Hybrid Grapes for a Sustainable Viticulture in South Italy: Parentage Diagram Analysis and Metal Assessment in a Homemade Wine of Chambourcin Cultivar

The aim of this work was to explore a more sustainable approach in the viticulture of Mediterranean countries that could derive from growing hybrid grape varieties inheriting tolerance/resistance characters from the wild vines utilized for their selection. Among the plethora of hybrid grapes developed in the last decades, some are able to produce high-quality wines whose flavor resembles European varieties, thus overcoming a typical limit of several old hybrids based on V. labrusca whose wine was characterized by a distinctive wild flavor. In this context, we examined some characteristics of Chambourcin, one of the most promising hybrid cultivars producing quality red wine and requiring much less phytosanitary interventions than European grapevine. In detail, the scope of this study included the investigation of the parentage diagram for this hybrid grape variety and the chemical analysis of a Chambourcin wine produced in South Italy. We filled the gaps corresponding to some of the Vitis ancestors participating in its complex pedigree by means of a literature analysis and a mathematical approach. We found high ancestry of V. vinifera (about 41%), followed by V. berlandieri (about 28%), V. rupestris (about 19%) and to a lesser extent other American wild vines. The significant content of V. berlandieri and V. rupestris genome in Chambourcin explains the considerable resistance of this variety to the two main pathogens affecting grapevines, i.e., downy mildew and powdery mildew. We then analyzed an organic Chambourcin wine produced in South Italy from grapes obtained without any phytosanitary treatment by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) in order to assess heavy metal content and found it comparable to other (red and rosè) V. vinifera wines obtained from family-run vineyards. Heavy metals contents detected were not of concern for any of the wines analyzed, however, copper accumulation in V. vinifera vineyard soils, and pollution deriving from other phytosanitary chemicals remain issues that in the case of Chambourcin vineyards could be solved at least in large part.

Vacuum steam treatment of Metrosideros polymorpha logs for eradication of Ceratocystis huliohia and C. lukuohia

A new and devastating disease, rapid ohia death (ROD), in Hawaii led to a state quarantine that regulates inter-island transport of ohia wood and plant material to prevent spread of the causal pathogens. Heat treatments of ohia logs in commercial trade were considered for phytosanitary treatment. Vacuum steam (VS) was evaluated for its ability to eradicate the pathogens, Ceratocystis lukuohia and/or C. huliohia, in main stem logs from ROD-affected forest trees. Replicate loads of three de-barked logs (24 to 43 cm diameter; 1.7 to 2.0 m long) were VS-treated at 56° C for 30 min (5 loads) or 60° C for 60 min (4 loads) at a sapwood depth equal to 70% of log radius. Percent isolation of Ceratocystis from VS and ambient temperature logs prior to treatment and summarized by source tree ranged from 12 to 66% and 6 to 31% based on carrot baiting assays of tissue taken from outer and inner sapwood, respectively. No viable Ceratocystis was detected in either sapwood locations for the 60° C/ 60 min schedule or for the inner locations for the 56° C/ 30 min schedule following treatment. Only one subsample (0.48%, n=208) of the latter schedule treatment yielded Ceratocystis. Time required for treatment ranged from 7.4 to 15 h for the 56° C/ 30 min schedule and from 8.6 to 19.2 h for the 60° C/ 60 min schedule. These results demonstrate VS is an effective and efficient method for treating large diameter ohia logs that mill owners and regulatory plant pathologists may consider for use in Hawaii.

Effect of hot-water immersion on eggs and larvae of Anastrepha grandis (Macquart, 1846) (Diptera: Tephritidae) “in vitro” and on squash (Cucurbita moschata Duchesne, 1786)

There are risks involved in the production and exportation of fruit fly hosts due to the possible spread of tephritid pests during distribution. Anastrepha grandis attacks cucurbit fruits and is considered an A1 quarantine pest in many countries. The objective of this study was to evaluate the effect of hot water treatment on the eggs and larvae of A. grandis in vitro, and on ‘Atlas’ squash (Cucurbita moschata). The eggs and third-instar larvae of A. grandis were exposed to hot water at temperatures of 42.0, 44.0, 46.0, 46.5, 47.0, 47.5, 48.0, 49.0 and 50.0 (± 0.5) °C for durations of 0 (control), 10, 20, 30 and 60 minutes. Water temperatures of at least 44 °C affected the in vitro larval eclosion of A. grandis during all exposure times. No adults were obtained when in vitro A. grandis larvae were treated at 49 °C and 50 °C at all exposure times and, 48 °C for 30 and 60 minutes. No adults were obtained when squashes infested with A. grandis eggs or larvae were treated at temperatures of 49 °C and 50 °C during any exposure time, as well as subjected to 48 °C for 20 minutes. Anastrepha grandis larvae were slightly more susceptible to hydrothermal treatment than eggs in squashes. Hot water treatment applies at a temperature of 48 °C for 20 minutes is an effective phytosanitary treatment for squashes cv. Atlas infested with eggs and larvae of A. grandis.

