West Indian Cherry Research Articles

NPK fertilization modulates enzyme activity and mitigates the impacts of salinity on West Indian cherry.

Salt stress causes several physiological and biochemical disorders and impairs plant growth. However, adequate fertilization can improve the nutritional status and may reduce significantly the harmful effects caused by salt stress. From this perspective, this study aimed to evaluate the impact of different combinations of nitrogen, phosphorus and potassium fertilization on the antioxidant activity and accumulation of organic and inorganic solutes in West Indian cherry leaves, in the second year of production. The experimental design was in randomized blocks, with treatments distributed in a 10 × 2 factorial arrangement corresponding to ten fertilization combinations (FC) of NPK (FC1: 80-100-100%, FC2:100-100-100%, FC3:120-100-100%, FC4:140-100-100%, FC5:100-80-100%, FC6:100-120-100%, FC7:100-140-100%, FC8:100-100-80%, FC9:100-100-120%, and FC10:100-100-140% of the recommendation) and two levels of electrical conductivity of irrigation water (ECw) (0.6 and 4.0 dS m-1), with three replications. The multivariate analysis showed that irrigation with water of different electrical conductivities (0.6 and 4.0 dS m-1) resulted in different responses concerning the enzyme activity, production of organic compounds, and accumulation of inorganic solutes in the leaves. Under irrigation with low salinity water, there was greater accumulation of K+, soluble carbohydrates, and proline, and lower activity of antioxidative enzymes, especially SOD and APX. Under high salinity water, greater enzyme activity and higher concentrations of Na+ and Cl- were observed. The results indicate that the response of West Indian cherry to salinity was more towards redox homeostasis than osmotic homeostasis through the accumulation of compatible solutes. Fertilization combination FC5 (100-80-100% corresponding to 200, 24 and 80 g plant-1 of NPK) modulates the enzyme activity of SOD and APX attenuating the impacts of salinity, being an efficient combination to preserve redox homeostasis in West Indian cherry plants grown under salt stress.

NPK combinations mitigate the deleterious effects of salt stress on the morphophysiology of West Indian Cherry

Under salt stress, plant growth and development are negatively affected due to physiological changes,requiring strategies such as fertilization management to minimize these effects. In this scenario, this study aimedto evaluate the effect of combinations of nitrogen, phosphorus, and potassium on the growth, leaf waterstatus, electrolyte leakage, and gas exchange of West Indian Cherry grown under water stress in the secondyear of production. The experiment was conducted in a protected environment in Campina Grande - PB.The treatments were distributed in a randomized block design with a 2 × 10 factorial arrangement with threereplications corresponding to two electrical conductivity levels of irrigation water– ECw (0.6 and 4.0 dS m-1)and ten combinations of fertilization with nitrogen, phosphorus, and potassium (80-100-100; 100-100-100; 120-100-100; 140-100-100; 100-80-100; 100-120-100; 100-140-100; 100-100-80; 100-100-120, and 100-100-140% of therecommendation in the second year of production). Irrigation with the ECw of 4.0 dS m-1 negatively affectedplant growth, the leaf water status, electrolyte leakage, and the leaf gas exchange of West Indian Cherry.However, the 40% increase (C4 -140-100-100% of the recommended N-P2O5-K2O level) in the nitrogen levelmitigated the deleterious effects of salt stress on the relative water content, internal CO2 concentration, and theCO2 assimilation rate of West Indian Cherry plants in the second year of production.

