The World Vegetable Center has a collection of over 50 moringa accessions, majority of which belong to M. oleifera. The planting of this species in southern Taiwan started some 35 years ago. The World Vegetable Center initiated research on moringa in 2001. A small project was established to introduce and evaluate a number of moringa accessions collected from Asia, Africa and USA. The accessions were evaluated for growth characteristics and horticultural traits, aiming at high leaf production and nutritional value. A total of 50 accessions were collected and from this collection, seeds of 42 accessions representing four species (Moringa oleifera, M. stenopetala, M. drouhardii and M. peregrina) were germinated and transplanted to the field for seed multiplication, characterization and evaluation. Twenty-two accessions produced sufficient seeds for replicated evaluation trials and seed distribution. Ten promising accessions were selected and evaluated in replicated trials over a two-year period. Among those, three accessions showed fresh young shoot yield averaging 20-40 t ha^-1. The effects of leaf type (age), harvest season and variety on nutrient content were investigated as a component of this study. Results showed no significant differences for most nutrient contents among accessions. Mature leaves are more nutritious than young leaves or shoots. Nutrient content varied with harvest season. Calcium, vitamins A and E were higher in hot-wet season in southern Taiwan than during winter, whereas Fe and vitamin C were higher in cool-dry season than in summer. Subsequent field evaluation studies revealed the variability of Moringa accessions in terms of horticultural traits. The accessions varied significantly in plant height, stem diameter, leaf and stem biomass, number of side shoots, tolerance to flooding and survival after heavy rainfall and strong wind brought about by tropical typhoons. Superior and promising accessions are being multiplied to meet the increasing demand for seed and planting materials of moringa. During the last ten years, the World Vegetable Center has distributed moringa germplasm to universities, government organizations, non-governmental organizations and private companies in 15 countries. The Philippines, Malaysia, Thailand, Germany, Vietnam, Egypt, The Netherlands, and Pakistan were the top recipient countries. Moringa is also distributed in seed kits for home garden projects in Asia and Africa....

Low-pressure drip irrigation has been introduced to small-scale vegetable farmers in several countries in Asia and Africa for almost two decades, but adoption and impact of the technology have been limited due to several ...

In rainfed cropping systems limited water supply is a major constraint for increased crop production during the dry season. The use of affordable drip irrigation systems can increase crop yield, water use efficiency, and labor productivity in dry season vegetable production. Farmer participatory research was conducted in Cambodia during the 2008 dry season to evaluate the performance and benefits of a low-cost drip irrigation system for improving small-scale vegetable production. The effect of integrating improved soil nutrient management through fertilizer deep placement on crop yield and economic returns were determined for selected vegetable crops. Compared with traditional practice of hand-watering, drip irrigation increased yield of chili (Capsicum annuum), cucumber (Cucumis sativus), and eggplant (Solanum melongena) by almost 50%, but reduced average net income by 25%. Drip irrigation decreased water use by 33%, and increased water use efficiency by 63% and labor productivity by 74%. The use of fertilizer deep placement with drip irrigation resulted in higher yield (18%) compared with commercial NPK fertilizer irrespective of irrigation methods. Significant response was shown in yard-long bean (Vigna unguiculata var. sesquipedales) with 35% yield increase and 50% increase in net income. Under drip irrigation the use of fertilizer deep placement reduced water use by 48%, increased water use efficiency by 70% and labor productivity by 78%. This study demonstrated the potential benefit of low-cost drip irrigation and fertilizer deep placement for improving smallholder vegetable production in Cambodia during the dry season through higher yield, increased water use efficiency, and higher economic returns and labor productivity compared with farmers’ traditional practice of hand-watering and fertilizer application....

A major constraint limiting yield and production of sweet pepper (Capsicum annuum) during the hot-wet season in the highland tropics is the high incidence of soil-borne diseases including bacterial wilt-BW (Ralstonia solanacearum) and Phytophthora blight-PB (Phytophthora capsici). High temperature and humidity during the wet season favor development of these soil pathogens. A technology on grafting sweet pepper scion onto chili pepper rootstock with resistance to both diseases and flooding was developed at AVRDC – The World Vegetable Center since 2002. Several chili pepper lines were identified with high resistance to BW and PB. From 2007 to 2008, on-farm trials were conducted in Nantou, Central Taiwan to evaluate disease resistance and subsequent yield of sweet pepper cultivars grafted onto resistant chili pepper rootstocks. In both years, the incidence of PB and BW was significantly (P<0.05) lower in grafted than non-grafted plants. Marketable fruit yields averaged over four sweet pepper cultivars (scions) were significantly (P<0.05) greater in plants grafted onto seven chili rootstock lines compared to non-grafted plants. Outstanding and high yielding sweet pepper cultivars were ‘Andalus’ and ‘Hazera’. Six outstanding chili pepper rootstock lines with low incidence of BW and PB were identified in these trials. This study indicates that grafting technology is effective in reducing soil-borne diseases of sweet pepper which leads to increased yield and production during the hot-wet season in tropical highlands....