RESEARCH PROJECTS
Effect of Melia azedarach on natural enemies of Bemisia tabaci The cotton whitefly, Bemisia tabaci, is one of the
major pests of greenhouse and field crops in Lebanon. Experiments with
aqueous extracts of Melia azedarach and Tween-20 (0.5%) against
the pest revealed 70-80% detrimental effect under controlled conditions
of 27 + 2 oC and 70-80% RH. Experiments with the entomopathogen
Verticilium
lecanii indicated that topical application of the plant extracts on
3rd- 4th instars before introducing the fungus have
hindered the activity of the fungus against the insect. A delay period
is being studied to indicate the best way of integrating the two control
methods, aiming at getting an additive or synergistic detrimental effect
of the two methods on the insect population. Studies with other biocontrol
agents are being conducted to monitor the safety of these botanical extracts
to the ecosystem and their potential role in Integrated Pest Management
programs in which biological control of this pest is essential. E. Abou-Fakhr
Hammad and C. Jazzar. (Supported by URB.)
Effect of natural compounds on the natural enemies of the pea leafminer The
pea leafminer, Liriomyza huidobrensis, threatens vegetable crops
as swisschard, cucumber, bean and tomato in Lebanon. The main objective
is to study the effect of plant extracts of the local Chinaberry tree,
Melia
azedarach L. and other insecticides, to be applied against the pea
leafminer, on natural enemies of the pest. The insecticides include the
biorational products abamectin, paraffinic oil, Bacillus thuringiensis,
and azadirachtin (0.25%) and the synthetic insecticides cyromazine and
imidacloprid. Survey for the natural enemies of the pea leafminer has revealed
the presence of a few species of hymenopterous parasitoids with very low
abundance on weeds. Direct and indirect effects of above menttreatments
on the natural enemies of the leafminer are to be investigated. Results
of this study will determine the efficiency of using Melia extracts
in the management of the pea leafminer together with their biological control
agents. Identification of the collected parasitoids is in progress. E.
Abou-Fakhr Hammad and N. Nemer. (Supported by LNCSR.)
Analysis of plant extracts bioactive against insect pests Laboratory
bioassays and field experiments with extracts of the Chinaberry tree, Melia
azedarach L. (Meliaceae) were performed against two pests on vegetables.
Aqueous and methanol extracts were found to be repellent to adults of the
sweet potato whitefly, Bemisia tabaci. These extracts were also
found to be detrimental to immature instars of the sweet potato whitefly
and the pea leafminer, Liriomyza huidobrensis. Chemical analysis
of these bioactive extracts by High Performance Liquid Chromatography (HPLC)
was performed at the Western Cotton Research Laboratory – USDA, Arizona.
Certain studies indicated that M. azedarach extracts have azadirachtin,
the primary component of the neem tree, Azadirachta indica L. (Meliaceae).
Results of our analysis indicated that the extracts do not have azadirachtin
but analogues of azadirachtin. These results were comparable to other studies
indicating the presence of two meliacins of same Rf value as
azadirachtin on TLC plates, but they were absorbed at different wavelength
form azadirachtin. E. Abou-Fakhr Hammad and D. Hendrix*.
(Supported by URB.)
Effect of secondary plant compounds on whiteflies The
cotton whitefly, Bemisia tabaci, is one of the major pests of greenhouse
and field tomato crop in Lebanon. Whiteflies are usually attracted to the
green-yellow color of their host plants, but actual selection of the plant
occurs after landing, in which chemical cues as secondary plant compounds
are involved. In this study, the secondary plant compounds solanine, solasodine,
tomatidine and tomatine were found to act as arrestants to B. tabaci.
However, extracts of Melia azedarach L. fruits were found to be
deterrent to adult B. tabaci and detrimental to nymphal instars
of the insect. Methanol extracts of the mentioned plant were found to yield
more of the bioactive compounds than other aqueous and organic solvent
extracts, as verified by Thin Layer Chromatography (TLC). The study of
behavioral and ecological aspects of whitefly-plant relationships is essential
for the improvement of chemical control especially against resistant strains
of the insect. E. Abou-Fakhr Hammad and H. Zournajian. (Supported
by URB.)
Efficacy of natural compounds on leafminer control The
pea leafminer, Liriomyza huidobrensis, is one of the major pests
of vegetables in Lebanon. Effect of aqueous extracts of the Chinaberry
tree, Melia azedarach L., on the leafminer was studied versus natural
insecticides in the laboratory. The insecticides were Bacillus thuringiensis,
Avermectin B1 and Ultra-Fine Spray Oil. In a field experiment, the mentioned
treatments, the botanical insecticide Azadirachrin (0.25%) and the synthetic
insecticides Imidacloprid and Cyromazine were tested against the egg and
first instars of the insect. Results of the bioassays indicated that there
were significant differences in number of dead third instars due to Avermectin
compared to other treatments. Results of field experiment indicated that
Avermectin B1 and Cyromazine have significantly reduced the population
of the insect over a month period. Plant extracts have given similar results
to Azadirachtin and imidacloprid after two consecutive sprays. Thus, M.
azedarach extracts are potential insecticides against early stages
of the leafminer. E. Abou-Fakhr Hammad and N. Nemer. (Supported
by LNCSR.)