Potassium-phosphorus fertilization to reduce salt stress in West Indian cherry

West Indian cherry stands out in the Brazilian fruit scenario due to the nutritional quality of its fruits, making it a promising crop in the generation of employment and income. However, the occurrence of water sources with high concentrations of salts is a limiting factor for the expansion of crop area. In this context, the objective was to evaluate the production and post-harvest quality of West Indian cherry cv. BRS 366 Jaburu under prolonged saline stress and potassium-phosphorus fertilization combinations in the second year of cultivation. The experiment was carried out in 250 L lysimeters in a greenhouse in the municipality of Campina Grande-PB, Brazil. Treatments were distributed in randomized blocks in a 5 × 4 factorial scheme, with five levels of electrical conductivity of irrigation water - ECw (0.6, 1.4, 2.2, 3.0, and 3.8 dS m−1) and four combinations of potassium-phosphorus fertilization (100/100, 85/85, 60/60, and 45/45% of K2O/P2O5 recommendation for the second year of cultivation) with three replicates. Irrigation water salinity of up to 3.8 dS m−1 does not compromise the post-harvest quality of West Indian cherry. The increase in water salinity reduces mean fruit weight and water consumption of plants, while waters with electrical conductivities of 3.0 and 2.0 dS m−1 promote the maximum values of total soluble solids and ascorbic acid in the fruits, respectively. The supply of 45/45% K2O/P2O5 of the fertilization recommendation provides the higher content of ascorbic acid in West Indian cherry fruits and, when associated with ECw of 1.4 dS m−1, promotes the higher production of the crop.

Soil chemical attributes under west indian cherry fertigated with nitrogen and humic substances

The use of humic substances (HS) in the soil can increase the efficiency of nitrogen fertilizers and contribute to the increment in soil organic matter and plant nutrient availability. Hence, this study aimed to evaluate, in two production cycles, the effect of applying HS and different nitrogen (N) doses on the chemical attributes and organic matter fractions of a soil cultivated with West Indian cherry in the Brazilian semiarid region. The experiment was set up in split plots, arranged in strips with four replicates. The absence or presence of HS using KS100 as the source was tested in the plots, and N fertilization (50; 75; 100; 125 and 150% of the recommended dose), using urea, was tested in the subplots. Soil pH, H+Al, Al3+, and Na+, K+, P, Ca2+, Mg2+, Fe2+, Mn2+ and Zn2+ contents were determined, and cation exchange capacity and bases saturation (V %) in the 0-0.2 and 0.2-0.4 m layers were calculated. Analyses of stocks of total organic carbon and carbon (C) of the humic acid, fulvic acid and humin fractions, and humic substances were performed. It was possible to observe that, in the second production cycle of West Indian cherry, the soils showed higher contents of nutrients available to plants. Increase in N availability did not enable a clear trend in the behavior of chemical attributes and organic C stocks in the soil. Under the studied conditions, KS100 application allowed a reduction in the C stocks of the HS of the soil.

Production and Quality of West Indian Cherry (Malpighia emarginata D. C.) under Salt Stress and NPK Combinations

This study aimed to evaluate the effect of fertilization combinations of nitrogen (N), phosphorus (P), and potassium (K) on the production and quality of West Indian cherry grown under salt stress in the second year of production. The study was conducted in a protected environment following a randomized block design with treatments distributed in a 2 × 10 factorial arrangement referring to two levels of electrical conductivity of irrigation water (0.6 and 4.0 dS m−1) and 10 NPK fertilization combinations (80-100-100; 100-100-100; 120-100-100; 140-100-100; 100-80-100; 100-120-100; 100-140-100; 100-100-80; 100-100-120 and 100-100-140% of the recommendation in the second year of production), with three replicates and one plant per lysimeter. Production and post-harvest variables evaluated were: the total fruit weight, total number of fruits, mean fruit weight, the polar and equatorial diameter, total soluble solids, pulp pH, titratable acidity, maturity ratio, vitamin C, reducing sugars, total phenolic compounds, total anthocyanins, and flavonoids. The results indicate that irrigation with water having a salinity of 4.0 dS m−1 negatively affected all production variables. The interaction between the ECw of 0.6 dS m−1 and the 100-80-120 NPK fertilization combination increased the total number of fruits and the total fruit weight of West Indian cherry.

Photosynthetic pigments and quantum yield of West Indian cherry under salt stress and NPK combinations.

