Lupins

[Retraceh]

Struggling to find nodules on my blue lupin roots. What sort of numbers have other growers got? Roots are good in size and plenty of laterals off the main root. They have been in the ground just over 7 weeks.

 

[Simon Chiles]

Struggling to find nodules on my blue lupin roots. What sort of numbers have other growers got? Roots are good in size and plenty of laterals off the main root. They have been in the ground just over 7 weeks.

I suspect you're looking too early, modern types of rhizobium inoculants are difficult to get wrong unlike the good 'ol days when you had to mix them with the seed in a cement mixer! If they were pre inoculated then you'd have had to leave the seed out in blazing hot sun for hours before you started to affect the rhizobium. Even if you had to mix the inoculant it is fairly difficult to get it wrong the Lupins only need a sniff of it and it tends to get covered all over the inside of the drill and seeding tubes. Lupins tend to go through a stage where they start to look pale before the rhizobium kicks in and then they go darker green. If you dissect the nodules at this stage they should be pink inside if they are healthy.

 

[Kiwi Pete]

the Lupins only need a sniff of it

Yes, it's usually around Christmas here for lupin, so about a month to 6 weeks away for you guys I'd suspect? (that's not via digging them up, just general observation over summer beach trips) they change colour about then.
An interesting aside, as my mate is farming on the sand at sea level- it has almost no P or K retention- we dug down 4 feet and took a sample: pH was 11 vs 5 at the surface; olsen P was 45 vs 4 at the surface! hence the lupins and lack of much else

 

[Retraceh]

Had a look this afternoon and can see them and a nice pink stem. Counted about 6 on this plant.