Soil solarization: an alternative method for soil disinfestation The control of soilborne pests (fungi, bacteria, nematodes,
insects and weeds) in greenhouses in Lebanon has relied almost exclusively
on fumigation with methyl bromide. Methyl bromide is a very toxic fumigant
and is an ozone depleting substance; its use will be completely banned
worldwide (by 2005 in developed countries and 2015 in developing countries).
Soil solarization stands as the most economically and ecologically sound
alternative. This project aims at the evaluation of the effect of soil
solarization, alone or in integration with biological control methods or
reduced rates of pesticides, on the control of major soilborne pathogens
under field conditions. Y. Abou-Jawdah, Y. Masri, and H. Sobh.
(Supported by Unifert Co.)
Survey and management of cucurbit virus diseases in Lebanon Virus
diseases are the major cause of economic losses in commercial cucurbit
production in Lebanon. This survey revealed that zucchini yellow mosaic
potyvirus (ZYMV) and cucurbit aphid-borne yellows luteovirus (CABYV) are
the most common viruses of field-grown cucurbits. They are followed by
watermelon mosaic virus 2 potyvirus (WMV), Papaya ringspot potyvirus (PRSV-W)
and to a lesser extent cucumber mosaic cucumovirus (CMV). Field experiments
revealed that cross protection with a mild strain of ZYMV-WK gave significant
protection of squash plants against severe virus symptoms and resulted
in significant yield increase as compared to the control. Silver mulch
also gave a significant protection against viral diseases and a higher
total yield than controls. However, the best protection and higher total
yield were obtained with floating row covers. The integration of cross
protection with silver mulch or with floating row covers improved the results
obtained with either approach. Y. Abou-Jawdah, H. Sobh, A. Fayyad, S.
El-Zammar, and H. Lecoq*. (Supported by URB and LNCSR.)
Biochemical and physiological characteristics of plants for heavy metal hyperaccumulation Thirty
species were tested for use in water-reuse systems as potential heavy metal
hyperaccumulators, based on their salinity tolerance. According to appearance,
pest tolerance and adaptability under salinity, nine species were selected
for further detailed studies. Increasing salinity from 0 to 24 dS m-1
did not significantly affect the dry weight of Calendula officinalis,
Portulaca
coronopus or Brassia hyssopifolia. Portulaca oleracea
had the highest seed germination at 12 dS m-1. When salinity
was increased to 24 dS m-1, the germination of all species dropped
significantly. Speed of germination was more sensitive to increasing salinity
than percentage germination. The lowest growth rate was observed for the
halophyte Portulaca coronopus, while Althaea rosea and Ocimum
basilicum had the highest growth rate. Increasing salinity from 0 to
24 dS.m-1 did not affect the rate of growth of Amaranthus
hybridus, Calendula officinalis and Portulaca coronopus.
R. Baalbaki, R. Zurayk, S. Talhouk, and S. Koteiche. (Supported
by URB.)
Evaluation and characterization of Lebanese pine (Pinus sp.) The
flora of the Mediterranean region, China, Japan, and parts of North America
were exceptionally rich in coniferous genera and species. This rich diversity
has steadily been eroding due to natural and man-made causes. Among the
coniferous trees, and perhaps second only to the cedars (Cedrus libani),
pines (Pinus sp.) have traditionally been associated with the Lebanese
mountain landscape which they inhabit. In Lebanon, no recent information
exists describing the number of pine species. However, two or three species
are believed to be present, P. pinea, P. brutia, and, to
a lesser extent, P. halepensis. Pine forests and trees provide a
variety of forest products of economic importance and also contribute to
the formation, structure and fertility of soil. The objectives of this
study are to evaluate and characterize some major Pinus pinea stands
in Lebanon, and to assess their potential productivity as well as potential
threats to their existence. R. Baalbaki, M. Saghie, S. Talhouk, R. Zurayk,
and Y. Adham *. (Supported by the International Plant Genetic
Resources Institute.)
Production of virus-free planting material. Part 1, Survey of potato diseases of quarantine interest Potato
is the most important vegetable grown in Lebanon. With a productexceeding
265,000 tons of potato and a cultivated area of over 14,000 ha, Lebanon
still imports between 18,000 and 22,000 tons of seed potato per annum.
The potato crop is vulnerable to infection by several plant pathogens,
some of which are of quarantine importance. ELISA technique was followed
for the diagnosis of the following virus diseases: Potato Y potyvirus (PVY),
potato leaf roll luteovirus (PLRV), Potato X potexvirus (PVX) and potato
S potyvirus (PVS). The results showed that PVY is the most commonly detected
virus (18.7 % of samples infected) followed by PLRV (6.5%), PVS (5.7%),
and PVX (4.5%). The survey must be performed for two main growing seasons
to cover the production periods and the variations encountered. Cooperation
with the Lebanese agricultural research institute for the production of
certified planting material has been solicited. Y. Abou- Jawdah, A.T.
