Die Bodenkultur - Journal for Land Management, Food and Environment
E. Kübler, H.-P. Kaul and W. Aufhammer:
Comparative study of crop stand establishment and dry matter production of the pseudocereals buckwheat (Fagopyrum esculentum), quinoa (Chenopodium quinoa), amaranth (Amaranthus sp.) and the cereals millet (Panicum miliaceum) and tef (Eragrostis tef) in a marginal environment
Small seeds and high sensitivity against soil crusting combined with high minimum temperatures for germination and long vegetation periods impede the establishment of productive crop stands of quinoa, millet and predominantly of amaranth and tef on marginal locations. During 2-years field experiments the effects of sowing dates and sowing rates on field emergence, crop density at harvest, shoot dry matter production and distribution, were examined, thus affecting environmental conditions for germination and intraspecific competition, respectively. Except tef, each species was represented by four genotypes. All crops were sown at an early and a late sowing date at three specific sowing rates. The dates of field emergence were noted and the seedling densities were counted, which allowed for the calculation of field emergence percentages. From plant samples shortly before harvest we recorded the plant or panicle densities, the shoot dry matter and the grain yield. In parallel with the seed size, the field emergence percentages decreased in the sequence buckwheat > millet > quinoa > amaranth > tef. The high temperature level after the late as compared to early sowing date, mainly in 1996, caused a faster field emergence. For millet and amaranth the emergence percentages were also higher, but for buckwheat and quinoa they dropped compared with earlier sowing. Plant density and the shoot dry matter were graduated similar to field emergence. Elevating sowing density increased competition for water with quinoa and millet due to smaller seed distances within the row especially with low rainfall in 1997. After shallow broadcast seeding of the highest sowing rate in 1997, additionally a missing water supply for germination (quinoa) and bird feeding (buckwheat, millet) reduced field emergence percentages. However, in most field plots elevated plant densities were realized and subsequently shoot dry matter increased. The harvest index was only negligibly affected by sowing date or sowing rate. With decreasing seed size of the different species difficulties to establish sufficiently productive crop stands increased. The use of highly germinable seed material, early varieties, mulch seeding, row distances according to the sowing rate and an exact, seed size adapted sowing depth might be approaches for improvement.
Key words: pseudocereals, millet, field emergence, dry matter production, grain yield.