What is the impact of boron deficiency on rapeseed?
Did you know that +2 cm/day it’s the average growth of rapeseed root, during early stages, under optimal conditions?
- DEEP ROOTING CAPACITY OF RAPESEED
Rapeseed yield depends on many parameters. The first one to establish is the number of plants per m². To maximize this component, farmer must pay attention to the three following objectives: a good seedbed preparation (structure + pH), a good germination and, a good root development.
During early stages of development, rapeseed taproot system develops quickly: around +2cm/day (Kirkegaard et al. (2020)) under optimal conditions. This quick growth is essential to ensure the three main roles of rapeseed root system:
– Establishment (part of yield component),
– Nutrition in both water and nutrients,
– Storage. Rapeseed quickly produces biomass and assimilates coming from photosynthesis are quickly stored in the taproot to ensure a good restart post-winter and a good seed filling at the end of the cycle.
To support this high capacity to deep rooting, its is essential to provide quickly to the seedling all the nutrients it requires. For this reason, TIMAC AGRO developed a specific microgranule range. Microgranules are not an alternative to basic fertilization, they are complementary to it as they act as starter due to their ultra-localization.
- ULTRA-LOCALIZED FERTILIZATION BENEFITS
Microgranule range has been developed with a granulation process and formulations perfectly adapted to ultra-localized fertilization, meaning the microgranule is positioned right next to the seed. The aim of this type of fertilization is to be close to a 100% efficiency of the fertilizer units provided. Indeed, thanks to this high proximity, seedlings only require embryonic roots to access and uptake nutrients provided.
To avoid any risk of burn or intoxication of the seedling, those microgranules are made of non-aggressive raw materials and very low salinity and their formulation is perfectly adapted to early stages needs.
With their starter effect, microgranules stimulate root development to:
– Optimize seedling nutrition for a better growth and a better resistance to potential early stress,
– Avoid nutrients losses into the environment and therefore improve all the units provided efficiency.
- BORON REQUIREMENTS FOR ESTABLISHMENT
To support high plant requirements during early stages of development (from sowing to winter), it is essential to provide to the plant sufficient amount of N, P, K and S but also B. Indeed, in addition to flowering and pollen fertility, B also has an essential role on cellular walls synthesis (structural and protection roles), carbon hydrate metabolism (energy production role), protein metabolism (structural and biological roles) and cellular division and elongation (new organs formation/development role).
Among all these functions, Pommerrenig and al. (2018), highlighted the important role of B on root development. They transferred rapeseed plant from an agar medium with sufficient B levels (5 µM B) to a new agar medium with either sufficient (5 µM B) or deficient (0.01 µM B) B concentrations. Seedlings from almost all cultivars decelerated the growth of their roots after the transfer to a B-deficient medium within a day and fully ceased it after 3 more days.
This study also highlighted effect of B on leaves development for both B-efficient (E) and B-inefficient (IE) rapeseed genotypes with 200 µM B (B1) vs 0 B (B0). Most plants grown under B0 conditions exhibited strong B deficiency symptoms and leaf development has been highly negatively affected.
Ahmad et al. (2012) made a review of many studies done on B deficiency. They reported several soil factors and conditions render soils deficient in boron. Among them, low soil organic matter content, coarse/sandy texture (leaching), high pH, liming, drought and intense cultivation.
==> management is therefore essential to get strong rapeseed plants before winter and help them to face this stressful period. But be careful, threshold between toxicity and deficiency is very small on B!
TIMAC AGRO Technologies are perfectly adapted to early stages needs of rapeseed and can insure optimal root development and a better overall nutrient absorption!