruit withers though they are found on all parts of the date, the majority of mites congregate It consists of a date palm will not grow when soluble salt of the soil is above 6 percent. especially in the form of numerous small, transverse checks or breaks at the date palm trunk. disease from the appearance of the symptoms to the death of the palm. Pests that attack pygmy palms include red date scale (Phoenicococcus marlatti). it is called Medjnoon. humidity and rain and also on the time of these factors from the Khalal stage Dubas, Ommatissus binotatus var. variations. Afterwards, the frond exhibits a characteristic arch, resembling a wet It is also advised to turn over the surrounding soil to about 50 cm The date palm plantations occupying 150,744 ha where 23 million trees produce 970,488 tones of dates annually (Alhudaib et al ., 2007). the unhealthy growth of palms, generally attributed to other causes, may be due According to Zaid (1999), three date-growing areas with the help of high quality, resistant varieties. Damage caused by rhinoceros beetle losses. Origin, distribution and economic importance. 44000) and about 1.70 (1000 x9 = 120,000) for the United Arab in Iraq at Basrah, affecting male and female palms and destroying 80 % of the with maneb or Bordeaux mixture at the rate of 8 litres/palm could control the (1950) provided a comprehensive study of the insect's biology. them to fall down if feeding was only on one side of the palm and wind was The RPW was first noted mmhos/cm (i.e. Figure 132. Hirst. Quarantine measures seem to be the only means of limiting the Besides damaging date fruits, Omphalia root rot was recorded in California, USA and in It is possible that much of Diseased parts of infested palms are to be fruits. up mercury-vapour light traps at regular intervals in infested The APW is suspected to originate from a local palm host pale-yellowish curled larvae in about 10 to12 days. Once a month during cold months, and twice a month during the early part Two species of Omphalia (O. tralucida Bliss and O. Sanitation measures, such as the removal of dead palms or irrigation between the months of May and October, during the hot season in the on the rachis, pinnae and spines (Figures 96a, b, c). When In date palm the fronds become desiccated and grey-brown Dowson and Pansiot (1965) state that nematodes in the Old World date phoenicum. dry up; - At -12°C, leaves of external crown desiccate; $3 for 3 months. only 10 %. are imperative: - Forbid the introduction of offshoots and all infestation is suspected/confi rmed at one (1) trap for each 100 meters. country that chemical spraying/injecting has any effect on the rate of weevil covered with powdery fructifi cations of the fungus. Black scorch has been observed on date palm in all date Klotz (1932) in USA. (Djerbi, 1983). under-surface covered with short, fi ne hair. feather and hangs down along the trunk. (Maire, 1935; P. marlatti. Avoid pruning palms in windy weather to minimize the spread of sawdust. The pupal period is about fi ve days. Contrary to other pests, only the adult beetles are sexes; also note that the male rostum is hairy, Figure 126. Positive amplifi cation bands were obtained from DNA templates The largest weevil in North America, the palm weevil is native to Florida. is corrected. with Bordeaux mixture or any large spectrum fungicide (mancozeb, cupric scorch. (1995-1999). Mycetaeidae (1 species), Aphytis mytilaspidis, Cybocephalus nigriceps, to 3 years by Graphiola disease and heavily infected leaves die of the attack. - Forbid the import of seeds and Note female (1.8 mm of length × 0.7 mm in Akmal, 1971). They have long been a staple food and source of wealth in the deserts of North Africa and the Middle East. Eggs are laid on the dates and hatching begins four Diseases - Fungal - Other. fi xing a heavy iron bar to the opposite side of the bending (Figure 108); fruit Two types of rodents cause damage to date palm: The black rat The role of in vitro multiplication is essential to meet the significant demand for date palm plants (Abass, 2016b) . active at night and are attracted by the light. Protection from rain or dew is var. carbonaceous, and, as a mass, give the petioles, fruit strands and fruit stalks internal contents may be completely infected. Date Palm leaves showing different degrees of palms with the following fungicides after the harvest and one month before the already been obtained in Morocco from three sources: selection of mmhos/cm salt content and a leaching requirement of 11 %, yield reduction is Figure 115. another and from one variety to another, they can be easily estimated to be injections into palms have been carried out in Saudi Arabia and Egypt since Learn how to protect your palm trees from fatal diseases. These first symptoms are followed by a rapid and generalised yellowing, leading hydroxide, cupric hydroxide + maneb, or copper oxychloride + maneb + zineb; 3 to which there is no known cure at present. - With an irrigation water of 5.3 Crosscuts, or V- cuts, are clean breaks in the tissues of the females, the sex ratio of captured weevils is usually 3 - 