Effects of Localised Irrigation and Fertigation on Vegetative and Reproductive Growth of 'Merlot'

Grapevines in Albania have been cultivated until recently on dry soils, due to their tolerance to drought. There is no confirmed experience in the country on the localised irrigation of grapevine and even less on fertigation. The scope of this research was to optimise the irrigation of cv. Merlot through fertigation in gravel soils. The study was conducted from 2007-2009 on Merlot grafted on Kober 5BB, on the 6th year, pruned dopio Gyo, with average of 18-22 buds, in the estuary of Mat river, where soils suffer from the absence of moisture during the vegetation as well as quick leaching of minerals. The first treatment consisted of 6 irrigations with 2 fertigations, starting from the fruiting stage, with duration of 12 hours and delivering 4 litres/hour, supplying 48 litres per plant and wetting of soil to a depth of 70-80 cm. First fertilisation was combined with first irrigation using 25 kg/ha crystalline NPK 20 x 20 x 20 + 4 microelements. The second fertilisation was combined with the third irrigation, using 25 kg/ha crystalline fertiliser N15P0K46 + 7 microelements, during the slowing of the growth rate of the shoot and achieving the characteristic size of the fruit. In the second treatment, the number of irrigations was reduced to 4 to create a light stress for the plant starting from the swelling of the fruit. The third treatment was the control. Ten plants per treatment were randomly selected. Irrigation and fertigation has remarkably improved both vegetative growth and production of the first year as well as the differentiation for the next year. Treatments have increased production as well as quality indices like must and sugar content.