Open Access Original Research Article

Use of Crop Water Stress Index for Irrigation Scheduling of Soybean in Mediterranean Conditions

Begüm Tekelioğlu, Dursun Büyüktaş, Ruhi Baştuğ, Cihan Karaca, Köksal Aydinşakir, Nazmi Dinç

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/JEAI/2017/37058

Canopy temperature measured via infrared thermometers is an important parameter to determine crop water stress. The crop water stress index (CWSI) is the most often used index based on difference of canopy-air temperature and vapor pressure deficit (VPD) to detect crop water stress and to schedule irrigation for field crops. The aim of this study is to determine the relationship between the canopy-air temperature difference and the vapor pressure deficit in order to calculate the CWSI value in soybean plants. The study is carried out in randomized complete block design with six different irrigation treatments and three replications at the Batı Akdeniz Agricultural Research Institute (BAARI), Antalya, Turkey. Plots were irrigated when the cumulative evaporation in Class A pan is 25±5 mm using drip irrigation system based on the plant-pan coefficient (kpc) of 0, 0.25, 0.50, 0.75, 1.00, and 1.25. Before and after each irrigation, canopy temperature was measured using a portable infrared thermometer in all treatments between 11.00 to14.00. Throughout the season, before irrigation, soil moisture content was measured. The CWSI values were determined using empirical approach. When using this technique in Antalya conditions, it is suggested to keep the seasonal mean CWSI value approximately 0.26 and index value of 0.40 can be used to start irrigations. Additionally, it is suggested that the amount of irrigation can be equal to the amount of evaporation measured until the index value reach 0.40. According to the results obtained, it is concluded that infrared thermometer can be used to schedule irrigation of the soybean plant under Mediterranean (Antalya) conditions of Turkey.

Open Access Original Research Article

Effect of Gibberellic Acid (GA3) on Rootstock on the Evolution of the Mandarin Tree Induction "Nadorcott"

Nabil Rachdi, Abdelhadi Ait Houssa, Mohamed Midaoui, Bouchra Et Takaouy, Kawtar Semaoui, Redouane Bakkali, Mohamed Benbella, Mohamed Ibriz

Journal of Experimental Agriculture International, Page 1-18
DOI: 10.9734/JEAI/2017/36958

An application of gibberellic acid (GA3) was applied to different doses (0; 15; 30 ppm) on Nadorcott trees transplanted on five rootstocks (Macrophylla citrusCarrizo citrangeTroyer citrangeC35 citrange and Swingle citrumelo) during the fruits coloration shifting. A monitoring of the evolution of the floral induction by the counting of leaves and the flowers/ fruits for the sensitive stages: flowering, fruiting and end physiological drop, with physico-chemical analyzes of the leaves at the physiological dropping stage, of caliber during the magnification stage. The shoots on the Swingle Citrumelo rootstock had more flowers than the Citranges and even more than the Macrophylla citrus. This classification is still valid for fruits during fruiting, results of a standard drop for the different rootstocks with the dominance of leaved inflorescence with unique flower. On the other hand, the physiological drop was different from rootstock to the other, more accentuated in Swingle citrumeloTroyer and Carrizo citrange, and moderate in C35 citrange and Macrophylla citrus. While the GAtreatment did not significantly affect either the floral induction or the drop in its two phases. It is noted that with the evolution of the flowering there is a significant positive effect of the treatment and of the GAdose on the fruits hooking, with a 23% increase for the dose of 30 ppm GA3 compared to the control. However, the variation in size is better for fruits on leaved inflorescence with unique flower, as well as on the Macrophylla citrus rootstock, followed by Citrange (C35 followed by Carrizo and Troyer), and finally Swingle Citrumelo (10% less in comparison with Macrophylla citrus).

Open Access Original Research Article

Assessment of Passion Fruit Trees Genotypes in Terms of Fruit Quality and Yields in Rio Grande do Sul - Brazil

Diego Weber, Jair Costa Nachtigal, Caroline Farias Barreto, Marcelo Barbosa Malgarim

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/JEAI/2017/37819

Aims: This study aimed at evaluating genotypes of passion fruit regarding the quality and yield of their fruits in southern Brazil.

Study Design: The experimental design randomized complete block design with four genotypes and eight repetitions. The experimental unit, which was constituted by four plants, total forty plants per treatment.

Place and Duration of Study: The experiment was carried out at the Centro Agropecuário da Palma, which belongs to the Universidade Federal de Pelotas, located in Capão do Leão, Rio Grande do Sul, Brazil. The experiment was conducted during the 2013/2014 and 2014/2015 seasons.

Methodology: Experiments were carried with the following genotypes: Passiflora edulis Catarina, Passiflora alata Urussanga, Passiflora edulis BRS Sol do Cerrado and Passiflora edulis BRS Rubi do Cerrado. We measured in the present study productivity, yield per plant, number of fruits per plant, number of fruits per hectare, mean fruit mass, soluble solids, titratable acidity, SS/TA relation, epidermis color, pericarp thickness, mean fruit length, mean fruit diameter and pulp yield.

