Use Efficiency of Cyanobacteria and Olive Vegetation Water (Cyano/Ovw) Biofertilizer for Olive Trees under Different Mineral Npk Levels

Document Type : Original Article


 THIS STUDY was conducted during the two growing seasons of 2013 and 2014 on 13-year old Manzanillo olive trees cultivated at 5×8 m apart in sandy loam soil under standard cultural practices and drip irrigation in a private farm located at km 50 of Cairo-Alexandria road in the north west of Egypt to evaluate the effect of the bio-organic fertilizer Cyano/OVW, formulated from a successful cultivation of cyanobacteria mixed strains (Nostoc muscorum, Anabaena oryzae and Spirulina platensis) in 1:1 tap water-diluted of olive vegetation water (OVW), on some soil properties, growth parameters, mineral content, flowering, fruit set, yield and fruit quality. The bio-organic fertilizer (Cyano/OVW) was applied as soil drench or as foliar spray application methods. This study also highlighted the economic feasibility of these practices in improving fruit quality and crop yields. As soil drench application, Cyano/OVW was diluted with tap water (1:1) and added at the rates of 24, 36 and 48 liter/tree combined with three levels of 100, 75 and 50% of the recommended mineral NPK fertilizers. As for foliar spray application, constant volume of Cyano/OVW (1 liter/tree) was diluted with tap water (1:5) and sprayed from 4 directions (100%), 3 directions (75%) and 2 directions (50%) surrounding the trees which all received 100% of the recommended mineral NPK fertilizers. The control received the full dose of the recommended mineral NPK fertilizers only. Results revealed that all tested parameters i.e., soil biological and chemical properties, vegetative growth, fruit quality, fruit yield, fruit oil content, some physiological parameters and mineral contents of leaves were improved while, total phenolic compounds in soil and leaves were reduced in response to Cyano/OVW bio-organic fertilizer soil drench or foliar spray applications methods comparing with control. Application of foliar spray of 2 directions (50%) surrounding the trees + 100% of the recommended mineral fertilizers during the six months from January to June, twice each month was the most promising comparing with other treatments in improving soil moisture, growth, quality and productivity of Manzanillo olive trees fruits. This treatment would be recommended under this study and also under similar conditions as confirmed by the economic study.