Dear Vinay,

Are your losses related to bulb rots or shrink?

Bulb decay (e.g., as caused by Botrytis)  is a major cause of postharvest loss. Avoid storing at high RHs.

 dear Brenda,

                  its related to bulb rot.

Dear Vinay,

Please go through www.dogr.res.in. You will get sufficient information. besides,

Post harvest diseases are major cause for PHL.

It is directly related to storage conditions/ which type of storage structure you use.

Kharif varieties have very poor storage life while rabi varieties such as Bhima Kiran have good storage ability up to 5-6 months.

While harvest neck cutting should be done leaving 1-2 cm neck region and curing should be done in shade.

Hope these some points may help u.

Thanks

Hi Vinay,

Where are you working?  Are you most concerned with fungal or bacterial rots?  Proper curing is critical, but so is effective management in the field prior to storage.  I have attached some PDFs from manuscripts on curing information relative to bacterial storage rots.  I hope that this is of some help to you.

Brenda

 Hi Dr. Brenda, 

              Thanks a lot. ya I  am  concern with fungal or bacterial rots.  I am working in ( NIFTEM) India.I have started my work. I will take help from you time to time.

Best of luck to you.  Do not hesitate to contact me if you need help.  I do not have all the answers, but I am happy to help the best that I can.

Brenda

Look for Aceria tulipae -Acari, Eriophyidae 

and Maurice Sabelis, The Netherlands - who worked on biological control of this mite.

Dear Mr. Kumar

Please have a look these papers

http://www.indianjournals.com/ijor.aspx?target=ijor:pa&volume=17&issue=2&article=016

Best wishes

Total losses in storage at National level (India) was 2.16% during 2013-14 based on survey and observation. These losses are mainly due to in appropriate storage structure. Curing is to be done before storage of onion. AICRP on PHET, HAU Hisar centre has developed storage structure (perforated drum) of 100 kg capacity suitable for kharif onion storage.

Some preventive recommendations for reducing postharvest diseases in onion:

Preharvest:

Avoid excessive irrigation

Avoid excessive use of nitrogen

Appropriate field curing

Avoid mechanical injuries

Postharvest:

Avoid excessive air humidity. Recommended storage conditions: 0 C, 65% to 70% relative humidity.

For more information on storage/postharvest management and diseases:

https://www.ars.usda.gov/ARSUserFiles/oc/np/CommercialStorage/CommercialStorage.pdf

Post harvest loss results from fungal or bacterial rot at harvest to a couple of months and from weight loss or physiological disorder such as transluscent or water scale in intermediate day type onions. Normally disease rot is mainly affected by unsuitalbe preharvest management such as late or excessive nitrogen application or excessive irrigation, failure to disease management including Botrytis spp. Fusarium spp. or black mold etc.

Please open Attach and recognised some articles for postharvest losses of onion.........

Post harvest losses can be prevented by proper curing of onions after harvest. Putting them in a well ventillated storage structures where there is good air circulation. Further it depends upon genotype to genotype. If you are trying to store kharif onion it will not store. In rabi onion, varieties line N241, Bhima Kiran, Pusa Red are having very good storage periods. In white onions, the problem of Aspergillus niger is there. But again it depends upon the genotype.

I completly agree wit Dr Anil Khar. I only will add before harvestingstop irrigation andharvest when more than 70% neck fall. if we reduce the moisture content before haresting followed by proper curing in field and stored in ventilated place with very low (near zero) humidity....