Survival of Fusarium circinatum in colonized pine needles and wood pieces was measured. Naturally colonized branches and their needles were cut into small pieces and placed in mesh bags on the soil surface at two locations in northern Spain. Pieces were recovered periodically, cultured on a selective medium, and microscopically examined to identify the species. After 507 days, F. circinatum was recovered from 0 to 27% of the wood pieces and from none of the needles. After 858 days, F. circinatum was not recovered from any wood pieces but was found to be present on 1 out of 220 needle pieces analysed. Artificially infested pieces of wood and needles were placed on 5‐mm sieved soil either in plastic boxes at controlled temperature or in mesh bags under field conditions. No survival was recorded after 794 days under field conditions and the decline over time occurred more rapidly in inoculated pieces under field conditions. Soil was also infested with conidia of F. circinatum and survival was estimated. No conidia were recovered after 224 days at 30 °C, although at 20 and 5 °C the respective populations were 20 and 3700 cfu/g soil. Fusarium circinatum was not recovered from 2‐mm‐sieved soil collected under pitch canker‐infected pines. Results indicate that branch segments and needles naturally colonized by F. circinatum will not be a potential source of inoculum, and the fungus in soil is not likely to contribute to reinfection of new plantations after 2 years.

During surveys carried out for assessing the occurrence of cucurbit-infecting soil fungi, melon plants exhibited necrosis on the basal stem, wilt and death. Mycological analysis and experimental inoculations showed the causal agent to be Fusarium solani f. sp. cucurbitae. This is the first report of F. solani f. sp. cucurbitae as the causal agent of crown rot of melon in Europe.

Fusarium circinatum, the causal agent of pitch canker disease on pines, can be disseminated by wood produced in infested areas. The purpose of the study was to evaluate the effect of wood preservatives, commonly used against sapstain and wood-decay fungi, on growth and sporulation of Fusarium circinatum. Seven active ingredients of antisapstain and anti-wood-decay preservatives were evaluated by their inhibition of mycelial growth. Propiconazole, tebuconazole, and 3-iodo-2-propinyl butyl carbamate (IPBC) were effective against F.circinatum, whereas hydroxycarbonate of cooper was not. An assay was also conducted to evaluate the efficacy of three commercial antisapstain and two anti-wood-decay preservatives on Pinusradiata sapwood blocks that were previously inoculated with Fusarium circinatum. The product with the best efficacy was an antidecay preservative composed of tebuconazole, propiconazole, and dichlofluanid. None of the antisapstain preservatives tested was effective even though they contained fungicidal ingredients. Effects of dosage, product application, and formulation on the efficacy of these preservatives are discussed.

Zucchini (Cucurbita pepo) is intensively cropped in approximately 4,500 ha of plastic houses in southern Spain. In 2008 to 2009, Consul, Cronos, and Tosca zucchini plants showed symptoms of leaf wilting, basal stem necrosis, and plant death. Incidences of dead plants were 20 to 30% and these plants were distributed in clusters. Phytophthora capsici Leonian was isolated from the basal stems of symptomatic plants, using PDA and cornmeal agar amended with a pimaricin, ampicillin, and rifampicin. Five resultant isolates (PCl-211, PCl-221, PCl-611, PCl-612, and PCl-811) on lima beans agar (LBA) produced white mycelia with lemon-shaped and papillate sporangia borne on long pedicels, but no oospores or chlamydospores. These isolates had an identical ribosomal DNA ITS sequence, matching with that of P. capsici in GenBank. The sequences of two representative isolates, PCl-211 and PCl-811, were deposited in GenBank with accession nos. KC662328 and KC688317, respectively. The pathogenicity of these five isolates was tested on zucchini cv. Consul in 1-liter containers filled with vermiculite in May and September of 2009. Plants were inoculated at the 2 to 3 true-leaf stage. Plates with LBA fully covered with colony of each isolate were separately blended and homogenized with 300 ml of sterile distilled water. Inocula were poured around stem at 50 ml per plant. Each experiment had three replicates and four plants per replicate. Treatments with different isolates were arranged in a randomized complete block design. In both experiments, 12 uninoculated plants served as controls. Test plants were maintained for a month following inoculation in a greenhouse with mean temperatures ranging from 21.9 to 27.9°C and from 20.7 to 24.6°C for the May and September experiments, respectively. The first wilting occurred 5 days after inoculation. At the end of the May experiment, all control plants and those inoculated with PCl-221 remained asymptomatic while 83.3% of those inoculated with PCl-211 and 100% of those with the other isolates were dead. Inoculated plants exhibited crown and root rots, excluding the secondary roots. In the September experiment, 83.3% and 33.3% of plants inoculated with PCl-211 and PCl-221, respectively, were symptomatic, while all plants inoculated with the other isolates were dead. The control plants remained healthy. The pathogen was consistently recovered from symptomatic plants in both experiments. Although P. capsici was reported in peppers (Capsicum annuum) in several provinces of Spain (1), to our knowledge, this is the first report of P. capsici as the causal agent of crown rot in zucchini plants in plastic houses in the Almería Province of Spain, one of the world's largest concentrations of greenhouses. Reference: (1) J. L. Andrés et al. Span J Agric Res 3:326, 2005.

