This study was conducted during 2002 and 2003 seasons at Nobaria Horticulture Research Station to investigate the response of “Zaghloul" date palm yield to various organic and inorganic fertilization types as factor (A), fruit-thinning models as factor (B) as well as interaction among their levels.
Factor (A) levels were: (a1) no animal manure + 5 kg NH₃SO₄, (a2) 25 kg animal manure + 4 kg NH₃SO₄, (a3) 50 kg animal manure + 2 kg NH₃SO₄ and (a4) 100 kg animal manure + no NH₃SO₄  levels. Factor (B) levels were: (b1) non-thinned fruits (the basic bunch number was 8 bunches per palm), (b2) removing of 25% from total bunches number, (b3) thinning of 25% from total stalks in each bunch, (b4) removing of 50% from total bunches number and (b5) thinning of 50% from total stalks in each bunch. The possible combinations among these levels were represented as field experimental reatments.
The results indicated that studied yield as well as fruits characteristics were significantly affected by both A and B factor levels as well as the experimental treatments except pit diameter trait. Regarding the fertilization types factor, the results declared that a3 and a4 levels lead to the best significant values of bunch weight, fruit weight and dimensions, flesh thickness as well as other fruit quality traits. Differences betweenconducted values were not significant.
Viewing the fruit-thinning models factor, the results illustrated that the b4 level produced the highest bunch weight value. Level b5 caused the statistical better fruit weight and dimensions; fruit flesh thickness; pit weight and length criteria. As well as b3 and b4 levels for fruit diameter, flesh thickness and pit weight criteria in both study seasons. For fruit quality traits, thinning models lead to the highest TSS (%) values comparing with non thinned palms in both study seasons. Acidity (%) and total protein traits did not statisticaly affected by fruit-thinning levels. Total sugers (%) was increased while soluble tannins was decreased as responses to b5 level.                 Concerning the action of field treatments, a4b4 treatment was statisticaly superior regarding the bunch weight criterion in both study seasons. Also, a3b5 treatment produced the significant highest fruit weight. Highest pit length value was recorded by a1b3 and a1b5 treatments for the 1^st and 2^nd seasons, respectively. Also, results observed that a4b5, a4b4, a4b3, a4b2, a3b5, a3b4, a3b3 and a3b2 treatments were related with best significant values of fruit quality traits.