Since the properties of wood significantly change with its moisture content, it is important to know the effect of different moisture conditions on wood. A brief summary is provided on this topic in the first part of this article. The compression along the wood grain is a modification resulting in better pliability. The moisture dependence of mechanical properties of longitudinally compressed wood is not known yet. For this purpose, the results in this article are considered as basic research results. Bending-and compression tests on beech specimens compressed longitudinally by 20% were carried out at different moisture contents. Changing moisture content has almost no significant effect on the modulus of rupture of wood that has been longitudinally compressed, compared to the sensitivity to changes in moisture content of untreated wood. However, the effect of moisture content on the change of bending modulus of elasticity, compressive strength parallel to the grain and bendability coefficient diverges significantly. As a result of these changes, there is a great difference in the pliability with different moisture contents of treated wood. For the best pliability during bending, the moisture content of longitudinally compressed wood must be close to its fiber saturation point.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Pleating is an optimal way to increase bendability of wood used in diverse industrial applications. It results in the excessive buckling of cell walls and modifications of constitutive polymers. However, thoughtful understanding of the physical–chemical mechanisms of that modification process is very limited. The main purpose of the present study was to identify changes in functional groups of wood polymers induced by longitudinal compression. Four types of wood samples prepared from beech and sessile oak (untreated, steamed, longitudinally compressed and fixated for 1 min as well as longitudinally compressed and fixated for 18 h) were assessed by infrared spectroscopy. The spectra interpretation revealed that changes can be observed in hydroxyl as well as in carbon–oxygen single and carbon-hydrogen functional groups of polysaccharides and lignin. Beech wood seems to be more susceptible to investigated modification processes as compared to oak. Detailed interpretation of infrared spectra allows identification of changes in the hygroscopicity of wood as well as alterations in the linkage between structural elements in the polymer matrix of wood induced by the applied treatments. Graphic Abstract

Nitrogen is typically applied to cotton (Gossypium hirsutum L.) in two or three split applications, however, with subsurface drip irrigation (SDI), nitrogen can be applied daily. The major objective was to show yield and grade response of cotton where nitrogen was applied daily through a SDI system at two nitrogen application strategies compared with overhead sprinkler (SP) and non-irrigated (DRY) regimens. The SDI system provided daily irrigation and nitrogen to a randomized block design with three irrigation levels (100%, IL1; 75%, IL2; and 50%, IL3); two nitrogen levels, N1 and N2, (67 and 101 kg ha-1); two drip tube lateral spacings, IR and AM (individual row = IR, alternate row middles = AM), with three replications per treatment. Nitrogen was applied in split applications to the SP and DRY areas in a randomized block design. Cotton was planted following peanuts during the 1999 and 2000 growing seasons on a Tifton sandy loam soil (fine-loamy, kaolinitic, thermic Plinthic Kandiudults). In 1999, there was a 6% lint yield increase for N2 (total lint: 1484 kg ha-1), but there was no lint yield difference with nitrogen levels in 2000 (total lint: 1280 kg/ha). There was no yield difference with drip tube lateral spacing or irrigation level except at IL3 (50%) in 1999. Lint yield was higher in both the SDI and SP compared with the DRY regime. Differences within grade parameters were not consistent across years for micronaire, fiber strength, or fiber uniformity with respect to nitrogen applied or irrigation system. Overall, the application of nitrogen on a daily basis with SDI had the same lint yield and grade compared with SP and higher lint yield than the DRY. The lower nitrogen rate (N1) had the same yield as the higher nitrogen rate (N2) which suggests that lower nitrogen rates may be appropriate when using SDI.

Economic benefits from irrigating peanuts in the humid Southeast are often marginal or negative because proper consideration must be given to the complex relationships of plant, soil, pest and weather. Computer programs EXNUT and MOISNUT were developed to consider these complex relationships and to recommend timely irrigation of peanuts. A 3-yr study was conducted to evaluate the feasibility of using these computer programs for scheduling peanut irrigation on sandy and medium textured soils in Georgia. During 1994-1996, irrigation was applied two to nine times as recommended by these two computer programs. Net returns to irrigation were $490/ha higher for irrigated plots with these two programs than for nonirrigated plots. Serious compaction problems negated irrigation benefits in 1994 on the medium textured soil, and poor fertility and high disease pressure on the sandy soil negated irrigation benefits in 1995. Without these problems, the average benefit was $920/ha. During 1996, the irrigation benefits from using EXNUT and MOISNUT programs and the fungicide Folicur averaged $1098/ha and $1011/ha for sandy and medium textured soils, respectively. On the average, market grade of the irrigated peanuts were higher than for the nonirrigated peanuts. No aflatoxin (< 1 ppb) was found in edible grade peanuts where these computer programs were used to manage irrigation. Based upon this study and previous research, the EXNUT and MOISNUT computer programs are very useful for scheduling irrigation on peanuts. Proper use of these computer programs should minimize the negative aspects of irrigation for fields with high disease pressure and fields that produce plants with shallow root systems.

-Knowledge of hygroscopicity is extremely important both in the use of native wood and modified wood. In this study, the modification method was steaming at 100 °C, then longitudinal compression at a rate of 20%. The moisture content (MC) of treated and untreated green beech wood (Fagus sylvatica L.) was reduced in a climate chamber with gradual reduction of air humidity at 20 °C. The difference of calculated fibre saturation points between control samples and samples compressed for a long time was 6% (MC%). In the course of desorption, this difference decreased, and finally disappeared at 10% moisture content (40% relative humidity). In the second step of the research work, the speed of vapour adsorption was checked. The absolute dry samples were placed in air with 95% relative humidity. The highest deviation in the moisture content was 1% (MC%) between the control and the compressed samples. The compressed wood dries faster than the control samples under the same conditions. Furthermore, during adsorption, the moisture content of the compressed samples at room conditions is lower. equilibrium moisture content / fibre saturation point / sorption / wood bending / steaming / longitudinal compression Kivonat -A rostirányú tömörítés hatása a faanyag higroszkóposságára. A higroszkóposság ismerete rendkívül fontos a kezeletlen és a modifikált faanyagok alkalmazása esetén egyaránt. A modifikációs eljárás gőzölés volt 100 °C-on, majd hosszirányú tömörítés 20% arányban. Élőnedves kezelt-és kezeletlen bükk faanyagok (Fagus sylvatica L.) nedvességtartalmát (MC) redukáltuk klímaszekrényben a páratartalom fokozatos csökkentésével 20 °C-on. Az eltérés a kontroll, valamint a hosszú ideig tömörített minták számított rosttelítettségi pontjai között 6% (MC%) volt. A deszorpció során ez az eltérés csökkent, majd 10% nedvességtartalomnál eltűnt (40% relatív páratartalom). Második lépésben a párafelvétel sebességét vizsgáltuk, az abszolút száraz mintákat 95% relatív páratartalmú légtérbe helyezve. A nedvességfelvétel során a kontroll és a tömörített minták nedvességtartalma között maximum 1% (MC%) eltérés mutatkozott. Az előzőek alapján megállapítható, hogy a tömörített faanyag gyorsabban szárad azonos körülmények között, továbbá a tömörített mintáknak a felhasználási körülmények közötti egyensúlyi nedvességtartalma alacsonyabb, mint a kontroll mintáké. egyensúlyi nedvességtartalom / rosttelítettségi pont / szorpció / fahajlítás / gőzölés / hosszirányú tömörítés *