Results: In 2013/2014 season, the yield of the yellow passion fruit BRS Sol do Cerrado, BRS Rubi do Cerrado and Catarina stood out. In this seasons, in general, the yellow passion fruit showed more productive capacity than the selection of the sweet passion fruit Urussanga. In 2014/2015 season, the genotype BRS Sol do Cerrado (20.36 Mg ha-1) had better data on yield than both genotypes Catarina (18.07 Mg ha-1) and Urussanga (12.05 Mg ha-1). The genotypes BRS Sol Cerrado, BRS Rubi do Cerrado and Catarina excelled in fruit mass, fruit length, fruit diameter and pulp yield. The passion fruit Urussanga had the lowest titratable acidity (2,05% citric acid in 2013/2014 and 2,07% citric acid in 2014/2015) and the highest contents of soluble solids (13,98°Brix in 2013/2014 and 14,27°Brix in 2014/2015)  in fruits.

Conclusion: However, all evaluated genotypes show potential for production in southern Brazil. The physical-chemical quality of the fruits of the genotypes, show differences between them, however all are within the acceptable parameters.

Open Access Original Research Article

Application of Compost, Lime and P Fertilizer on Selected Soil Properties and P Use Efficiency of Maize in Acidic Soil of Assosa, Western Ethiopia

Biruk Teshome, Tamado Tana, Nigussie Dechassa, T. N. Singh

Journal of Experimental Agriculture International, Page 1-14
DOI: 10.9734/JEAI/2017/36976

Soil fertility loss due to soil acidity is a major constraint for crop production in western Ethiopia. A study was conducted in the acidic soil of Assosa for two main growing seasons (2014 and 2015) to assess the effect of integrated application of compost, lime and phosphorus on selected properties of soil and P use efficiency of maize. The treatments were factorial combinations of compost (0 and 5 t ha-1), lime (0, 1.5 and 3 t ha-1) and phosphorus (0, 20 and 40 kg P ha-1) in randomized complete block design with three replications. The combined analysis of the two season data showed, significant (P<0.01) interaction effects of season with compost and season with P on soil pH; compost with P; and lime with P on apparent P recovery and utilization efficiency; season, lime and P on exchangeable acidity; and interactions of season, compost, lime and phosphorus on the available P. The highest soil pH (6.23) was observed due to compost (5 t ha-1) in the first season (2014) and the highest reduction in exchangeable Al (0.05 cmolc kg-1) was due to lime (3 t ha-1) in the first season (2014). The highest P apparent recovery (6.29%) and utilization efficiencies (169.12 kg kg-1) were observed due to combination of compost (5 t ha-1) with P (20 kg P ha-1). The exchangeable acidity was highly reduced due to combination of lime at 1.5 t ha-1 with P at 40 kg P ha-1 in the first season; while the highest available P (15.04 and 14.65 cmolc kg-1) was observed due to combination of compost at 5 t ha-1, lime at 1.5 t ha-1 and P at 40 and 20 kg P ha-1 in the first season. Therefore, combination of compost with P or combination of compost, lime with P could be helpful treatments in reducing the exchangeable acidity and increase the available P use efficiency, respectively.

Open Access Original Research Article

Effect of Intercropping Maize and Promiscuous Soybean on Growth and Yield

Habineza M. Jean Pierre, Josiah . M Kinama, Florence M. Olubayo, Susan W. Wanderi, James. W Muthomi, Felister M. Nzuve

Journal of Experimental Agriculture International, Page 1-21
DOI: 10.9734/JEAI/2017/36923

An study was carried out in Kenya to assess the suitability of three promiscuous soybean varieties (SB19, GAZELLE and TGX1990-5F) intercropped with Maize (Duma 43). A randomised complete block design was used replicated three times with seven treatments. The arrangement of intercropping was 1:1. Data collection included germination %, plant height, days to 50% flowering, days to 75% maturity, yield biomass per plant, 100 grain weight, grain yield, harvest index and Land Equivalent Ratio for both crops. Shattering score, pods per plant, and seeds per pod for soybean only. Data were subjected to ANOVA and means separated using LSD0.05. The results showed that the earliest variety to 50% flowering and 75% maturity was SB19 (p ≤ 0.05) followed by GAZELLE while the latest variety was TGX1990-5F. Intercropping did not affect days to 50% flowering, days to 75% maturity and seeds per pod. Variety TGX1990-5F was resistant to pod shattering while others were moderately resistant. TGX1990-5F recorded the highest plant height, pods per plant, soybean biomass, grain yield and LER while GAZELLE had higher HI and SB19 recorded higher seeds per pod in sole crop and in intercrop in both sites and rainy seasons. Intercropping reduced soybean plant height, pods per plant, soybean yield biomass, soybean grain yield and soybean HI in both sites and seasons. LER showed advantage between component crops in both seasons.TGX1990-5F was suitable promisuous soybean variety for intercropping with maize because it had good perfomance under intercropping compared to others.