Improving sugar beet yield, quality, and water use efficiency by nursery and transplanting practice under semi-arid conditions

Transplanting is a useful technique to produce sugar beet (Beta vulgaris L.) in arid and semi-arid regions that face water scarcity and salinity. The major challenge in transplanting is to improve the economic benefits that smallholder farmers have in the self-production of transplants. The objective of this study was to evaluate the yield, quality, and water use efficiency (WUE) of sugar beet in response to transplanting and different options in transplant production process. Two field experiments were conducted at two sites. The first experiment investigated the effects of seedling age at transplanting, volume of the substrate, and transplanting date. The second experiment investigated the effects of substrate media and transplant production conditions on sugar beet yield and quality. In both experiments, transplanting was compared to the direct seeding on the conventional planting date at both sites. The highest white sugar content (12.1% and 13.5%) and white sugar yield (10.2 and 12.1 t ha(-1)) were obtained from plants transplanted in mid-May at sites 1 and 2, respectively. Also, root yield, total sugar content, and WUE were higher in transplanting than direct seeding. The 40-day-old transplants produced in 22 mL cell volume when transferred to the field in mid-May had higher WUE than the direct seeding. The transplants produced outside the greenhouse (uncontrolled conditions) had nearly the same yields as those produced inside a greenhouse under controlled conditions. We suggest that using readily available substrates and not requiring greenhouse conditions for transplant production is a cost-effective way for smallholder farmers to produce their own seedlings.