Effect of cattle manure and reducing mineral fertilizer on growth, fruit quality and nutrient content of pecan trees [electronic resource].

Includes references.

A field experiment was conducted at the experimental farm of Kaha Research Station (kalubia governorate) during the two successive seasons of 2002 & 2003 to study the effect of different fertilizers i.e., mineral (ammonium sulphate, potassium sulphate & Calcium super phosphate) or organic manure (cattle manure) or their combinations on growth, fruit quality and leaf mineral contents of five pecan cultivars namely: Cape Fear, Choctaw, Desirable, Graking and Grazona. The obtained results showed that, Choctaw & Graking cvs. showed the tallest shoots and highest values of leaves dry weight, while, Desirable cv. exhibited the greatest number of leaves/shoot. In addition, the maximum average of leaflet area was significantly coupled with Choctaw & Grazona cvs. Shoots of Cape Fear & Desirable trees had higher number of fmits/ shoot than other cvs. The highest records of growth characteristics, i.e. number of leaves/shoot, leaflet area and leaves dry weight were obtained from plants treated with 75% organic manure + 25% mineral fertilizers. . On the other hand, 25 % organic manure in combination with 75 % mineral NPK fertilizers were promising for producing the maximum number of fruits I shoot & the tallest shoots. Applying organic manure succeeded in enhancing nut properties as compared with the full dose of mineral fertilization treatment especially when supplemented with 25% or 75% of recommended dose of (NPK) fertilizer. Furthermore, nut length, width. shape index. weight & flesh oil content were significantly higher in Graking CV., while average kernel weight and % of total nut were greater in Choctaw cv. Moreover, the application of the combination between half recommended rates of organic & NPK fertilizers exerted higher positive effect on flesh weight and % of oil content Using 25% organic manure + 75% NPK gave higher records of chlorophyll (A). The highest N, Mn & chlorophyll (8) contents were recorded in Choct. trees. while leaves of Grazona trees contained larger amounts of Zn and Fe contents. The highest levels of N (especially in till season) & chlorophyll (8) contents were observed in 75% organic manure + 25% (NPK) treatment. However. P in leaves of pecan trees didn't significantly respond to fertilizer treatments. In addition. all combinations between organic & mineral fertilizers resulted in a positive remarkably effect on leaf K content. Leaf Zn significantly increased with increasing the levels of organic manure (except at 100% level) in 1st season and with 50%/. organic manure + 500/. (NPK) treatment in 2l.!!lseason. Fertilizing pecan.

Summary in Arabic.

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