Minimizing 50% of chemical npk fertilizers by compost and em and their impact on growth, nutritional status, productivity and fruit quality of washington navel orange trees

الملخص EN

This research was conducted during the 2018 and 2019 seasons on 9-year-old Washington navel orange trees budded on Sour orange rootstock planted 5 x 5 meters apart under the surface irrigation of a private orchard in Manzala Village, Toukh Area, Qalubia Governorate, Egypt.

The five treatments used in this experiment is defined as follows: T1-100% of chemical NPK, T₂ - 50% of chemical NPK + compost @ 2 ton /fed, T₃ - 50% of chemical NPK + compost @ 2 tons/fed.

+ EM @ 20ml per tree, T₄ – 50% of chemical NPK + compost @ 3 ton/fed and T₅ - 50% of chemical NPK + compost @ 3 ton/fed + EM @ 20ml per tree.

The main goal was directed towards increasing growth of Washington navel orange trees, and fruiting aspects associated with lower its production cost through investigating the minimizing of chemical NPK fertilizers by compost and EM.

Data obtained showed that all the evaluated treatments increased the growth parameters as well as the total chlorophyll and nutritional status of the leaf were also positively responded, fruit set% , yield/tree and fruit quality were also improved.

However, T1-100% of chemical NPK and T₅- 50% of chemical NPK + compost @ 3 ton/fed.

+ EM @ 20ml per tree was statistically superior.

Moreover, T4 - 50% of chemical NPK + compost @ 3 tons/fed ranked statistically second in this concern.