Log sawing positioning optimization and log bucking of tropical hardwood species to increase the volume yield

The sawmill industry is a very important link in the Mozambique forest products value chain, but the industry is characterized by undeveloped processing technology and high-volume export of almost unrefined logs. The low volume yield of sawn timber has been identified as a critical gap in the technological development of the industry. To improve the profitability of the industry, there is thus a need to develop methods and techniques that improve the yield. In this paper, different positioning of logs prior to sawing and the possibility of increasing the volume yield of crooked logs by bucking the logs before sawing have been studied. A computer simulation was used to study the cant-sawing and through-and-through sawing of the logs to determine the volume yield of sawn timber from the jambirre (Millettia stuhlmannii Taub.) and umbila (Pterocarpus angolensis DC.) species. The optimal position, i.e. the position of the log before sawing that gives the highest volume yield of sawn timber for a given sawing pattern when the positioning parameters, offset, skew and rotation, are considered gave a considerable higher volume yield than the horns-down position. By bucking very crooked logs and using the horns-down positioning before sawing, the volume yield can be of the same magnitude as that obtained by optimal positioning on full-length (un-bucked) logs. The bucking reduces the crook of the logs and hence increases the volume yield of sawn timber.     

Versuche mit Herbiziden in Baldrian Valeriana officinalis L. in Thüringen

Between 1998 and 2008 12 experiments with 25 herbicides were carried out in valerian in experimental stations and on valerian fields of Thuringian farms. The main objective of the tests was to get the necessary data for the authorization procedure according to the regulations of § 18 a PflSchG. The use oft the herbicides Devrinol FL, Lentagran WP, Stomp Aqua and Stomp Raps is authorized for the application in valerian according the regulations of § 18 a PflSchG. The herbicides Basagran, Boxer, Roundup UltraMAX and Targa Super can be used in valerian according the regulations of § 18 b PflSchG. Further experiments with herbicides in valerian are intended to the authorization to more herbicides and to unsolved problems with the weed control in this crop like for example the often insufficient effects of the recently authorized herbicides against Solanum spec., Galinsoga spec., Polygonum spec. and other weeds.     

Comparing potato tuberization and sprouting: Opposite phenomena?

The regulation of tuber formation and tuber sprouting are compared. As a starting point it is hypothesized that these two phenomena are opposite to each other. This idea is tested from three points of view: hormonal regulation, gene expression, and carbohydrate metabolism. It is concluded that there is only limited evidence to support the hypothesis. On the contrary, several examples are given indicating that similar mechanisms might be operative during tuber formation and tuber sprouting.     

Versuche mit Herbiziden in Pfefferminze Mentha x piperita L. in Thüringen

Between 1996 and 2007 31 experiments with 34 herbicides were carried out in peppermint in experimental stations and on peppermint fields of Thuringian farms. The main objective of the tests was to get the necessary data for the authorization procedure according to the regulations of §?18a PflSchG. Peppermint plants are susceptible against some herbicides like Callisto, Monitor. Other herbicides like Afalon, Basta, Boxer, Centium 36 CS and Roundup Ultra can cause severe damages on peppermint if they are applied to the false stage of development of the plant. The use oft the herbicides Basagran, Fusilade MAX, Lentagran WP, Lontrel 100 and CLIOPHAR 100 is authorized for the application in peppermint according the regulations of §?18a PflSchG. The herbicides Bandur, Boxer, Stomp SC and Targa Super can be used in peppermint according the regulations of §?18b PflSchG. Further experiments with herbicides in peppermint are intended to the authorization to more herbicides and to unsolved problems with the weed control like for example the often insufficient effects of the recently authorized herbicides against Solanum spp., Galinsoga spp., Polygonum spp. and other weeds.     

玉米干酒糟及其可溶物在畜产动物日粮中应用的最新研究进展

现在,玉米干酒糟及其可溶物(Distiller Dried Grains with Solubles,DDGS)的产量越来越大,人们对该产品的营养特性也积累了更多的知识,并从实际的角度提出了有关在动物日粮中使用玉米干酒糟及其可溶物的很多问题。本文主要介绍美国多所大学在猪、家禽和奶牛日粮中使用这些生物燃料副产品的最新研究进展。     

Propagation of two miombo woodland trees by leafy stem cuttings obtained from seedlings

The rooting ability of leafy stem cuttings harvested from four to five month old seedlings of B. spiciformis Benth and P. angolensis DC was tested in low-technology non-mist propagators suitable for the rural tropics. Both species were successfully rooted; P. angolensis was a faster rooting species (86% after 61 days) compared with B. spiciformis (59% after 154 days). Regression analysis suggested that P. angolensis had more stored carbohydrates, which facilitated its rooting while B. spiciformis was more dependant on current assimilates produced during the period of propagation. The results of this study suggest that it is possible to develop clones of genetically superior trees of B. spiciformis and P. angolensis for use in agroforestry or reforestation programmes.This revised version was published online in November 2005 with corrections to the Cover Date.     

Farm Management Effects on Rhizosphere Colonization by Native Populations of 2,4-Diacetylphloroglucinol-Producing Pseudomonas spp. and Their Contributions to Crop Health

ABSTRACT Analyses of multiple field experiments indicated that the incidence and relative abundance of root-colonizing phlD+ Pseudomonas spp. were influenced by crop rotation, tillage, organic amendments, and chemical seed treatments in subtle but reproducible ways. In no-till corn plots, 2-year rotations with soybean resulted in plants with approximately twofold fewer phlD+ pseudomonads per gram of root, but 3-year rotations with oat and hay led to population increases of the same magnitude. Interestingly, tillage inverted these observed effects of cropping sequence in two consecutive growing seasons, indicating a complex but reproducible interaction between rotation and tillage on the rhizosphere abundance of 2,4-diacetlyphloroglucinol (DAPG) producers. Amending conventionally managed sweet corn plots with dairy manure compost improved plant health and also increased the incidence of root colonization when compared with nonamended plots. Soil pH was negatively correlated to rhizosphere abundance of phlD+ pseudomonads in no-till and nonamended soils, with the exception of the continuous corn treatments. Chemical seed treatments intended to control fungal pathogens and insect pests on corn also led to more abundant populations of phlD in different tilled soils. However, increased root disease severity generally was associated with elevated levels of root colonization by phlD+ pseudomonads in no-till plots. Interestingly, within a cropping sequence treatment, correlations between the relative abundance of phlD and crop stand or yield were generally positive on corn, and the strength of those correlations was greater in plots experiencing more root disease pressure. In contrast, such correlations were generally negative in soybean, a difference that may be partially explained by difference in application of N fertilizers and soil pH. Our findings indicate that farming practices can alter the relative abundance and incidence of phlD+ pseudomonads in the rhizosphere and that practices that reduce root disease severity (i.e., rotation, tillage, and chemical seed treatment) are not universally linked to increased root colonization by DAPG-producers.