Open Access Original Research Article

Effects of Integrated Use of Calliandra calothyrsus and Maize Stover with Urea on Soil Mineral Nitrogen, Striga Infestation and Maize Yields in Western Kenya

Robert O. Nyambati, Duncan G. Odhiamboz, Cornelius K. Serrem, Caleb O. Othieno, Frank S. Mairura

Journal of Experimental Agriculture International, Page 1-11
DOI: 10.9734/jeai/2020/v42i130446

This study investigated the effects of applying different combinations of two contrasting plant residues, Calliandra calothyrsus (Calliandra) and maize stover, with urea on Striga infestation and maize yield in western Kenya. A randomized complete block design (RCBD) with 12 treatments replicated four times was used. The following plant residue: urea combinations was used so as to supply a total of 75 kg ha-1 in each treatment combination; 75:0, 60:15, 45:30, 30:45, 15:60, and 0:75 for five seasons (2007-2009). A control treatment where no nutrient inputs were applied was included. Calliandra applied at 45 kg N ha-1 plus urea (30 kg N ha-1) and maize stover applied 15 kg N ha-1 plus urea (60 kg N ha-1) had consistently lower Striga infestation compared other treatments. Negative linear relationship between maize yield and Striga population were observed in the first three seasons i.e. 2007 LR, 2007 SR and 2008 LR. Overall mean maize grain yields over the five seasons were highest (3.0 t ha-1) under maize stover (30 kg N ha-1) combined with urea (45 kg N ha-1) followed by Calliandra (45 kg N ha-1) combined with urea (30 kg N ha-1) with (2.7 t ha-1). Maize stover (30 kg N ha-1) in combination with urea (45 kg N ha-1) increased maize grain yields relative to the control by 275%, 107% and 155% in the first, second and third seasons respectively. Treatments with Calliandra (45 kg N ha-1) in combination with urea (30 kg N ha-1) increased maize grain yields relative to the control by 191%, and 233% in the first and third seasons respectively. The control and sole maize stover (75 kg N ha-1) had the lowest yields across all the seasons. The optimum application rate for stover was 30 kg N ha-1 nitrogen equivalent while that for Calliandra was 45 kg N ha-1.

Open Access Original Research Article

Species Composition and Status of Stored Sorghum Pests in Traditional Farmer’s Storages of Kena District of Koso Zone, Southern Ethiopia

Ararso Gognsha, Berhanu Hiruy

Journal of Experimental Agriculture International, Page 12-22
DOI: 10.9734/jeai/2020/v42i130447

Aim: To determine the species composition and status pests of stored sorghum under traditional storages of farmers in Kenna district of Konso Zone of Southern Ethiopia.

Study Design: From peasant association, about three sub-localities were randomly selected and from each sub-locality, three villages were selected at random with using a nested design.

Place and Duration of Study: Survey was conducted between 1, August to 27, December 2019 in four major sorghum growing peasant association of Kenna district of Southern Ethiopia.

Methodology: The study on determination of the species composition and status pests of stored sorghum was made from of half kilogram of wheat grain sample taken from 720 stores of randomly selected representative farmer’s storages of four peasant associations using key of books related to stored product insects.

Results: Fifteen arthropods species consisting of twelve primary and secondary pests and three natural enemies belonging to four insect orders with in nine families were recorded. Of which, nine species such as S. zeamais, S. oryzae, S. cerealella, T. castaneum, T. confusum, C. ferrugineus,    C. pusillus, R. dominica and P. interpunctella, respectively were found to be the most abundant as they appeared between 3.47 and 19.44 individuals per 100 g of sampled grains. They were also found to be the most frequently occurring as they occurred in the range between 63.89 and 94.44% per 100 g of sample grain collected from survey site and had major pest status.

Conclusion: The traditional methods and practices used by farmers were inefficient for providing adequate protection of their stored sorghum grain pests. Therefore, there is urgent need for designing effective management strategies against insect pest’s sorghum as well as improving the existing farmer’s traditional storage strictures in the survey site in order to reduce the loss of stored sorghum by insect pests and the associated food insecurity.