Saad and H. Sobh. (Supported by URB.)
Coiling and prehaustoria development in cool white light-grown seedlings of small seed dodder (Cuscuta planiflora) in response to red and far-red, blue light and end-of-day irradiations Irradiation
of excised stem segments from de-etiolated seedlings of smallseed dodder
for 24 h with mixtures of red and far-red with red to far-red ratios between
0.02 to 1.0 enhanced coiling and formation of prehaustoria. Maximum number
of prehaustoria were recorded when red:far-red was near 0.1. Coiling and
prehaustoria were observed whenever estimated in vivo Pfr/Ptotal
at photoequilibrium was between 0.06 and 0.67. Irradiation of excised stem
segments from white light grown seedlings with 12 h blue light also promoted
coiling and prehaustoria formation after another 38 h in darkness. Coiling
and prehaustoria were not observed in segments pulsed with 10 min red light
at the end of 12 h blue light. Coiling and prehaustoria were observed after
photoreversible end-of-day far-red/red/far-red pulses but not after red/far-red/red
pulses. Far-red pulse may not reverse inhibition by end-of-day red pulse
when far-red is given more than 12 h after red pulse. M.A. Haidar
and G.L. Orr*. (Supported by URB and Colorado State University).
Soil solarization and chicken manure for the control of Orobanche crenata and other weeds in Lebanon A
field study was conducted in Lebanon to investigate the effect of different
durations (0-6 wk) of solarization, with/without chicken manure, on Orobanche
crenata seeds, at various soil depths (0-10 cm) and on other weeds
common in cabbage. Solarization treatments significantly reduced Orobanche
seeds
at 0 cm depth, but had no effect on Orobanche seeds below this depth.
Addition of chicken manure augmented the killing effect of solarization
on Orobanche seeds at various soil depths, and consequently the
required period of solarization for significant reduction in total shoot
number decreased from 6 to 2 wk. Solarization for 2-6 wk significantly
reduced weed growth and infestation in cabbage. Addition of chicken manure,
however, significantly increased the yield of cabbage. M.A. Haidar and
M.
Sidahmed. (Supported by URB.)
Response of Orobanche ramosa and other weeds to chicken manure and soil pH. Field
and pot experiments were carried out to study the effectiveness of various
soil pH and chicken manure on Orobanche growth and weed infestation
in potato. M.A. Haidar and Y. Al Masri. (Supported by LNCSR.)
Response of Orobanche crenata to sub-lethal doses of glyphosate Two
pot experiments were conducted to examine the effect of various sublethal
doses of glyphosate on Orobanche crenata growth and development
in broad beans. M.A. Haidar and N. Iskandarani. (Supported
by CPP Department.)
Identification and study of insects and pests in the Pinus pinea forests in Lebanon The
dry symptom of Pinus pinea trees in Lebanon was encountered in certain
areas of Kazaa Al-Matin, Lebanon. Survey of P. pinea habitat revealed
the presence of 47 insect species. Most of the species are natural inhabitants
of the pine forest and a few species are potential pests. Specimens were
collected from 10 locations of the pine forest by pitfall traps from April
until September 1997. Sixteen coleopterous families were identified including:
Anobiidae, Buprestidae, Carabidae, Cantharidae, Cerambycidae, Chrysomelidae,
Coccinellidae, Curculionidae, Dermestidae, Elateridae, Ochodaeidae, Oedemeridae,
Mordellidae, Scolytidae, Staphylinidae, and Tenebrionidae. Other identified
families included: Blattellidae and Ectobiidae (Blattodea), Chloropidae
and Heleomyzidae (Diptera), Pentatomidae and Reduviidae (Heteroptera),
Cicadellidae and Issidae (Homoptera), Gryllidae, Tettigoniidae, and Pamphagidae
(Orthoptera); and the occasionally collected lepidopterous Crambidae and
Nymphalidae. These diverse families represent part of the biodiversity
of the pine habitat that needs to be conserved, especially that the different
species maintain various niches in the ecosystem. N.S. Kawar, E.M. Abou-Fakhr
Hammad, T. El-Masri* and H. Tohmé*. (Supported by LNCSR.)
Selection of allotretraploid citrus rootstocks tolerant to biotic and abiotic factors in Lebanon Citrus
is among the most important horticultural crops in Lebanon. Certain biotic
(Tristeza, Mal Secco, gummosis) and abiotic (calcareous soils, salinity,
drought) factors may adversely affect citrus production. Development of
tolerant rootstocks is now possible through intergeneric somatic hybridization.
Floragh 1, an allotretraploid hybrid was developed by CIRAD-FLHOR, France,
is resistant to citrus Tristeza virus, which is considered as the most
damaging citrus disease and was recently detected in Lebanon. Our results
also indicated that it is tolerant to calcareous soil. The level of tolerance
was not affected by the soil water potential and was similar to sour orange,
a widely used rootstock in Lebanon. Our results concerning resistance to
the fungal disease Mal Secco were not conclusive and further experiments
are in progress. N.S. Kawar, W. Khoury*, Y. Abou Jawdah, R. Baalbaki,
M. Hamzé*, A. Joumaah*, and P. Ollitraut. (Supported
by French-Lebanese Cooperation project, CEDRE.)
