Clear Plastic Mulch Improved Seedling Emergence of Direct-seeded Pepper

Abstract

Pepper (Capsicum annuum L. `Piquillo de Lodosa') was seeded and then covered with clear plastic mulch, and various cultural practices to improve seedling emergence were compared. Planting dates (8, 12, and 25 Apr. 1991), seeding systems (raised bed vs. flat, 1991), and one or two rows per bed (1991 and 1992, respectively) were evaluated for their effects on stand establishment and yield. Plant stand was 60% when seed was under plastic mulch, compared to 0% when no mulch was used. Maximum plant stand was obtained 4 weeks after seeding in mulched soil. With plastic mulch, earlier (on or before 12 Apr.) season plantings were best because soil temperatures were so high (≥35C) later as to reduce plant stands. The risk of excessive high temperatures was greater when seeding was on a raised bed rather than flat ground; however, using plastic mulch, temperatures were higher, often resulting in acceptable plant stands regardless of bed arrangement. Higher yields were realized with raised beds compared to flat ground sowing. When two rows per bed were used, higher temperatures on the south side reduced emergence compared to the north side of the east–west-oriented beds. Direct seeding of pepper appears to be commercially acceptable in our Mediterranean conditions, provided seed is under plastic mulch and seeding is completed on or before 12 Apr.