Variation of Thermal Time, Phyllochron and Plastochron in Passion Fruit Plants With Irrigation Depth and Hydrogel

Abstract

The passion fruit demands water for its growth and production. Water management is relevant in regions characterized by low rainfall indices, such as semi-arid regions. In this direction, the use of hydrogel in the soil allows the water that is supplied through irrigation to be better utilized by the plants, reducing leach losses. The objective of this experiment was to evaluate the influence of hydrogel in soil cultivated with passion fruit and irrigated to various water depths on the thermal time of the phenological stages, phyllochron and plastochron of the plants. Treatments were distributed in randomized blocks in a 2 × 5 factorial arrangement, referring to the soil without and with hydrogel and raising the irrigation depth from 60% to 70%, 80%, 90% and 100% of crop evapotranspiration in four replications. The thermal requirements of the phenological phases and of the whole plant cycle, phyllochron of the main stem and the productive branches, and plastochron were evaluated. Increasing the irrigation depth from 60% to 100% reduced the total thermal time values from 3,811.8 to 2,401.3 °C day and from 3,707.8 to 2,628.7 °C day in the soil without and with hydrogel, respectively. The thermal time of the phenological phases and the phyllochron of the main stem and productive branches of the passion fruit were stimulated by an increase in irrigation depth.

Hydrogel Improved Growth and Productive Performance of Mango Trees under Semi-Arid Condition

“…The present result is confirmed by the previous work of Kaplan [ 23 ], who found that the application of hydrogel at a moderate concentration gave maximum growth parameters using a level of 500 g∙plant −1 apple ‘Gala Must’ variety. These results concur with those of Awad et al [ 24 ] in the apple seedling and those of Cavalcante et al [ 25 ] in passion fruit. In addition, by increasing the ratio of hydrogel in the substrate’s culture, Hüttermann et al [ 26 ], Akhter et al [ 27 ], and Chirino et al [ 28 ] found increases in shoot height.…”

Physiological Aspects of Yellow Passion Fruit With Use of Hydrogel and Mulching

“…The transplanting of yellow passion fruit seedlings was done on 09/13/2016 when the seedlings had four pairs of fully expanded leaves and height between 23 and 25 cm. The system used to support the plants was a espalier type, with a height of 2.3 m, consisting of a 12 smooth wire installed on top of the stakes (CAVALCANTE et al, 2018b).…”

“…is also negatively affected under water deficit, as reported by Souza et al (2018), who found that reduction in stomatal conductance caused a negative effect on plant growth and biomass accumulation. This makes yellow passion fruit dependent, under these conditions, on irrigation in different phenological stages (CAVALCANTE et al, 2018b).…”