User:Fortheorlingas/sandbox

Stress tolerance of landraces
Rheintaler Ribelmais is a so called landrace. A landrace differs in several ways from "normal" races. It is adapted genetically to a certain environment, which can include nutrient-poor soil conditions, traditional agriculture or other cultural practices. Furthermore, it has a higher genetic heterogeneity than a modern hybrid. These traits makes Rheintaler Ribelmais potentially more tolerant to stress. Genetically uniform plant species, such as hybrids have lost their natural resilience: If one plant becomes susceptible to a stress factor, as a consequence all of them will become susceptible.

However, maize is a cross-pollinator. In countries with small scale agriculture, as it is the case in Switzerland, fields are comparatively small. With decreasing numbers of neighbouring plants, as it is the case on small fields, genetic diversity is reduced. This increases the risk of malformations. In recent years, Ribelmais has become more susceptible to pests, which were unproblematic in earlier days. This contradicts the common assumption mentioned before, that landraces are better adapted to local conditions. To ensure trait quality, nowadays Rheintaler Ribelmais needs to be observed and altered by breeding programmes. Modern varieties could therefore be better adapted than traditional landraces.

Cold tolerance of Rheintaler Ribelmais
Maize is a chilling-sensitive species, as it originates from the tropics. To make maize cultivation possible in Europe, it is planted during late spring. To increase yield, breeding programs mainly select for early maturing maize. Another approach is to breed for increased chilling tolerance. This would make earlier sowing possible and elongate the vegetation period. Consequently, yield would increase. Moreover, seedlings get more competitive against weeds. However, there is no scientific evidence that Rheintaler Ribelmais is more cold tolerant compared to modern hybrids.