Influence of sources and rates of mineral nitrogenous fertilization and bio-stimulants on garlic productivity and efficiency of its extracts against pathogen activities

Abstract EN

Garlic is a worldwide important vegetable crop, and increase its growth and productivity a crucial objectives especially via good agricultural practice; i.e., mineral nitrogen fertilization and bio-stimulants.

Two field experiments were conducted to study the influence of nitrogen fertilizer sources (ammonium sulphate and ammonium nitrate), rates (90 and 120 kg N/fed.) and bio-stimulants (Halex-2, yeast extract, Halex-2 + yeast extract and without bio-stimulants) as well as their interactions on vegetative growth, productivity, bulb quality and chemical constituents of garlic (Allium sativum, L.).

Moreover, garlic extracts were tested against two pathogen activities (Fusarium oxysporium and Alternaria alternate).

Garlic cloves were planted during two winter seasons of 2013/2014 and 2014/2015 at a newly reclaimed area at Sadat City, Egypt.

Inoculation garlic plants with bio-stimulants showed superior effects on most of the studied characters especially for garlic productivity.

Most of the studied vegetative characters, yield, yield components and bulb quality characteristics significantly affected with nitrogen sources, nitrogen rates and bio-stimulants as well as their interactions during the two seasons.

Inoculation garlic plants with Halex-2 + yeast extract was found to have positive effective in reducing the mineral nitrogen fertilizer being applied by 25 % as compared with the commonly recommended dose.

Data revealed that the fertilization combination treatments; 120 kg nitrogen /fed.

at the form of ammonium sulphate + Halex-2 + Yeast extract and 90 nitrogen kg/fed.

at the form of ammonium sulphate + Halex-2 + Yeast extract significantly gave the highest values for phenol content.

The plant extracts obtained from the same two previous fertilization combinations gave the highest inhibition against Fusarium oxysporium and Alternaria alternate.

The in vitro results showed that using concentration 2.5% of the selected extracts gave the highest mycelial growth inhibition for the tested pathogens.

These results may contribute to develop environmentally safer alternatives antifungal agent against plant pathogenic fungi.