This work was aimed at testing the involvement of ethylene in the maturation of grain and senescence of the foliar structures of the wheat inflorescence . Whole wheat ears emitted ethylene to the atmosphere . From pre-anthesis, ethylene emission progressively increased from 0.76 nl g -1 FW h -1 to a peak 1 .53 nl g -1 FW h -1 at the hard dough stage of the grains, to fall to a minimum of 0 .10 nl g -1 FW h -1 at the dormant seed stage . Ethephon increased the ethylene release, hastened the process of grain maturation and senescence of the ears . Aminoethoxyvinylglycine and silver thiosulfate produced the opposite effects . It is concluded that ethylene plays a role in grain maturation and in the senescence of the green bracts of the inflorescence .Abbreviations : Ag+ = silver ion ; AVG = aminoethoxyvinylglycine ; SAM = S-adenosylmethionine ; STS = silver thiosulfate ; TGW = thousand grain weight 107

Treatment of flag leaves and ears of wheat plants with MJ (jasmonic acid methylester) (10 −5 and 10 −4 M) did not increase ethylene production, but it did accelerate senescence as indicated by the loss of chlorophyll. MJ also caused the closure of stomata, and consequently the rates of transpiration and photosynthesis decreased. Early maturity shortened the grain filling period, so the thousand grain weight was lower. Although ethylene elicited the same physiologic effects, the syndrome of senescence by MJ is independent of the former. We conclude that senescence and death in wheat are far from being elucidated; however, MJ and ethylene seem to participate in the phenomenon.

About ten years ago nurseries began to test several novel apricot stocks developed either to reduce plant vigour and boost early as well as high cropping or as a more suitable replacement for Myrabolan (Prunus cerasifera) and Apricot seedling in water-logged or chlorotic soils. These stocks were the Italian bred selections of Prunus domestica Penta and Tetra, the P. cerasifera Adara and the Prunus insititia Adesoto® 101, both Spanish-bred seedlings, and Plumina®, a Prunus bessey × P. cerasifera hybrid developed in France. Performance testing was carried out under a national project. The trials were set up in 2001 in plots of pilot orchards at Imola in Bologna Province, Ancona, Caserta, Palermo and Cagliari, their soil profiles differing notably from each other. They were tested against Apricot seedling and Myrabolan 29C controls grafted to cv. San Castrese. The experimental layout was split-plot with 15 replicates per plant and the trees were trained to delayed vase. Performance results after the first seven years indicate the viability of Penta and Tetra and, contrary to expectations, that Adesoto® 101 is incompatible with apricot and Adara is too weak in heavy soils.

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