Influence of increased salinity on yield, fruit quality and growth of hydroponic grown tomatoes

Abstract EN

Tomato (lycopersicon escuientum Mill.

cv.

Special Pack) was grown and maintained at salinities 2.4, 7.6, 12.8, 18.0 dS nr1 in solution batch culture.

The six week harvest period was evenly divided into early, mid and late pe¬riods.

Results showed significant reduction in seasonal [marketable and to¬tal 1 yield and seasonal [marketable and totall fruit number at increased salin-ity levels.

Non-marketable fruits consisted of those of Blossom End Rot in early harvesting period, cracked in mid period and small or less than 50g (58%) and cracked (42%) in the late period.

No incidence of sunscald was observed.

Average marketable fruit weight was significantly decreased (at early harvest) with increased salinity more than 7.6 dS and decreased (p<0.05) at 18.0 dS m"1 for the mid season harvested fruits.

Increased salini¬ty improved fruit quality by decreasing pH, increasing %TSS (total soluble solids) at 12.8 and 18.0 dS nr1 and %TA (titratable acidity) at 12.8 and 18.0 dS m_1.

Fruit’s Na+ and Cl" content showed a marked increase from 0.0 to 70.3 and 210 to 295 fieq.g'1 dry weight, for Na+ and Cl", respectively as sa¬linity increased from 2.4 to 18.0 dS nr1.

Although the number of seeds/fruit decreased from 114 [2.4 dS m_I] to 85 [18.0 dS m-11}, increased hydrophonic salinity did not affect fruit specific gravity, number of locules/fruit, fruit firmness and lycopen content.

On the other hand, vegetative growth re¬sponded negatively to increased salinity at 12.8 and 18.0 dS m-1.