Low levels of manganese concentrations in lupin seed can affect germination vigour and crop establishment in next season’s crop.
Grain analysis is an extremely accurate and cost-effective method of measuring seed manganese levels.
Harvesting during hot/dry conditions and high drum/rotor speeds in the header can result in physical cracking and damage of the seed which is not directly related to manganese but might be mistaken for it.
Looking for the typical visual symptom of split seeds as per the photo may give an indication that manganese levels are low, but visual symptoms are not always observed or are in such low numbers that other causes can be assumed.
Sampling gives you and your CSBP advisor the most accurate information to assist in making the decision to retain or replace seed. Seed levels of manganese are ideally above 15 mg/kg of Mn, levels below 10 mg/kg of Mn will most likely contain split seed, however levels between 10-15 mg/kg of Mn might look ok but still have poor germination and or vigour. The picture below had manganese levels of 9.9 mg/kg of Mn.
Image 1 - Split seed manganese sample. CSBP grain analysis highlighted low Mn levels (9.9mg/kg) which made the sample undesirable for a seed source for the following season.
When preparing and sending samples to the CSBP lab ensure you select the ICP test only which does not include the nitrogen test which can save on analysis costs.
Please contact your CSBP area manager to organise your lupin seed analysis for the upcoming harvest.
Image 2 – ICP test is the most cost effective means to test for grain manganese levels. A minimum of 500gm should be sent to the lab for analysis.