Salt balance in substrate and growth of 'Tahiti' acid lime grafted onto Sunki mandarin hybrids under salinity stress

The salinity of water or soil may cause disturbance in growth and production of crops, particularly in citrus, which is considered sensitive to this abiotic factor. For this reason, it is important to choose tolerant materials of rootstocks and scion-rootstock combinations, and to evaluate the salt balance in soils. The effect of saline water irrigation on plant formation of 'Tahiti' acid lime ['C. latifolia' (Yu. Tanaka) Tanaka] seedlings grafted onto six rootstock genotypes of hybrid Sunki mandarin ['C. sunki' (Hayata) hort. ex Tanaka] was evaluated. Plants were evaluated for salt tolerance and the mineral balance in the plant cultivation substrate 300 days after seeding. The study consisted of five levels of saline water (0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1) that were used for the irrigation of six different rootstock genotypes; on each the 'Tahiti' acid lime was grafted as scion. The rootstocks were five hybrids of 'Sunki' mandarin and one 'Santa Cruz Rangpur' lime plant, as control. The design consisted of randomized blocks with three replications and four plants per plot. The water salinity level treatments were applied starting 60 days after seeding (DAS) and continued until 300 DAS. The chemical contents of the soil and the total plant dry matter for the scion-rootstock combinations were determined. The increase in electrical conductivity of the irrigation water resulted in the accumulation of minerals in the substrate. The common hybrid of 'Sunki' mandarin (TSKC) (Rangpur lime 'Poncirus trifoliata') - 040 is the most tolerant to the salinity of irrigation water. The TSKC x 'Troyer' citrange - 012 hybrid is the most sensitive. Water with an electrical conductivity greater than 2.4 dS m-1 is not recommended for use with 'Tahiti' acid lime grafted onto rootstocks.