Rose is among the most important cut flower crops worldwide. The vase life is an important indicator of cut rose quality. The composition of the vase solution directly affects vase life. Neoagaro-oligosaccharides (NAOS) are degraded seaweed-derived polysaccharides that constitute a group of compounds with small molecular weight and good water solubility. Oligosaccharide treatment can extend the postharvest longevity of certain types of cut flowers; however, little information is available on the utility of NAOS for preservation of cut rose flowers. To explore the effects of NAOS on the longevity and quality of cut flowers of rose ‘Gaoyuanhong’, 100 mg·L−1 NAOS alone and in combination with 10 g·L−1 sucrose were incorporated in the vase solution. Distilled water was used as the control. Physiological indicators, comprising maximum flower diameter, fresh weight, water balance, vase life, bacteria number in the vase solution, and hormone contents of the outer petals, were determined in fresh cut flowers and analyzed. Compared with the control, 100 mg·L−1 NAOS treatment increased the maximum flower diameter (mean 8.21 cm), induced the maximum rates of change in flower diameter and cut flower fresh weight, maintained the best water balance, significantly extended the vase life to 16 days, and reduced the number of bacteria in the vase solution. The abscisic acid content of the outer petals in the control and 100 mg·L−1 NAOS treatments were significantly lower than that of the other treatments on day 9. The results showed that NAOS is useful to improve the postharvest quality and extend the vase life of cut rose flowers, and might contribute to the development of novel alternative preservatives for the cut rose industry.
Ventilation and soil moisture influence greenhouse cultivation. Experiments were conducted at Xinxiang Irrigation Research Base of the Chinese Academy of Agricultural Sciences, Henan Province, China, to identify how ventilation and irrigation affected the greenhouse microenvironment. To develop ventilation and irrigation protocols that increase crop yield and improve the quality of drip-irrigated tomatoes grown in the greenhouse, three ventilation modes (T1, T2, and T3) were developed by opening vents in different locations in a completely randomized pattern. T1 had open vents on the north wall and roof of the greenhouse. T2 had open vents on the north and south walls and the roof. T3 had open vents on the north and south walls. Three irrigation treatments (W1, W2, and W3) were designed based on the accumulated water surface evaporation (Ep) of a standard 20-cm evaporation pan. The irrigation quantities were 0.9×Ep (W1), 0.7×Ep (W2), and 0.5×Ep (W3). The spatial and temporal distributions of temperature and humidity were analyzed for different combinations of ventilation and irrigation to identify their effects on tomato yield and fruit quality. Major results were as follows: 1) In addition to solar radiation, ventilation had an important influence on Ep and, on a daily scale, ventilation had a significant effect on Ep (P < 0.05). 2) Ventilation had a significant effect on indoor wind speed, but the effect varied during different growth stages. During the flowering and fruit setting stage, wind speed for T2 significantly differed from those of T1 and T3 (P < 0.01). During the harvest stage, the three ventilation treatments had significantly different effects (P < 0.01). A correlation analysis showed high correlation between T2 wind speed and T3 wind speed (R = 0.831), but low correlation between T2 wind speed and T1 wind speed (R = 0.467). 3) The effect of ventilation on greenhouse humidity and temperature was greater than the effect of irrigation. The differences in air temperature among various combined treatments of ventilation and irrigation were significant for the flowering and fruiting stages (P < 0.05), but they were not significant for the late harvest stage (P > 0.05). There were significant differences in humidity on sunny days (P < 0.01), but no significant differences on cloudy or rainy days (P > 0.05). Air temperature at 2 m was greater than canopy temperature, but humidity at 2 m was less than that at canopy level. 4) Irrigation water quantity was positively correlated with tomato yield and negatively correlated with the fruit quality indicators total soluble solids, vitamin C content, organic acid content, and soluble sugars content. Ventilation had an effect primarily during the harvest period; it had no significant effect on yield (P > 0.05). However, it had a significant effect on vitamin C content and the sugar:acid ratio (P < 0.01). The combination treatment of T2W2 is recommended as the optimal treatment for greenhouse tomatoes using drip irrigation to produce an optimal combination of crop yield and fruit quality. This study provides theoretical and technical support for the improvement of greenhouse climate control by optimizing greenhouse ventilation and irrigation techniques to promote tomato yield and improve fruit quality.