Structure and floristic composition of old-growth wet evergreen forests of Nelliampathy Hills, Southern Western Ghats

We analyze the structure and composition of old-growth wet evergreen forest of Nelliampathy hills, the chain of hills lying immediately south of Palghat Gap, in the southern Western Ghats of India. We sampled 30 plots of 0.1 ha each (50m×20m) at six locations enumerating all plants≥10cm girth at breast height. We pooled the data and computed various structural parameters. There were 152 species of 120 genera and 51 families of the study area. Of these, 118 (77%) were trees, 24 were climbers (16%) and 10 were shrubs (7%). Species richness varied from 58 99 per 0.5 ha sample and Shannon indices of diversity ranged from 4.4 to 5.2. Fifty-nine per cent (89 species) of the species were Indian Sub-continent elements and 34% (51 species) are endemic to the Western Ghats. Fifteen species are listed in various threat categories. Aglaia and Litsea were the most species-rich genera. Numbers of families ranged from 27 43 per 0.5 ha sample. Euphorbiaceae and Lauraceae were the most species-rich families. Stand density varied from 1714 to 2244 stems·ha -1 and basal area from 53.6 to 102.1 m 2 ·ha -1 . The vegetation was dominated by 3 6 species and six dominance patterns characterized the species composition within the hill complex. The old-growth evergreen forests of Nelliampathy exist as small fragments rich in biodiversity and can be used as benchmarks for comparison with disturbed forests.     

Viability retention of seeds of shisham (Dalbergia sissoo Roxb.) on the trees after maturity

In 1991 and 1992 studies on Dalbergia sissoo Roxb. showed the availability of ample amount of viable seed from November to May. Viability of seeds collected from December to March was more than 90 per cent. There was a slight but significant decrease in germination from March to may. Again germination per cent was slightly and significantly decreased from May to July. Thereafter, seed availability and viability were got drastically reduced. Sufficient viable seed of Dalbergia sissoo Roxb. can be collected at any time from November to July.     

Über Parasitierung und Farbformen des LärchenbockesTetropium gabrieli Weise (Col., Cerambycidae) in Südtirol

In June of 1984 lying stems of larch trees were heaveliy attacked by the larch cerambycidT. gabrieli near Brixen/South Tyrol. From 229 larvae 134 adultTetropium and 95 larval parasites (=41%) emerged. The parasite species were:Rhimphoctona lucida Clém. (Hym., Ichneum.) 55 indiv.;Helcon dentator F. (Hym., Bracon.) 1 indiv., andBillaea triangulifera Zett. (Dipt., Tachin.) 39 indiv. These results are compared with those got bySchimitschek (1929) in ?SR and Lower Austria. Furthermore the different colour formes of the population ofTetropium occurred near Brixen are examined.     

Relationships between height and yield in near-isogenic spring wheats that contrast for major reduced height genes

The effect of two major dwarfing (Rht-B1b and Rht-D1b) genes varies with environment. Near-isogenic pairs (i.e., tall and semidwarf) of six spring wheat lines, included in the International Adaptation Trial (IAT), were grown in 81 trials around the world from 2001 to 2004. Trial yields ranged from 1 to 8 t ha⁻¹ with a mean of ca. 4 t ha⁻¹. Overall, the yield advantage of the lines possessing the dwarfing gene was ca. 10% and was particularly evident in trials where the mean height of semidwarf isolines exceeded ca. 80 cm. However, the yield advantage was greater in the slightly taller and older lines (Pavon and Galvez) than in the newer lines Nesser and Kauz and the two durum lines. Sixteen pairs of semidwarf/tall near-isolines were grown in six managed drought environment trials at CIMMYT in northwestern Mexico. In these trials, height and yield differences were small and/or negligible in the most droughted environment (2.5 t ha⁻¹) and the slope of yield versus height for each isoline pair became consistently negative with increase in irrigation. In the IAT, the slope of the yield versus height was much more variable at low heights or yields, presumably due to the fact that there were many more factors driving the response. Even at the point where the slope became consistently negative (ca. between 2 and 4 t ha⁻¹), there were some trials where tall isolines equaled or exceeded the yield of semidwarf isolines, particularly in the most recent developed cultivar, Kauz. For submission to Euphytica as part of special issue “Challenges to International Wheat Breeding”. From the International Symposium on Wheat Yield Potential: Challenges to International Wheat Breeding, Days Inn, Ciudad Obregón, Sonora, Mexico, March 19–24th, 2006.     