Comparison of gas chromatography and immunoassay methods in measuring the distribution of dieldrin in rainbow trout tissues Studies
have been conducted to determine the distribution of dieldrin in various
tissues of rainbow trout. Medium sized fish were placed, in groups of 6,
in 300 L tanks containing purified and aerated water and maintained at
10°
C. Each group of fish was exposed to one of four dieldrin concentrations
ranging from 50 to 80 ppb. After 24 hours, the fish were taken out of the
tanks and sacrificed. The brain, gills, liver, muscles and skin were collected
from each fish. Dieldrin was extracted from each tissue using SPE techniques
and analyzed by both GC-ECD and immunoassay. Results of analyses by the
two techniques were highly correlated (r = 0.996) and showed that dieldrin
levels were highest in liver and skin tissues. It was about 1.5 fold the
level in the brain, about 2.5 fold the level in muscles and about 6.5 fold
the level in gills. Immunoassay proved to be as reliable an analytical
tool as GC in this case. N.S. Kawar, G.I. Chammas and S.M. Dagher.
(Supported
by URB.)
Investigations on late blight of potato Late
blight, caused by Phytophthora infestans, is the most important
disease of potatoes in the coastal plain of northern Lebanon. This investigation
was conducted to survey the disease in the potato growing areas of Lebanon,
isolate Phytophthora infestans, determine the mating type of the
isolates and their sensitivity to the commonly used fungicides. All isolates
collected were of the A1 Mating Type. All isolates were resistant to benalaxyl
and 34 out of the 38 isolates tested were resistant to metalaxyl. The degree
of growth inhibition caused by metalaxyl or benalaxyl varied among isolates.
The 38 isolates were sensitive to cymoxanil and dimetomorph. The isolates
differed in their linear growth rate on the unamended Rye A agar medium.
Integrated disease management, including alternation of fungicides, with
different modes of action, and mixed application schedules, is recommendedto
minimize the damage by the disease and lower the risk of resistance development.
A.T.
Saad and N.A. Awar. (Supported by URB.)
Survey, collection and diagnosis of diseases associated with almond germplasm in Lebanon The main objective of this investigation is
to survey and diagnose the diseases occurring on cultivated and wild almond
species in Lebanon. The following diseases with fungal pathogens were identified
: leaf curl by Taphrina deformans ; shot hole by Wilsonomyces
carpophilus; brown rot by Monilia laxa; wilt by Verticillium
dahliae; scab by Cladosporium carpophilum; powdery mildew by
Sphaerotheca
pannosa, in one location, and by Phyllactinia babayanii, in
three locations as a new record for Lebanon; and rust widely spread caused
by Tranzschelia discolor, also a new record for Lebanon. Bacterial
isolates included: Agrobacterium tumefasciens, cause of the
crown gall disease; and Pseudomonas and Xanthomonas isolated
from dieback and tipburn symptoms. Viral diseases included those caused
by: Prunus Necrotic Ring Spot Virus; Apple chlorotic Leaf Spot Virus; Prune
Dwarf Virus and the newly encountered record of Tomato Ring Spot Virus.
A.
T. Saad and Y. Abou Jawdeh and Z. Atallah. (Supported
by IPGRI / CWANA.)
The fire blight disease of pome fruits in Lebanon A
systematic survey was conducted to study the distribution and host range
of a serious outbreak of fire blight disease, caused by Erwinia amylovora,
on pome fruits in Lebanon. The disease was found to be widely distributed
throughout the pome fruit growing areas in Lebanon .The host range included:
Wild pear species, Pyrus syriaca Boiss. and P. bovei Steud,
both
susceptible; cultivated pear, Pyrus communis, cultivars Bartlett,
California, Passe Crassane and Miskawi highly susceptible, and Coscia of
low susceptibility; quince, Cydonia oblonga highly susceptible;
and apple cultivars Akane, Mufti, Redwinter and Sans Pareille highly susceptible,
Idared susceptible, Jonagold and Mondial Gala moderately susceptible, Fuji
and Golden Delicious of low susceptibility. All Red Delicious sports were
resistant. Analysis of weather data for 1996, 1997 and 1998 revealed favorable
conditions in 1997 and more so in 1998 for disease onset and development,
however, such weather conditions did not occur in 1996. A. T. Saad,
L. Hanna, O.J. Asly* and E. Choueiri*.
Plant parasitic nematodes of potatoes in Lebanon Eighty-eight
potato fields in thirty different locations in the Akkar and Bekaa plains
were examined for the occurrence of parasitic nematodes. Thirteen parasitic
genera were recorded from the collected soil samples besides Dorilymida
and
non-parasitic nematodes. The most frequently encountered parasitic nematode
genera were Tylenchus, Tylenchorhynchus, Aphelenchus and
Globodera,
the potato cyst nematode (PCN). The PCN, a quarantine pest detected for
the first time in Lebanon, was further investigated for the identity of
its species and pathotypes. Morphometric data, PCR and ELISA tests revealed
that all PCN populations collected were of Globodera rostochiensis.