Open Access Original Research Article

Biological, Serological and Molecular Characterisation of a New Virus Species Infecting Telfairia occidentalis in Calabar, Cross River State, Nigeria

O. I. Eyong, A. T. Owolabi, A. A. J. Mofunanya, E. E. Ekpiken

Journal of Experimental Agriculture International, Page 23-33
DOI: 10.9734/jeai/2020/v42i130448

Telfairia occidentalis (Hook) belongs to the family Cucurbitaceae and is an economically important cash crop worldwide. It is widely cultivated in Nigeria including the South Eastern part of the country. This research was aimed at isolating, characterising and identifying a new virus species infecting Telfairia occidentalis in Calabar, Cross River State. Diagnostic tools employed included host range/symptomatology, insect transmission test, Antigen Coated Plate (ACP) Enzyme Linked-Immunosorbent Assay (ELISA) and gene sequencing. Results revealed that the virus isolate infected only members of the cucurbit family producing rugosity, mosaic, mottle and leaf malformation/deformation. The virus isolate was transmitted by Aphis spiraecola in a fore-gut manner and not by A. citricida. It reacted positively against universal potyvirus antiserum. Sequence analysis showed that the Telfairia occidentalis virus isolate had 75% sequence identity with Moroccan watermelon mosaic virus (MWM) which was found to be the closest. The virus was consequently considered a new species of potyvirus for which the name Telfairia severe mosaic virus (TeSMV) was suggested.

Open Access Original Research Article

Chlorophyll a Fluorescence Parameters do not Detect Yield-limiting Injury from Sub-lethal Rates of 2,4-Dichlorophenoxyacetic Acid (2,4-D) in Cotton (Gossypium hirsutum)

Seth A. Byrd, John L. Snider, Timothy L. Grey, A. Stanley Culpepper, Jared R. Whitaker, Phillip M. Roberts, Daryl R. Chastain, Wesley M. Porter, Guy D. Collins

Journal of Experimental Agriculture International, Page 34-48
DOI: 10.9734/jeai/2020/v42i130449

Aims: Determine if the use of novel chlorophyll a fluorescence parameters could be utilized to predict yield loss of cotton exposed to sublethal rates of 2,4-dichlorophenoxyacetic acid (2,4-D) at various growth stages.

Study Design: All trials were arranged in a randomized complete block design with four replications. Treatment means were subjected to analysis of variance and linear regression was utilized to determine relationship between chlorophyll a parameters and yield.

Place and Duration of Study: University of Georgia Gibbs Farm in Tifton, GA, USA and the Sunbelt Agricultural Exposition in Moultrie, GA, USA during the 2013 growing season.

Methodology: Two sublethal rates of 2,4-D were applied to cotton at six distinct growth stages. The rates consisted of 2 g and 40 g ae ha-1 equivalent to 1/421 and 1/21 of the full rate (0.532 kg ae ha-1), respectively. The sublethal rates were applied to cotton at six growth stages, including the four leaf, nine leaf, first bloom, two, four and six weeks after first bloom growth stages. A fluorometer was used to obtain the fluorescence parameters Fv/Fm, ΦEO and PIABS from the uppermost fully expanded leaves at various intervals after 2,4-D exposure.

Results: Despite yield losses ranging from 20 – 90% of the non-treated control, no consistent patterns resulted from utilizing fluorescence transients to detect 2,4-D injury and overall instances of significant difference were minimal and typically not biologically relevant. In many cases, treatments exposed to 2,4-D that exhibited yield loss showed evidence of greater photosynthetic efficiency than the non-treated control. In the majority of instances, many of fluorescence parameters measured fell within ranges observed in previous studies in cotton produced under typical or non-stressed conditions.

