Yield of faba bean (Vicia faba, l.)‎ as influenced by planting density, humic acid rate and phosohorus fertilization level under drip irrigation system in sandy soils

الملخص EN

Two field experiments were carried out in the Agricultural Research Station, Faculty of Agriculture, Zagazig University, El-Khattara Region, Sharkia Governorate, Egypt, during the two winter seasons of 2015/2016 and 2016/2017 to find out the response of faba bean (improved Giza 3 cv.

) to three planting densities (80000, 100000 and 120000 plants/fad.

), three humic acid rates (zero, 2 and 4 kg humic acid/fad.

) and four phosphorus levels (zero, 15.5, 31 and 46.5 kg P₂O₅/fad.

).

The results of the combined analysis revealed that increasing planting density significantly decreased number of pods and branches/plant, and seed weight/plant as well as protein yield/fad.

, while, plant height and biological yield/fad.

, were significantly increased by increasing plant densities up to 120000 plants/fad.

The highest value of seed yield/fad.

, was obtained by planting faba bean on density 100000 plants/fad.

Results of the combined analysis also showed that, increasing humic acid rates up to 4 kg/fad.

, significantly increased number of pods/plant, weight of seeds/plant and protein yield/fad.

, but, hundred seed weight, plant height and number of branches/plant were not affected by the application of humic acid.

Meanwhile, biological and seed yields/fad.

, were responded to the application of humic acid rate up to 2 kg/fad.

In general, application of phosphorus fertilizer up to 46.5 kg P₂O₅/fad.

, significantly increased all traits under study such as number of branches and pods/plant, weight of seeds/plant, seed and biological yields/fad.

, and protein yield/fad as compared to other rates (combined data), while, hundred seed weight significantly increased by increasing P levels up to 31 kg P₂O₅/fad.

Interaction results showed that, faba bean plants received 31 kg P₂O₅/fad.

, and 2 kg humic acid/fad.

, or received 2 kg humic acid under medium density (100000 plants/fad.

) produced the highest value of seed yield/fad.