Intercambio de gas y productividad de maracuyá amarillo irrigado bajo salinidad y fertilizado con potasio y biofertilizante

Abstract

. 2017. Gas exchange and productivity of yellow passion fruit irrigated with saline water and fertilized with potassium and biofertilizer. Cien. Inv. Agr. 44(2): 168-183. The salinity of irrigation water can affect the growth and development of most plants of commercial interest. Aiming to study these aspects in passion fruit culture, an experiment was performed to evaluate the effects of bovine biofertilizer and potassium fertilization on gas exchange and production of the passion fruit 'BRS Giant Yellow' irrigated with non-saline and saline water. The treatments were arranged in randomized blocks with sub-subdivided plots using the 2×(3×5) scheme, which refers to two levels of electrical conductivity of the irrigation water as the main plot (0.35 and 4.00 dS m -1 ) and the combination of three potassic fertilization practices (without fertilization, fertilized with conventional and slow release KCl) with five doses of bovine biofertilizer (0, 25, 50, 75 and 100% of dose of 15 L m -2 ) in the subplots, with three replicates and 12 plants per plot. The physiological variables and the productivity were evaluated in two harvests, and the data were submitted to statistical evaluation of samples repeated in time. The application of bovine biofertilizer and potassium in soil with a sandy texture irrigated with saline water did not inhibit the degenerative effect of the salts on the photosynthetic rates of the plants. The salinity of the irrigation water reduced stomatal conductance, transpiration and net photosynthesis of the plants, but in the second crop, the instantaneous water use efficiency was higher. Although the productivity decreased from the first to the second harvest, the biofertilizer associated with potassic fertilization increased the yield of the crop, which surpassed the average of Brazil, the Brazilian Northeast and the State of Paraiba, Brazil.

Saline Water, Pit Coating and Calcium Fertilization on Chlorophyll, Fluorescence, Gas Exchange and Production in Passion Fruit

“…**: significant at 1% probability As noted by Dias, Cavalcante, Nunes, Freire, and Nascimento (2012), an increase in the electrical conductivity of irrigation water of 0.5 to 1.5 dS m -1 reduced passion fruit yield by 19%, while at a salinity of 3.5 dS m -1 , yields were reduced by 40%. The decrease observed in this study (45%) with the use of water of 4.0 dS m -1 reflects the sensitivity of passion fruit to saline water (Ayers & Westcot, 1999), with implications in physiology (Freire et al, 2014;Nunes et al, 2017). Lateral pit coating, even with the potential to maintain soil moisture and dilute the effects of salts (Cavalcante et al, 2005), was not effective in mitigating stress because, most likely, the moist root environment favored the absorption of the soil solution and, consequently, of salts.…”

“…Reduced photosynthesis in passion fruit, caused by water salinity, has also been observed by Nunes et al (2017), in full bloom, and by Freire et al (2014), at the end of the productive phase. However, the moist root environment, caused by the coating pit (Cavalcante et al, 2005), intensified the decline in the assimilation of…”

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

“…The semi-arid region of the Brazilian Northeast is characterized by high evapotranspiration rates, irregular rainfall, poor soil drainage and the water sources usually have electrical conductivity above 1.5 dS m -1 , which can limit agricultural production, causing morphological, physiological and biochemical alterations in plants, compromising fruit development, production and quality (NEVES et al, 2009;FREIRE et al, 2014;NUNES et al, 2017). The effects of salts at high levels in the soil manifest through alterations in physical and chemical attributes, which reduce the osmotic potential of the soil solution, and through the direct action of specific ions on the mineral nutrition of the plants, culminating in yield loss (CAVALCANTE et al, 2009;.…”

Leaching of salts and production of sour passion fruit irrigated with low- and high-salinity water

“…In northeastern Brazil, the rise in soil salinity is related to high evaporation rates, rainfall irregularity, and inadequate management of fertilizers and irrigation and drainage, which contribute to a significant increase in salt-affected areas (Nunes et al, 2017;Lima et al, 2020a;Moura et al, 2020). However, in this region, the practice of irrigation is essential to increase crop yield.…”