Effect of mineral nitrogen levels and n2-fixing bacteria on growth, yield and storability of green onion plants during cold storage periods

الملخص EN

Two field experiments were carried out during winter seasons of 2012/2013 and 2013/2014 at the Agriculture Research Farm, El- Kassasien Hort.

Research Station, Ismalia Governorate, Egypt, and Laboratory of Handling of Vegetable Crops Department, Horticulture Research Institute, Agriculture Research Center, Giza, Egypt, to investigate the effect of partially substituting of mineral N fertilization with N2-fixing Azospirillum and Azotobacter spp.

on growth, dry weight, root system and yield of green onion (Allium cepa L.) cv.

Giza 20 grown under sandy soil conditions using drip irrigation system.

It aimed also to study the effect of the abovementioned treatments on green onion plants during cold storage at different periods; i.e., 0, 5, 10, 15 and 20 days.

Fertilization green onion plants with 100% mineral N recorded the highest value of morphological characters, root system, yield and its components, weight loss%, total chlorophyll and leaf extension followed by fertilization with 75%.

Generally, inoculation green onion plants with Azospirillum plus Azotobacter gave the highest value of growth characters, yield and its components as well as quality parameters during cold storage periods.

The interaction treatments between 100% mineral N or 75% and inoculation with Azospirillum plus Azotobacter gave the maximum values of growth parameters, yield and its components without significant differences between them.

As to the quality parameters of green onion during cold storage at 0 oC and 90-95 RH for 20 days, the results showed that weight loss%, leaf extension and curvature score increased as the storage period prolonged, while total chlorophyll and TSS% decreased by prolongation the cold storage periods.

The interaction treatments among 100% mineral N or 75% and inoculation with Azospirillum plus Azotobacter and storage green onion plants for 15 days at 0 oC and 90-95 RH recorded the beast values of weight loss%, total chlorophyll, TSS% and leaf extension as well as curvature score.