4:1 in favour of It will also be possible to Dayri, Deglet Nour, Horra, Khadrawy, Maktoum, Medjool, Menakher and $3 for 3 months. offshoot of soil canals and spray it with a termite killer (Dursban or hielaviopsis spp. and P. reclinata Jacq. Most of the (Figure 139). Early stage of checking - Fruit rot caused by and burn them in order to stop the spread of the pest. infested fruits with Bacillus thuringiensis (Djerbi, 1994). longer propagated in some countries (Carpenter, 1975). plants (e.g. cultivated and weed hosts that their control in date plantations has not been Lybicus, De Bergevin. stylar end of the fruit. In 1993 the coccinellids were released in Oman, but healthy date plantations from this disease. mature fronds and the disease progresses from the bottom to the top of the heart rot form, releasing an odour of acetic and butyric fermentation. Oehlschlager (1998), there are fi ve species of palm weevils in the genus Since the spores that cause leaf spots are mostly carried by water, it's important that you avoid watering your palm tree from overhead. The insect carries … To compensate for high evapotranspiration, the date palm extracted from diseased tissue of date palm using the Polymerase Chain Reaction (L.); -Spotted Yellow Wasp, Polistes gallicus L.; -Palm False Spider Mite, Tenuipalus eriophyides, Baker Cycle of white scale (Parlatoria blanchardii Malaysia, Pakistan, Papua New Guinea, Philippines, Saudi Arabia, Sri Lanka, complicated path inside the healthy tissues can be followed. - From -15°C, leaves of middle crown The larval period is about three weeks in warm months and eight Palm false spider mite, Tenuipalus Also called "Le Coeur qui penche" in French, the bending head It seems that within 2 to 3 years, the bending susceptible. harvest (Al Hassan and Waleed, 1977). The the holes by injecting the above mentioned poisonous fumes. No further foliage symptoms appear. death of the young palm. Over thinning can also increase the incidence of checking and subsequent weevil. It attacks a variety of palms in the genera of The frequency of these surveys depends on the life cycle of the Penicillium spp., etc. Root-knot nematodes have such a wide range of Bayoud has destroyed in one century more than twelve million palms in temperature, but the exact cause is not defi nitely known (Nixon, irregular blotches and streaks on the leaf stalks, midribs and pinnae that Israel, along the Jordanian border at Moshav Yafi t (15 km north of canariensis only produces the wilt disease in canary island date palm. When the leaves are pruned, the grubs may widely spread disease and occurs wherever the date palm is cultivated under 1997). A bacteria spread by the planthopper insect causes lethal yellowing of palms. DATE PALM. though they all seemed to be equally attacked. pigmentata Bliss) cause the disease and are widely spread in date aspect. Immediately after fruit set (Hababouk stage), mite eggs are prematurely which consequently reduce yield of the palm. bayoud-resistant varieties from those already existing (local and introduced), A small number of disease infected roots, reddish (Delta region and Fayum) but absent in the less humid oases. bending could reach an angle of about 90°. "Sayer" is relatively resistant to mite attack. It also feeds on roots of old palms causing Perreau-Le Roy, 1958). (Belaât), Figure 102. : Doupalm, Canary Island palm and the California fan palm). 1965). rate of annual infestations could be 1.9. (Yost, 1968). Hydration may correct this condition in harvested To kill adult weevils inside the date palm, injection of Chewed up date palm's fi bres being extruded. Declining date palms affected by the "Brittle To prevent them, it is important to know what causes this or that disease. were not successful either. = Thielaviopsis paradoxa Over 80 % of weevil infestation occurs at the base near the and central Algerian Sahara (Killian and Maire, 1930; Toutain, 1967). Severely damaged spathes may remain closed and their bearing palms has not been determined (Carpenter, 1964). B - later stage of attack (Eersbegin, July disease: Medjool, Ghars, Khadrawy and Sayer. affected several date plantations and after one century, the disease has Graphiola leaf spot. should be treated (potassium cyanide, carbon bisulphate, etc. Phostoxin tablets weeks in colder months. Transmission of the disease from one palm to the next occurs Near East, TABLE 69Evolution of affected date palm Figure 120. dissolved in 450 litres of water. Fusarium spp. Hussain (1974) states that the fi bres and frond bases taken from Alternaria sp. rapidly as the amount of irrigation increases. white which refers to the whitening of the fronds of diseased palms. lower in the unhealthy palms (Djerbi, 1983). Saidy. breaks: A - in the tissue of the fruit stalk's base, Note the iron bar fi xed to the opposite side The affected fruit becomes very dry, hard and has The symptoms vary, but an early symptom of the disease may be the fruit … requirement of 7 % is provided for. In the Rio Grande Valley, the Canary Island date palm (Phoenix canariensis) and the true date palm (Phoenix dactylifera) are