FERTIGATION IMPROVES FRUIT YIELD AND QUALITY OF PAPAYA

To assess the influence of fertigation on nutrient use and yield improvement in papaya, investigations were carried out in papaya cv. Co.7 during 2006-2008 at Horticultural College and Research Institute, Coimbatore. Nitrogen and potassium were fed through drip as urea and muriate of potash while phosphorous was applied through soil as single super phosphate. The treatments include 100% recommended dose of N and K 2 O through drip (T 1 ), 75% recommended dose of N and K 2 O through drip (T 2 ), 50% recommended dose of N and K 2 O through drip (T 3 ) and soil application of recommended dose of fertilisers (50 g N:50 g P 2 O 5 :50 g K 2 O per plant) at bimonthly interval starting from 3 rd month after planting (MAP). Application of 100% recommended dose of N and K 2 O (50 g N and 50 g K 2 O) through drip irrigation (T 1 ) resulted in flowering at the shortest height (96.32 cm). Plant height, stem girth and number of leaves were also found significantly higher in T 1 . Leaf N and K showed significant changes while P exhibited no variations among the treatments. Treatment, T 1 resulted in more number of fruits, fruit weight, TSS and low fruit cavity index. The increase in number of fruits and fruit weight is attributed for higher fruit yield per tree (73.97 kg) and the resultant total fruit yield per hectare (184.9 tonnes) with high B:C ratio (1:1.97) in plants treated with 100% recommended dose of N and K 2 O (50 g N and 50 g K 2 O) through drip irrigation, in addition to soil application of 50 g P 2 O 5 . It is concluded that fertigation of papaya cv. Co.7 with 100% recommended dose of N and K 2 O through drip (50 g N at 6.25 g/plant/week and 50 g K 2 O at 6.25 g/plant/week for a two months period), in addition to soil application of 50 g P 2 O 5 in bimonthly intervals resulted in maximum fruit yield. The physiological as well as biochemical changes in plants due to fertigation are also discussed in this paper.