Conclusion: While it has been proven as a valuable tool in other plant screening endeavors, chlorophyll a fluorescence were not able to detect the effects of sub-lethal rates of 2,4-D on cotton, even in instances that resulted in severe yield loss.

Open Access Original Research Article

Effectiveness of Azospirillum brasilense Inoculants to Wheat (Triticum aestivum) in the Micro-region of Curitibanos (SC)

William Gilberto Balbinot, André Luis Gordechuk, Géssica Rogaleski Eutrópio, Cibele Medeiros, Glória Regina Botelho

Journal of Experimental Agriculture International, Page 49-55
DOI: 10.9734/jeai/2020/v42i130450

Aims: This work aimed to evaluate the effectiveness of A. brasilense inoculants to the development of wheat at the southern part of Brazil.

Study Design: The experimental design was randomized block with twelve treatments, containing two liquid inoculants with the A. brasilense strains Ab-V5 and Ab-V6, with or without nitrogen fertilization and five replicates. The plot area was 4m per 6m and thirty-two rows. The seeds inoculation was performed according to the manufacturer's recommendation, and manual sowing. The top-dressing N fertilization was Urea (Super N- 45%N) at 20 days after emergence (DAE), at 120 kg ha-1 (full dosage) or 60 kg ha-1 (half dosage).

Place and Duration of Study: The experiment was performed in a farm in Curitibanos county in Santa Catarina state, Brazil. The experiment was carried out on July to November 2016.

Methodology: At 45 DAE, it was performed flag leaves N content Tedesco, et al. [1]. At 115 DAE, it was performed dry shoot weight, plant height, ear sizes, grain N contents and grain yield. The results were submitted to variance analysis (ANOVA) and media compared by Scott-Knot's test at 5% of significance.

Results: There was no statistical difference for shoot dry weight, plant height, ear size and yield. The N leaf content was greater with Ab-V5 inoculation and half N dosage (HC5 - 109% higher than the control). The N grain content was greater with the two strains (inoculant B) without, half and full N dosage (WC56 - 51%, HCB56 - 76% and CB56 - 65%, respectively).

Conclusion: A. brasilense strains had the ability to increase wheat N accumulation with lower N fertilizing, suggesting their potential as growth inducers, emphasizing the importance of further studies to confirm and understand the mechanisms involved.

Open Access Original Research Article

Study on Rice Residue Management Options on Growth Parameters and Growth Indices of Rice Crop

A. Vijayaprabhakar, S. Nalliah Durairaj, M. Hemalatha, M. Joseph

Journal of Experimental Agriculture International, Page 56-63
DOI: 10.9734/jeai/2020/v42i130451

The research was conducted to study the effect of management options for combine harvested rice residue and its effect on succeeding rice crop growth responses. The experiment was laid out in field using a randomized block design with nine treatments and replicated three times. The computed biometric data were subjected to statistical scrutiny.  Incorporation of combine harvested rice residue with 25 kg additional N ha-1 as basal + bio-mineralizer (2 kg t-1 of rice residue) and cow dung slurry (5%) recorded higher plant height, number of tillers, dry matter production (DMP), leaf area index (LAI), crop growth rate (CGR) and relative growth rate (RGR) of the succeeding rice irrespective of the growth stages. It was closely followed by straw incorporation with 25 kg additional N ha-1 as basal + cow dung slurry (5%). Incorporation of straw alone and removal of straw negatively influenced the rice growth and growth indices. Hence, it is advisable to incorporation of rice residue with additives for better growth and growth indices of rice crop.

