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Blueberry (Vaccinium corymbosum L.) production under tunnels has spread in recent years. However, there is little information on the productive and physiological responses of blueberry grown under high tunnels. The objective of this research was to evaluate the effect of high tunnel microclimate on the physiological and productive responses of blueberries. A total of 1296 plants of highbush blueberry 'O'Neal' were grown in high tunnels, leaving the same amount of plants under open fields (control). Environmental temperature (T, °C) and relative humidity (RH, %), diffuse and total photosynthetically active radiation (PAR diffuse and PAR total , µmol m -2 s -1 ), stomatal conductance (g s , mmol m -2 s -1) and maximum photochemical efficiency of photosystem II (F v /F m ) of the leaf were measured. Fruit yield, date of harvest initiation and fruit growth rate were also determined. The maximum T was on average 10-12 °C higher inside the high tunnel than the control, whereas the minimum T averaged only 2-5 °C higher. PAR total decreased an average of 25% under tunnel, while levels of PAR diffuse increased more than 150%. The g s ranged between 42% and 99% higher in the high tunnel compared to the control, and was positive and statistically related (r 2 = 0.69**) to PAR diffuse variations. Blueberries under high tunnel recorded an accumulated yield 44% higher, while harvest started 14 d earlier compared to control. The results suggest that high tunnels in blueberries increases fruit yield and improves precocity due to higher temperatures during the flowering stage and fruit set. Particular light conditions under tunnels would favor higher leaf stomatal conductance in this crop.

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Borage (Borago officinalis L.) is an oilseed with a high gamma-linolenic acid (GLA) content in its seed. The objective of this study was to determine the response of borage seed yield, oil content, and fatty acid composition to N, P, K, and S fertilizer treatments. Three experiments were conducted in Osorno (40º22' S, 73º04' W; 72 m.a.s.l.), Chile. The first experiment was conducted during the 2005-2006 growing season, with four N rates (0, 100, 200, and 300 kg N ha-1), three P rates (0, 60, and 120 kg P 2 O 5 ha-1) and two K rates (0 and 150 kg K 2 O ha-1). The second experiment was conducted in 2006-2007 and evaluated only the effect of four N rates (0, 50, 100 and 150 kg N ha-1) was evaluated because there was no response to P and K in the first experiment. The third experiment was conducted in the 2005-2006 and 2006-2007 and evaluated only two rates of S, 0 and 40 kg S ha-1 were evaluated. Seed yield was not affected by N, P, K, or their interactions in any of the experiments. As N rates increased GLA content increased. Mean seed yield increased to 98 kg ha-1 when appliying of 40 kg S ha-1. Results indicate that borage has a higher response to S applications than N. Further research is needed to determine the interactions between N and S applications, given that the experiments were conducted on soils with high levels of P and K levels.