Effect of planting distances and weed control treatments on faba bean yield and associated weeds

الملخص EN

Two field experiments were carried out in the Farm of Agricultural Research and Experimental Center of Agriculture Faculty at Moshtohor, Benha University, Qalyubia Governorate, Egypt, during 2017/18 and 2018/19 seasons.

The study were investigated the effect of three planting distances, i.

e.

20, 25 and 30 cm between hills with six weed control treatments, i.

e.

acetochlor at rate of 840 g active ingredient (a.

i)/fed (Harness 84 % EC), pendimethalin at rate of 773.5 g a.

i/fed (Stomp extra 45.5 % CS), metribuzin at rate of 210 g a.

i/fed (Sencor 70 % WP), bentazon at rate of 240 g a.

i/fed (Basagran 48 % AS) + clethodium at rate of 62.5 g a.

i/fed (Select super 12.5 % EC), hand hoeing twice and the unweeded check on growth, seed yield/fed and its yield components of faba bean cv.

Giza 843 as well as associated weeds.

Faba bean planted at narrow planting distance (20 cm between hills) gave the lowest values of weed biomass compared with the other two planting distances (25 and 30 cm between hills) at 70 days after sowing as well as produced the greatest values of leaf area index, plant height and seed yield/fed during the both seasons.

While, the highest values of No.

of branches, No.

of pods, No.

of seeds and seed weight/plant as well as 100-seed weight were obtained from planting faba bean at wide planting distance (30 cm between hills) in the both seasons.

The main findings show that experimental field was infested by annual weeds for the unweeded check by 659.9 and 1041.8 kg dry weight of weeds/fed, exhibited seed yield loss of 74.82 and 79.65 % faba bean yield/fed compared with the best treatment (hand hoeing twice) in 2017/2018 and 2018/2019 seasons, respectively, planting faba bean under hand hoeing twice or using bentazon + clethodium surpassed the other weed control treatments in depressing weed biomass at 70 days after faba bean sowing.

On the other hand, the two treatments gave the greatest values of all faba bean traits without significant difference between them.

The highest depression in weed biomass and the maximum values of plant height and seed yield/fed were recorded from planting faba bean at 20 cm between hills and weed control by hand hoeing twice or using bentazon + clethodium.

While, the greatest values of No.

of pods/plant, No.

of seeds/plant and seed weight/plant in both seasons which obtained from planting faba bean at wide planting distance (30 cm between hills) under weed control by hand hoeing twice or using bentazon + clethodium.

Analyzing the faba bean seeds found that there was no residual detected of herbicides used.

The economic analysis indicate that planting faba bean at 20 cm between hills and weed control by hand hoeing twice gave the net benefit valued 10435 and 8465 L.

E.

/fed in the first and second seasons, respectively without herbicides residues.

It could be summarized that planting faba bean cv.

Giza 843 at planting distance 20 cm between hills with using hand hoeing twice or chemical control by bentazon + clethodium depression weed biomass and maximized seed yield/fed accompanied with the highest values of gross income, net benefit and benefit/cost and without herbicides residues.