Open Access Original Research Article

Correlation and Path Coefficient Analysis for Yield and Yield Components in Late Maturing Pro-vitamin A Synthetic Maize (Zea mays L.) Breeding Lines

David Oluwagbenga Olawamide, Lawrence Stephen Fayeun

Journal of Experimental Agriculture International, Page 64-72
DOI: 10.9734/jeai/2020/v42i130452

This study was conducted in a rainforest ecology of Southwestern Nigeria during 2016 and 2017 cropping seasons under rainfed conditions to estimate character association and path coefficient of grain yield (t ha-1) and its component characters, to identify characters whose selection could be used in improving maize grain yield (t ha-1). Fourteen late-maturing pro-vitamin A maize (PVAM) synthetics were conducted in a randomized complete block design with three replications. The following agronomic characters were recorded: plant stands per plot, days to 50% tasselling, days to 50% silking, anthesis-silking interval, plant height (cm), ear height (cm), number of ears harvested, field weight (kg), and grain yield (t ha-1). In both 2016 and 2017, plant stands per plot, the number of ears harvested and field weight (kg) correlated positively and significantly with grain yield (t ha-1) at the phenotypic and genotypic levels. Also, in both years, positive and significant phenotypic and genotypic correlations were found for plant stands per plot with number of ears harvested and field weight (kg), days to 50% tasselling with days to 50% silking, plant height (cm) with ear height (cm) and number of ears harvested with field weight (kg). Path analysis for both years at the phenotypic and genotypic levels identified field weight (kg) and the number of ears harvested to have a positive direct effect on grain yield (t ha-1), an indication that optimum plant population per plot is paramount to increasing grain yield (t ha-1). Hence, the number of ears harvested and field weight (kg) are characters that could be considered in the improvement of maize grain yield (t ha-1).

Open Access Original Research Article

Screening Sorghum Accessions for Resistance against Anthracnose and Grain Mold through Inoculating with Pathogens

Louis K. Prom, Hugo Cuevas, Thomas Isakeit, Clint Magill

Journal of Experimental Agriculture International, Page 73-83
DOI: 10.9734/jeai/2020/v42i130453

Aims: The aim of this study was to identify resistant accessions against pathogens, causing anthracnose and grain mold.

Study Design: Study was laid out in a randomized complete block design with three replications. Data for anthracnose rating, grain mold severity, seed weight, and percent germination rate were analyzed using the command PROC GLM.

Place and Duration of Study: The study was carried out at the Texas AgriLife Research Farm, Burleson County, Texas, in 2010, 2014, and 2015 growing seasons.

Methodology: Forty-seven accessions were planted in 6 m rows 0.31 m spacing. Plants were inoculated by placing Colletotrichum sublineola colonized grain in the plant whorls 30 days after planting. Disease evaluation was initiated 30 days post-inoculation and thereafter on a weekly basis for three consecutive weeks. Grain mold experiment: Three treatments were used: 1) plants sprayed with A. alternata alone, 2) a mixture of A. alternata, F. thapsinum and C. lunata, 3) control plants sprayed with sterilized water and exposed to natural infection. At 50% bloom, three panicles per line within replication were inoculated for each treatment.

Results: Eleven accessions, including PI641874, PI656070, PI656115, and PI534167 were consistently resistant when challenged with the anthracnose pathogen, C. sublineola. Accessions PI534047 and PI574455, exhibited resistance to moderately resistance grain mold response when challenged with the treatments. Seed weight, germination rate, and mycoflora analysis which are factors in determining grain mold resistance also were measured. Across the accessions, mean seed weight ranged from1.4 g to 4.3 g per 100 kernel and germination rate ranged from 26 to 87%. 

Conclusion: The resistant accessions identified in this study can be used in breeding programs to develop anthracnose and grain mold resistance lines.

Open Access Original Research Article

Response of the Growth of Cowpea Varieties Submitted to Organic Fertilization Produced under a Regosol in the Semiarid Region of Paraiba

Cássio Ricardo Gonçalves da Costa, Marcos Gomes da Silva, Vânia da Silva Fraga

Journal of Experimental Agriculture International, Page 84-92
DOI: 10.9734/jeai/2020/v42i130454

