| Twenty-five
mango orchards in Nuzuvid (Andhra Pradesh), Srinivaspur (Karnataka), and
Krishnagiri (Tamil Nadu), India, were evaluated for leaf and soil
nutrient status from 1994 to 1997. Banganapally was grown in 5 orchards,
Alphonso in 5 orchards, and Totapuri in 15 orchards. The trees in
Karnataka and Andhra Pradesh were 30- to 40-year-old, whereas those in
Tamil Nadu were 20-year-old. The high-yielding trees had higher leaf N
content than the low-yielding trees. The orchards in Andhra Pradesh had
the highest leaf and soil nutrient (N, P, and K) levels. The available
soil N significantly varied between high-yielding and low-yielding
trees only before the flowering stage. The available soil P and K did
not significantly vary with the growth stage. The high-yielding
orchards recorded higher soil N and P, and lower soil K than the
low-yielding orchards. Fruit yield was positively correlated with leaf
N before and during flowering, with leaf P after harvest, and with leaf
K before flowering. Fruit yield was positively correlated with the
available soil N at the pea-size fruit stage, and with available soil K
before and during flowering, and at the pea-size fruit stage. Leaf N
accounted for 40.17 and 29.50% of yield variation before and during
flowering, respectively. In terms of soil nutrient status at 1.0 m
radial distance from the trunk, the greatest yield variation was
attributed to soil K before flowering, whereas the lowest yield
variation was attributed to soil N at the pea-size fruit stage. Leaf and
soil P contents were not significantly correlated with fruit yield. Leaf
nutrient status had greater effects on fruit yield than soil nutrient
status. |
