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Panama disease (aka Fusarium wilt) of banana (Musa spp.) has been a destructive problem for well over a century. Race 1 of the pathogen, Fusarium oxysporum f. sp. cubense (Foc), was responsible for the demise of the first export trades of banana that were based on the cultivar ‘Gros Michel’. Currently, tropical race 4 (TR4) impacts the Cavendish cultivars, which are most important in both export and smallholder production. TR4 was confirmed in Jordan in 2013, but has probably been present in the country since at least 2005. The outbreak in Jordan was apparently the first occurrence of Panama disease in the Middle East, but it also represented a considerable expansion of TR4’s distribution, which had previously been restricted to the Far East. How TR4 arrived in Jordan is not known. However, it is clear that TR4 has spread within Jordan, and is now also present elsewhere in the Middle East and Africa. We review the history, epidemiology and management of Panama disease, and discuss the current distribution of TR4 and its potential impact on banana production in the Middle East.

A field experiment was conducted to investigate the effect of a flat-roof screenhouse on banana transpiration (Tr) and microclimate during the summers and falls of 2005 and 2006 in Northern Israel. The clear polyethylene screen reduced radiation by between 8 and 25% depending on dust accumulation and aging. In the screenhouse, wind speed, global radiation and air temperature were reduced by more than 60, 20 and 1%, respectively, and relative humidity increased by 8% relative to an external meteorological station. Class A pan evaporation and reference crop evapotranspiration (ET 0 ) were reduced by about 44 and 33% in the screenhouse, respectively. Inside, banana transpiration (Tr), measured with thermal dissipation probes, was about 90% of that outside the screenhouse. The relatively small reduction in Tr inside was caused by increased canopy conductance in the screenhouse during much of the day, which at mid-day was double that outside. Hourly average canopy conductance increased with increasing vapor pressure deficit (VPD) during much of the day and decreased late in the afternoon. Inside the screenhouse, leaves were large and whole with a high boundary layer resistance, but outside leaves were torn by the wind, which, we estimate, reduces the characteristic leaf dimension by an order of magnitude from 1.4 to 0.14 m, decreases boundary layer resistance and reduces the decoupling coefficient. The decoupling coefficient outside was up to 0.3 in the morning and declined to less than 0.1 in the afternoon when wind speed increased. Inside, the corresponding values were 0.8 and 0.5, respectively. This indicates that inside radiative factors dominate, while outside aerodynamic factors dominate during much of the day. A sensitivity analysis showed that the reduction in ET 0 in the screenhouse is mainly due to the combined reductions of wind speed and global radiation. Inside, the screenhouse Tr was similar in two irrigation treatments (85 and 100% of class A pan evaporation) and also similar to outdoor pan evaporation.

We examined the impact of two different approaches to managing irrigation water salinity: salt leaching from the field (“conventional” management) and water desalination before field application (“alternative” management). Freshwater commonly used for irrigation (FW) and desalinated water (DS) were applied to the high-water-demanding crop banana at four different rates. Both irrigation rate and water salinity significantly affected yield. DS application consistently produced higher yields than FW, independently of irrigation rate. The highest yield for FW-irrigation was achieved with the highest irrigation rate, whereas the same yield was obtained in the case of DS-irrigation with practically half the amount of water. Yield decreased with FW-irrigation, even when the water salinity, ECi, was lower than the limit considered safe for soil and crops. Irrigating with FW provided a massive amount of salt which accumulated in the rhizosphere, inducing increased osmotic potential of the soil solution and impairing plant water uptake. Furthermore, applying the “conventional” management, a significant amount of salt is leached from the rhizosphere, accumulating in deeper soil layers, and eventually reaching groundwater reservoirs, thus contributing to the deterioration of both soil and water quality. Removal of salt excess from the water before it reaches the field by means of DS-irrigation may save significant amounts of irrigation water by reducing the salt leaching requirements while increasing yield and improving fruit quality, and decreasing salt load in the groundwater.

