Yield and its attributes of two maize cultivars and associated weeds as affected by some weed control methods and nitrogen fertilizer levels

Abstract EN

These experiments were performed for two successive summer seasons of ٢٠١٣ and ٢٠١٤ at Gemmeiza Agric.

Res.

Station, Gharbia Governorate, Egypt.

The ultimate aim of this work was to evaluate the effect of four weed control methods [١- un-weeded check W١,, ٢- hand hoeing twice at ١٨ and ٣٠ days age W٢,, ٣- using Harness herbicide (Acetochlor) ٨٤% Ec at the rate of one liter/fad., sprayed directly after planting and before irrigation,W٣ and at last, ٤- using Harness herbicide ٨٤% Ec plus one hand hoeing conducted at ٣٠ days old W٤], three nitrogen levels, viz: ٩٠, ١٢٠ and ١٥٠ kg N/fad., and their interactions on the yield, its attributes, quality of the two maize cultivars, being: ١- white cultivar SC ١٢٨ and ٢- yellow cultivar SC ١٦٨ as well as on the associated weeds.

The experimental design was a split-split plot system of three replicates.

The obtained results indicated that the four weed control treatments exhibited significant variations in most of the studied characters for both weeds and maize, where the W٤ treatment (using Harness herbicide ٨٤% Ec plus one hand hoeing) produced markedly greater mean averages in each of: weed reduction percentage, maize plant and ear heights, ear length and diameter, number of rows / ear, number of grains/row, grain index, shelling percentage, grain yield / fad, protein content and yield / fad., when compared with W٣, W٢ and the unweeded check, orderly.

But, opposite trend was seen regarding the total weed dry weight (g/m٢), since the un–weeded check was extreme in this regard.

Such inclination was clearly manifest in both seasons and over them too.

Also, SC ١٢٨ maize cultivar was significantly superior to its counterpart SC ١٦٨ in all yield attributes and yield/fad., in both trials and across them as well and vice versa regarding the total weed dry weight (g/m٢).

In addition, the three N levels tested gave significant changes in all the studied traits for both weeds and maize, where the highest N level of ١٥٠ kg N/fad was most effective in enhancing such tested characters (except the total weed dry weight in g/m٢) if compared with both ٩٠ and ١٢٠ kg N levels/fad.

Grain yield/fad., of maize correlated positively and strongly with each of: plant and ear heights, ear length and diameter, rows/ear, grains/row, ١٠٠- grain weight, shelling and protein percentages, but weed biomass gave negative and significant relations with grain yield/fad.

Such correlation results referred significantly to the effective treatments tested in this study to suppress the competitive ability of weeds and maize grain yield enhancement.

Based on this research findings, keeping maize field weed-free by using Harness herbicide (Acedochlor) ٨٤% Ec pre-emergence at the rate of one liter/fad., plus one hand hoeing at ٣٠ days old to control the spread weeds either broad– leaved or grassy as well as adding the appreciable N level of ١٥٠ kg N/ fad, especially in low deficient N soil, could be taken into account in depressing the domenant competitive weeds and maximizing the final yields/fad., from grain and protein for the SC ١٢٨ cultivar under Gemmeiza location conditions, Gharbia Governorate, Egypt.