Emergence of `Genesis' Triploid Watermelon following Mechanical Scarification

Abstract

ADDITIONAL INDEX WORDS. Citrullus lanatus, seedless watermelon, seedlings, seedcoat adherence ABSTRACT. Production of triploid watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] transplants is hindered by poor, inconsistent emergence, and frequent seed coat adherence to cotyledons. Seed coat adherence leads to weakened and slow growing plants. High seed costs, coupled with stand establishment problems, discourages transplant producers from growing this crop. Improvement of triploid watermelon emergence will lessen financial risks to growers and transplant producers and will provide a more reliable production system. Mechanical scarification was evaluated as a means to overcome inconsistent emergence and seed coat adherence. Seeds of 'Genesis' triploid watermelon were placed in a cylinder with 100 g of very coarse sand (1.0 to 2.0 mm diameter) and rotated at 60 rpm for 0, 6, 12, 24, and 48 hours in a series of experiments. Number of emerged seed was recorded daily, to obtain emergence dynamics. No significant differences were observed in seed coat adherence among treatments. The longest duration of scarification However, enhanced emergence as compared to the control in three of four experiments. These data support earlier suggestions that a thick or hard seed coat is a factor contributing to poor germination and emergence of triploid watermelons.

Treatment with Hydrogen Peroxide and Seedcoat Removal or Clipping Improve Germination of `Genesis' Triploid Watermelon

“…Splitting the seedcoat of tetraploid watermelons laterally improved germination (Nerson et al, 1985). Recently, Duval and NeSmith (1999) confirmed that mechanical scarification improved and increased the consistency of emergence of 'Genesis' triploid watermelon; however, emergence was still not at an acceptable level. Alternative mechanical pretreatments, with or without chemical treatment, of triploid watermelon seed could improve germination and stand establishment.…”

Excess Moisture and Seedcoat Nicking Influence Germination of Triploid Watermelon

“…Genesis was improved when seeds were clipped, with the greatest improvement when the seedcoat was completely removed. Duval and NeSmith (1999) also reported that scarified seed germinated more uniformly than did nonscarified seeds. Nerson et al (1985) found that lateral splitting of seeds did not improve germination in diploids, but increased in tetraploids.…”

Stratification, Scarification and Application of Phytohormones Promote Dormancy Breaking and Germination of Pelleted Scots Pine (Pinus sylvestris L.) Seeds

“…Seed scarification, another germination promoting method used for pelleted pine seeds, involves intentional damage to the impervious seed coat, enabling more rapid and even water uptake and gas exchange to the embryo [5]. Germination is also controlled by plant growth regulators such as auxins and gibberellins.…”