Most banana screenhouses are currently equipped with transparent screens, with a nominal shading of 8–15%. Two types of screens are widely used, woven or knitted, which differ in their texture and hence in their radiative and aerodynamic properties. These differences may induce different micro-climatic conditions and hence different atmospheric water demand, plant response and yield. We have investigated four types of screens based on different shading levels (8%, 10% or 13%) and different screen textures (woven or knitted). A large commercial banana plantation in Northern Israel was covered with patches of the four different screen types, each in 4–5 replicates, randomly located. Air velocity, temperature, humidity and net radiation were measured simultaneously below two out of the four screen types: the 10% woven and 10% knitted. The results showed that both the net radiation and air temperature were similar under these two screens. Nevertheless, under the knitted screen the horizontal mean air velocity was 18% higher and the specific humidity 8% lower than under the woven screen. Leaf lamina tearing (typical wind damage) and estimated reference evapotranspiration were higher under the knitted screen; the latter mainly during the fall–winter season. However, the horticultural measures of flowering and fruit yield characteristics were the same under all four screen types, with results typical of screenhouse banana plantations in this region. Hence, the results suggest a potential increase in water use efficiency under the woven as compared to the knitted screen.

The objective was to investigate the combined effect of irrigation regime and fruit load on trunk-diameter variation patterns of ‘Hass’ avocado trees grown in lysimeters, at different phenological periods. Plant water uptake of both fruited and defruited trees was monitored at high temporal resolution during successive growth stages. The trunk growth rate (TGR) during all the experiments was not affected by the irrigation treatments, yet daily TGR fluctuated significantly during the season, probably in association with periodic changes in the priority of partitioning of carbohydrates between reproductive and vegetative plant organs, i.e., flushes of shoot or root growth. Fruit load clearly played a dominant role in determining TGR, very likely because of the dramatic effect of fruit load on stomatal conductance and leaf carbohydrate concentration and, therefore, on the overall availability of assimilates. Thus, analyses of trunk diameter variation (TDV) data that lead to evaluation of TGR and maximum trunk diameter variation (MTDV) reflect phenological stages and periodicity of shoot, fruit and root growth, and also may provide an integrative, “holistic viewpoint” of overall tree status. The observed high dependency between the MTDV and irrigation treatments may indicate that MTDV actually depends on water-stress history rather than on the actual plant-water status. Thus, MTDV cannot be used on an absolute basis for irrigation management control. On the other hand, it may be a very efficient aid to control irrigation when used on a relative basis, after identifying the impacts of local phenological and environmental factors on the MTDV. Furthermore, the immediate MTDV response to accidental faults may illustrate the advantages of using dendrometer devices for remotely controlling irrigation systems.

There is little information on bruxism related to illicit drug use. Prolonged drug use may damage the stomatognathic system via oral motor overactivity. The aim of the present study was to compare the rates of bruxism and temporomandibular disorders (TMDs) between prisoners with and without drug-use disorders, to evaluate the association between methadone treatment and bruxism and to assess the possible relationship between bruxism and pain. The sample included 152 male prisoners, 69 of whom were drug users maintained on methadone. All prisoners were examined by an experienced dentist and completed a questionnaire on their oral habits, with the aim of detecting signs or symptoms of TMD and/or bruxism. Additional data were collected from medical files. The prevalence of sleep bruxism and awake bruxism, but not of TMDs, was significantly higher among drug-user than non-drug user prisoners (52.2% vs. 34.9% for sleep bruxism, 59.7% vs. 30.1% for awake bruxism, and 46.3% vs. 25.6% for TMDs, respectively). Participants with awake bruxism were statistically more sensitive to muscle palpation compared with participants with sleep bruxism [rating scores (mean ± SD): 0.32 ± 0.21 vs. 0.19 ± 0.28, respectively]. An association was found between sleep bruxism and awake bruxism. It seems that there is a direct or an indirect association between methadone maintenance treatment and sleep bruxism or awake bruxism in male prisoners.