Ethyl Formate as a Methyl Bromide Alternative for Fumigation of Citrus: Efficacy, Fruit Quality, and Workplace Safety

Ethyl formate (EF) was evaluated as a potential alternative to methyl bromide (MB) for phytosanitary treatment of imported citrus fruit in the Republic of Korea. Planococcus citri (Risso) (Hemiptera: Pseudococcidae), a mealybug with known tolerance against EF and MB, was used as a representative pest to test efficacy of the two fumigants against eggs. In nine commercial-scale refrigerated container (67.5 m3) trials using imported orange, lemon and grapefruit, EF applied at the currently approved dose for citrus (70 g·m-3 at 5°C for 4 h, developed for Aspidiotus excisus Green (Hemiptera: Diaspididae), a species less EF tolerant than P. citri) resulted in 76.9–98.3% mortality of P. citri eggs. The EF treatment did not affect the sugar content or the color of peel and pulp of the treated fruit. When oranges were treated according to the current MB (64 g·m-3 at >5°C for 2 h) or EF treatment guidelines, the concentration of fumigant around the fruit fluctuated between 9.4 and 185.1 ppm for EF and 9.5–203.0 ppm for MB during the 72-h post-fumigation processes (venting [0–2 h], transportation to storage [2–24 h], and storage periods [24–72 h]) with both EF and MB maintained between 10 and 100 ppm during the storage period. Considering the efficacy of EF, its apparent lack of phytotoxicity, and its more manageable threshold limit value for humans (100 ppm EF compared to 1 ppm MB for an 8-h time weighted average exposure), our results suggest that EF may be a promising alternative to MB for the phytosanitary treatment of imported citrus in Korea.

Sterilizing of Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae) irradiated in pupa stage

Worldwide the loss of stored grain is a problem of economic order of importance, in view of the concern of the increased supply of food for a world population increasingly expanding. Associated with this fact, there is the problem of nutritional deficiency due to lack of protein, especially for the less privileged populations in the resources of a country. This lack could be met by adequate supply of grain produced, requiring for it, a system that provides optimum grain storage conditions in securing the quality until the time of consumption. The use of radiation in stored grain can solve the problem of the losses in these products, as it does not induce resistance of insects and leaves no toxic residue to the consumer, and is considered an effective and safe method. The aim of the experiment was to determine the sterilizing dose of ionizing radiation from cobalt-60 to Alphitobius diaperinus (Panzer, 1797)(Coleoptera: Tenebrionidae) in peanuts irradiated in pupa stage. The experiment was conducted in the laboratory of Radiobiology and Environment of the Center for Nuclear Energy in Agriculture - CENA / USP., Piracicaba, SP, Brazil. Peanuts samples infested with pupae of A. diaperinus were utilized in the experiment that consisted of 8 treatments with 5 repetitions. Each repetition consisted of 20 pupae a total of 100 individuals per treatment. Were irradiated with doses of 0 (control), 25, 50, 75, 100, 125, 150 and 175 Gy, in a source of cobalt-60, Gammacell-220 type, with a rate dose of 381Gy / h. The experiment was conducted in a room with temperatures of 25 ± 5 ° C and relative humidity of 70 ± 5%. After of irradiation process was evaluated of the number of emerged adult insects in each repetition in the treatments. The results show that the sterilizing dose in F1 generation was 125 Gy and the pupa lethal dose 150 Gy. The dose of 150 Gy of gamma radiation can be used as phytosanitary treatment to control of immature stages of A. diaperinus infested peanuts.

Photodynamic inactivation of Lasiodiplodia theobromae : lighting the way towards an environmentally friendly phytosanitary treatment

The fungus Lasiodiplodia theobromae is one of the main causal agents of trunk canker and dieback of grapevine. The objective of this work was to evaluate the efficiency of photodynamic inactivation (PDI) of L. theobromae with synthetic and natural photosensitizers and irradiation with either sunlight or artificial photosynthetically active radiation. Although the growth of the mycelium could not be completely prevented with natural sunlight irradiation, phenothiazine dyes (methylene blue, MB; toluidine blue O, TBO), riboflavin and a cationic porphyrin (Tetra-Py + -Me) caused complete inhibition under continuous irradiation with artificial light. Free radicals were the main cytotoxic agents in the PDI with MB, indicating the predominance of the type I mechanism. PDI with MB or Tetra-Py + -Me may represent a promising approach for the sanitation of vine material in greenhouse nurseries, in order to reduce the risk of infection upon grafting.

Effect of Phytosanitary Irradiation Treatment on the Storage Life of ‘Jiro’ Persimmons at 15 °C

Irradiation is becoming a more accepted phytosanitary market access treatment for some international horticultural trades. However, there is little information on the effects of phytosanitary irradiation treatment on persimmon fruit quality. ‘Jiro’ persimmon fruit were treated with an average of 769 Gray (Gy) at a commercial phytosanitary irradiation X-ray facility to examine the effect of this market access treatment on fruit quality during storage. After treatment, fruit were stored in air at 15 °C for up to three weeks. The results showed that, in general, there was no effect of irradiation treatment on fruit weight loss, calyx appearance, fruit firmness (objective and subjective), total soluble solids (TSS), titratable acidity (TA), internal appearance, and ethylene production rate. There were some treatment differences in fruit respiration rates and some aspects of fruit appearance and colour, where irradiated fruit had higher respiration rates and were slightly darker with higher levels of skin blemish, although these measured differences were not commercially significant. This study showed the promise of using low dose irradiation as a phytosanitary treatment for ‘Jiro’ persimmons, but more work is required to test other persimmon cultivars and other storage and marketing environments.