This trial is the fourth in a series of winter cauliflower variety trials dating from 1978. Previous trials have established that best quality is obtained with varieties that mature in April or May in average years. Very early varieties are less hardy, often fail to produce sufficiently large frames to support large heads, and may suffer frost damage to the curd. Several varieties maturing in late May and June have good yield potential but poor curd quality. This trial focused on mid-maturity varieties to determine those with the best combination of yield and quality.
Methods
Thirteen varieties were seeded in 2-inch pots in a glasshouse on July 27, 1982. Sixteen plants of each variety were transplanted on 3 x 1.5 foot spacing on September 3. The plot area received a broadcast, incorporated application of 700 pounds/acre of 10-20-10, 50 pounds/acre Epsom salts, 10 pounds/acre Solubor, 20 pounds/acre of a soluble trace element mix, 0.75 pounds/acre trifuralin, and 2.0 pounds/acre fonofos. Diazinon was applied as a drench (2.0 pounds of 50 WP/25 gallons) to the base of the plants in early October. On February 16, 1983, 35 pounds N/acre as ammonium sulfate, 40 pounds N/acre as calcium nitrate, and 100 pounds/acre of 0-45-0 was sidedressed on the soil surface. Ammonium nitrate at 75 pounds N/acre was sidedressed on March 14. Two varieties headed in January and were harvested at weekly intervals from January 7 through January 20, 1983. All other varieties were harvested twice weekly between March 11 and April 26.
Results and Discussion
The 1982-83 winter was unusually mild. Plants made good growth but curd tended to form before plants achieved maximum size. There was no significant winterkill. Peak harvests averaged one to two weeks earlier than average and three weeks earlier than in 1982.
The varieties which headed in January (RS 1831 and Cervina) were not true overwinter types. Plant size was small and the curd was usually freeze-damaged. The earliest of the true overwinter types was Tolteca. Harvest was very concentrated and the percentage of grade #1 heads (no defects) was low because of yellow, fuzzy curds and green stems.
Of the remaining eight varieties, highest gross yields were obtained with Arminda, Armado May, and Maya; highest yield of #1 heads was obtained with Markanta; the highest percentage of #1 heads was obtained with Markanta, Armado April, and Inca (Table 1). In all trials to date, this was by far the best performance of the variety Markanta. This variety often has leaves in the curd but this was not a problem in 1983. Averaged over four trials, the most consistent varieties have been Armado April (early), Inca (early), Maya (late) and Arminda (late). Curd quality of some varieties was below average because of slug damage and a higher than normal incidence of diseases. Notes on causes of poor curd quality are found in Table 2.
Table 1. Yield and source of overwinter cauliflower varieties, 1983 Harvest range Mean wt.of Gross yield Yield of #1 %#1 Variety First Peak Last #1 heads(lb) (T/A) heads(T/A) heads Source RS 1831 1/07 1/07 1/20 1.0 5.4 0.6 13 1Z Cervina 1/07 1/07 1/20 1.0 4.9 0.6 14 1 Tolteca 3/11 3/11 3/14 2.2 6.2 3.0 46 2 Marchpast 3/21 3/24 4/01 1.5 7.9 3.7 53 3 Armado April 3/21 3/28 4/04 1.4 6.7 4.5 69 3 Inca 3/24 3/28 4/04 1.6 6.3 4.9 64 2 Armado May 4/01 4/08 4/19 2.0 7.8 4.5 47 2 Markanta 4/01 4/15 4/15 1.9 7.9 6.5 71 3 Aprilex 4/01 4/15 4/19 1.9 8.3 4.3 47 3 Armado Clio 4/12 4/19 4/22 1.2 5.6 3.6 60 1 Mirado 4/12 4/22 4/22 1.1 4.6 2.1 40 1 Arminda 4/15 4/22 4/22 2.6 12.9 4.9 38 1 Maya 4/19 4/19 4/26 1.8 8.3 3.9 44 2 Z1 = Royal Sluis, 2 = Bejo Zaden, 3 = Elsoms. Table 2. Comments on overwinter cauliflower varieties, 1983 Variety Comments Aprilex Low to medium vigor, upright leaves, good cover; but half of heads had yellow curd. Armado April Medium vigor, upright leaves, good cover. Twenty-five percent of heads had yellow curd. Armado Clio Medium vigor, fairly good cover. One-third of heads with yellow curd. Armado May Variable plant growth: some tall and upright, others low and spreading. Some yellow curd, some bracts in curd. Arminda Medium to high vigor, upright leaves. Majority of heads yellow and/or brown spotting (disease or slug damage). Cervina Small plants, one pound heads, matured during severe weather. Inca Low growing, lots of leaves, but only fair cover, tends to be open. Some bracts in curd. Marchpast Sprawling, medium to high vigor, fairly good cover. Yellow curd on nearly half of heads. Markanta Low vigor, sprawling but good cover. Some yellow curd and Some leaves in curd. Maya Medium-low vigor, good cover, one-third of heads with yellow curd. Some leaves in curd. Mirado Tall, upright, sparse stovepipe. Conical curds and majority of plants had yellow curd. RS 1831 Small plants, one pound heads, matured during severe weather. Tolteca Medium vigor. Fuzzy, yellow curd. Green stems.