Workshop on Towards an Ecologically Sound Fertilisation in Field Vegetable Production, Wageningen, Surinam, 11 - 14 Eylül 2000, ss.51-57
The present study was conducted to determine the response of greenhouse grown cucumber to nitrogen applied by fertigation or furrow irrigation. Cucumber cv Seyhan was treated with nitrogen at 0, 100, 200, and 300 ppm. In the drip-fertigation treatment (DF), the nitrogen solutions were applied twice a week and also a 200 ppm K, 40 ppm Mg and 2.5 ppm Fe containing solution was supplied to all replicates once a week. In the furrow irrigation treatment (FI), plants received the same amount of nitrogen and potassium as in the DF treatment. In these plots half of the total N and K were incorporated into the soil before transplanting and the rest was applied at the fruit setting stage. Drip fertigated plants gave a higher yield (78 ton/ha) when compared to furrow irrigated plants (72 ton/ha). However, early yield (7.8 ton/ha) was higher with furrow irrigation. Irrespective of the irrigation, 200 ppm nitrogen level produced the highest yield (89.3 ton/ha). Although there was a significant difference between irrigation treatments for total fruit number per plant, there was no significant effect on mean fruit weight. Nitrogen level had significant effects on both total fruit number and mean fruit weight. They both increased with increasing nitrogen level. While stem diameter was affected neither by irrigation nor by nitrogen treatment, root length was affected by irrigation treatment. The DF plants had the shorter roots. Irrigation treatments also significantly effected leaf composition, resulting in higher leaf N, P and K contents in drip-fertigated plants. Neither irrigation nor nitrogen level had significant effects on soil pH, EC and P content of the soil. However soil K was affected by both treatments. Drip-fertigated plots had higher soil K compared to furrow-irrigated plots and increasing nitrogen level also gave rise to an increase in soil K. The results of this study, conducted on a sandy loam soil, showed that cucumber can be grown successfully by applying 200 ppm N twice a week and 200 ppm K, 40 ppm Mg and 2.5 ppm Fe once a week via a drip irrigation system, beginning three weeks after transplanting and terminating one week before the last harvest. Phosphorus should be incorporated into the soil before transplanting.