investigations were initiated this year to develop field and laboratory viability assays for stored walnut pollen, indentify conditions suitable for in vitro pollen germination and pollen tube growth, and determine pollen tube growth rates in pistillate flowers. Results of this project will provide background information for future investigations of transmission of pollen-borne virus, factors i...

This year’s research focused on further evaluation of potential alternate bearing with multiple year ReTainTM treatments. After three years of treatment with ReTainTM, there does not appear to be any negative effect on yield. There was a lower reduction in PFA than was expected, but this is thought to be unrelated to multiple year treatments. Treatment of a Chandler orchard with ReTainTM was do...

Magnolia sprengeri Pamp. is an ornamentally and ecologically important tree that blooms at cold temperatures in early spring. In this study, thermogenesis and variation in the chemical compounds of floral odours and insect visitation in relation to flowering cycles were studied to increase our understanding of the role of floral thermogenesis in the pollination biology of M. sprengeri. There we...

The breeding system and the embryology of Consolea spinosissima, a tree-like opuntioid endemic to Jamaica, were investigated. Morphological and embryological studies revealed that the species is subdioecious, with three sexual morphs present in the 150 × 120 m plot studied at Hellshire Hills, Jamaica. The female morph has pistillate flowers with open stigma lobes, no pollen grains, and sets fru...

Pollination services of pumpkin, Cucurbita pepo L., provided by the European honey bee, Apis mellifera L., were compared with two native bee species, the common eastern bumble bee, Bombus impatiens (Cresson), and Peponapis pruinosa Say, in New York from 2008 to 2010. Performance of each species was determined by comparing single-visit pollen deposition, percentage of visits that contacted the s...

The hormone levels of auxin and gibberellin were studied in monoecious cucumber plants treated with growth regulators e.g. 2-chloroethylphosphonic acid (ethrel), gibberellic acid (GA3) and maleic hydrazide (MH). The studies were conducted at Vegetable Crops Research Programme, National Agricultural Research Centre Islamabad, Pakistan during 2003 and 2004. The greatest increase in female flower ...

BACKGROUND AND AIMS The reproductive biology of Syngonanthus mucugensis and S. curralensis (Eriocaulaceae) was studied in areas of 'campo rupestre' vegetation in the Chapada Diamantina, north-eastern Brazil. These species are herbaceous and the individuals have a grouped distribution. Their leaves are united in a rosette, and their inflorescence is monoecious, of the capitulum type. The stamina...