Boron (B) is known to accumulate in the leaf margins of different plant species, arguably a passive consequence of enhanced transpiration at the ends of the vascular system. However, transpiration rate is not the only factor affecting ion distribution. We examine an alternative hypothesis, suggesting the participation of the leaf bundle sheath in controlling radial water and solute transport from the xylem to the mesophyll in analogy to the root endodermis. In banana, excess B that remains confined to the vascular system is effectively disposed of via dissolution in the guttation fluid; therefore, impairing guttation should aggravate B damage to the leaf margins. Banana plants were subjected to increasing B concentrations. Guttation rates were manipulated by imposing a moderate osmotic stress. Guttation fluid was collected and analysed continuously. The distribution of ions across the lamina was determined. Impairing guttation indeed led to increased B damage to the leaf margins. The kinetics of ion concentration in guttation samples revealed major differences between ion species, corresponding to their distribution in the lamina dry matter. We provide evidence that the distribution pattern of B and other ions across banana leaves depends on active filtration of the transpiration stream and on guttation.

The performance of ‘Hass’ avocado trees grown in lysimeters under different irrigation regimes obtained by manipulating drip irrigation frequency and root volume was examined. The experimental design comprised six treatments (3 × 2) with three irrigation frequencies and two container volumes (100- and 200-L). The three irrigation frequencies were: pulsed irrigation (10–20 min every 30 min) throughout the day (Irg1), one daily irrigation event beginning at night and terminated in the morning every day (Irg2) and one irrigation event every two days (Irg3). Irrigation management induced significant differences in water availability in the root zone and subsequently, the diurnal and periodic water uptake. Water uptake of trees in the Irg1 treatment closely followed changes in the meteorological conditions (air temperature, pan evaporation and vapour pressure deficit) while that of trees in the Irg2 and Irg3 treatments was depressed by intermediate and severe water stress, respectively. The experimental treatments had little effect on the vegetative growth, flowering or fruit-set processes. However there were significant treatment differences on fruitlet abscission and accordingly, on fruit yield. Black spots initiated from the seed became apparent on some of the fruits at the beginning of June, and about two weeks later an intensive abscission of fruitlet begun that ended at the beginning of July. The abscission was more intense in the 100-L than the 200-L containers, in the following order: Irg3 > Irg2 ≫ Irg1 regardless of the container volume. Net CO2 assimilation during periods of fruit growth decreased in trees exposed to moderate or severe water stress (Irg2 and Irg3, respectively) and therefore, it is plausible that fruitlet abscission resulted from carbohydrate stress. Improvement of water and nutrient availability, especially in periods where the activity of the root system was weak as a result of low carbohydrate supply presumably played a dominant role in seeds or fruit function.

Transmittance of short wave radiation components by seven different agricultural screens made of white, off-white, or clear threads was investigated. Theoretical models of non-scattered transmittance of direct and diffuse radiation based on screen dimensions and solidity were developed. Transmission of photosynthetic, global, and near infra-red (NIR) radiation components by the screens was measured outdoors using an array of sensors and 3 × 3 m screens mounted above a roof. Free Open Area ( F , the complement of solidity) of the screens, determined from transmittance of direct radiation, ranged from 36 to 74%. F from analyses of screen geometry or scanner images differed from that by less than 13%. Direct transmittance declined with solar elevation angle and became zero below a cutoff angle depending on inter-thread spacing and thread width. Although transmissivity of direct and diffuse radiation was predicted adequately by the models, significant downward scattering of direct radiation by the screens increased transmittance to total radiation, so models underestimated actual transmittance. Empirical trigonometric equations fitted results well, and can be used for prediction. Orientation of screens with rectangular holes has a significant influence on transmission, with clear implications for screen deployment above agricultural crops. Measurements in a screenhouse covering a banana plantation showed that transmission decreased linearly with time by about 0.1% day −1 during the rainless summer due to dust accumulation on the screen, but recovered after rain. The implications of the findings for agriculture are discussed.

Turgor pressure provides a sensitive indicator for irrigation scheduling. Leaf turgor pressure of Musa acuminate was measured by using the so-called leaf patch clamp pressure probe, i.e. by application of an external, magnetically generated and constantly retained clamp pressure to a leaf patch and determination of the attenuated output pressure P(p) that is highly correlated with the turgor pressure. Real-time recording of P(p) values was made using wireless telemetric transmitters, which send the data to a receiver base station where data are logged and transferred to a GPRS modem linked to an Internet server. Probes functioned over several months under field and laboratory conditions without damage to the leaf patch. Measurements showed that the magnetic-based probe could monitor very sensitively changes in turgor pressure induced by changes in microclimate (temperature, relative humidity, irradiation and wind) and irrigation. Irrigation effects could clearly be distinguished from environmental effects. Interestingly, oscillations in stomatal aperture, which occurred frequently below turgor pressures of 100 kPa towards noon at high transpiration or at high wind speed, were reflected in the P(p) values. The period of pressure oscillations was comparable with the period of oscillations in transpiration and photosynthesis. Multiple probe readings on individual leaves and/or on several leaves over the entire height of the plants further emphasised the great impact of this non-invasive turgor pressure sensor system for elucidating the dynamics of short- and long-distance water transport in higher plants.

