Organic production of greenhouse tomatoes utilizing the bag system and soluble organic fertilizers

M. M. Peet, J. M. Rippy, P. V. Nelson and G. L. Catignani

Abstract
Two soluble commercial organic mixes and an ‘in-house’ organic blend, were compared to conventional fertilizer. Fertilizers were applied using drip irrigation to greenhouse tomatoes growing in bags filled with peat/perlite.

Plant development rates were similar among treatments, but by the end of the experiment, vigor varied widely. All three organic fertilizers tested resulted in significantly lower yields than conventional fertilizers.

The ‘in-house blend’, which most closely resembled conventional fertilizer N-P-K, had comparable vigor to conventionally grown plants and good pH and CEC characteristics, but the nitrogen source (bloodmeal) was difficult to keep in solution. Lower yields in the blend compared to the conventional fertilizer may have been a result of initial emitter clogging and low N levels. Substrate pH levels were below optimal in all treatments, although in our previous study utilizing vermicompost, pH levels were above optimal. This demonstrates the difficulty of predicting pH in organically fertilized container-grown plants.

Although some of the differences between fertilization treatments in fruit lycopene and carotene were significant, no consistent differences between organic and conventional treatments were observed


Source
Acta Horticulturea (2004) 659: 707-719


Posted April 2010