Spanish Journal of Agricultural Research

In Chile, gray mold (Botrytis cinerea) and leak (Rhizopus stolonifer) are the major storage diseases of strawberry (Fragaria x ananassa Duch.) that considerably reduce yields and quality, limiting its international commercialization. The effect of preharvest fungicide treatments and postharvest treatments against storage decays was studied. Based on the results obtained, the incidence of B. cinerea and R. stolonifer was significantly lower on "Camarosa" strawberry fruits treated with boscalid or boscalid + pyraclostrobin between blossom and harvest. Similarly, incidence of B. cinerea and R. stolonifer significantly decreased at 5 deg C and 20 deg C after immersion treatments with boscalid (600 to 700 mg LE-1) or cyprodinil + fludioxonil (371 + 250 mg LE-1). These postharvest treatments provided 5 and 15 days protection against these molds when strawberry fruits were stored at 20 deg C and 5 deg C, respectively. Fenhexamid (750 mg LE-1) arrested B. cinerea, but it was ineffective against R. stolonifer. Variable results were obtained with iprodione (750 mg LE-1). Fungicide treatments had no adverse effect on total soluble content, titrable acidity and firmness. Only boscalid + pyraclostrobin affected the external color of the treated fruits. In conclusion, fungicide treatments using new reduced-risk fungicides can be useful to extend strawberry shelf life for over a 15 day period. However, further research is needed to establish a commercial recommendation.

Mục tiêu của nghiên cứu này là đánh giá tác động của melatonin đến sự trưởng thành và thụ tinh trong ống nghiệm của noãn cừu, cũng như quá trình nuôi cấy phôi trong ống nghiệm. Noãn từ buồng trứng cừu thu thập tại lò mổ được chia thành bốn nhóm, hai trong số đó được xử lý với melatonin với nồng độ 10E–5 M (M5) hoặc 10E–6 M (M6), trong khi hai nhóm khác đóng vai trò là nhóm đối chứng không được xử lý (C5 và C6). Sau khi thụ tinh trong ống nghiệm bằng tinh trùng tươi của cừu đực, phôi tạo ra trong mỗi nhóm được chia thành hai bộ, một bộ được nuôi cấy với melatonin (M5M, C5M, M6M và C6M), và bộ còn lại không có melatonin (M5C, C5C, M6C và C6C). Nồng độ melatonin 10E–6 M đã cải thiện tỷ lệ trưởng thành (82,5% so với 73,7% của M6 và C6, tương ứng; P < 0,05) và có xu hướng tăng tỷ lệ phân cắt 36 giờ sau khi thụ tinh trong ống nghiệm (79,4% so với 72,6% của M6 và C6, tương ứng, P = 0,08). Nồng độ melatonin cao hơn (10E–5 M) không có ảnh hưởng đáng kể đến các thông số đó. Tỷ lệ phôi nang vào ngày thứ 8 không khác biệt đáng kể giữa các nhóm.

The objective of this study was to identify grapevine epiphytic yeasts and bacteria for biocontrol of Botrytis cinerea on grapes. Antagonistic yeasts and bacteria were isolated from the epiphytic flora associated with grape berries and leaves cv. ‘Thompson seedless’ from vineyards in Iran and identified by sequencing the conserved genomic regions. A total of 130 yeast and bacterial isolates from the surface of grapevine were screened in vitro for determining their antagonistic effect against B. cinerea and used to control postharvest gray mold. Among the 130 isolates, five yeasts and four bacterial isolates showed the greatest antagonistic activity in vitro against B. cinerea. Two yeasts species including Meyerozyma guilliermondii and Candida membranifaciens had high antagonistic capability against the pathogen. Also, 4 bacterial isolates belonging to Bacillus sp. and Ralstonia sp. showed significant biocontrol effect against B. cinerea. The isolates were capable of producing volatile and non-volatile substances, which suppressed the pathogen growth. The antagonistic activity of selected yeasts and bacteria against the pathogen was investigated on wounded berries of ‘Thompson seedless’. On small clusters with intact berries, all of the antagonistic isolates considerably reduced the decay on grape berries and inhibition of gray mold incidence on fruits treated by these isolates was less than 50%, except for the isolate N1, which had higher capability in inhibiting the disease incidence. These results suggest that antagonist yeasts and bacteria with potential to control B. cinerea on grape can be found in the microflora of grape berries and leaves.