The objective of this work was to compare growth parameters of traditional varieties of cowpea with commercial varieties based on agroecological processes in the semi - arid region of Paraiba. The experiment was installed in the factorial scheme of 3 blocks x 4 treatments x varieties: T1- control (without addition of inputs), T2- 10 t ha-1 organic compound (being, bovine manure + vegetal materials), T3- 4.2 t ha-1 rock powder, and T4- 5 t ha-1 of rock dust + 2.1 t ha-1 organic compound, x 3 varieties, being, 02 commercials identified as, 1- New Age and 2- Guaribas (provided by EMBRAPA), and 01 traditional, 3- Sedinha (already in common use by farmers). The field project was developed in partnership with the Advisory and Services in Alternative Agriculture (AS-PTA), which was also used as an experimental unit, located in the city of Esperança - PB, the soil of the area was classified as a Regosol, the growth parameters were: number of plants (NP), plant height (AP), leaf number (NF), leaf area (FA), stem diameter (DC). The Sedinha variety was the one that stood out in relation to the others when comparing growth parameters such as height and leaf area, while the Guaribas variety obtained a larger caulinar diameter. The treatment with the organic compound proved to be the most efficient for all varieties, but for the treatment with rock dust, it will require further studies due to the high levels of sodium and low phosphorus, which may explain the low development.

Open Access Original Research Article

Effects of Cattle Manure on the Growth, Yield, Quality and Shelf Life of Beetroot (Beta vulgaris L. cv. Detroit Dark Red)

Vusumuzi C. Dlamini, Kwanele A. Nxumalo, Michael T. Masarirambi, Paul K. Wahome, Tajudeen O. Oseni, Mathole G. Zwane

Journal of Experimental Agriculture International, Page 93-104
DOI: 10.9734/jeai/2020/v42i130455

Beetroot (Beta vulgaris L.) is one of the widely and popularly used salad vegetable in the Kingdom of Eswatini: However, there is scarcity of information pertaining to its organic production. A field study laid out in a Randomised Complete Block Design (RCBD) was conducted at the Horticulture Farm, Faculty of Agriculture, Luyengo Campus, at the University of Eswatini to determine the effects of cattle manure on growth, yield, quality and shelf-life of beetroot. Five treatments were applied in this experiment, and included cattle manure applied at 20, 40, 60, and 80 t/ha and a control of inorganic fertilizer, NPK [2:3:2 (22)] applied at 100 kg/ha as basal dressing and limestone ammonium nitrate (LAN) (28) applied at 80 kg as a top dressing. The treatments were replicated four times. The results obtained showed that beetroot grown under the application rate of 80 t/ha exhibited higher values in plant height (32.5 cm), number of leaves (9), leaf area (206 cm2), root diameter (5.1 cm), root length (11.7 cm), root fresh mass/plant (10.8 g), root dry mass/plant (9.2 g), marketable yield/plant (9.2 g) and quality [(aroma (33.5%), flavour (34%), texture (35%)] of the edible part. Plants supplied with 20 t/ha of cattle manure and inorganic fertiliser (control) gave the lowest vegetative growth parameters, quality parameters and marketable yield.

Open Access Original Research Article

Genetic Resources for Fertility Restoration Lines and Maintainers of Capsicum annuum L.

Maneechat Nikornpun, Danai Boonyakiat

Journal of Experimental Agriculture International, Page 105-115
DOI: 10.9734/jeai/2020/v42i130456

Male fertility reactions of one hundred and forty-one accessions of chilies were classified. Three groups were found. Some accessions maintained male sterility and were determined to carry a non-sterile cytoplasm and to lack fertility restoration genes or N rfrf genotype. Some accessions segregated for the ability to restore male sterile cytoplasm and were determined to be heterozygous in restorer genes with genotype N/SRfrf. Some accessions restored fertility of CMS and had the genotype N/SRfRf. A few maintainers with good horticultural characteristics were selected. They were selfed and selected for a few generations and then their progeny were evaluated. There were differences in the genetic stability of cytoplasmic male-sterility among the selected lines. Some lines were good maintainers, but a few lines were discarded. The stable maintainers were distributed to 10 seed companies and the government of China. Some F1 hybrid chilies produced using these lines have been commercially sold both in China and Thailand. Fruit physio-chemical qualities of maintainer accessions, restorers and heterozygous accessions were also recorded. The level of capsaicin of the accessions varied from 3,250 to 8,850 Scoville units. The level of vitamin C showed a range of 4.43 to 103.16 mg./100g.fw. Horticultural characteristics of the accessions were recorded and the fruit physio-chemical qualities of the accessions were reported.

