Nitrogen, phosphorus and potassium content in maize dry biomass under the effect of different levels of mineral fertilization

L. Nenova*, M. Benkova, Ts. Simeonova, I. Atanassova

Institute of Soil Science, Agrotechnologies and Plant Protection “N. Pouskarov”, 7 Shosse Bankya str., 1331 Sofia, Bulgaria

(Manuscript received 20 August 2019; accepted for publication 8 November 2019)

Abstract. The aim of the study was to assess the influence of different fertilizer doses on the content of macroelements (nitrogen, phosphorus and potassium) in dry biomass and grain of maize during the 2016 – 2018 period. A field experiment with fertilization of maize was carried out on Alluvial-meadow soil (Fluvisol) in the region of Tsalapitsa village, near Plovdiv. Three variants of mineral fertilization were studied V2 (N15P10K0), V3 (N20P15K0) and V4 (N25P20K0), and a control variant V1 (N0P0K0) – without fertilization. It was established that N% content in maize dry biomass was affected significantly by the variants of fertilization (18% of the variance). Significant differences (P≤0.05) between the control variant and all the variants of fertilization were established. Increasing the fertilizer dose, nitrogen content in dry biomass increased, too. The highest was the average content of nitrogen in maize leaves (0.94%), followed by the cobs (0.71%) and the lowest was the content in the stems (0.58%). Phosphorus and potassium content of dry biomass were affected significantly by the year of the study (10% and 9% of the variance, respectively). At the 7-8th leaf growth stage of maize, the highest nutrients content (N, P, K) in dry biomass were reported. With aging of plants the nutrient content in their biomass decreased. Nitrogen, phosphorus and potassium content in maize grain was significantly affected by the year of the experiment. Mineral fertilization had impact mostly on the nitrogen content of the grain, which was the highest in V3 variant, accepted as optimal – 0.66% on average.

Effect of conservation agriculture on grain yield and income of maize under maize based cropping system in far western Nepal

H.K. Prasai1*, S.K. Sah2, A.K. Gautam3, A.P. Regmi3

1Nepal Agricultural Research Council, Regional Agricultural Research Station, 10801 Bhagetada, Dipayal, Doti, Nepal 2Agriculture and Forestry University, Rampur, 44209 Chitwan, Nepal
3Nepal Agricultural Research Council, Singh Durbar Plaza, 44617 Kathmandu, Nepal

(Manuscript received 1 September 2018; accepted for publication 25 October 2018)

Abstract. The adoption of Conservation agriculture (CA) contributes to sustainable production and its advantages include lower inputs and stable yields. This study was conducted in the research field of Regional Agricultural Research Station, Bhagetada, Dipayal, Doti during 2014 and 2015 to identify the effect of CA on grain yield and income of maize in Maize based cropping system. Both conservation and conventional agricultural (ConvA) practices were evaluated on two maize based cropping systems namely maize-wheat-mungbean (M-W-MB) and maize-lentil-mungbean (M-L-MB). For this purpose two maize varieties namely Raj Kumar and Arun-2 were used. The average productivity of maize under M-L-MB cropping system was 1.6% higher (5.75 t/ha) than M-W-MB cropping system (5.66 t/ha). The average grain yield of maize under CA was 16.7% higher (6.15 t/ha) than ConvA (5.27 t/ha). Rajkumar produced 43% higher average grain yield (6.73 t/ha) than Arun-2 variety (4.69 t/ha). The average net benefit was slightly higher (US$ 597.33/ha) under M-L-MB cropping system than M-W-MB cropping system (US$ 573.89/ha). Similarly, the average net benefit from CA was 102% higher (US$ 783.67/ha) than ConvA (US$ 386.79/ha). Rajkumar variety gave 127% higher average net benefit (US$ 813.49/ha) than Arun-2 (US$ 357.81/ha). The average benefit – cost (B:C) ratio of M-L-MB cropping system was slightly higher (1.72) than the average B:C ratio of M-W-MB cropping system (1.70). The average B:C ratio of CA was 42% higher (2.01) than ConvA (1.41). The average B:C ratio of Rajkumar variety was found 33% higher (1.95) than Arun-2 (1.46). The higher grain yield, net profit and B:C ratio were found in CA practices under M-L-MB cropping system and Rajkumar variety. This study suggests that hybrid maize planting and the adoption of M-L-MB cropping system should be used to increase grain yield and economic performance under CA practices.