Pitch canker is a disease that affects pines in many countries throughout the world. Fusarium circinatum, the causal agent of pitch canker, has recently been reported in Europe, where it is regulated as a quarantine pest. This pathogen represents a substantial threat to natural Pinus forests and plantations. To date, two mating types of F. circinatum have been described, both of which are present in Spain. To assess the potential risk of F. circinatum to Pinus in Spain, the main conifer species grown in Spain, namely Pinus sylvestris , P. nigra, P. pinaster, P. radiata , P. halepensis P. pinea and P. uncinata , were examined for their susceptibility to four Spanish isolates of F. circinatum. Two-year-old shoots were wounded and then inoculated with the four Spanish isolates, and lesion lengths were measured 2 weeks after inoculation. Pinus radiata was found to be the most susceptible species to the Spanish isolates, whereas P. pinea, P. halepensis, P. nigra, P. uncinata and P. pinaster were found to be relatively resistant and showed a significantly different lesion size from P. radiata. For P. pinaster, variations in resistance were found between provenances. One particular provenance (Meseta Castellana) was found to be more resistant than the three other provenances tested. No differences in virulence between the Mat-1 and Mat-2 isolates were detected. Overall, the low susceptibility of all native species to pitch canker suggests a moderate potential risk to the Spanish natural forests and a high potential risk to the exotic forestry of P. radiata.

A new disease causing wilt and death of adult plants of Phaseolus vulgaris was discovered in plastic-house crops of southeast Spain in 2004. The causal agent was shown to be a Pythium species with a unique type of oogonium ornamentation different from any of the described species. Zoospores were not observed, but globose or subglobose hyphal swellings, intercalary or terminal, were frequently found. Moreover, the ribosomal ITS region showed a unique sequence, significantly different (>14%) from any other known species of Pythium. This paper describes and illustrates the morphology of the new Pythium species and its pathogenicity to green beans. Its taxonomic position and phylogenetic relationships with other Pythium species are discussed.

Cucumber, melon, watermelon, and zucchini are intensively cropped in the southern part of Spain where approximately 20,000 ha of the crops are grown in greenhouses. In the spring of 2007, zucchini plants (Cucurbita pepo) at the fruit-bearing stage in three commercial plastichouses in Almería exhibited necrosis on the basal stem, wilt, and death. The incidence of dead plants was 20 to 30%. Fusarium solani was consistently isolated from the basal stems of symptomatic plants on potato dextrose agar (PDA). Cultures of six single-hyphal transfers were identified on the basis of molecular sequences and morphological characteristics (2). Sequences of ribosomal DNA from ITS1 region, 5.8S rDNA, and ITS2 were identical for all six isolates of F. solani. The rDNA sequence of isolate Fscl-3 of F. solani was deposited as GenBank Accession No. AM940070. The pathogenicity of these six isolates of F. solani was tested in two experiments conducted in one plastichouse in Almería. Pregerminated seeds of zucchini cv. Consul were sown in 1-liter containers filled with vermiculite on 21 May and 22 June, 2007 (experiments 1 and 2, respectively). Plants at the one- to two-true-leaf stage or younger were inoculated with a soil drench of 2.0 to 8.4 × 105 propagules per ml). One colonized PDA petri plate of each isolate was blended and homogenized in 500 ml of distilled water. Inoculum (50 ml per plant) was poured around the stem of zucchini plants growing in vermiculite. The experimental design was a randomized complete block with three replicates with each plot comprising four plants (one plant per container). In both experiments, 12 uninoculated plants of the same cultivar served as controls. Plants were maintained for 1 month following inoculation in a greenhouse with mean temperatures ranging between 20.7 and 24.6°C and 23.3 to 29.8°C for experiments 1 and 2, respectively. Wilting first occurred 9 days after inoculation, and 14 days later, all plants inoculated with the F. solani isolates died. Inoculated plants exhibited lesions on the stem base without rot of secondary roots. At the end of the experiment, the uninoculated plants remained asymptomatic. Results of experiment 2, with higher temperatures, were similar. The pathogen was consistently recovered from symptomatic plants in both experiments, fulfilling Koch's postulates. Although F. solani f. sp. cucurbitae race 1 was reported in field squash (C. maxima) in the province of Valencia of east-central Spain (1), to our knowledge, this is the first report of F. solani as the causal agent of crown rot of zucchini plants in plastichouses in the Almería Province of Spain, one of the world's largest concentrations of greenhouses. References: (1) J. García-Jiménez et al. Plant Dis. 81:1216, 1997. (2) C. M. Messiaen and R. Cassini. Taxonomy of Fusarium. Page 427 in: Fusarium: Diseases, Biology, and Taxonomy. P. E. Nelson et al., eds. Pennsylvania State University, University Park, 1981.

