At harvest the following data was collected using the methodology described:

Transcription

1 TITLE OF PROJECT: Processing standard sweet corn cultivar evaluations - Pillsbury NAME OF CONTRIBUTOR(S) AND THEIR AGENCY: J.W. Zandstra and R.C. Squire, University of Guelph, Ridgetown Campus, Ridgetown, Ontario, NOP 2CO. METHODS: Nine Pillsbury su sweet corn cultivars were seeded on 19 May, and 16 June, 2006 on a Brookston clay loam soil on the Ridgetown research farm. The corn was seeded at a population of 117,500 seeds/ (47,000 seeds/acre) and thinned to 58,750 plants/ha (23,500 plants/acre) when the corn was in the five leaf stage. Weeds were controlled with a preplant incorporated tank mix of Dual plus Aatrex 480. Weed escapes were controlled with a post-emergent application of Accent and oil. Further weed escapes were controlled with cultivation and hand hoeing. Nitrogen fertilizer was applied preplant at a rate of 110 kg/ha actual N. Phosphorous and potassium applications were based on soil analysis. Corn insects were controlled with sprays of Sevin, Matador, Pounce, and Decis. There were a total of 6 insecticide sprays applied. DATA COLLECTION: Four weeks after seeding, the number of plants per plot were counted to determine the percent plant stand, and ten plants were measured for extended leaf height. Disease ratings were completed just prior to harvest. Smut incidence was low, so the number of infected plants per plot (70 plants) are given. Date of 80% silking was determined daily by counting the cobs with silks emerged. A rough harvest date was determined to be 18 days after 80% silk, which was fine tuned by determining the moisture content with a CEM Model AVC 80 moisture/solids analyser. The target moisture was 68-72%. From this data the number of days to maturity and the corn heat units were determined. At harvest the following data was collected using the methodology described: a) height - average height of 5 plants measured to the tip of the tassel. b) height - average height of 5 plants measured to the base of the cob. c) Tillers - the number of plants per plot (70 plants) with tillers taller than 30 cm. e) Tip cover - mean of 5 cobs evaluated on a scale of 1-5 where: 1 = exposed 4 = 2.5 cm 2 = just covered 5 = greater than 5.0 cm 3 = up to 2.5 cm f) Shank - mean of 5 cobs rated on a scale of 1-5 where 1 = cm 4 = 7.5 to 10 cm 2 = 2.5 to 5.0 cm 5 = greater than 10 cm 3 = 5.0 to 7.5 cm g) weight (husk on) = average weight of 10 marketable cobs with the husk on. h) weight (husk off) = average weight of 10 marketable cobs with the husk off. 1

2 i) Fresh kernel weight = average fresh weight of cut kernels from 10 marketable cobs. j) Husking percentage = husk weight/cob weight (husks on) * 100 k) Processing recovery = kernel weight/marketable cob weight (husks on) * 100. l) Field recovery = processing recovery * % marketable cobs. m) Marketable yield - weight of cobs from the 2 centre rows which were greater than 5 cm diameter expressed as t/ha or T/ac n) Percent moisture EXPERIMENTAL DESIGN AND DATA ANALYSIS: The trials were established in a randomized complete block design with four replications. A single plot consisted of 4 rows, 8 m in length with 75 cm between the rows. Prior to harvest, a 7.0 m section of the centre 2 rows was marked and used for harvest in order to eliminate the effect of edge plants. Data was collected on only the centre 2 rows. The data was statistically analysed using analysis of variance for a randomized complete block design. A protected LSD was used to separate the treatments with significant differences. Means followed by the same letter do not differ significantly (P<0.05, Duncan s New MRT). Data is sorted by descending marketable yields. Trial Tables ing Date SWCN May 19 SWCN June 16 DISCUSSION: Growing conditions in the summer of 2006 were very good for sweet corn production. Warm weather with timely rains resulted in good quality and yields. Insect pressure at Ridgetown was managed well with timely insecticide sprays, which was made easier due to OMAFRA insect traps near the plots. Weed control was poorer than previous years due to the rains and our reluctance to use herbicides with the potential for carryover. Raccoon and skunk damage was not present due to the use of electric fences. 2

3 Table 1. stand, 4 week plant height, and maturity of standard processing sweet corn cultivars - Pillsbury early planting. University of Guelph, Ridgetown Campus, Percent Stand (cm) Days to Harvest Corn Heat Units C bc C cd C abc C abc C d C abc C ab C abc C a LSD C.V P-Value (0.05)

