The Pollination of Strawberries by Honey-Bees

Pollination of strawberries by honey-bees increased the percentage of flowers that set fruit, the weight of the berries, and the percentage of well-formed berries.     

The Response of Malling Jewel And Malling Exploit Raspberries to Different Soil Moisture Conditions and Straw Mulching

The raspberry varieties Mailing Jewel and Mailing Exploit were used to study growth and crop responses to mulching and irrigation from 1957 to 1962 inclusive.

Treatment A consisted of a wheat straw mulch applied deeply enough to form a complete surface cover; treatments B and C of water applications on unmulched cultivated soil at soil moisture tensions of 20 cm. and 50 cm. of mercury respectively, measured at 1 ft. depth. Treatment B was changed after i960 to a single 2-in. water application given when the raspberry fruits began to ripen. Plots under treatment D were cultivated, unwatered and unmulched.

Irrigation greatly increased the rate of cane growth but this was found to be a disadvantage in raspberries grown as continuous rows because the new cane tended to chafe and obscure ripe berries. Restricting irrigation to the pre-picking period reduced height growth but did not appear to reduce cane numbers or crop yield. Crop yield was increased by irrigation to about 30% more than was produced on the unwatered and unmulched plots, mainly as a result of increased berry size, but the full effect of irrigation on yield was not realized because cane numbers and height were restricted. Under the conditions of this experiment, in which the canes were thinned to a given density and tipped to a given height, a single 2-in. application of water at the commencement of ripening, i.e. when the berries showed the first tinge of pink, was a very economic irrigation treatment. Irrigation slightly delayed ripening, probably because of the harder tipping required by the irrigated canes.

The mulch conserved the equivalent of 2 in. of moisture and was intermediate in effect between the irrigation treatments B and C and treatment D in height growth, crop yield and berry size, but had a depressing effect on the production of new canes by the weaker-growing variety Mailing Jewel.     

Morphogenetic Effects of Seasonal Conditions on Head Development of Cos Lettuce (Lactuca Sativa L. Var. Romana) Growing in a Subtropical Climate

Head development of cos lettuce growing under natural conditions was studied during the four main annual growing seasons. Two fundamental processes, the accumulation of similar-length leaves and leaf-folding, governed the heading process in all seasons, their relative or absolute contribution to heading greatly affecting the final structure and firmness of the mature lettuce head. When no bolting occurred at the end of the growing season the heads disintegrated, mainly as a result of leaves unfolding, the plant thus returning to the rosette state. This phenomenon showed that leaf folding in cos lettuce can be a reversible process.     

Distribution and Phytoavailability of Lead in a Soil Contaminated with Lead Shot

Water, Air, &; Soil Pollution - This paper presents a study of Pb contamination of soil at a clay target shooting facility in Canterbury, New Zealand. The spatial distribution of Pb...     

Kinetic study of the thermal hydrolysis of Agave salmiana for mezcal production

The kinetics of the thermal hydrolysis of the fructans of Agave salmiana were determined during the cooking step of mezcal production in a pilot autoclave. Thermal hydrolysis was achieved at different temperatures and cooking times, ranging from 96 to 116 °C and from 20 to 80 h. A simple kinetic model of the depolymerization of fructans to monomers and other reducing sugars and of the degradation of reducing sugars to furans [principally 5-(hydroxymethyl)furfural, HMF] was developed. From this model, the rate constants of the reactions were calculated, as well as the pre-exponential factors and activation energies of the Arrhenius equation. The model was found to fit the experimental data well. The tradeoff between a maximum fructan hydrolysis and a critical furan concentration in allowing for the best ethanol yield during fermentation was investigated. The results indicated that the thermal hydrolysis of agave was optimal, from the point of view of ethanol yield in the ensuing fermentation, in the temperature range of 106-116 °C and the cooking range time of 6-14 h. The optimal conditions corresponded to a fructan hydrolysis of 80%, producing syrups with furan and reducing sugar concentrations of 1 ± 0.1 and 110 ± 10 g/L, respectively.     

über den Einflu? von Standortfaktoren auf die Besiedlung des bayerischen Hochgebirges durch Waldameisen (Formica spp.) (Hymen., Formicidae)

Zusammenfassung  Der Waldameisenbestand der Staatsw?lder der Oberbayerischen Alpen wurde in den Jahren 1986–1990 und 1995/96 erhoben. Wegen der Vielzahl der auf 108269 ha Holzbodenfl?che vorkommenden Nester von Gebirgswaldameisen wurden bei den Aufnahmen statistische Methoden (Probstreifen) angewandt. Die Hochrechungen ergaben einen Bestand von 221212 Nestern der beiden Gebirgswaldameisen; davon entfielen aufF. aquilonia 85% und aufF. lugubris 15%. Die Nester der selteneren Flachlandwaldameisen wurden einzeln gez?hlt; ihre Summe erreichte knapp 1% des gesamten Waldameisenbestands. Der Einflu? der wichtigsten Standortfaktoren (Boden, H?henlage, Exposition, Bestandsform, Bestandsalter und Bestokkungsgrad) auf die Besiedlung der Gebirgsw?lder durch Gebirgswaldameisen und durch Flachland-Waldameisen, wurden untersucht. Die unterschiedlichen Standortansprüche der beiden Gebirgswaldameisen und der Flachland-Waldameisen wurden in einer übersicht zusammengestellt. Innerhalb des natürlichen Verbreitungsgürtels der Gebirgswaldameisen (700–1800 m Meeresh?he) spielt der Einflu? des Waldbestands, insbesondere dessen Bestockungsgrad (Beleuchtungsverh?ltnisse auf dem Waldboden), eine entscheidende Rolle auf die Verbreitung bzw. das Fehlen dieser Tiergruppe.

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The impact of habitat factors on the colonization of Red Wood Ants (Formica spp.) in the Bavarian Alps

During several years the density of nests ofFormica spp. was determined in the State Forests of the Bavarian Alps using the statistical methods of strip survey. The measured density was between 0.32 and 17.78 nests/ha and the calculated abundance on a total forest area of 108269 ha were 221212 nests ofFormica spp., 85% of which wereF. aquilonia and 15%F. lugubris. The typical wood ant species of the lowland were very rare in the mountain region and their nests made up less than 1%. The most important habitat factors (soil, altitude and exposition as well as type, age and density of the stands) were investigated in regard to their impact on the distribution of mountain ants species. Results are summarized in tables. It could be shown that the stand, especially its density was the most important factor which determined the presence of mountain ant species in their colonization region between 700 and 1,800m above NN.