Base-temperature, plastochron and chia (Salvia hispanica L. - Lamiaceae) yield for different sowing times

ABSTRACT Chia is a plant whose seeds are used in cooking and is a natural source of omega-3 fatty acids, fiber and protein, as well as other important nutritional components such as antioxidants. The objective of this work was to estimate the base temperature, plastochron and chia seed yield for different sowing times in Cruz Alta, Rio Grande do Sul, Brazil. The experimental design was completely randomized and the treatments consisted of different sowing times (September, October and November). For the determination of the base temperature for node emission in the main stem of the plants, the method of least mean square error of linear regression between the number of nodes and the accumulated thermal sum was used. Regarding estimation of the plastochron at each sowing time, a simple linear regression was obtained between the number of nodes in the main stem and the accumulated thermal sum. Seed yield was measured at harvest. Sowing in times with air temperature below 19 ºC should be avoided so that the development of plants is not impaired. Plastochron ranges from 28.01 ºC to 32.26 ºC day for successive node emission in the main stem of chia plants and September sowing promotes higher seed yield.

摘要：奇亚（Chia）是一种种子可用于烹饪的植物，其天然含有Omega-3脂肪酸、膳食纤维与蛋白质，同时还包含抗氧化剂等多种重要营养组分。本研究旨在估算巴西南里奥格兰德州克鲁扎阿尔塔地区不同播期下奇亚的基部温度、出叶间隔期（plastochron）及种子产量。本试验采用完全随机设计，试验处理设置为三个不同播期：9月、10月及11月。为测定植株主茎节数生成的基部温度，本研究采用节点数与累积积温间线性回归的最小均方误差法。针对各播期下出叶间隔期的估算，本研究通过主茎节数与累积积温间的简单线性回归模型完成计算。种子产量于收获期进行测定。应避免在气温低于19℃的时段播种，以免植株生长发育受到抑制。奇亚植株主茎连续节数生成对应的出叶间隔期为28.01至32.26℃·日，且9月播种可获得更高的种子产量。