Adult bean plants (Phaseolus vulgaris cv. Festival) growing in a commercial greenhouse in southeastern Spain developed symptoms of root necrosis, necrotic streaks on the basal stems, and plant wilt. A Pythium sp. was isolated consistently from roots and basal stems on selective agar (P5ARP). Single-hyphal transfers produced intercalary antheridia, oogonia (23 to 26 μm in diameter), oospores (18 to 20 μm in diameter), and zoospores in toruloid sporangia. Cardinal temperatures were a minimum of 10°C, an optimum of 28 to 34°C, and a maximum of 40°C. Daily growth rate on corn meal agar at 25°C was 15 mm. The internal transcribed spacer 1 (ITS 1) rDNA sequence of the isolate matched the sequences of Pythium aphanidermatum in GenBank. The sequence of isolate Py-294 was deposited in GenBank, Accession No. AM396563. This isolate was identified as P. aphanidermatum on the basis of morphological and cultural characteristics (1) and the ITS rDNA sequence. To fulfill Koch's postulates, 50 ml of inoculum of isolate Py-294 was used to inoculate bean plants (cvs. Donna and Emerite) at the five-leaf stage. The inoculum was prepared by homogenizing 2-week-old potato dextrose agar-petri plate cultures in 300 ml of distilled water. The plants were maintained in a greenhouse at temperatures of 18.8 to 30.3°C. Irrigation water had an electric conductivity of 0.5 to 0.6 dS·m-1 while the nutrient solution had 1.9 to 2.1 dS·m-1. Two months after sowing, 35.4 and 100% of cvs. Donna and Emerite, respectively, developed root necrosis, while control plants grown in bags containing noninoculated perlite remained healthy. The pathogen was reisolated from roots and basal stems of symptomatic plants. The test was repeated with similar results. To our knowledge, this is the first report of P. aphanidermatum as the causal agent of root and crown necrosis of adult bean plants in Spain. Reference: (1) A. J. Van der Plaats-Niterink. Stud. Mycol. 21:242, 1981.

The Melon Necrotic Spot Virus is the cause of a serious disorder in greenhouse melon crops. The symptoms are chlorotic or necrotic spots in leaves, necrotic streaks in stems and occasionally plant death. In nature the virus is transmitted by the fungus Olpidium radicale (=O. bornovanus), whose resting spore preserves it in the soil for years. To prevent virosis in subsequent years it is then necessary to eradicate this type of conservation structures from contaminated soils or substrates. The objective of the experiments was to study the effects of solarization and sodium hypochlorite disinfection of the growth medium on O. radicale. Two experiments were conducted in span and multispan greenhouses in years 2001 and 2002 respectively. Perlite bags contaminated with roots of a previous cucurbit crop inoculated with a MNSV carrier O. radicale bulk isolate were used as substrate. The obtained results in these experiments indicate the conservation of O. radicale and MNSV in the substrate bags through the summer season. The tested disinfection methods (solarization, treatment with sodium hypochlorite) were not effective against O. radicale in year 2001; however in 2002 solarization during 60 days showed to be effective controlling O. radicale.