The genetic diversity among Tunisian pomegranate cultivars has been investigated. Using universal primers, the random amplified polymorphic DNA (RAPD) method was used to generate banding profiles from a set of twelve cultivars. Data was then computed with appropriate programs to construct a dendrogram illustrating the relationships between the studied cultivars. Our data proved the efficiency o...

Despite recent issues, Norway spruce remains the most important commercial tree species which might be demanded henceforth for its broadly utilizable wood. Even before foresters faced both bark beetle outbreaks and decline, monospecific stands were known to prone also other damage due snow wind. On this basis, measures that help prevent such failures looked for, resulted in establishment of int...

The existence of mast fruiting has not been well documented in the Neotropics. The occurrence of a mast fruiting episode in the population of the tree Peltogyne purpurea in the Osa Peninsula of Costa Rica is described. In February and March of 2000 most of the trees of this species produced a large fruit crop, compared with 1995-1999, when the number of fruit producing trees was very low or zer...

Methyl bromide is an effective pre-plant soil fumigant used to control nematodes in many high-input, high-value crops in the United States, including vegetables, nursery plants, ornamentals, tree fruits, strawberries, and grapes. Because methyl bromide has provided a reliable return on investment for nematode control, many of these commodities have standardized their production practices based ...

Inflorescence development of the 'Hass' avocado (Persea americana Mill.) was investigated at the macro and microscopic level. Near the end of shoot extension, two secondary axis meristems were present in the axils of inflorescence bracts. The primary axis meristem changed shape from conical to flattened to conical followed by the initiation of additional bracts and associated secondary axis inf...

Aflatoxins, carcinogenic toxins produced by Aspergillus fungi, contaminate maize, peanuts, and tree nuts in many regions of the world. Pistachios are the main source of human dietary aflatoxins from tree nuts worldwide. Over 120 countries have regulations for maximum allowable aflatoxin levels in food commodities. We developed social network models to analyze the association between nations' af...

Changing climatic conditions impose a challenge both to biodiversity and food security. The effects of climate change affect different aspects of the plant or crop, such as morphological and phenological aspects, as well as yield. The effects of greenhouse conditions might be comparable in some cases to a permanent extreme disturbance in climate and weather, thus, contributing to our knowledge ...

Honeydew excreted by phloem-sap sucking scale insects (Ultracoelostoma sp.) living in the bark of beech (Nothofagus solandri) trees growing at a high elevation (900 m) site in the Craigieburn range of Canterbury, New Zealand, was measured over four days during 1–10 May 1996. Average standing crop of honeydew sugar was 3.1 mg m-2, and ranged from 0.4 to 5.5 mg m-2. Daily production of honeydew s...

Rubber is the most widespread smallholder tree crop in South-East Asia. Although initially large estates planted the bulk of the region’s rubber, smallholders soon captured most of the production. Currently, Indonesia’s rubber plantations cover 3.4 million ha, of which smallholders account for more than 75% (BPS, 1999). In peninsular Malaysia, the area in rubber has declined since the 1970s, bu...

Vitex negundo Linn. belong to family Verbenaceae. It is an important medicinal plant. Literature survey of V. negundo revealed the presence of different classes of natural products including essential oil, triterpenes, diterpenes, sesquiterpenes, lignan, flavonoids, flavones glycosides, iridoid glycosides, and stilbene derivative. The plant is traditionally reported for its use for the treatmen...