Effect of Type and Method of Fertilization on Marrows (Cucurbita pepo L.) Yield and Fruit Quality

Aims: The main aim of this study is to determine the influence of foliar and soil fertilization upon the nutritious value of fruit of marrows and to clarify the opportunity for using Blue tetrazolium chloride (BTC) as a reagent for determination of micro quantities of manganese in plant samples.

Study Design: The investigation was conducted in the period 2007–2009 in an open field condition with the marrows (Cucurbita pepo L.) cultivar Izobilna F1 on the experimental field of the Agricultural University of Plovdiv, Bulgaria.

Methodology: Treatments of the experiment: 1. Control - non fertilized; 2. Foliar fertilization with 0.3% Fitona; 3. Foliar fertilization with 0.3% Hortigrow; 4. Foliar fertilization with 0.3% Humustim; 5. Soil fertilization with N160P160K160; 6. Soil fertilization with N160P160K160 + 0.3% Fitona; 7. Soil fertilization with N160P160K160 + 0.3% Hortigrow; 8. Soil fertilization with N160P160K160 + 0.3% Humustim. Total carbohydrates, dry matter, content of nitrates and manganese were determined in the fruits of marrows. Materials were collected in the phase of mass fruit production.

Results: The results show that application of foliar fertilizers Fitona, Hortigrow and Humustim increased yields of marrows in preserved and improved product quality. The effect occurred more strongly when foliar fertilizers were applied on a background of soil fertilization. The BTC method can be successfully applied to the determination of manganese in plant samples.

Conclusion: The use of foliar fertilizers containing different macro- and micronutrients in the period of growing marrows influenced on the content of mn in their fruit. The highest content of mn in the fruits of marrows was found after combined soil and foliar fertilization with 0.3% hortigrow the decrease in yield induces a concentration in manganese in the fruit of marrows. The trend is more clearly expressed in the mixed application