Knezha 560 – a new mid-late maize hybrid

  1. V. Valkova, N. Petrovska

 

Maize Research Institute, 5835 Knezha, Bulgaria

 

DOI: 10.15547/ast.2018.03.036

(Manuscript received 14 May 2018; accepted for publication 29 June 2018)

 

Abstract. Тhe article presents a short characteristic of morphological, biological and economic qualities of a new maize hybrid Knezha (Kn) 560. The hybrid is a single cross, from mid-late group – FAO 500-599. It is recognized in 2017 by the Expert Commission of Executive Agency of Variety Testing, Field Inspection and Seed Control (EAVTFISC). At the points of ecological variety trails (EVT) and EAVTFISC it was compared with the American hybrid PR 35 P 12 and the Bulgarian hybrid – Knezha 509. During the testing period in the experimental field of the Maize Research Institute (MRI) – town of Knezha, the three-year average grain yield of hybrid Knezha 560 exceeded the standard PR 35 Р 12 hybrid by 19.3% and Knezha 509 hybrid by 37.3%. In the EAVTFISC system, the new hybrid exceeds the middle standard by 0.8%. The hybrid is stress-tolerant and resistant to economically important diseases and pests of maize. With this high-yielding and competitive maize hybrid, the group of mid-late maize hybrids offered on the Bulgarian seed market is being filled.

Achievements and problems in the weed control in grain maize (Zea mays L.)

  1. G. Delchev, M. Georgiev

Department of Plant Production, Faculty of agriculture, 6000 Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 28 November 2016; accepted for publication 5 February 2018)

Abstract. Chemical control has emerged as the most efficient method of weed control. Herbicides combinations and tank mixtures of herbicides with adjuvants, fertilizers, growth regulators, fungicides, insecticides, are more effective than when they are applied alone in maize crops. Their combined use often leads to high synergistic effect on yield. There are maize hybrids resistant to imidazolinone for Clearfield technology, but they have not yet been introduced in Bulgaria. Data regarding herbicide for chemical control of perennial graminaceous weeds in maize crops are quite scarce even worldwide. The problem is the persistence of some herbicides used in the predecessors on succeeding crops, which is directly related to the weather conditions during their degradation. Most of the information in maize relates to conventional technology for weed control. There is not information about the new Duo system technology in grain maize and the hybrids used are resistant to cycloxydim. A serious problem is also the volunteers of the Clearfield and Express sun sunflower. They have resistance to herbicides different from that of conventional sunflower hybrids. There is no information yet in scientific literature about control of these volunteers.

Evaluation of the combining ability of mutant maize lines

V. Valkova*, N. Petrovska

Maize Research Institute, 5835 Knezha, Bulgaria
(Manuscript received 6 June 2016; accepted for publication 18 August 2016)

Abstract. The study shows the results of a preliminary evaluation of the combining ability for grain yield of 17 mutant maize lines. For the purpose the top cross method for early testing and the mathematical model of Savchenko for analysis of the general and the specific combining ability were used. The lines were tested on three testers with high general combining ability that belong to two genetic groups: K 46 52 and XM 552 from SSS and N 192 – Lancaster. For the purposes of evaluation of the productive abilities of the received top cross two preliminary varietal experiments were carried out at the experimental field of Maize Research Institute, Knezha As a result of the conducted experimental work and the analysis it was found that the highest general combining ability have lines XM 11 6 and XM 12 1. These lines can be included as components of high-yielding synthetics or as testers in analyzing crosses to determine general combining ability in early stages of the selection process. The above lines with high specific combining ability – XM 11 13 and XM 11 46 are suitable for inclusion in combinations to develop high-yielding hybrids. Three of the tested lines XM 11 7 11 XM 10 and XM 11 11 have both high GCA and SCA. These lines can be used in corresponding breeding in the selection programs.

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Variations of maize yield and some quality indices of grain depending on the type of main soil tillage

P. Yankov*, M. Drumeva, D. Plamenov

Abstract. The investigation was carried out during 2008 – 2010 on the trial field of Dobrudzha Agricultural Institute, General Toshevo, Bulgaria, on slightly leached chernozem. To clarify the effect of different types of main soil tillage on the vertical distribution of maize seeds in the soil layer and the development of the plants, the following variants of a stationary field trial were analyzed: plowing at 24 –26 cm, disking in autumn and double cultivation in spring (check); double disking at depth 10 –12 cm accompanied by autumn disking and double spring cultivation; cutting at 24 –26 cm, disking in autumn and double cultivation in spring; direct sowing – pre-sowing treatment of the area with total herbicides. Hybrid Anasta was sown at crop density 55000 plants/ha. The brief replacement of the deep plowing with cutting without turning of the surface layer and adapted direct sowing led to slight increase of grain yield by 1.0 and 2.8 %, respectively. Lowest and with the highest variation were the yields from maize over years after main soil tillage performed as disking. The highest absolute grain weight was obtained after adapted direct sowing and constant cutting in comparison to conventional plowing, and the lowest absolute grain weigh was measured after annual disking. The replacement of annual plowing before planting maize with minimal tillage or tillage without turning of the soil layer did not cause statistically significant variations in the content of raw protein and oils in grain

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Effect of different types of main soil tillage on the vertical distribution of maize seeds in the soil layer and on the development of the plants