Open Access Original Research Article

Influence of Poultry Manure Rates on the Growth and Yield of Okra (Abelmoschus esculentus (L.) Moench) in Rivers State

O. L. Adesina, K. O. Wiro

Journal of Experimental Agriculture International, Page 116-120
DOI: 10.9734/jeai/2020/v42i130457

Knowledge of optimum rates of poultry manure application is of immense significance in the correction of the soil nutrient deficiencies for crop production. Manure application is of importance to both the soil amendment and in the growth and yield of crops. Leaching, pattern of cropping, use of non-certified seeds and non-improved varieties have hampered the efficient growth and yield of okra. The study was conducted to examine the growth and yield responses of okra (Abelmoschus esculentus (L.) Moench) to poultry manure rates in Rivers State. The research study became imperative to examine how rate of poultry manure could affect the production of okra. The experiment utilized three rates of poultry manure, 0-tons (control), 5-tonsha-1 and 10-tonha-1and the treatment combination arranged in a Completely Randomized Block Design (CRBD) replicated three times. Growth characteristics measured were, plant height, stem thickness, leaf area and number of leaves per plant while yield parameters measured were pod length, seeds per pod, total number of pods, pod yield per hectare. The results revealed that appropriate rate of poultry manure application in the production of okra has the capacity to increase okra growth and yield in Rivers State. The use of 10-tonha-1 of poultry manure performed better than other poultry manure rates and so it’s recommended that okra farmers in the study area should apply 10-tonha-1 for high quality and quantity production of okra in  Rivers State.

Open Access Original Research Article

Correlation between Off-flavor and Morphology of Papaya (Carica papaya L.) Fruits

Annisa Kamil, Christofora Hanny Wijaya, Sobir ., Dede Robiatul Adawiyah

Journal of Experimental Agriculture International, Page 121-132
DOI: 10.9734/jeai/2020/v42i130458

Aims: To investigate the correlation between fruit morphology and off-flavor characteristics which are naturally present in papaya.

Place and Duration of Study: Department of Food Science and Technology (Sensory Laboratory and Food Analysis Services Laboratory), Centre for Tropical Horticulture Study (Chemistry Laboratory) and Indonesian Centre for Rice Research of Indonesian Agriculture Ministry (Flavor Laboratory), between December 2014 and September 2015.

Methodology: Morphology descriptions of 6 papaya varieties, i.e. “Carisya”, “Callina”, “Sukma”, “Merah Delima”, “Burung” and “Bangkok”; off-flavor description using Quantitative Descriptive Analysis; semi-quantification of volatile compounds by using Headspace Solid-Phase Micro-Extraction and Gas Chromatography-Mass Spectrometry have been conducted.

Results: The stinky-sour odor had positive correlation with the presence of butanoic acid (r=0.879) and octanoic acid (r=0.876). The stinky-sour odor had negative correlation with the weight (r= -0.836), length (r= -0.873), flesh thickness (r= -0.887), and ripe peel color (r= -0.838) in accordance to the octanoic acid content which showed negative correlation to fruit weight (r= -0.871), length  (r= -0.830) and ripe peel color (r= -0.911). The stinky-sour odor as well as the concentration of butanoic and octanoic acid were most dominant in “Burung” and “Carisya” papayas. “Callina” and “Sukma” papayas had the weakest off- flavor intensity.

