Morphophysiology of guava under saline water irrigation and nitrogen fertilization

Abstract

A B S T R A C TThe aim of this study was to evaluate the growth of grafted guava cv. 'Paluma' subjected to different concentrations of salts in irrigation water and nitrogen (N) fertilization. The plants were transplanted to 150 L lysimeters and under field conditions at the Science and Agri-food Technology Center of the Federal University of Campina Grande, in the municipality of Pombal -PB. The experiment was conducted in randomized block design in a 5 x 4 factorial scheme, with three replicates, and the treatments corresponded to five levels of electrical conductivity of irrigation water -ECw (0.3; 1.1; 1.9; 2.7 and 3.5 dS m -1 ) and four N doses (70, 100, 130 and 160% of the N dose recommended for the crop). The doses equivalent to 100% corresponded to 541.1 mg of N dm -3 of soil. Irrigation water salinity above 0.3 dS m -1 negatively affects the number of leaves, leaf area, stem diameter, dry phytomass of leaves, branches and shoots . A significant interaction between irrigation water salinity and N fertilization was observed only for the number of leaves and leaf area at 120 days after transplanting. N dose above 70% of the recommendation (378.7 mg N dm -3 soil) did not mitigate the deleterious effects caused by salt stress on plant growth.Morfofisiologia da goiabeira sob irrigação com águas salinas e adubação nitrogenada R E S U M OObjetivou-se, com esta pesquisa, avaliar o crescimento de plantas enxertadas de goiabeira cv. Paluma, submetidas a diferentes concentrações de sais na água de irrigação e doses de adubação nitrogenada, cujas plantas foram transplantadas em lisímetros de 150 L de capacidade e sob condições de campo do Centro de Ciências e Tecnologia Agroalimentar da Universidade Federal de Campina Grande, no município de Pombal -PB. Utilizou-se o delineamento experimental de blocos casualizados, em esquema fatorial 5 x 4, com três repetições, e duas plantas por lisímetro, sendo os tratamentos correspondentes a cinco níveis de condutividade elétrica da água de irrigação -CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m -1 ) e quatro doses de nitrogênio (70, 100, 130 e 160% de N, da dose recomendada para a cultura). A dose referente a 100% de N correspondeu a 541,1 mg de N dm -3 do solo. A salinidade da água de irrigação acima de 0,3 dS m -1 afeta negativamente o número de folhas, a área foliar, o diâmetro de caule e a fitomassa seca da parte aérea de plantas de goiabeira cv. Paluma. Houve interação significativa entre a salinidade da água de irrigação e adubação nitrogenada apenas para o número de folhas e área foliar aos 120 dias após o transplantio. A dose de N acima de 70% da recomendação (378,7 mg N dm -3 do solo) não mitigou os efeitos deletérios ocasionados pelo estresse salino sobre o crescimento das plantas.

Water salinity and nitrogen fertilization in the production and quality of guava fruits

“…The decrease in fruit production in guava plants (both in number and weight), due to the increase in water salinity, should also be related to the action of the osmotic component, besides the possibility of occurrence of ionic toxicity (especially Na + and Cl -), which hinders the entry of water into the cells (SANTOS et al, 2012), promoting negative interference in the processes of CO 2 assimilation, translocation of carbohydrates and the diversion of energy to other processes, such as: osmotic adjustment, synthesis of compatible solutes, repair of damage caused by salinity and maintenance of basic metabolic processes (LUCENA et al, 2012). Lima et al (2018) in a study with the cultivation of grafted West Indian cherry under conditions of saline stress, also verified a decrease in the production of fresh fruit mass due to the increase in levels of irrigation water salinity.…”

“…The increase in the effects are also related to the time of plant exposure to saline stress conditions, that causes intensification of osmotic effects and excessive accumulation of potentially toxic ions in the plant tissues (FLOWERS, 2004), causing decrease in growth and consequently the production of plants (MUNNS & TESTER, 2008). Lima et al (2018), while evaluating the production of the West Indian cherry, post grafting, as a function of irrigation with waters of different salinities (ECw of 0.8 and 3.8 dS m -1 ) also observed decrease in the total number of fruits as ECw increased from 0.8 to 3.8 dS m -1 . and equatorial fruit diameter -FED (E) of guava cv.…”

“…The values decreased from 68.69 to 44.16 g fruit -1 and from 70.27 to 54.57 g fruit -1 between plants subjected to 0.3 and 3.5 dS m -1 , causing losses of 36.63 and 22.33% in the first and second cycles, respectively. The effect of saline stress on the nutrient uptake reduce crop production initially by the osmotic effects, causing water deficiency, and later by the ionic effects, impairing the balance in the absorption of essential nutrients for plants (MUNNS & TESTER, 2008;BEZERRA et al, 2018). These interactions affecting nutrient availability, absorption and transport are highly complex independently of saline conditions, however, salinity adds an even higher level of complexity, which alters the activity of ions in solution and the processes of absorption, transport, assimilation and distribution (SILVA et al, 2011).…”

Salt stress and exogenous application of hydrogen peroxide on photosynthetic parameters of soursop

“…As a result, studies have been conducted using saline waters for cultivation in the Northeast region, for instance of sugar apple (Sá et al, 2015), citrus (Barbosa et al, 2017) and guava (Bezerra et al, 2018). Hence, it is extremely important to conduct research aiming to assess other fruit crops such as soursop, because studies involving the use of saline water in its cultivation are scarce.…”

Growth and quality of soursop (Annona muricata, L.) seedlings under saline stress and hydrogen peroxide (H2O2)

“…Plants irrigated with 3.5 dS m -1 water showed a reduction of 21.21% in RGRSD compared with those subjected to 0.7 dS m -1 , i.e., the diameter of plants under the lowest saline level grew 0.003 mm mm -1 per day more than that of plants cultivated at the highest saline level, from 85 to 145 DAS. Irrigation water salinity negatively affected plant growth, possibly due to the osmotic and specific effects of the ions, retarding cell expansion and division, causing negative consequences on the photosynthetic rate and compromising plant physiological and biochemical processes (Bezerra et al, 2018). Sena et al (2017), studied the guava crop under saline stress conditions (ECw from 0.3 to 3.5 dS m -1 ).…”