Title : Agronomic practices to increase the seed yield of chia (Salvia hispanica L.) crop
Abstract:
Chia (Salvia hispanica L.) is an ancestral crop from Mexico that today is one of the main sources of fatty acids Omega-3. This source of Omega-3 is more sustainable, safer and cheaper than others ones used in the world. The estimated potential chia seed yield (SY) is about 3 tons ha-1 but the actual SY is only 0.3 - 0.7 tons ha-1. The main reason for this low production is that chia crop has not been fully integrated into the modern agriculture and farmers do not know how to manage chia crop. On the other hand, the importance of the chia as raw material in the nutraceuticals production is enormous. In 2013, the agricultural research team in Amway Corporation started a long-term research project to improve chia SY at the Nutrilite farm located at El Petacal, Jalisco, México. The objectives of this project are (1) to develop new chia varieties with breeding program; and (2) to investigate the effect of fertilization, pest and disease control, and the planting dates on the yield of the chia. The results indicated that the use of improved varieties and N fertilization are two best agronomic practices to increase Chia SY. Furthermore, the improved genotypes are more efficient to use the N applied via fertilization than the inbred varieties. Recently, Amway Corporation submitted a patent application for a new chia variety named the Rehnborg. The SY of Rehnborg is 1.72 tons ha-1 which is not only higher than the SY of its progenitor, Pinta cultivar (1.35 ton ha-1) but also other inbred varieties commonly used in Mexico, such as Black Puebla and White Acatic (1.28, and 1.27 ton ha-1, respectively). The high SY of the Rehnborg variety is associated with its efficiency to use the N fertilizer applied (8.1 kg of Seed Yield kg-1 N applied), that is 2.5, 1.6, and 1.7 times as much as that for the cultivars Pinta, White Acatic and Black Puebla (3.2, 5.1 and 4.8 kg of Seed Yield kg-1 N applied, respectively). Currently the chia crop is growing during the summer season in our farm. This is the option for temperate regions but not for tropical zones where the high temperature and rainfall resulted in the high incidences of pests and diseases that frequently decreased chia SY. Farmers and researchers consider the chia crop as resistant to pest and diseases, however, we found that when chia is planted in the summer season, Diabrotica sp. and Fusarium sp. reduced 43 and 55 % of SY, respectively if pests and diseases were no controlled. Also, we have observed that in central Mexico area where free of frost, it is possible to grow and harvest chia seeds for two cycles each year. It is feasible for farmers to obtain high SY in both cycles, however, farmers must use the improved varieties along with proper irrigation, adequate fertilization, optimal sowing dates, proper plant density and an integrated management of pests and diseases in their production system.