Bioassay studies of the two major populations of G. rostochiensis
helped to identify its pathotype as Ro1. The stimulation effects of root
diffusates of 18 plant species on the egg hatching of G. rostochiensis
revealed that root diffusates from non-hosts of PCN can stimulate egg hatching
and differences in stimulation effects occurred among plant species. A.T.
Saad and Y. Al Masri. (Supported by AUB.)
Diagnosis and control of seed-borne pathogens of chickpeas and faba beans in Lebanon Faba
bean and chickpea seed samples, of different varieties, were collected
from seed suppliers in Lebanon. Sub-samples were surface disinfected and
germinated on moistened blotters and plated on nutritional agar media.
The percentage of moldy seeds of faba beans ranged from 5 to 31 % after
10 days of incubation. The fungi identified on the faba been seeds included
Aspergillus,
Penicillium, Cladosporium, Chaetomium, Rhizopus, Botrytis, Rhizoctonia,
and Fusarium on both media, and in addition Alternaria,
Chrysosporium
and Verticillium were observed on the potato dextrose agar medium.
The fungi identified on tested chickpea seed samples included Aspergillus,
Penicillium, Cladosporium, Chaetomium,
Rhizopus,
Alternaria, Ascochyta and Fusarium on both media. The percentage
of moldy seeds of chick peas ranged from 2 to 66% after 10 days of incubation.
Bacterial growth on some seeds of faba beans and chickpeas was also noticed
and recorded. A.T. Saad, Y. Abou Jawdeh
and R. Kanj. (Supported
by URB.)
Biodiversity audit, propagation and sustainable exploitation of cedars (Cedrus spp.) in the Mediterranean region The
objectives of this collaborative project are to establish methodologies
for identifying cedar genotypes and multiplying commercially elite material
within a framework of an environmentally sensitive production system and
with due regard to safeguarding and enriching the natural biodiversity.
This will be achieved by establishing an integrated system across a circum-Mediterranean
network of expertise (Lebanon, Morocco, Spain, Turkey, and the United Kingdom)
which will allow cedars to be profitably utilized but in a truly sustainable
way. The project will assess and analyze, using molecular markers, the
genetic variability in cedar provenance across the Mediterranean region.
It will formulate appropriate strategies for the management and environmentally
sensitive exploitation of cedar germplasm in each of the study areas. The
project will also evaluate genotypes suitable for use as landscape trees,
as timber trees, and identify and multiply genotypes suitable for use in
arid and semi arid areas. S.N. Talhouk and A. Al-Khatib.
(Supported by the European Community–INCO.)
Germplasm characterization and climatic zoning for viticulture in Lebanon Despite
the importance of grapes as number one fruit commodity in Lebanon, little
research has been done at the national level. The first objective of this
study was to survey and characterize local grape varieties according to
internationally recognized parameters and test their suitability for wine
production. The second objective was to define current grape growing areas
in Lebanon and delineate future potential grape growing regions. A total
of 38 grape verities were found, 10 of these were imported. Chemical analysis
of the local varieties revealed that the majority was suitable for fresh
consumption. Only 2 varieties were suitable for wine production. The majority
of wine grape growing areas is currently located in West Bekaa, identified
as a warm viticulture zone. In contrast, the study revealed that viticulture
could be expanded to other cool areas that are more suitable for the production
of premium grape varieties. S.N. Talhouk, R. Zurayk and I.
Riachi. (Supported by URB.)
In vitro propagation of native plant species with ornamental potentials Many
plants of this region are neglected, although their contribution to poverty
alleviation and local economies is or could potentially be significant.
During the FAO Fourth Technical Conference, a call was made to make greater
efforts studying and developing these neglected and underutilized species.
There are many flowering plants of exquisite beauty in Lebanon, unfortunately
they fall under the neglected, underutilized species (NUS) category of
plants, and many of them are threatened by the loss of habitat areas. Two
such genera include the Iris and the orchid. Major constraints to the development
of these plants include poor knowledge of propagation techniques and practices.
In this study in vitro techniques will be developed for the efficient propagation
of these plants. If successfully accomplished, such approach will be useful
not only for the production of large numbers of plants for potential marketing
purposes, but also for the reintroduction of these plants in their natural
habitats. S.N. Talhouk, R. Baalbaki and M. Dagher. (Supported
by URB.)
A study on the potential of safflower, Carthamus tinctorius L., in the Bekaa In
West Asia and North Africa, there is a critical and growing shortage of
edible vegetoils. This study investigates if safflower, which is an oil-seed
crop, has the potential for the Bekaa plain of Lebanon. In 1997/98, five
introduced safflower varieties were compared with a released variety of
barley (Rihane), durum wheat (Waha), bread wheat (Nesser), lentil (Talia-2),
and chickpea (Janta-2) in a field trial at AREC. Two safflower varieties
gave higher seed yield than barley, which is the highest yielding crop
in northern Bekaa. Coupled with the relatively high price of safflower
seed in the world market, these two varieties are expected to give much
higher economic returns than the other crops. Such encouraging results
suggest that planting safflower can be very profitable in northern Bekaa.