West Indian cherry cultivation has proved to be an important economic activity in northeastern Brazil. However, irrigation with brackish waters limits cultivation, requiring new strategies to minimize the effect of salt stress. In this context, the present study aimed to evaluate the effect of nitrogen (N), phosphorus (P), and potassium (K) combinations on the photosynthetic pigments and quantum yield of West Indian cherry cultivated under salt stress, in the second year of production. The assay was conducted in a protected environment by adopting an experimental design in randomized blocks, with treatments distributed in a 2×10 factorial arrangement referring to two electrical conductivity levels of irrigation water - ECw (0.6 and 4.0 dS m-1) and 10 NPK fertilization combinations - FC (80-100-100; 100-100-100; 120-100-100; 140-100-100; 100-80-100; 100-120-100; 100-140-100; 100-100-80; 100-100-120, and 100-100-140% of the recommendation, in the second year of production), with three replications, each consisting of one plant. Irrigation with the electrical conductivity of 4.0 dS m-1 negatively affected the synthesis of photosynthetic pigments and the photochemical efficiency of the West Indian cherry cv. Flor Branca. The NPK combinations did not attenuate the effects of salt stress on the analyzed variables. However, the combinations referring to 120-100-100%, 140-100-100%, and 100-120-100% of NPK recommendation improved the quantum yield of photosystem II by reducing the initial fluorescence and increasing the maximum fluorescence of the West Indian cherry cv. Flor Branca.

Unusual pollinator attractants increase the fructification rate on West Indian Cherry Trees

AbstractAlthough West Indian Cherry (WIC) trees have abundant flowering, specimens of this species have low fructification rates, potentially associated with the dependence of these plants on pollinators for cross‐pollination and fruit production. We quantified fructification rates and assessed the market value of pollination services by conducting an experiment with six treatments, including manual and open pollination, pollinator exclusion treatment, and open pollination with blue and yellow attractants. The investigation occurred at two sampling periods (November–December 2015 and January–February 2016) in a commercial orchard of WIC in Brazil. Despite the six different treatments in the two sampling periods, the fructification rate only differed in open pollination treatments with colour attractants, increasing the fructification rate between 160% (for blue‐coloured attractants) and 240% (for yellow‐coloured attractants). Considering that yield is directly affected by the increase in the fructification rate, the yield might be enhanced by up to 70 ton/ha by the coloured attractants. Economically speaking, this result means an approximate 130% increase in the earnings for farmers and maybe transferable to other crops contributing to food production and recognizing the importance of biodiversity and associated ecosystem services.

Standardization of propagation methods in minor wild fruit crops

The study was carried out to find out the ideal propagation techniques of wild and minor fruit crops at ICAR-IIHR, Bengalure, during 2016–19. Two year's data revealed that fresh seeds of most of the species, viz. karonda (Carrisa carandas), wood apple (Feronia limonia syn. Limonia acidissima) avocado (Persea americana) noni (Morinda citrifolia) wild jamun (Syzygium cumini) Alangeum (Alangium salvifolium) carombola (Averhoa carambola), Canito (Chrysophyllum cainito), bael (Aegle marmelos) kokum (Garcinia indica), yellow mangosteen (Garcinia xanthochymus) and Malabar tamarind (Garcinia gummigutta) did not have dormancy and their germination was more than 60 per cent. Although the days taken for germination varied in these fruits. Some fruits, viz. mulberry (Moris alba) gave good response (80%) for multiplication through cuttings. Air-layering was found successful in Governor's plum (Flacourtia indica) Karonda (Carrisa carandas) natal plum (Carrisa macrocarpa), Citrus hindsi Surinam cherry (Eugenia uniflora) and West Indian cherry (Malpighia emarginata) with 75% and 60% survival. The grafting was found successful (90%) in avocado (Persea americana) and wood apple (Feronia limonia)

Saline waters and nitrogen/potassium fertilization combinations on physiological aspects and production of West Indian cherry

