SILVA, F. A.; http://lattes.cnpq.br/7603029169428951; SILVA, Francisco Alves da.
Resumen:
The low annual rainfall and irregularity of seasons in semi-arid regions hamper
the development of rainfed agriculture, which leads to the need of sustainable irrigation systems.
Plants with little demand for water, such as the citrus ones, enhances the efficiency of
agriculture. The identification of genotypes with high tolerance to water stress becomes essential
to meet this demand. In this study, we investigated the growth, physiology, and adaptability to
water stress of pre-flowering citrus plants at different combinations of canopy/rootstocks under
different irrigation depths in the semi-arid region of Paraiba. The experiment was carried out
during 270 days, from August 2016 to April 2017, at the Experimental Farm of the Center for
Agrifood Science and Technology of the Federal University of Campina Grande, São Domingos,
Paraíba, Brazil. We applied a randomized block design, with eleven canopy/rootstock
combinations and two irrigation depths, each treatment had three replicates, totaling 66
experimental units. The following genotypes of rootstock were grafted with the „Tahiti‟ acid
lime: 1. Rangpur (LCR); 2. Common Sunki Mandarin (TSKC) x [LCR x Poncirus trifoliata TR]
– 01; 3. TSKC x (LCR x TR) – 018; 4. TSKC x (LCR x TR) – 020; 5. TSKC x (LCR x TR) –
029; 6. TSKC x Citrumelo Swingle CTSW – 022; 7. Florida Sunki Mandarin TSKFL x (LCR x
TR) – 038; 8. TSKFL x (LCR x TR) – 044; 9. TSKFL x (LCR x TR) – 049; 10. TSKFL x (TCR
x TR) – 062; and 11. TSKFL x (LCR x TR) – 069. These combinations were submitted to two
irrigation depths, 50 and 100% of the reference evapotranspiration (ETo). After 15 days from the
transplanting (DAT), we started to measure, bimonthly, the physiological variables and plant
growth during the pre-flowering period. The genotypes grafted on the 'Tahiti' acid lime tree can
be grown in the Paraíba semi-arid, even under low under irrigation mounth of 50% from the
daily reference evapotranspiration during prefloration stage, due to the maintenance of the
physiological activity of the plants and non-occurrence damage to the photosynthetic apparatus;
the evaluation of gas exchange allows to differentiate genotypes resistant and susceptible to
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water stress; hybrids from Florida Sunki mandarin (TSKFL), when grafted with the 'Tahiti' acid
lime tree, maintain lower water status and provide the canopy variety a greater growth, even
under a lower irrigation mounth and the combinations less sensitive to water deficit were
composed of Tahiti grafted with TSKFL x (LCR x TR) - 049, TSKFL x (LCR x TR) - 062,
TSKFL x (LCR x TR) - 69.