The Accidental Smallholder Forum

Growing => Vegetables => Topic started by: cloddopper on July 13, 2019, 10:04:39 pm

Title: Waaaagh ! My onions
Post by: cloddopper on July 13, 2019, 10:04:39 pm
my onions have been showing signs of being read to crop , the garlics were done last weekend  ..quite a reasonable crop but could have been bigger I suppose.

The onions were a different story
 I'd planted 36 Japanese shallots , the tops were yellowing and they'd split apart like shallots do into bunches of five or six onions.

On pulling a group up all were good save one onion. Careful looking saw the base root area of  the poor one riddled with 10  mm long white maggots & the occasional tiny slug , I put slug nematodes on last weekend .. it's got the big slugs and most of the snails too . But of the maggots I was at a loss I've never had them in the onions before .

 Out came Dr DG Hessayon's vegetable expert .. ...lo & behold the onions have been too dry and in dry conditions the onion fly lays it's eggs on the dry stems low to the ground.

 This puzzled me , for a fair while the onion beds have had 4 daily x 3 min micro misting sprays . on lifting all the shallots the whole bed is as a dry as a bone from  five inches below the surface right down to 18 inches deep .

So obviously the misting was only wetting the top ..the onion roots went down well past the 18 inch depth  .

 There is no treatment for onion fly attack other than keep the beds watered  but not too wet or you'll get onion rot instead. 

You're supposed to burn any affected onions & if you get repeat attacks each year  grow a resistant onion type or better still starve the soil of onion taint for four years & try again with plenty of irrigation.

 I've given the other four onion beds a real good 20 min soaking on each bed
 after an hour dug a test hole 15 inches deep  & slipped in a moisture metre which tipped towards dry .

 They all got another 20 min soak plus several bucketsful of water with a drop of tomato feed in them  . An hour later another 15 inch deep test hole showed moist .

 I've put brassicas in the  harvested bed and put two micro sprays over it .

Title: Re: Waaaagh ! My onions
Post by: Fleecewife on July 14, 2019, 12:42:15 pm
What a total bummer!!  I'm now worried that the onions in my polytunnel could be too dry.  I tend to keep them a bit dry as when I grow them outdoors the problem is too wet, so they don't store.  I'm off to have a poke around in the soil.  Thanks for sharing that info  :thumbsup:
Title: Re: Waaaagh ! My onions
Post by: cloddopper on July 14, 2019, 10:28:18 pm
You also tend to get red spider mite in polytunnels that are too dry      so having a moisture probe meter is handy to ensure things are as Mirranda would say " Moist "