Fragen der insektiziden Wirkung bifluoridhaltiger Holzschutzmittel

Zusammenfassung Es wurde experimentell untersucht, ob ein bifluoridhaltiges Holzschutzsalz bei Anwendung in der zur vorbeugend-insektiziden Behandlung vorgeschriebenen Dosierung von 50 g/m² Holzoberfläche gleichzeitig eine bekämpfende Wirkung aufweist. Als Versuchstiere dienten im Durchschnitt 7 mg schwere, d. h. verhältnismäßig kleine Larven des Hausbockkäfers (Hylotrupes bajulus L.). Als Ergebnis war zu verbuchen, daß je nach Schärfe der Versuchsbedingungen 77–100% der Larven abstarben. Dieses Resultat wurde mit Holzproben erzielt, deren Behandlung 6 1/2 Jahre zurücklag. Aufgrund der Kenntnis über den Verlauf der Fluorabgabe aus geschütztem Holz ist anzunehmen, daß der ermittelte Bekämpfungseffekt noch eine weitere Reihe von Jahren vorhält.Diese Festellungen beziehen sich ausdrücklich lediglich auf kleinere Larven. Halbwüchsige und größere Larven, gegen die sich in der Baupraxis vorgenommene Bekämpfungsmaßnahmen hauptsächlich richten, bedürfen zur Abtötung stärkerer Dosierungen. Es wird daher davor gewarnt, die vorgeschriebene Bekämpfungsdosis von 100 g/m² zu unterschreiten.

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Summary Tests were carried out to show, if a wood-preserving salt containing fluorine, when applied in the dosage of 50 g/m² surface of wood as prescribed for prophylactic insecticide treatment, has also controlling capacities. Larvae of the House Longhorn Beetle (Hylotrupes bajulus L.) of an average weight of 7 mg, i. e. relatively small ones, were used as test insects. In the experiments, under conditions of different severity, mortalities of 77–100% of the larvae were registered. These results were attained with pieces of wood which were treated with the wood-preserving agent 6 1/2 years ago. According to our knowledge of the progressive loss of fluorine out of treated wood it can be expected that the controlling effect found in the experiments will last for several more years.It must be emphasized, however, that these results were reached only with relatively small larvae of the House Longhorn Beetle. To kill halfgrown larvae or larger ones, i. e. those, against which pest-control measures in buildings usually are directed, higher dosages of the salt are required. Under these circumstances one should be cautious not to apply less than the dosage of 100 g/m² prescribed for control measures.

     

Crop productivity under differently lopped canopies of multipurpose trees in Central Himalaya, India

Ficus species are multipurpose trees well known by rural populations in Sahelian and Sudanian zones of Africa. Their uses are well documented but their amenability for vegetative propagation has not been extensively studied. This paper compares the rooting ability of stem and aerial root cuttings from thirteen Ficus species found in West Africa. It highlights the differences between species belonging to the sub-genera Sycomorus and Urostigma. The former show no capacity to propagate from cuttings whereas the latter, with epiphytic development, can be propagated by cuttings, although this capacity varies among species. Thus, F. thonningii, F. leprieurii and F. ovata are easily propagated, while F. platyphylla and F. elasticoides are propagated with difficulty. The rooting capacity also varies depending on the cutting material used. It decreases in the following order: long leafless hardwood cuttings (pole) > nodal cuttings > apical cuttings. Rooting potential increases when the cuttings are harvested towards the end of the dry season(March to May). Aerial root can be used for cuttings in all species of the sub-genus Urostigma. The capacity of root cuttings to regenerate is greatest when cuttings are collected at the beginning of the dry season (November). In this case, wound-induced adventitious roots arise at the basal end of the cutting while de novo buds are developed from the cambium at the distal end. The subsequent morphological development is identical to that of a stem cutting. These results clarify and allow the optimal use of the knowledge and methods developed by the indigenous people of the Sahel and could assist and promote fig tree (Ficus sp.) domestication in the dry tropics.This revised version was published online in November 2005 with corrections to the Cover Date.