Garibaldi A.,University of Turin |
Gilardi G.,University of Turin |
Baudino M.,CRESO |
Ortu G.,University of Turin |
Gullino M.L.,University of Turin
Plant Disease | Year: 2012
During an extensive survey carried out in Piedmont (northern Italy) aimed at identifying the emerging soilborne diseases affecting tomato in commercial fields where alternatives to methyl bromide have been implemented in response to national and international regulations, sudden collapse of tomato plants, cv. Tomahawk, grafted on cv. Beaufort, were repeatedly observed in a commercial plastic tunnel operation. Affected plants suddenly collapsed 60 days after transplant during the month of May 2010. Symptoms included chlorosis, stunting, and severe root and crown rot, leading to sudden collapse of approximately 25% of the plants within 60 days of transplant. Symptomatic tissues from the root and collar of infected plants were surface disinfested for 1 min in a 1% NaOCl solution, rinsed for 5 min in water, and submerged in selective medium based on corn meal agar. A Phytophthora-like organism (2) with characteristic coenocytic hyphae was consistently isolated and transferred to V8 agar. The sporangia were spherical to ovoid, papillate, and 40 to 77 × 23 to 34 (average 55.1 × 30.3) μm. Oospores were globose and 22.2 to 30.8 μm. The internal transcribed spacer (ITS) region of rDNA of a single isolate was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis (1) of the 750-bp segment showed a 100% homology with the sequence of Phytophthora capsici JN382543.1. The nucleotide sequence has been assigned the GenBank Accession No. JX090306. Pathogenicity tests were performed on healthy 30-day-old tomato plants cv. Beaufort by using one strain of P. capsici grown for 15 days at 22 to 25°C on a mixture of 2:1 wheat/hemp kernels, and then 1 g per L of the inoculum was mixed into a substrate based on peat blonde/peat black (15:85 v/v). Two plants were transplanted into 3-L pots, with five replicates. Ten non-inoculated plants represented the control treatment; the trial was repeated once. All plants were kept in a greenhouse at temperatures ranging from 22 to 25°C. Inoculated plants became chlorotic 7 days after inoculation and root and crown rot developed 30 days after inoculation. Control plants remained symptomless. P. capsici consistently was reisolated from inoculated plants. In Italy, the presence of P. nicotianae on hybrids of Solanum lycopersicum × S. hirsutum is known (3), while, to the best of our knowledge, this is the first report of P. capsici on the hybrid S. lycopersicum × S. hirsutum in Italy. The economic importance of the disease can increase due to the expanding use of grafted tomato plants. © 2012 The American Phytopathological Society.
Costa G.,University of Bologna |
Spinelli F.,University of Bologna |
Soto A.,University of Bologna |
Nardozza S.,University of Bologna |
And 2 more authors.
Acta Horticulturae | Year: 2011
In kiwifruit, plant bioregulators (PBRs) have found several applications. In nursery, auxin containing compounds (NAA and IBA) are used to enhance root formation in woody and herbaceous cuttings; in micropropagation techniques, auxins are routinely used to promote root formation and cytokinins to induce shoots proliferation. In field conditions, the application might start very early in the season. During dormancy, dormancy breaking agents (Dormex, Hi-cane, Citokin and Armobreak) are used to overcome lack of chilling requirements enhancing bud break and fertility. Therefore, after blooming, auxins, gibberellins (Triclopir, Spray Dunger Global) and cytokinins (forchlorfenuron) are used to affect fruit morphogenesis. Recently, other new PBRs, such as jasmonates, were tested in kiwifruit to affect flesh colour in fruits of Actinidia chinensis, and to reduce water use in both A. chinensis and deliciosa, such as abscisic acid. In post-harvest conditions, the use of molecules able to interfere with ethylene biosynthesis, such as 1-MCP, are suggested to prolong fruit storage and shelf-life.
Ughini V.,University Cattolica ore |
Malvicini G.L.,University Cattolica ore |
Roversi A.,University Cattolica ore |
Acta Horticulturae | Year: 2014
To obtain robust and extensible experimental results on the agronomic convenience of mechanical pruning of old bush trained hazelnut orchards in Piedmont, during the period 2006-2010 four trials to compare mechanical, manual and no pruning trees were made in 4 representative locations (=orchards). The orchards, located on flat or sloping grounds and growing TGL trees 6 to 18 years old, were pruned in March or in September, obtaining for each location 6 plots of 10-15 trees replicated twice and pruned once during the period 2006-2008. Observations generally regarded: pruning duration (s/tree) and amount of pruned wood; yielding and nut quality for at least 3 years after pruning operations. The results of the four trials were the following: - mechanical pruning duration was 1.4-3.9% higher than that of manual pruning. These figures can increase to 8-10% if device position time, manual finishing of larger cuts and desuckering are also considered; - the cumulative yield, 4 years after pruning operations, is equal but often greater for the mechanically pruned trees compared to non-pruned or manually pruned ones. These results are evidenced both in March and September trials. The cumulative production of manually pruned trees reached the amounts of the nonpruned plots only after 4-5 years. The convenience of pruning both by mechanical or manual system is evident starting from the first year after the cuts because of the better technological traits of nuts (e.g., seed weight, commercial rate, incidence of external and internal defects). However, these results are not registered for the younger orchard.