This study evaluated the influence of combinations of nitrogen and potassium doses on the physiology and fruit production of West Indian cherry irrigated with waters of different salinities in the second year of cultivation. The experiment was conducted in the municipality of Pombal-PB, Brazil, in plastic containers adapted as lysimeters installed in the field, in a randomized block design, 5 x 4 factorial scheme corresponding to five levels of electrical conductivity of irrigation water (ECw): 0.3, 1.3, 2.3, 3.3 and 4.3 dS m-1, and four combinations of nitrogen and potassium fertilization: 70% N + 50% K2O; 100% N + 75% K2O; 130% N + 100% K2O and 160% N + 125% K2O of the dose recommended for West Indian cherry, with three replicates and one plant per plot. The cv. ‘Flor Branca’ was grafted on the cv. ‘Junco’, between 420 and 550 days after transplanting. Nitrogen and potassium combinations did not mitigate the deleterious effects of water salinity on the physiology and fruit formation of West Indian cherry. An increase in ECw intensifies the intercellular electrolyte leakage and reduces the water potential in the branch, chlorophyll content in the leaves, CO2 assimilation rate, equatorial and polar diameters as well as the mass of fruits. Fertilization of plants with 70% N + 50% of K2O, compared to the other fertilization combinations, causes less intercellular electrolyte leakage and promotes higher CO2 assimilation rates, higher chlorophyll content in leaves, and fruits of larger size and mass.
 Keywords: Malpighia emarginata D. C, mineral fertilization, salt stress.

Fruit quality of West Indian cherry under saline water irrigation and nitrogen-potassium fertilization

ABSTRACT The presence of waters with high salt concentration stands out as a limiting factor for the quality of agricultural production. Thus, this study aimed to evaluate the fruit quality of West Indian cherry cv. Flor Branca, subjected to irrigation with water of different salinity levels and combinations of nitrogen-potassium fertilization, between 630 and 750 days after transplanting in the field. A randomized block design was used in a 5 × 4 factorial arrangement, with three replicates, whose treatments consisted of five values of electrical conductivies of irrigation water - ECw (0.3, 1.3, 2.3, 3.3 and 4.3 dS m-1) and four combinations of nitrogen and potassium fertilization (70-50, 100-75, 130-100 and 160-125% of recommendation of N and K2O, respectively). Electrical conductivity of irrigation water above 0.3 dS m-1 reduces the polar and equatorial diameters, hydrogen potential and flavonoid concentration and increases titratable acidity in West Indian cherry fruits. N-K2O combination of 70/50% of fertilizer recommendation reduces the effect of salt stress of irrigation water on the anthocyanin concentration in the fruits at ECw of 1.3 dS m-1 and ascorbic acid at ECw of 3.3 and 4.3 dS m-1.

Gas exchange and photosynthetic pigments of West Indian cherry under salinity stress and salicylic acid

A aceroleira e uma fruteira que se destaca pela sua importância socioeconomica no semiarido do Nordeste brasileiro, devido sua utilizacao na industria alimenticia e farmaceutica. Neste contexto, objetivou-se com esse trabalho avaliar as trocas gasosas e os pigmentos fotossinteticos da aceroleira cv. BRS Jaburu em funcao da irrigacao com aguas salinas e procedimentos de acido salicilico. O trabalho foi conduzido em casa de vegetacao em Campina Grande-PB. O delineamento estatistico de blocos casualizados, em esquema fatorial 5 x 4, combinados os tratamentos consistiram de cinco niveis de condutividade eletrica da agua de irrigacao - CEa (0,8; 1,6; 2,4; 3,2 e 4 , 0 dS m -1 ) e quatro especialidades de acido salicilico - AS (0; 1,0; 2,0 e 4,0 mM), com 3 repeticoes. A salinidade de agua a partir de 0,8 dS m-1 reduziu a transpiracao, a taxa de assimilacao de CO 2 e a eficiencia instantânea do uso da agua das plantas de aceroleira. O acido salicilico nao amenizou os efeitos deleterios do estresse salino sobre as trocas gasosas e clorofila a sob salinidade da agua superior a 0,8 dS m -1 . A concentracao de acido salicilico de 4,0 mM promoveu incremento no teor de clorofila total das plantas de aceroleira.