P. Yankov, M. Drumeva
Abstract. The investigation was carried out during 2008–2010 in the trial field of Dobrudzha Agricultural Institute on slightly leached chernozem. To determine the effect of different types of soil tillage on the vertical distribution of the maize seeds in the soil layer and the subsequent development of plants, the following variants of a stationary field experiment were analyzed: plowing at 24–26 cm, disking in autumn and double cultivation in spring (check variant); cutting at 24–26 cm, pre-sowing treatment with total herbicide (adapted direct sowing); double disking at 10–12 cm accompanied by autumn disking and double spring cultivation. Hybrid Anasta was sown at plant density 55 000 plants/ha. The most even vertical distribution of the maize seeds in the soil layer was ensured at adapted direct sowing performed with high quality. Under constant cutting and annual disking, the percent of maize seeds below and above the optimal depth increased in comparison to adapted direct sowing. The variation in the depth of planted seeds was the highest when sowing the seeds in the plowed soil. At planting under conditions of lower temperatures, cutting, adapted direct sowing and disking retarded the rates of germination in comparison to plowing and elongated the developmental stage of maize with 3–5 days. The number of germinating plants under these main types of soil tillage decreased by 6 to 15 %. Under favorable thermal regime after planting, the rate of germination of maize seeds in the variants with reduction and exclusion of the main soil tillage was more intensive only at the beginning. The duration of the germinating stage and the percent of germinating plants were the same under all types of tillage. At the early stages of maize development, plant growth in height was the most intensive after shallow main tillage performed as disking. With the advance of vegetative development, the stems of maize were higher and with greater diameter after adapted direct sowing, plowing and cutting in comparison to annual disking.
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Studying the effect of irrigation furrows in maize grain

A. Stoyanova, M. Georgiev, L. Plescuta

Abstract. Experience was conducted during 2004-2006 in southern Bulgaria, the soil type Vertisol. Has studied the performance of maize grain in a water deficit. A shortage of moisture created by a spatial deficit. Irrigation is supplied in one or two grooves, with the repeal of irrigations. The effect of irrigation is highest in the optimal option waterings (30,6%). Upon submission of irrigation water EOF 100% and 50%, respectively, the effect is 25,9% and 17,4%. The decline in yields in furrow irrigation EOF 50% reduction in irrigation rate is within 6,7%. In the present conditions of water deficit irrigation in the furrow is recommended to apply on soils with good capillary properties. Irrigation in EOTF reduced yields by 13,9% compared to the optimal option. The results are significantly lower than those of the optimal option, but in terms of lack of sufficient water for irrigation may be given this type of irrigation-in two furrows. The coefficient of efficiency of irrigation (K) water is highest in furrow irrigation EOF 50% and options without the watering (0,76-1,04).

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Evaluation the relative resistance of 14 corn cultivars to Fusarium mais rot infection

L. Ashnagar, S. Rezaei, M. Darvishnia, M. Zamani
Abstract. In order to evaluate the reaction of 14 corn cultivars to Fusarium ear rot infection (Fusarium verticillioides) and identify resistant or tolerant cultivars, an experiment was conducted in a randomized complete block design (RCBD) with 14 treatments (cultivars) and three replications through artificial inoculation by nail punch method in Khorram Abad. Fungal inoculum consisting of a mixture of spores was applied to each ear 7 to 10 days after silk stage by the injection of 3 ml of inoculums (1×106 spore/ml) to cause Fusarium ear rot infection. At physiological maturity, at harvest time, disease incidence and disease severity was evaluated based on the disease progress in each ear, and resistance of experimental cultivars were measured. Depend on disease severity (Jeffers et al., 1994) to Fusarium ear rot (1st-6th index), cultivars categoried into resistant, tolerant and susceptible groups. The results showed that KSC 700 and DS 499 were resistant and Karduna 630 was the most susceptible cultivars.

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Combining ability for grain yield of mid-late maize inbred lines

N. Petrovska

Abstract. In the partial system of diallele crosses by Savchenko (1973) eleven mid-late maize lines which belong to two genetically different groups – SSS and Lancaster are involved for study of Combining Ability of grain yield. The hybrids obtained from these lines are tested in two years – 2008 and 2009. The highest GCA from the studied lines have 215/3-1-1(C ), 45/1-1-2(C ) and 7/1-2-1(C ) from SSS group and 220/2-1-1(C ) and 178/2-2-1(C ) from Lancaster, which are 2 1 3 2 2 recommended in the breeding programs for creating high-yield synthetics. With highest SCA are the lines 9/1-1-1(C ), 45/1-1-2(C ), and 119/1-1(C ) from SSS 2 1 3 group and 220/2-1-1(C ), 178/2-2-1(C ) and 88/1-2-1 (C ) from Lancaster, which could be used in the heterosis breeding for developing high productive hybrid 2 2 3 combinations.

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