Typical salt stress symptoms appear in banana (Musa sp., cv. 'Grand Nain' AAA) only along the leaf margins. Mineral analysis of the dry matter of plants treated with increasing concentrations of KCl or NaCl revealed significant accumulation of Na+, but not of K+ or Cl(-), in the affected leaf margins. The differential distribution of the three ions suggests that water and ion movement out of the xylem is mostly symplastic and, in contrast to K+ and Cl(-), there exists considerable resistance to the flow of Na+ from the xylem to the adjacent mesophyll and epidermis. The parallel veins of the lamina are enclosed by several layers of bundle sheath parenchyma; in contrast, the large vascular bundle that encircles the entire lamina, and into which the parallel veins merge, lacks a complete bundle sheath. Xylem sap containing a high concentration of Na+ is 'pulled' by water tension from the marginal vein back into the adjacent mesophyll without having to cross a layer of parenchyma tissue. When the marginal vein was dissected from the lamina, the pattern of Na+ distribution in the margins changed markedly. The distinct anatomy of the marginal vein plays a major role in the accumulation of Na+ in the margins, with the latter serving as a 'dumping site' for toxic molecules.

Boron (B) is known to accumulate in the leaf margins of different plant species, arguably a passive consequence of enhanced transpiration at the ends of the vascular system. However, transpiration rate is not the only factor affecting ion distribution. We examine an alternative hypothesis, suggesting the participation of the leaf bundle sheath in controlling radial water and solute transport from the xylem to the mesophyll in analogy to the root endodermis. In banana, excess B that remains confined to the vascular system is effectively disposed of via dissolution in the guttation fluid; therefore, impairing guttation should aggravate B damage to the leaf margins. Banana plants were subjected to increasing B concentrations. Guttation rates were manipulated by imposing a moderate osmotic stress. Guttation fluid was collected and analysed continuously. The distribution of ions across the lamina was determined. Impairing guttation indeed led to increased B damage to the leaf margins. The kinetics of ion concentration in guttation samples revealed major differences between ion species, corresponding to their distribution in the lamina dry matter. We provide evidence that the distribution pattern of B and other ions across banana leaves depends on active filtration of the transpiration stream and on guttation.

A qualitative description and information are given on somaclonal variants of seven in vitro propagated banana cultivars. Variants were expressed in plant stature, abnormal leaves, pseudostem pigmentation, persistence of flowers and split fingers. Dwarfism was the most common variant, indicated by mutation of intermediate-height cultivars to a dwarf height and, in one case of a low-statured cultivar, to an extra dwarf. Tall mutants were very rare. No dwarfs were found in cultivar ‘Red’. The second most common was a group of variants which are characterized by different degrees of thick and rubbery narrow leaves with variable pale green mottling (mosaic). These variants occurred in the Cavendish subgroup and in ‘Red’, and are suspected to be aneuploids. Data are presented on vegatative and reproductive parameters of dwarf and mosaic, as compared with normal plants. Other variants which occurred at a low rate are described. To facilitate screening out of the variants during the propagation procedure, the stage at which the different variants can be detected is described. The incidence and rate of occurrence of somaclonal variants are presented and discussed.

Biomass accumulation (annual net primary productivity, NPP) in a plantation of Musa sp., Musaceae is linearly correlated with solar irradiance (IR) between 100 and 32% of ambient levels (NPP = 0.82 IR + 20.42, p

A method for forecasting banana flowering distribution in the Jordan Valley, using the previous year's meteorological and flowering data, is described. The forecasting is done at the beginning of May of each year, for the subsequent flowering season. Reliable prediction of flowering distribution is of great importance for planning agrotechnical operations, work scheduling and establishing marketing policy.