Influence of rootstock vigor on scion growth and fruit yield in citrus under saline conditions

Abstract:

Soil salinity is one of the defining constraints for citrus cultivation in coastal and semi-arid tracts worldwide, and rootstock selection remains the most practical tool available to growers for managing its effects on tree performance. This research evaluated six commercially available rootstocks for their influence on scion growth, fruit yield, and quality of Mosambi sweet orange (Citrus sinensis Osbeck cv. Mosambi) under saline irrigation conditions at Kerala Agricultural University, Thrissur, during 2020-2023. Trees budded onto Rough Lemon produced the tallest canopy (284.6 cm), highest canopy volume (8.72 m³), and greatest fruit yield (48.2 kg/tree), while Cleopatra Mandarin gave the lowest yield at 28.3 kg/tree. Leaf sodium concentration was lowest in Rough Lemon (0.31%) and Volkamer Lemon (0.34%), with corresponding K⁺/Na⁺ ratios of 2.84 and 2.67. Juice quality parameters including TSS and vitamin C content followed the same ranking pattern. Vigorous rootstocks that restricted sodium translocation to the scion maintained better photosynthetic efficiency and higher yields under salinity stress of 4.2 dS/m irrigation water.