There is a great deal of interest for diffuse glass in Dutch horticulture ever since higher light transmission values and the diffusing characteristics of diffuse glass have increased production for some crops. Thus an experiment was designed to examine the effects of a variation in haze factors and light transmissions for diffuse glass or a diffuse coating on the growth and production of tomato. The influence of diffuse glass with a haze factor of 45, 62 and 71% and light transmission equal to or greater than that of standard glass, as well as standard glass with a commercial coating with a haze factor of 50% and 6% less light transmission than that of standard glass was compared to that of standard glass. The crops were planted midDecember 2010 and grown to the middle of November 2011. The influence of diffuse light on light interception, crop morphology, photosynthesis and growth was measured and analysed. Light penetrated deeper into the crop resulting in a higher photosynthetic capacity in the lower canopy, but only in winter. Tomato grown under diffuse glass was more generative, transferring more into fruit production than vegetative growth, in comparison to standard glass or coated glass. The production under the three diffuse glass coverings showed a 7-9% increase in June relative to that under standard glass, and retained this increased production to the end of the year, ending with 8-11% more production. The most important reason for the increased production was an increase in individual fruit weight by 5-8 g. Plants grown under diffuse glass or coating were less susceptible to Botrytis spp. during the last months of the crop, possibly due to a higher dry matter content. The coating was applied in the beginning of May and the treatment continued through August when the global radiation diminished and more light was necessary in the crop and the coating was removed. The overall production under the coating was 5% higher than that under standard glass. An estimation of the benefits and consequences of diffuse light characteristics on the growth, development and production of tomato under Dutch conditions are discussed, along with recommendations for the optimal characteristics for diffuse glass.

ABSTRACT:The present experiments were conducted to investigate the effects of dietary chitosan on growth performance, nutrient digestibility, and digestive enzyme activities in weaned pigs. A total of 180 weaned pigs (35 days of age, 11.56 ± 1.61 kg of body weight (BW)) were selected and assigned randomly to 5 treatments containing 0, 100, 500, 1000, and 2000 mg chitosan per kg feed, respectively. Each treatment involved six replicate pens and six pigs per pen. On days 14 and 28, all pigs were weighed and six from each treatment (one from each replicate pen) were killed, and the contents of the stomach, jejunum, and rectum were collected and used for determining nutrient digestibility and digestive enzyme activity. The results showed that supplementation of chitosan improved quadratically average daily gain (ADG) (P < 0.05). Moreover, dietary chitosan quadratically (P < 0.05) increased apparent digestibility of crude protein (CP) on days 14 and 28, and quadratically increased apparent digestibility of dry matter (DM) on day 14 and of Ca and P on day 28, whereas decreased (P < 0.05) apparent digestibility of ether extract in comparison with the control diet. In addition, dietary chitosan quadratically increased (P = 0.062) amylase activity of proximal jejunum and decreased (P < 0.05) lipase activity of distal jejunum compared with the control. These data indicated that diets supplemented with increasing levels of chitosan (0, 100, 500, 1000, and 2000 mg chitosan per kg) quadratically improved ADG of weaned pigs. The growth-promoting action was achieved probably by improved digestibility of major nutrients (DM, CP, Ca, and P) and increased amylase activity of jejunum.