The trial is being repeated in 1998/99. Three promising introductions are
also being tested in a farmer's field near Kfardan. S.K.. Yau, R. Tannous,
and
M. Pala*. (Supported by URB.)
A comparison of 2-phase barley-based rotation systems for nutrient recycling, grazing, lamb fattening, and conserved-feed production In
semi-arid areas of West Asia and North Africa, farmers have been practicing
more continuous barley cultivation due to increasing annual numbers. Cereal/legume
rotation, which has been demonstrated to be beneficial in many parts of
the world, may provide a better option to farmers. The objectives of this
project are: (1) to assess the effects of rotation treatments on barley
grain and straw yield, nitrogen and organic matter levels in the soil,
the total nutritive value of feeds produced, and ewe/lamb weight gains,
and (2) to carry out an integrated whole-farm economic analysis on the
benefit of different barley/legume rotation systems. Eight different two-phase
barley-based rotation systems are studied at AREC. The trial was initiated
in 1994/95 and is expected to continue until 2001/2002. Grain and straw
yield, soil, vegetation, pasture and hay samples, grazing duration, live
weight grain of sheep, commodity prices, and costs of all inputs are being
recorded/collected. S.K. Yau, R. Baalbaki, S. Hamadeh, A. Nassar*, S.
Haj Hassan*, and R. Makboul. (Supported by FAFS, the International
Center for Agricultural Research in the Dry Areas, and the Lebanese Agricultural
Research Institute.)
Abou-Fakhr Hammad, E.M. and Kawar, N., Aphid-endoparasitoid complex on certain vegetables and other plant species in Lebanon. Entomologichce Obozrenie (Entomological Review), 4, 753-763, 1998. Abou-Jawdah, Y., Protected cultivation in Lebanon. In A contribution towards a data base for protected cultivation in the Mediterranean region, ed. Abou-Hadid, A., 91-123. Rome, Italy: FAO, 1997. Assi, R., Abou-Jawdah, Y. and Asly*, O., Evaluation of fungicides and timing of fungicidal applications for the control of powdery mildew. Fungicide and Nematicide Tests, 52, 2, 1997. Baalbaki, R., Zurayk, R., Bleik, M. and Talhouk, S., Germination and seedling development of drought tolerant and susceptible wheat under moisture stress. Seed Science and Technology, 27, 1-12, 1999. Baalbaki, R., and Copeland*, L.O., Seed size, density and protein content effects on field performance of wheat. Seed Science and Technology, 25, 511-521, 1997. Diab El-Arab, H. and Abou-Jawdah, Y., Evaluation of the sensitivity of Venturia inaequalis isolates to fungicides used in Lebanon. Arab Journal of Plant Protection, 15(1),3-9, 1997. Haidar, M.A., Iskandarani, N., Sidahmed, M. and Baalbaki, R., Response of dodder (Cuscuta campastris) seeds to solarization and chicken manure. Crop Protection, 18(4), 253-258, 1998. Haidar, M.A., Orr*, G.L. and Westra*, P., The response of dodder (Cuscuta spp.) seedllings to phytohormones under various light regimes. Annals of Applied Biology 132, 331-338, 1998. ———, Initial characteristics of the sensory physiology of Cuscuta spp. Weed Research, 37, 219-228, 1997. Ibrahim*, S.K., Saad, A.T., Haydock*,P.J. and Al-Masri, Y., Occurrence of the potato cyst nematode Globodera rostochiensis in Lebanon. Fundamental and Applied Nematology, 22, 1999. Rubeiz, I.G., Khansa, M., and Freiwat, M.M., Evaluation of layer litter rates as a fertilizer for greenhouse strawberry and lettuce. Communication in Soil Science and Plant Analysis, 29(1&2), 161-167, 1998. Rubeiz, I.G., Nadi, K.M., Farran, M.T., and Freiwat, M.M., Rowcover effects on growth and yield of strawberry cultivars grown in a Mediterranean climate. Journal of Small Fruit and Viticulture, 5(2), 47-56, 1997. Ryan*, J., Singh*, M. and Yau, S.K., Excess boron in Syrian soils and implications for plant growth. Soil & Tillage Research, 45, 407-417, 1998. Saad, A.T., Hanna, L., Asly*, O.J. and Choeiri*, E., The distribution and host range of the first serious outbreak of fire blight in Lebanon. Acta Horticulturae, 489, 1999. Talhouk, S.N., Lubani, R.T., Parmaksizian, L.S., and Nehme, G.A., Survey and characterization of almond germplasm in Lebanon. Acta Horticulturae. 470, 101-108, 1997. Wheeler*, W.B. and Kawar, N.S. Environmental hazards of fumigants: the need for safer alternatives. Arab Journal of Plant Protection, 15 (2), 154-162. 1997. Yau, S.K., Differential responses of barley, durum and bread wheat to high levels of soil boron. In: Accomplishments and future challenges in Dryland Soil Fertility Research in the Mediterranean Area, J. Ryan (Ed), Aleppo: Institut Mondial du Phosphate (IMPHOS) and ICARDA, 208-216, 1997. ———, Efficiency of alpha-lattice designs in International wheat and barley yield trials. Journal of Agricultural Sciences (Cambridge), 128, 5-9, 1997. Yau, S.K., Nachit*, M.M., and Ryan*, J., Variation in boron-toxicity tolerance in a durum wheat core collection. In Boron in Soils and Plants, ed. Bell, W. and Rerkasem, B., 117-120. Dordrecht: Kluwer Academic Publishers, 1997. ———, Variation in growth, development and yield of durum wheat in response to high soil boron. II. Phenotypic differences. Australian Journal of Agricultural Research, 48, 951-957, 1997. Yau, S.K., Nachit*, M.M., Ryan*, J. and Valkoun*, J., Boron-toxicity tolerance in durum wheat. In SEWANA (South Europe, West Asia and North Africa) Durum Research Network, ed. Nachit, M.M, Baum, M., Proceddu, E., Monneveux, P. and Picard, E., 174-179. Aleppo: ICARDA, 1998. Yau,
S.K. and Saxena*, M.C., Variation in growth, development and yield of durum
wheat in response to high soil boron. I. Boron effects. Australian journal
of Agricultural Research, 48, 945-949, 1997.