Effect of combined potassium-phosphorus fertilization on gas exchange, antioxidant activity and fruit production of West Indian cherry under salt stress

Salt stress is abiotic stress that directly affects the gas exchange and redox metabolism of the plants. However, some studies claim that the combination of potassium-phosphorus fertilization may increase salt tolerance in plants. In this context, the objective of this study was to evaluate gas exchange and the antioxidant enzyme activity responses to combined potassium-phosphorus fertilization in the tissues of West Indian cherry during the fructification phase, 240 days after application of treatments (DAT) in the second year of brackish water irrigation production. The treatments were distributed in randomized blocks, in a 5 × 4 factorial scheme, with five levels of irrigation water electrical conductivity – (ECw equal to 0.6 – control, 1.4; 2.2; 3.0 or 3.8 dS m−1) and four potassium-phosphorus fertilization combinations, 200/120; 170/102; 120/72 or 90/54 g K2O/P2O5 plant−1 per year, with three replicates. Irrigation water salinity impaired the gas exchange, showing a reduction of 47.94, 47.21, and 43.92% in the stomatal conductance, transpiration, and CO2 assimilation, respectively. In contrast, it increased the antioxidant metabolism, mainly the catalase enzyme activity (+ 67.7%). The average weight of fruits was increased by 85% in the combination of 90/54 under 1.4 dS m−1. Although the average number of fruits, in same combination (90/54) was 37% lower compared to high salinities. The threshold water salinity (1.12 dS m−1) indicates that West Indian cherry is a salt sensitive crop.

West Indian cherry production under irrigation with saline water and potassium-phosphorus fertilization

HIGHLIGHTS The salinity of the water reduces the number and diameter of the fruits and, the total weight of West Indian cherry fruits. Potassium-phosphorus fertilization attenuates the deleterious effects of salt stress on West Indian cherry production. The effect of water salinity on West Indian cherry fruit varies with salt stress intensity and expo-sure time to salinity.

Anaerobic co-digestion of acerola (Malphigia emarginata) agro-industry effluent with domestic sewage at mesophilic and thermophilic conditions

This study evaluated the effect of temperature on the anaerobic co-digestion of West Indian Cherry agro-industry effluent (EAV) and domestic sewage (EDT). The assays were performed in triplicates of reactor flasks using treatments with different mixture compositions (T1=5%EDT+95%EAV;T2=20%EDT+80%EAV;T3=30%EDT+70%EAV) and anaerobic sludge as inoculum (5g.L-1), at mesophilic (35°C) and thermophilic (55°C) temperatures. The analyses of soluble chemical oxygen demand (DQOs) and volatile fatty acids (AGV) were performed by determining the removal efficiency of the DQOs, the decay rate constant of the DQO (Kd), and the percentages of anaerobic biodegradability (%BD) and methanation (%M). The inoculum biomass of the treatments was observed through scanning electron microscopy at the end of the degradation process (12 days). Regardless of the temperature, the anaerobic digestion was considered efficient, with biodegradability above 60%. The mesophilic temperature favored the anaerobic co-digestion for all mixture compositions, presenting more diversified and structured biomass at the end of the assays, as well as higher removal efficiencies of the DQOs and methanization, especially for T3 at 35°C (63% and 51%, respectively). Furthermore, the kinetics of the degradation process proved to be more accelerated at mesophilic conditions (Kd 0.1d-1) and in the treatments with a higher percentage of sewage (T2M and T3M).

Chloroplast pigments and photochemical efficiency of West Indian cherry under salt stress and potassium-phosphorus fertilization

