|R.L. Hassell, T.L. Phillips, R.J. Dufault
There is a need to refine the standard commercial fertigation recommendations for muskmelon production to avoid confusion and excessive fertilizer applications.
To achieve this objective, fertigation applications, lower and higher than the standard commercial practice, were applied to Athena and PXC 221 cultivars.
Yield and melon size data were collected over a five week harvest period from 2002 to 2004 . Fertilizer treatments (28, 98, 166, 234 and 303 kg/ha N and K) were applied as fertigation beginning at transplanting to final harvest.
Pre-plant fertilizer application was broadcasted and incorporated in all plots at the rate of 28 kg/ha of actual N, P2O5, and K2O. In 2002, all fertilizer treatments significantly affected total and medium size melon numbers over the pre-plant control fertilizer treatment, but small and large size melons were unaffected by fertility and/or cultivar treatments.
In 2003, there was no difference in total and medium numbers between the 1x and 2x rates, but yield of these grades decreased with the 3x rate, and then inexplicably increased with the 4x similar to the 2x rate.
In 2004, only large and total numbers were affected by fertility treatment with a similar response with 1x and 2x rates but significantly lower than the 3x and 4x rates.
In 2002, during the first week of harvest, the number of medium size melons increased significantly up to the 2x fertility rates without any further increase with the 3x rate.
In 2003, medium size yield were equivalent between the 1x and 4x rates; and in 2004, the 2x rate produced more medium sized melons than the 4x rate.
In 2004, the 3x and 4x rates increased yield of large size melons in contrast to the 1x and 2x rates, but this was not reproduced in 2002 or 2003. Yield analyses did not verify that higher nitrogen and potassium tissue levels guaranteed higher fruit yields since using the standard 2x rate produced optimal yields in all years and fertilization at greater rates was unnecessary.
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