4 Table 2. and cob characteristics of standard processing sweet corn - Pillsbury early planting. University of Guelph, Ridgetown Campus, (m) (cm) Tillers per Plot (70 plants) Tip Cover (1-5) Shank (1-5) C ab 81 cd 0.1 bc 2.3 f 3.3 ab C ab 91 ab 0.2 a 2.8 def 2.6 b C b 86 bc 0.0 c 2.4 ef 2.9 b C d 63 e 0.1 c 3.6 bcd 3.2 ab C c 66 e 0.2 ab 2.9 c-f 2.5 b C cd 76 d 0.1 c 4.3 ab 4.1 a C a 94 a 0.1 c 4.5 a 2.9 b C c 64 e 0.1 abc 3.8 abc 2.8 b C cd 67 e 0.1 abc 3.2 cde 3.2 ab LSD C.V P-Value (0.05)

5 Table 3. and processing characteristics of standard processing sweet corn - Pillsbury early planting. University of Guelph, Ridgetown Campus, Husks On (g) Husks Off (g) Husking Percentage Fresh Kernel (g/cob) Processing Recovery (%) Field Recovery (%) C a 357 a 24.6 c a 47.4 a 45.3 a C abc 320 ab 24.8 c b 42.5 bc 40.8 ab C ab 337 a 25.6 c a 47.5 a 44.4 a C bcd 263 cd 34.2 a b-e 39.0 de 37.7 bc C cd 292 bc 25.0 c bc 44.8 ab 41.9 ab C cd 251 d 34.5 a cde 39.3 de 33.8 c C cd 281 cd 27.1 bc bcd 44.0 b 41.7 ab C bcd 260 cd 34.8 a de 36.9 e 34.5 c C d 247 d 30.6 ab e 40.1 cd 34.1 c LSD C.V P-Value (0.05)

6 Table 4. Yield parameters of standard processing sweet corn - Pillsbury early planting. University of Guelph, Ridgetown Campus, Yield Percent Percent t/ha t/ac Marketable Moisture Total Marketable Total Marketable Yield C a 23.5 a 10.9 a 10.5 a C ab 22.2 ab 10.3 ab 9.9 ab C abc 21.3 abc 10.2 abc 9.5 abc C de 19.5 de 9.0 de 8.7 de C cde 19.1 cde 9.1 cde 8.5 cde C bcd 18.8 bcd 9.6 bcd 8.4 bcd C de 18.1 cd 8.5 de 8.1 cd C ef 17.0 de 8.1 ef 7.6 de C f 14.1 e 7.4 f 6.3 e LSD C.V P-Value (0.05)

7 Table 5. stand, 4 week plant height, and maturity of standard processing sweet corn cultivars - Pillsbury late planting. University of Guelph, Ridgetown Campus, Percent Stand (cm) Days to Harvest Corn Heat Units C ab C c C b C ab C ab C b C ab C a C c LSD C.V P-Value (0.05) Table 6. and cob characteristics of standard processing sweet corn - Pillsbury 7

8 late planting. University of Guelph, Ridgetown Campus, (m) (cm) Tillers per Plot (70 plants) Tip Cover (1-5) Shank (1-5) C abc 76 abc bcd 2.8 abc C a 81 ab b 3.7 a C ab 85 a cde 2.0 c C ab 82 a a 2.6 bc C e 72 bcd bc 3.3 ab C de 64 de cde 2.4 bc C cde 61 e de 3.0 ab C bcd 68 cde e 2.3bc C 17 2 e 63 de de 2.6 bc LSD C.V P-Value (0.05)

9 Table 7. and processing characteristics of standard processing sweet corn - Pillsbury late planting. University of Guelph, Ridgetown Campus, Husks On (g) Husks Off (g) Husking Percentage Fresh Kernel (g/cob) Processing Recovery (%) Field Recovery (%) C a 457 a 18.8 c a 36.2 d 33.7 c C a 424 b 21.4 b bc 31.0 e 29.6 d C b 339 c 21.7 b ab 43.0 bc 41.5 b C bc 307 d 23.7 b b 45.7 ab 41.4 b C c 273 e 31.6 a bc 42.7 bc 40.5 b C de 242 fg 32.3 a cd 41.3 c 39.1 b C e 259 ef 23.9 b c 47.7 a 46.0 a C cd 259 ef 31.3 a c 41.7 c 37.6 b C e 223 g 32.0 a d 41.5 c 38.5 b LSD C.V P-Value (0.05)

10 Table 8. Yield parameters of standard processing sweet corn - Pillsbury late planting. University of Guelph, Ridgetown Campus, Yield Percent Percent t/ha t/ac Marketable Moisture Total Marketable Total Marketable Yield C a 23.2 a 11.2 a 10.4 a C b 22.3 a 10.4 b 9.9 a C bc 21.8 a 10.1 bc 9.7 a C c 19.3 b 9.5 d 8.6 b C d 18.1 bc 8.5 d 8.1 bc C de 17.0 cd 8.0 de 7.6 cd C de 16.7 cd 7.7 de 7.4 cd C de 16.5 cd 8.2 de 7.4 cd C e 15.6 d 7.5 e 7.0 d LSD C.V P-Value (0.05)