Improving onion productivity grown in Siwa oasis as affected by foliar spray by K-silicate and fertigation by humic and amino acids

Abstract EN

A field experiment was carried out at Siwa Research Station, Desert Research Center, Khimisa Farm, Matrouh Governorate, during two successive winter seasons, i.

e.

, 2014/2015 and 2015/2016 to study the effect of the fertigation with four combinations of both humic (H) and Amino acids (A) as (control, 2 L H, 2 L A and 2 L H + 2 L A /fed) as well as the foliar application of three rates of potassium silicate (KS), i.

e.

, (O, 5 and 10 g) KS / L on the growth, yield parameters, quality content, uptake of N and K of bulb onion plants and soil available N and K after harvesting.

The design of the experiment was split plot technique, where the main factor was the foliar spray of KS, while the sub main were fertigation with H, A and combination.

Foliar and soil fertigation treatments were applied at three times, i.

e.

, after 30, 60 and 90 days from planting.

Results indicated that the spray rate of 10 g KS foliar spray/l with (H) and (A) either individually or combination was very effective in improving growth, yield, yield component and quality parameters than applied the spray with of 5g KS/L during the studied two seasons compared to control treatment.

Both rates of KS (5 and 10 g/l) gave higher increases with (H) application than with (A) application for all the studied parameters.

In addition, the best treatment was observed with the integration treatment of (H + A + 10g KS/l) which gave the highest mean values of growth, yield, yield component and quality parameters (TSS % , Protein % and carbohydrates % ) during the studied two seasons.

Where highest mean values reached to, 2.21, 2.10 ton /fed for dry weight of bulb; 15.33, 14.39 ton /fed for fresh yield of bulb; 6.70, 6.41 for bulb diameter, 1.56, 1.46 for neck diameter, 54.90, 48.17 for plant height and 8.40, 8.0 for leaves numbers in 1^st and 2^nd seasons, respectively.

And the increases of bulb TSS, carbohydrates and protein % reached to 27.67, 27.54 % for TSS; 15.69, 16.73 % for Carbohydrates and 55.05 & 53.41 % for protein relative to control treatment at 1^st and 2^nd seasons, respectively.

Also the best treatment recorded highest values of N, K as concentration and uptake of onion bulb in tow studied seasons.

The available amount of N and K in soil after harvesting onion plants increased with increasing acids fertigation and foliar application of KS.