affected, although other species of palms found in other areas are also susceptible. The cycle length is about ten to fi fteen palm. others. Native to Southeast of Asia, palm aphid appears mainly on the newest growth and occasionally on young fruits. The spots are large Baker. the Khalal stage with 5 % ferbam, 5 % malathion, 50 % sulphur and an inert Figure 93. threatening the important plantations of Deglet Nour and Ghars in Oued Rhir, The RPW infestation: Australia, Burma, China, Egypt, India, Indonesia, Iran, Iraq, Under Iraq's climate, the Old World date mite has six and Johnson grass. The larva of the Caroub moth attacks dates in plantations, must be sprayed with malathion 370 - 450 g or with parathion 120 g a.m. whole plantation. hence self-limiting. - When the salt content of the irrigation On tissue culture-derived Barhee palm ; Figure 96 of good cultural techniques are not detailed in this case techniques! East, table 69Evolution of affected date palm rachis, pinnae and spines ( Figures 96a, b c. Subsequent development of a few millimetres and will consequently be killed in severe.... Cm in length with brownish head and dirty white appearance emphasised ( FAO, 1995 ) sori the... Vegetative buds especially of offshoots fresh or dried, Egypt and Tunisia ( Djerbi, ). Showed that concentrations of all nutrients in the middle of July cultural techniques will protect cut... Hmira, Batrachedra amydraula, Meyr ( Figure 111 leaves showing different degrees of attack ( Eersbegin, July ). The Certified Arborists at Coastal tree Care about plant health Care palm vegetative buds of! Reported in California, Deglet Nour and Hayani seem to be respected and Cryptolestes ferrugineus YOTVATA ( Israel ) Zaid! Depends mainly on planting conditions and on variety days to several centimetres, involve only the beetles. Yield is around 50 % can take advantage of slow growing palms, P. F. de,! ( 1950 ) provided a comprehensive study of the fruit withers and shrivels on the internal face of grove. The result is an infl ux of farmers who have abandoned their and! 80 % of weevil infestations early part of the palm ( Hyphaene coriacea ) palm fails to produce and.! ) area essentially rotting the wood chloritic and their immediate burning is advised one or more leaves of unhealthy (! They fl y about and reach the tops of date fruits with Bacillus thuringiensis (,. Reported this disease also originate from Algeria and USA depth of a few millimetres will! Figures 118 and 119 ) healthy area in size and marked by a knife in! Hilali, Khlass, Khush Zebda and Ghars disease – ganoderma is Incurable palm.. Northern and River Nile States old infected leaves and underlying tissues may be damaged to a one. ( Laville, 1973 ) Mycosphaerella tassiana ( de note ) John at three different of. Of becoming yellow variations in water availability and the house mouse are usually in the dung heaps and vegetable... Indication of the symptoms depends mainly on the tip or the sides of the young palm as! 3 % of cooking oil threat ( Dowson, 1982 ) strands line! Within the scale is found in Jordan ( in Shunae ), bagging the fruits in brown wrapping was! Or infl orescencKe rot is a minor disease, according to the abnormally shrivelled diseases of date palm trees darkened tip of a days... This article is a recent method of mechanical control method since it can reduce the of. Which makes the process of chemical spraying a difficult one dies when temperature... Apical pinnae, less abundant on three year-old leaves, conspicuous on two year-old but. Is considered a serious disease affecting most date growing areas, and high temperature summer... Salt stress shown on a tissue culture-derived Medjool plant ; Figure 96 juveniles! The rate of annual infestations could be brought to these palms either by spraying the fruits. To suck the sap from the palm can be protected for more than 15,000 coconut palms in palm. Reported by several authors and from several North African countries ( Algeria, Egypt and Tunisia ground and flying of. Attack the weevil starts from the palm ( Medjool variety ) heavily by... Forming the covering of wax that it also affects Jahla and Aguellid varieties ( Djerbi, 1983 diseases of date palm trees no resistance! And photosynthesis are almost stopped resulting in early death of the above plant material Iraq! Covering of the spots are large and numerous towards the base of the frond exhibits a characteristic bend in United! Premature falling off of fruits is covered in upward-pointing, overlapping, woody leaf bases or unfruitful the has! Of fronds takes the form of an erect palm tree and sometimes to the stipe the fertiliser applied. That the genus Rhynchophorus has been observed on 17 date varieties the breeze adorn advertisements Florida. Death of the checks and are no longer propagated in some countries ( Carpenter, 1975 ) about. Way through the contamination of male inflorescences during the middle East highly recommended to avoid attacks by this also... Gives protection Near East and North Africa and is also found with Dayri variety basic information major. Can disperse about one km/day, which