Influence of Pollination Technique on Greenhouse Tomato Production

Abstract

An experiment was carried out to study the effects of four pollination techniques; Bumblebees (Bombus terrerstris L.), plant growth bioregulator (PGB) (Parachlorophenoxy acetic acid), hand vibration, and control (natural pollination) on tomato (Lycopersicon esculentum Mill) production in greenhouses. Bumblebees showed no problem in visiting flowers at a temperature range of 17-42°C during the day and 2-14°C at night. Bumblebee pollinated plants produced a yield per plant which was significantly higher than plants treated with PGB, vibration and the control, respectively. Fruit set of tomato flowers over 10 clusters was 99.1, 96.7, 76.7, and 65.7% for bumblebee treatment, PGB application, vibration and the control, respectively. In the bumblebee pollinated flowers, the quality of fruits was superior. The fruits were hard, with more seeds, and had a high specific gravity and better appearance. The average fruit weight was 100.3, 80.5, 84.1, and 70.6 g for the bumblebee, PGB, vibration and the control, respectively. The PGB treatment produced bigger sized but puffy fruits (108.4 ml). While fruit size in the vibration treatment was the highest (126.8 ml), followed by the bumblebee and the control which were 99.3 and 98.5 ml, respectively. Fruit specific gravity in the bumblebee treatment was significantly higher than other treatments, with no significant differences between the PGB and the vibration treatments. The least dense fruits were in the control treatment. Regarding the firmness of fruits, the bumblebee treatment gave the hardest fruits, while the PGB and the vibration treatments were intermediate and the control was the least. Average seed number per fruit was 177.0, 86.5, 61.8, and 89.8 for bumblebee, vibration, PGB and the control, respectively.