The objective of this study was to evaluate chloroplast pigments and photochemical efficiency of West Indian cherry cv. BRS 366 Jaburu as a function of irrigation water salinity and potassium-phosphorus fertilization combinations in the second year of cultivation. The experiment was carried out in a protected environment in Campina Grande, Brazil. Treatments were distributed in randomized blocks, in a 5 × 4 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water ECw (0.6, 1.4, 2.2, 3.0 and 3.8 dS m-1) and four combinations of potassium-phosphorus fertilization (100/100, 85/85, 60/60 and 45/45% of the K2O/P2O5 recommendation for the second year of cultivation 200 g of K2O and 120 g of P2O5 per plant per year) with three replicates. Irrigation with saline waters hampered the biosynthesis of chloroplast pigments and the photochemical efficiency of West Indian cherry cv. BRS 366 Jaburu in the second year of cultivation. Water salinity from 2.6 dS m-1 reduced the maximum fluorescence, variable fluorescence, and quantum efficiency of photosystem II of West Indian cherry plants cv. BRS 366 Jaburu. Fertilization with 60/60 and 85/85% of the K2O/P2O5 recommendation promotes an increase in the synthesis of chlorophylls a and b, respectively, in the first and second production cycles of the second year of cultivation. Supply of 85/85% of the K2O/P2O5 recommendation promoted an increase in maximum and variable fluorescence in plants subjected to water salinities of 0.6, 2.2, and 3.8 dS m-1 in the second cycle and reduced the initial fluorescence, regardless of the salinity level in the first and second production cycles of West Indian cherry.

GROWTH AND POST-HARVEST FRUIT QUALITY OF WEST INDIAN CHERRY UNDER SALINE WATER IRRIGATION AND POTASSIUM FERTILIZATION

ABSTRACT The study was conducted to evaluate the growth and physicochemical quality of West Indian cherry cv. BRS 366-Jaburu, as a function of saline water irrigation and potassium fertilization. The research was conducted under greenhouse conditions in Campina Grande-PB. The experimental design was randomized blocks in a 2 x 4 factorial arrangement, which consisted of two levels of irrigation water electrical conductivity - ECw (0.8 and 3.8 dS m-1) and four levels of potassium of 50, 75, 100 and 125% of the recommendation, in which the dose of 100% was equivalent to 19.8 g of K2O per plant year-1, with three replicates and one plant per replicate. Water salinity of 3.8 dS m-1 inhibited the absolute and relative growth in diameter of the rootstock and scion of West Indian cherry plants, in the period from 100 to 465 days after transplanting. The interaction between saline levels and potassium doses was significant for hydrogen potential, soluble solids and anthocyanins levels in BRS 366-Jaburu West Indian cherry fruits, with the highest values obtained in plants fertilized with 125, 125 and 50% of the K2O recommendation and under water salinity of 3.8, 3.8 and 0.8 dS m-\ respectively. Increasing doses of K did not attenuate the effects of salt stress on the relative growth in rootstock stem diameter, fruit polar diameter and anthocyanin contents of West Indian cherry. Soluble solid contents in West Indian cherry pulp increased with application of K2O.

Fruit quality of west indian cherry irrigated with saline waters under combinations of nitrogen/potassium fertilization

West Indian cherry stands out among the fruits cultivated for the pharmacological and alimentary importance, but its quality can be affected by irrigation water salinity and fertilization management. In this context, this research aimed to study the effect of irrigation water of different salinities and combinations of nitrogen and potassium fertilization on the physical and physico-chemical quality of bioactive compounds in West Indian cherry fruits. The experiment was carried out in the field, using lysimeters of 60 L, in the Experimental Area of the Centro de Ciências e Tecnologia Agroalimentar (CCTA) of Universidade Federal de Campina Grande (UFCG), Pombal, PB, in a randomized block design, with treatments arranged in a 5 x 4 factorial scheme, referring to five irrigation water salinities (ECw): 0.3, 1.3, 2.3, 3.3 and 4.3 dS m-1 and four combinations (C) of doses of nitrogen (N) and potassium (K2O): C1 = 70% N + 50% K2O; C2 = 100% N + 75% K2O; C3 = 130% N + 100% K2O and C4 = 160% N + 125% K2O, of the recommended dose for West Indian cherry, with three replicates and one plant per plot consisting of a lysimeter. The cv. Flor Branca grafted on cv. Junco was used in the study. The increase in salinity of irrigation water reduced the size, weight and vitamin C content of the fruits, but, the combinations of N and K fertilization did not affect fruit shape and the content of anthocyanin, carotenoids, pH, titratable acidity, total soluble solids and fruit flavor. Fertilization combinations consisting of C1 and C2 treatments promoted the largest fruit size under irrigation with ECw of up to 1.3 dS m-1 and greater mass accumulation. Fertilization doses above C2 combinations negatively affected fruit quality.

