No abstract

A pot experiment was conducted in a net house to evaluate the effects of drought stress (a 20-day water withholding treatment from 100-120 days after planting) on the growth and physiology of five sugarcane cultivars. The results showed that water stress at an early stage significantly affected sugarcane growth and physiology. Water stress resulted in reductions in plant height, stalk diameter, and leaf number of sugarcane, in addition to reductions in the photosynthetic pigment content, Fv/Fm, and SPAD (Soil Plant Analysis Development) readings after the 20-day withholding water period (120 DAP), and in stem, root, and leaf fresh weights, and leaf area at 150 DAP. Besides, drought stress led to increases in stomata density and decreases in stomata length. Variation was also found among the cultivars in response to water stress. Significant genotypic differences in stem fresh weight and leaf area under water stress among the cultivars were observed. The highest value of stem fresh weight under stressed conditions was recorded in ROC22 (50.6 g), followed by QĐ159 (46.5g), ROC16 (46.2g), ROC10 (46.1g), and VL06 (44.4g). However, the highest DTI was recorded in ROC16, followed by VL06, ROC10, QĐ93-159, and ROC22, respectively.

Despite significant contributions of vegetable and flower production to the improvement of the livelihoods of household producers in the Central Highlands of Vietnam, several challenges facing the development of this sector require a general evaluation. This study aimed at assessing the current situation and economic efficiency of flowers and vegetables and analyzing the application of production techniques on the cultivation of these crops. Based on secondary data sources combined with a primary survey of 144 vegetable farmers and 74 flower growers in all five provinces (Lam Dong, Dak Lak, Dak Nong, Kon Tum, and Gia Lai) of the area in 2018, descriptive statistics and economic values were applied to provide an overview of the development of vegetable and flower production of the region. Findings showed that there were large differences in yields and economic efficiencies of vegetables and flowers among the five provinces of the Central Highlands. Accordingly, the yields and economic efficiencies of vegetables and flowers in Lam Dong were two to five times higher than those in other provinces (Dak Lak, Dak Nong, Kon Tum, and Gia Lai). In addition, the applications of technological advances in vegetable and flower production remained limited. Major challenges for flower and vegetable development included the lack of irrigation water, weak capabilities of building flower and vegetable brands, and limitations in market access. Solutions to improve production technology implications, develop brands of high-quality products, and raise the ability to access market for all vegetable and flower stakeholders are highly recommended.