Document Type : Research Paper
Abstract
Soaking of watermelon seed helps to germinate faster (especially in dry farming) and increases with the weeds. In this case seeds absorb considerable amount water and may also germinate. Because of some specifications of the seeds during germination, there should be a proper mechanism for seed metering and distribution. Four different types of mechanisms which were supposed to be useful in this regards were designed and compared in this research. Different mechanisms were planned on the basis of helping the seed to fall down through a pipe by water movement. On the other hand, using water can help the seed to hold more moisture and protect it against mechanical damages. Horizontal seed plates were used for all the mechanisms. Seed plates were provided in two types of internal holes and side holes which by a water injection (weight/pressure) and three speed levels of 1.5, 3 and 4.5 (km /hr) were tested for 50 cm space of hill sowing. Different mechanisms were tested and evaluated for planting of watermelon seeds. A factorial experiment in the form of complete randomized design was used with three replications. Percentage of hills with two or three or four seeds (ACP), performance index (PI), damage percentage (D) and volume of water (V) in each hill were determined in this experiment. Results showed that the type of seed plate, water injection, forward speed and interactions between injection method and speed on PI, V and ACP were significant. Interacted effect of injection method and speed was significant on PI while type of seed plates and speed had no significant effect on other parameters. Interaction effect of three mentioned parameters was only significant regarding the volume of water and seeds mechanical damages were found not to be significant in all the cases.
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