VEGETABLE CULTIVAR AND CULTURAL TRIALS

2006

PREPARED BY: D. WATERER

J. BANTLE W. HRYCAN

FUNDED BY:

AGRICULTURE DEVELOPMENT FUND

Department of Plant Sciences University of Saskatchewan, 51 Campus Drive Saskatoon, Saskatchewan, Canada, S7N 5A8

Telephone: (306) 966-5855 Fax: (306) 966-5015 E-mail: doug.waterer@usask.ca jackie.bantle@usask.ca Website: http://www.usask.ca/agriculture/plantsci/vegetable

77

Mulching Options for Sweet Corn

Germination and early growth of sweet corn can be enhanced by the soil warming provided byplastic mulches. Clear plastic provides the greatest degree of soil warming but weed growth canbe a problem under clear mulch. Wavelength selective (IRT) mulches provide almost as muchsoil warming as the clear plastic while also providing a high degree of weed control. Plantingcorn through any type of plastic mulch requires specialized machinery. A lower cost option usedby some growers is to create a shallow trench, and then to seed the corn into the trench usingstandard seeding equipment. Clear plastic mulch is then laid over the seeded rows. The trenchprovides sufficient space for the corn seedlings to develop for a week or two within thegreenhouse-like environment provided by the clear mulch. The plastic must be removed beforetemperatures in the trench become excessive.

This trial evaluated the performance of sweet corn on various mulching treatments.

Materials/Methods - The trial was conducted in 2006 at the University of SaskatchewanHorticulture Field Research Facility in Saskatoon. The heavy clay soil at the test site wasprepared by rotovating one week prior to laying the mulch and seeding the crop. The treatmentstested were;

1) Crop mechanically seeded using a push type small plot seeder. No mulch used2) Crop mechanically seed into a trench (ca 30cm wide * 10cm deep) cut by hand. Clear plastic mulch (1.1 mil) then laid over the trench 3) Crop hand seeded through clear plastic mulch (1.1 mil)4) Crop hand seeded through IRT mulch (1.1 mil)

The cultivars tested were ‘Navajo’ (earlymaturing Se type) and ‘Fantastic’ (latermaturing Sh2 type). For each mulchtreatment, each cultivar was seeded in twin4m long rows spaced 20cm apart, with 15cmbetween plants within a row. The trial wasseeded on May 23. Drip irrigation tape wasused to supply water as needed under thevarious mulch treatments.

Results - The crop emerged more quickly inthe trench and clear mulch treatments thanwhen the IRT mulch or no mulch was used. The clear plastic was removed from the trenchtreatment on June 14. By that time the plantshad grown to about 20cm in length but wereheld close to ground by the clear plasticmulch. Although temperatures were in themid-20's on several days prior to removal ofthe clear covering, there were no indicationsof high temperature stress to the corn plants inthe trench. However, growth of the plants inthe trench treatment appeared to slow afterremoval of the plastic covering. Considerable populations of commongroundsel and portulaca developed in alltreatments except the IRT .

Figure 1. Treatment #2. The clear mulch was sliced downthe centre of each trench to make room for the growingplants.

78

The mulch treatments had no effect on the rate at which ‘Navajo’ matured, but both of thestandard mulch treatments accelerated maturity of the later maturing ‘Fantastic’ (Table 1). Theclear produced the highest yields (cob number and weight), followed closely by the trenchtreatment for cob weight and the IRT treatment for cob number (Table 1). The no-mulchtreatment produced the lowest yields of both cultivars. Cob quality and flavor were not affectedby the mulch treatments.

Conclusion - This trial again demonstrated the potential benefits that can be obtained from usingmulches during production of sweet corn. Although it had no clear effect on the rate of cropdevelopment, clear mulch appeared most beneficial in terms of enhanced yields. This mayreflect a better stand or healthier cob development on the clear mulch. The trench + cleartreatment produced yields that were equivalent to the clear mulch, but without the added labor ormachinery cost associated with planting through the plastic.

Table 1. Influence of various mulching options on development and yields of sweet cornin 2006

Clear IRT Clear + Trench No Mulch

Time to 50% harvest

Navajo Aug. 18 Aug 18 Aug 18 Aug 18

Fantastic Aug 18 Aug 18 Sept 6 Aug 25

Yields (cobs/m row)

Navajo 26 24 20 13

Fantastic 30 20 22 15

Yields (kg/m row)

Navajo 9.5 9.0 9.0 5.1

Fantastic 9.1 7.0 9.6 6.0