Attributes related to seasonal herbage growth in white clover
When breeding temperate forage species is investigated, some attributes such as herbage accumulation and seasonal growth patterns have to be considered. To modify some of these traits, knowledge of the detailed process might be useful. In order to evaluate seasonal growth of contrasting white clover populations an experiment was carried out. Treatments were five cultivars and three local populations collected in Argentina. Weekly measures were taken during each season to calculate leaf appearance and flower appearance rates, stolon growing rate and dry matter (DM) net accumulation. Different germplasm of this species have different mechanisms for DM accumulation. Leaf size, more than leaf appearance rate, was the variable with most differences among germplasm and mostly related to dry matter accumulation. During spring and summer, inflorescences production had important effects on growing stolon rate, and differences among germplasm were evident. Some local populations showed favourable attributes that could be useful for breeding.
Research Note Reporting numbers in agriculture and biology: Don't overdo the digits
Texts in agricultural and biological sciences are full of numbers, but far too often these numbers are not presented well. The way that numbers are reported does matter, as it can either help or hinder the reader in understanding the message. In particular, how many digits are chosen for each number is important. This choice should be governed by the so-called effective digits, that is, those digits that vary in the given set of data. We give various examples to demonstrate this facet, and offer some guidelines for the selection of number of digits to be used. Our hope is that authors of research articles will use these guidelines in order to make their reports more readable and understandable.
Photomorphogenesis of white clover (Trifolium repens L.) phytochrome mediated effects on 14C-assimilate partitioning
Abstract White clover has a plagiotropic shoot system : it is a typical 'shade avoider' species. In this environment, white clover often experiences competition for light and nutrients from neighbouring plants. This paper reports a study in controlled environments on the effect of light quality on assimilate partitioning between source and sinks and the consequences on plant morphogenesis. The results demonstrated that the source-sink relationships were modified ; far-red plants partitioned more 14 C-assimilates to petioles and leaves than did control plants, at the expense of stolons and roots. These modifications in the transport of 14 C-labelled assimilates were evident less than 4 days after the commencement of the light treatments. Adding far-red at the end of each photosynthetic period modified plant morphogenesis ; far-red radiation decreased stolon branching and promoted the extension of petioles and internodes. Thus, the strategy of white clover in response to far-red is to redirect its development through a modification of its source-sink relationships in order to allow young leaves to be kept out of the shade. The shoot-root ratio was increased by far-red radiation ; thus phytochrome may act indirectly on nitrogen fixation and nutrient uptake by reducing carbohydrate allocation to the roots.