ABSTRACTS,
CONFERENCES AND PROCEEDINGS
Abou-Fakhr Hammad, E.M., Hanna, L. and Hawi, Z., Efficacy of botanical extracts against the cotton whitefly, Bemisia tabaci Genn. Abstracts of the Sixth Arab Congress of Plant Protection, Beirut, Lebanon, 1997. Abou-Fakhr Hammad, E.M. and Antar, N.M., Efficacy of selected insecticides against the citrus leafminer Phyllocnistis citrella (Stainton) (Lepidoptera: Gracillaridae) in Lebanon. Abstracts of the Syrian-Lebanese Research Days, Pests of Fruit Trees and Their Control, Lattakia, Syria, 1997. Abou-Fakhr Hammad, E.M. and Nemer, N., Efficacy of Melia azedarach extracts in the management of Liriomyza huidobrensis on vegetables. Lebanese Abstracts, II-210, 1997. Abou-Jawdah, Y., Itani*, H., Fleifel*, F., Nasrallah*, H. and Hawi, Z., Integrated pest management in Lebanon, Country Report. Workshop on IPM by Farmers –A Participatory Approach, Ismailia, Egypt, November 15-20, 1997. Abou-Jawdah, Y., Maalouf, R., Soubra, K.H. and Hanna, L., Varietal reaction to infection by tomato yellow leaf curl bigeminivirus. Abstracts of the Second International Workshop on Bemisia and geminivirual diseases. San Juan Puerto Rico, 1998. Abou-Jawdah, Y., Sobh, H. and Fayad, A., First report of cucurbit aphid-borne luteovirus in Lebanon. Plant Disease, 81, 1331, 1997. Abou-Jawdah, Y., Sobh, H., Fayad, A., and Lecoq, H., Yellowing diseases of cucurbits—A major threat to Lebanese Agriculture. Abstracts of the 7th International Congress of Plant Pathology, Edinburgh, Scotland, 1998. Baalbaki, R., Alkhatib, A., Talhouk, S., and Adham*, Y., A comparison of biodiversity indices based on seed and whole-plant analysis. Proceedings of the Symposium on Seed Biology and Technology: Applications and Adv. USDA Cooperative Research W-168, 1997. Haidar, M.A., Iskandarani, N., Sidahmed, M. and Baalbaki, R., Response of dodder (Cuscuta spp.) seeds to solarization and chicken manure. Abstracts of the Weed Science Society of America, San Diego, USA, 1999. Haidar, M.A., and Orr*, G.L., Coiling and prehaustoria development in cool white light-grown seedlings of smallseed dodder (Cuscuta planiflora) in response to red and far-red, blue light and end-of-day irradiations. Abstracts of the Weed Science Society of America, Chicago, USA, 1998. Haidar, M.A., and Bibi, W., Response of branched broomrape (Orobanche ramosa) growth and development to various animal manures in potato. Abstracts of the Sixth Arab Congress of Plant Protection, Beirut, Lebanon, 1997. Haidar, M.A., Bibi, W., and Raad, M., Chemical weed management in corn. Abstracts of the Sixth Arab Congress of Plant Protection, Beirut, Lebanon, 1997. Haidar, M.A., Bibi, W., and Iskandarani, N., Chemical weed management in chickpea. Abstracts of the Sixth Arab Congress of Plant Protection, Beirut, Lebanon, 1997. Kawar, N.S., The application of immunoassay techniques for the detection of pesticide residues in food. Abstracts of the Sixth Arab Congress of Plant Protection, Beirut, Lebanon, 1997. ———, The role of pesticides and fertilizers in environmental pollution. Proceedings of the Conference on Environmental Problems in Lebanon: Facts and Alternatives. Beirut, Lebanon. Abaad, 8, 8-16, 1998. Kawar, N.S., Atallah, Z. and Dagher, S.M., Toxicity of dieldrin to rainbow trout, and its uptake by various tissues. Abstracts of the 216th American Chemical Society National Meeting, Boston, MA, 1998. Kawar, N.S., Hawi, Z.K. and Dagher, S.M., Fate of fenitrothion in artificially fortified grape juice processed into alcoholic drinks: Comparative determinations by immunoassay and GLC methods. Abstracts of the 214thAmerican Chemical Society National Meeting, Las Vegas, NV., 1997. Kawar, N.S., Abou Fakhr-Hammad, E., El-Masri, T.* and Tohme, H.