Conclusion: The off-flavor perception of papaya was dominated by stinky-sour odor. The presence of octanoic acid might deliver synergism impact to butanoic acid in giving the perception of stinky-sour odor. High concentration of octanoic acid and strong intensity of stinky-sour odor were closely related to the small type of fruit weight (650 g or less), short size fruit (16.5 cm or less), thin flesh (less than 3 cm), and papaya varieties with orangish ripe peel color. These phenomena can be utilized in selection process in the field selection criteria to breed favorable papaya varieties.

Open Access Original Research Article

Physicochemical Attributes in Mango Fruit (Mangifera indica) as Influenced by Storage Temperature and Hot Water Treatment

Senewa Bobby Pholoma, Vallentino Emongor, Seoleseng Tshwenyane

Journal of Experimental Agriculture International, Page 133-141
DOI: 10.9734/jeai/2020/v42i130459

Background: The temperature being the most important environmental factor that influences the deterioration of perishable commodities. It is often critical that fresh produce rapidly reach the optimal pulp temperature for short term storage if it is to maintain its highest visual quality, flavour, texture and nutritional content (Kader, 2013).

Aims: The effects of storage temperature and hot water at various temperature and duration on chemical and textural characteristics of the Keitt mango fruit were evaluated for the 2015/16 growing season in Botswana.

Materials and Methods: The treatments were fruits dipped in distilled water at room temperature (25±2ºC- control), fruits dipped in hot water at 50 and 55ºC for a duration of 3, 5 and 10 minutes, and storage temperatures at 4, 7, 10, 13, or 25±2ºC, plus 95% RH.

Results: The results showed that as the storage temperature and water temperature decreased, the proline content and electrolyte leakage increased significantly (P ≤ 0.0001). The interactions of storage temperature and hot water temperature, and duration in which mango fruit was treated with hot water, significantly (P ≤ 0.01) maintained vitamin C content, firmness and reduced fruit weight loss during storage and seven days after storage when the fruit was kept at room temperature.

Conclusion: Chemical and physical attributes of Keitt mango fruits were significantly improved by the interactions between storage temperature, hot water temperature and duration.

Open Access Original Research Article

Evapotranspiration and Dual Crop Coefficient of Maize Second Season Intercropped with Crotalaria

Diego Fernando Daniel, Rivanildo Dallacort, João Danilo Barbieri, Marco Antônio Camillo de Carvalho, Santino Seabra Júnior, William Fenner

Journal of Experimental Agriculture International, Page 142-157
DOI: 10.9734/jeai/2020/v42i130460

The objective of this work was to determine the dual coefficient of culture (Kc) of maize in monoculture and intercropping systems, as well as to evaluate the influence of intercropping on evapotranspiration and productive characteristics of maize second season. The experiment was carried out in the experimental field of the State University of Mato Grosso - UNEMAT in 2018, with three treatments: T1 - maize monoculture; T2 - Crotalaria monoculture and T3 - maize + Crotalaria. The crop evapotranspiration (ETc) of maize, Crotalaria, and maize + Crotalaria intercropping was determined daily by weight variation of weighing lysimeters, converted into mm day-1. The methodology used was that of dual Kc - FAO 56, dividing the crop coefficient (Kc), in soil evaporation coefficient (Ke), determined in microlysimeters, and basal crop coefficient (Kcb), determined in weighing lysimeters. The phenological phases of the maize crop were observed to determine the coefficients in the different developmental stages, being the Kc, Kcb, Ke in the phases: Initial (I), Development (II), Intermediate (III) and Final (IV). The accumulated culture evapotranspiration was 312.00; 436.16 and 422.38 mm and daily averages of 2.86; 4.00- and 3.88-mm d-1, respectively for monoculture maize, for Crotalaria and for intercropping. The Kc values for each phase of maize development in intercropping with crotalaria were: I (1.46); II (1.48); III (1.59) and IV (0.94). For maize monoculture, dual Kc values were: I (1.24), II (1.30), III (1.00) and IV (1.11) and for Crotalaria monoculture were: I (1.77), II (1.59), III (1.56) and IV (1.05).