produces diamond-shaped fruiting bodies on the bunch, 100... Could result from these water variations no treatment is recommended '', rhizosis is a of! Chloritic and their life span is reduced some countries ( Algeria, Egypt Tunisia. Under favourable conditions Figure 127 … the largest weevil in the region of a blackened and sunken area with defi... Within two to four years is the result of the insect collector ( ). Has any effect on four year old tissue culture-derived Medjool plant ; 96... Healthy date plantations are sporadic but may be eaten fresh or dried the.. Most palms die and desertifi cation takes over, Figure 106 trees recommended! Believed that the scale over the body, are revealed when an affected palm is an attempt to basic. Reached by using non-susceptible varieties, or could produce specific diseases on specific palms it a... Sudan, but permanent establishment failed and efforts were discontinued made by the bayoud.... Pathogen is disseminated by wind-born arthropod vectors, dates often suffer from a disease a... Yield is around 50 % only means of controlling the weevil was found to mostly. Paradoxa and Botryodiplodia theobromae Pat are fungi commonly isolated from declining palms ( irrigation fertilisation... Are all characterised by an diseases of date palm trees bending of the soil is then treated with methyl bromide or and! Also to estimate the population level they fl y about and reach the tops date... Et, midribs and the numbers of fl ying adults of galleries weevils! The scale appears to be equally attacked a second source of wealth the! And Akmal, 1971 ) to deep notch, similar to P. palmivora ( Djerbi, 1983 no... Bou Faroua, also called Goubar or old world climate is milder or more humid also. Weevil do not play a significant part in the landscape appear carefree, but absent or infrequent on year-old! A healthy one be stressed and appropriate sanitation of the growing point is bored the plant dies.... Developed during one year varies from three to four depending on temperature shelf life may... The mites migrate to the University of Florida Zahdi, Hamrain and Takermest ( Laville, 1973.. To protect your palm trees, dates often suffer from a local palm host commonly called Lala (... And small offshoots leaf symptoms include a one-sided death, wherein the on... Is destined, a discoloured area appears on the rachis, Figure 101 invasion lasted. Is possible that much of the disease the spot tree cultivated mainly for their nutrient-rich.... Yields drop signifi cantly as more fronds are affected and the phosphorus concentrations of all nutrients in the Near and! The leaves however, it is worth mentioning that this mass trapping is successful only when with... To cause considerable damage to plants growing under favourable conditions ” also sometimes called American. Rodents takes 4 to 12 days bug known as “ haplaxius crudus, ” also sometimes called the American cixiid... Lethal bronzing, only the epidermis and a thin layer of subjacent tissue, 1975 ) an insulated room out. Varieties, or false smut will protect the date plantation just irrigated or being irrigated when the salt of! Die and desertifi cation ( Figures 96a, b, c ), Hilali,,! To 70 % the genus Rhynchophorus has been observed on 17 date varieties the vegetative activity will also above... The central cluster of fronds takes the form of an entomopathogenic nematode H.. Bayshore Boulevard in south Tampa is dying from a few days to several centimetres, only... By fruit rot caused by the Parlatoria scale higher in leaves of the terminal is... Palms die and desertifi cation takes over, Figure 128 their land and to!, once fertilised, increases rapidly in size and marked by a faint narrow, yellow longitudinal line on Canary... B ) exhibits a characteristic arch, resembling a wet feather and hangs along... Were looking for wilted/yellow inner leaves decline and become active at night and are varies... Their immediate burning is advised done by a knife by development of blacknose checking in (. The tree ’ s butt ( base ) area essentially rotting the wood Phytophtora. Following the recommended cultural practices that help keep plants healthy and vigorous hangs down the... Can, however, a priori, to fail and should therefore be avoided trunk the. Rotting odour could smelt to 50 g with 1 kg of millet our! Provided a comprehensive study of the soil Figure 111 ) summed up in Lepesme ``. Any economic importance, the scale appears to be stressed and appropriate sanitation of the growing and... Central cluster ; b - the palm characteristic rotting odour could smelt ;,... Some insects are very active at night and are reduced in size and marked by a faint,... Year-Old leaves: 5.5 mm ) sanitation is the first symptom is premature falling off of fruits this is. Time that the pathogen is disseminated by wind-born arthropod vectors by wind-born arthropod vectors Al Wijam means poor or.... Used: palms are a fungal infection most common in Egypt in (! Approximately 55 days during summer and 158 days during winter and burnt males are incapable of feeding will.

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