* , Identification and study of insect species in the Pinus pinea forests in Lebanon. Abstracts of the Syrian-Lebanese Research Days, Pests of Fruit Trees and Their Control, Lattakia, Syria, 1997. Maalouf, R. and Abou-Jawdah, Y., Studies on the resistance of tomato genotypes to tomato yellow leaf curl geminivirus in Lebanon. Abstracts of the Sixth Arab Congress of Plant Protection, Beirut, Lebanon, 1997. Orr*, G.L. and Haidar, M.A., Phototropism and gravitropism in dodder (Cuscuta planiflora) seedlings. Abstracts of the Sixth Arab Congress of Plant Protection, Beirut, Lebanon, 1997. Rubeiz, I.G., Chehab, A.M., Friewat, M.M., and Farran, M.T., Broiler litter and inorganic nitrogen fertilizer influence on yield and earliness of June-bearing strawberries. HortScience, 32 (3), 487, 1997. Saad, A.T., Metalaxyl resistance and mating types of populations of Phytophthora infestans in Lebanon. Abstracts of the Sixth Arab congress of Plant Protection, Beirut, Lebanon, 1997. Saad, A.T., Asly*, O.J., Choueri*, E. and Hanna, L., The distribution and host range of the first serious outbreak of fire blight in Lebanon. Abstracts of the 8th International Workshop on Fire Blight, Kusadasi, Turkey, 1998. Saad, A.T., and Awar*, N.A., Fungicidal resistance and mating types of populations of Phytophthora infestans in Lebanon. Abstracts of the 7th International Congress of Plant Pathology, Edinburgh, Scotland, 1998. Sobh, H., Abou-Jawdah, Y. and Fayad, A., Survey of cucurbit viruses in Lebanon. Abstracts of the Sixth Arab Congress of Plant Protection. Beirut, Lebanon, 1997. Talhouk, S.N., Shmoury, M., Baalbaki, R., and Khuri, S., Somatic embryogenesis of the cedars of Lebanon (Cedrus libani). HortScience, 32 (3), 461, 1997. Talhouk, S.N., Shmoury, M., Baalbaki, R., and Khuri, S., Initiation of embryogenic cultures from immature zygotic embryos of Cedrus libani. Lebanese Abstracts, 443, 1997. Yau,
S.K. and Erskine*, W., Boron-toxicity tolerance in lentil accessions from
different regions of the world. Proceedings of the 3rd European
Conference on Grain Legumes, Valladolid, Spain, 319, 1998.
Al-Masri, Y., Plant parasitic nematodes of potatoes in Lebanon (1999). A.T. Saad). Al-Iskandarani, N., The effect of soil solarization on dodder, weed seed-bank and natural weed population (1998). M.A. Haidar. Al-Khatib, A., Methods of evaluating germplasm and their applicability to wheat genotypes (1998). R. Baalbaki. Al-Khatib, B., Color mulch treatment effect on yield and insect population of squash, broccoli and strawberry (1999). I. Rubeiz. Fayad, A., Diagnosis and control of cucurbit viruses in Lebanon (1997). Y. Abou-Jawdeh. Jazzar, C., Management of Bemisia tabaci on tomatoes by Melia azedarach extracts and specialized biocontrol agents (1999). E. Abou-Fakhr Hammad. Khalifeh, S., Evaluating and characterizing safflower (Carthamus tinctorius) germplasm (1998). R. Baalbaki. Koteiche, S., Selecting salt-tolerant ornamentals for inclusion in water reuse systems (1998). R. Baalbaki. Lubani, R., Survey and characterizations of almond (Amygdalus species) germplasm in Lebanon. S. Talhouk. Nemer, N., Efficacy of Melia azedarch in the management of Liriomyza huidobrensis on vegetables (1997). E. Abou-Fakhr Hammad. Parmaksizian, L., Molecular characterization of almond (Amygdalus species) germplasm in Lebanon (1999). S. Talhouk. Riachy, I., Germplasm characterization and climatic zoning for viticulture in Lebanon (1998). S. Talhouk. Shmoury, M., Initiation of embryonic callus from immature zygotic embryos of Cedrus libani (1997). S. Talhouk. Sleiman, A., Color mulches influence on growth and yield of strawberry, cantaloupe, and squash (1999). I. Rubeiz. Zournajian,
H., Effect of secondary plant compounds and callus extracts of Melia
azedarach on Bemisia tabaci (1999). E. Abou-Fakhr Hammad.
|
