Effect of liquid organic fertilization techneqes on yield and chemical composition of pear and apricot trees grown on sandy sols at south tahrir province

الملخص EN

Two field trials were carried out on sandy soils cultivated with pears (cv.

Le-conte) and apricots (cv.

Canino) during two successive seasons of 2003-2004 to study the effect of applying liquid organic fertilizer contain a minimum of 2.9% humic acid, added as foliar spray on leaves (Sp), mixed with soil around the trees (So) and a combined treatment of spray on leaves + mixed with soil (Sp+So), in addition to a control treatment.

These applied treatments were repeated three times, i.e., at beginning of growth, June and August.

Data obtained indicated that the treatment of (So+Sp) gave the highest values of vegetative growth parameters of pears and apricots (length of current shoots, No.

of current shoots, No, of leaves on the current shoots, No.

of nodes on the current shoots and leaf area) as compared with the other treatments.

On the other hand, the effect of the applied treatments on apricot fruit characteristics was insignificant for all treatments, except of the fruit weight at the treatment of (Sp), which gave a significant increase as compared to the other ones.

Data revealed also that the available contents of NO3-N, P, K, Fe, Mn, and Zn in soil were higher as a result of applying the treatment of (Sp+So), followed by (So) and (Sp) techniques.

Available contents of NO3-N and P were relatively higher after two weeks from application at the second time of June.

Whereas, the relatively higher available of Fe, Mn and Zn were obtained at third time of August.

The positive effect of the superior treatment of (Sp+So) was extended to the grown trees, however, the results showed relatively higher contents of N, P, K, Fe, Mn and Zn concentrations in leaf tissues, followed by (So) and (Sp) treatments.

Thus, the beneficial effects of the applied treatments could be arranged as follows: (Sp+So) > So > Sp > control.

It is noteworthy to mention that at the second time of June, all the studied macro and micronutrients of N, P, K, Fe, Mn and Zn showed the highest concentrations in leaf tissues as compared with the third time of August.