Saline water and nitrogen doses in the cultivation of West Indian cherry in the post-grafting phase

This study aimed to evaluate the photosynthetic pigments and growth of the West Indian cherry cv. BRS 366 Jaburu in the post-grafting phase as a function of the salinity levels of the irrigation water and nitrogen fertilization under greenhouse conditions, in the municipality of Campina Grande-PB. The study was performed in randomized blocks, consisting of two levels of electrical conductivity of irrigation water - ECw (0.8 and 4.5 dS m-1) and four nitrogen doses (70, 85, 100, and 115% of the recommended dose for the crop), with three replications. The synthesis of chlorophyll a and carotenoids in the West Indian cherry plants was inhibited with ECw of 4.5 dS m-1. Nitrogen fertilization in the estimated doses of 92 and 80% of N reduced the effects of salt stress on the contents of chlorophyll a and b in West Indian cherry plants, at 630 days after transplanting. The increment in nitrogen fertilization increases quadratically the absolute and relative growth rate of the diameter in the rootstock of the West Indian cherry plants under irrigation with saline waters.

Growth and gas exchange of West Indian cherry irrigated with saline waters under combinations of nitrogen-potassium fertilization

Fertilization management has been one of the techniques used to mitigate salt stress in crops. In this context, this research aimed to study the effect of different combinations of nitrogen and potassium fertilization on growth and gas exchange of the West Indian cherry crop irrigated with salinized water at different vegetative stages. The experiment was conducted in field, in a randomized block design, with treatments arranged in a 5 x 4 factorial scheme, referring to five irrigation water salinities (ECw): 0.3, 1.3, 2.3, 3.3 and 4.3 dS m-1 and four combinations of nitrogen and potassium doses: C1 = 70% + 50%; C2 = 100% + 75%; C3 = 130% + 100% and C4 = 160% + 125% of N and K2O, respectively, of the recommended dose for West Indian cherry, with three replicates and one plant per plot, consisting of a 60 L pot. Harmful effects of water salinity manifested at 230 days after transplantation (DAT) on the stem and primary shoot diameter, from ECw of 2.32 dS m-1 on, and the tested fertilizer combinations did not mitigate them. Fertilization with 70% N + 50% K2O favored gas exchange activity and higher plant growth from 170 DAT, regardless of water salinity.

Cultivation of West Indian cherry irrigated with saline water under phosphorus and nitrogen proportions

The objective of this work was to evaluate the effect of water salinity and phosphorus:nitrogen ratios on growth, leaf macronutrients and sodium and the West Indian cherry production. The research was carried out in a protected environment, in lysimeters filled with a Regolithic Neosol of loamy clay texture and low initial phosphorus content. The experiment was carried out in a protected environment, in a randomized complete block design with treatments arranged in a 5 × 4 factorial scheme, with differing electrical conductivity levels of the irrigation water ECw (0.6, 1.4, 2.2, 3.0 and 3.8 dS m-1) and four proportions of phosphorus and nitrogen P/N (100:100, 140:100, 100:140 and 140:140% of P/N), with three replicates and one plant per replicate. Phosphorus and nitrogen doses corresponding to 100% of the recommendation for phosphate and nitrogen fertilization were 45.0 g of P2 O5 per plant year and 23.85 g of N per plant year, respectively. The West Indian cherry plants were maintained under irrigation with saline water for 365 days, where they were evaluated the growth characteristics, foliar mineral composition, and production. The increase of the salinity of irrigation water increases the levels of sodium in the tissues to levels detrimental to growth, foliar mineral composition and the production of the West Indian cherry. Fertilization with 140% of the phosphorus and nitrogen recommendation inhibits the action of saline stress, promoting greater production of West Indian cherry irrigated water plants with water up to 3.0 dS m-1.