A large interest is currently addressed to the no-food crops as an alternative source of energy. One of these crops is the biomass sorghum (Sorghum bicolor L. Moench) thanks to its high biomass productivity and high use efficiency of solar radiation and water. Aim of the research is assess the biomass sorghum response to the water in the Mediterranean environment. Biomass sorghum was subjected to four irrigation regimes, at 50, 75, 100 and 125% of ETc for three years (2008, 2009 and 2010). Water use efficiency (WUE), irrigation water use efficiency (IWUE) and water stress index (WSI) were calculated. Plant dry matter and green area index resulted different among the three years and the differences among irrigation treatments were more evident in 2009. The different soil water content at sowing among the three experimental years, affected the growth path during the growing crop cycle, explaining differences in term of biomass accumulation, leaf expansion and water consumption. WUE was higher in 2009 than in 2008 and 2010 with no differences among irrigation treatments for the first and third experimental year. WU ranged between 891 and 566 mm, the aboveground dry matter biomass between 4097 and 1825 g m-2 and WUE between 8.49 and 4.00 kg m-3. IWUE, similarly to WUE, was higher in the second year than in the first and third year, but with differences among irrigation treatments in the 2008 and 2010. WUE calculated from WU normalized with VPD gave a more stable parameter in the three years. This research showed the suitability of biomass sorghum as energy crop in Mediterranean environment and its ability to use water efficiently.

The effect of different irrigation strategies in water relations, vegetative growth and yield of early maturing peach trees, growing in Murcia, (Spain) was studied during two years. Treatments consisted on: a control T1, full irrigated (150% of ETc); T2, continuous deficit irrigation at 50% of ETc; T3, regulated deficit irrigation (RDI), irrigated at 100% of ETc only during stage III of fruit growth and 25% the rest of the growing season; and T4, with automatic control of irrigation based on capacitance FDR-type probe data, varying threshold values. The results indicated that irrigation deficits in T2 and T3 treatments induced the lowest soil water content and stem water potential(Ψstem) values during the postharvest period (e.g. ψstem up to –1.8 MPa in T3 during summer 2008); thus, a reduction in trunk growth and pruning weight, respect to control treatment values, was noted in both years. Also, peach yield was significantly reduced in both deficit irrigated treatments. The greatest irrigation water saving in T3 treatment (≈60%) caused the higher water use efficiency values in this treatment. For these reasons, water deficit during the postharvest periods (extended in the early maturing varieties) must be limited if fruit yield is not to be reduced. Irrigation scheduling based on capacitance probes have become a useful tool in the control of soil water content. When threshold values were precisely defined, the slight water deficits limited only vegetative growth while maintaining similar peach yield to that of well irrigated trees.

Over the last decade, much controversy has surrounded the usage of genetically modified organism (GMO) technology in commercial agriculture. More specifically, it is feared that GMOs may introduce new allergens into the food chain or contribute to antibiotic resistance. At the current time, the European Union (EU) adopts a zero tolerance policy toward "non-approved" GMO imports, whilst the approval process has not kept pace with the proliferation of new GMO varieties. In the EU livestock sectors, this apparent mis-match threatens to interrupt supplies of high protein feed inputs (e.g., soymeal) from countries with more relaxed regulations regarding GMOs. Employing a well known multi-region computable general equilibrium framework, this study quantitatively assesses the impact of a hypothetical EU import ban on unapproved GMO varieties of soybean and maize imports on livestock, meat and dairy sectors. The model code is heavily modified to improve the characterisation of the agricultural sectors and land usage, whilst a realistic baseline is employed to update the global database to 2008, the year the hypothetical ban is implemented. In the "worst case" scenario, there are significant competitive losses in EU livestock, meat and dairy sectors. In Spain, the negative impacts are particularly pronounced given the importance of pig production in agriculture. In contrast, all non-EU regions' trade balances improve, with notable trade gains in the USA and Brazil. To conclude, the EU must urgently find a long term strategy for GMOs if it is to reconcile political expediency with pragmatic economic concerns.