Seeds of `Champion' collard (Brassica oleracea L. var. acephala) were hydrated in water or a fluid-drilling gel (N-gel, hydroxyethyl cellulose) for 1 or 2 days at 20C (50 seeds/ml) before they were fluid-drilled into peat-lite in a greenhouse. Time to 50% seedling emergence from these seeds was more than 2 days earlier than from dry-sown untreated seeds, although emergence synchrony and percentage were unaffected. A second greenhouse study revealed more rapid seedling emergence from hydrated seeds that then were fluid-drilled than from dry-sown untreated seeds even when the delivery gel contained up to 25 g 9N-19.8P-12.5K/liter. Increasing fertilizer from 5 to 25 g·liter-1 led to increased shoot fresh weight 6 weeks after planting. When sown on two dates into field plots, hydrated seeds (1 day in either water or gel at 20C, 50 seeds/ml) that were fluid-drilled in 1.5% (w/v) N-gel containing 5 or 15 g 9N-19.8P-12.5K/liter yielded 42% greater final shoot fresh weights than untreated seeds sown dry.
J.M Kemble, J. Brown, and E. Simonne
The effect of various mulch colors (black, yellow, red, blue, white, and aluminum) on growth and development of `Vates' collards was evaluated in Fall 1996 at the E.V. Smith Research Center in Shorter, Ala. Black polyethylene mulch was installed onto raised, fumigated beds, then sprayed with a 1: 2 (v/v) mixture of exterior oil-based enamel paint to paint thinner with one of the five mulch colors listed. Five-week-old plants were transplanted into beds. Beginning two weeks after transplanting and continuing every other week thereafter, heads were harvested to determine head fresh weight and dry weight. Hourly soil temperatures at 10 cm soil depth were recorded and growing degree days (GDDs) with a base temperature of 4.4 °C were calculated. At two weeks after transplanting, average head fresh and dry weight were highest for the aluminum-colored treatment with head fresh (24.7 and 12.3 g, respectively) and dry weights (2.7 and 1.3 g, respectively) twice that of the yellow treatment (P ≤ 0.05). By four weeks after transplanting and up through the final harvest, marketable yield and average head fresh weights did not differ among the treatments (17,900 kg/ha, 1.4 kg per head, respectively). The red and black mulch treatments accumulated more GDDs than the other treatments, but total marketable yields did not differ among any treatments.
Jon R. Johnson
`Vates' is more susceptible to tipburn than `Blue Max' or `Heavi Crop' when grown under high temperature conditions. Nutrient solution culture studies were conducted to determine the influence of cultivar and Ca level in the nutrient solution on Ca uptake and distribution in the plant and to determine the physiological basis for differences in cultivar susceptibility to tipburn. Ca levels in the nutrient solution were 1 and 4,5 mM. Studies were conducted in the greenhouse at 32C during the day and 21C at night. Collard plants were 3 weeks old when the study was initiated. Cultivar and Ca level had no influence on Ca uptake during the first two weeks of the study. Ca uptake by `Blue Max' was greater than by `Vates' or `Heavi Crop' during the 3rd, 4th and 5th weeks of the study. Ca uptake for `Blue Max' was 73 ppm/week whereas for `Vates' and `Heavi Crop' it was 55 and 46 ppm/week, respectively during the 5th week of the study. Increasing the Ca level increased the Ca content of young leaves more for `Blue Max' than for `Vates' or `Heavi Crop'. Ca content of the petiole and stem was higher for `Blue Max' than for `Vates' or `Heavi Crop'. The influence of cultivar and nutrient solution Ca level on uptake and distribution of other nutrients will be discussed.
Mark W. Farnham
Collard (Brassica oleracea L. var. acephala) is an important vegetable the southeastern U. S. There are few (about 10) commercial cultivars, half being open-pollinating (OP) lines, the remainder more recent F1 hybrids. There is a potential untapped B. oleracea germplasm pool in the form of collard landraces perpetuated by southeastern gardeners and farmers. To determine the amount of genetic variation among cultivars and also whether landraces represent unique genotypes, ten cultivars and eight lines or landraces were evaluated using RAPD analysis. Decamer primers were used to amplify total genomic DNA and to differentiate collard lines and other B. oleracea crop cultivars. Additionally, individuals of an OP collard cultivar and a land-race were analyzed to evaluate intra-line variation. Virtually all primers detected polymorphic bands among lines although some identified considerably more variants. Intra-line analysis indicated that OP lines are genetically broad-based populations. Many unique RAPD markers were identified in landraces indicating that the lines represent unique genotypes and that further line collection is warranted.
K.D. Elsey and M.W. Farnham
The relative resistance of 18 cultivars of Brassica oleracea L. to attack by the sweetpotato whitefly [Bemisia tabaci (Gennadius)] was studied in screen cage (spring), field (autumn), and laboratory tests. The B. oleracea entries consisted of six types, including 16 green and two red cultivars. Cabbage (Capitata Group) and broccoli (Boytrytis Group) were less infested than other crops in a screen cage test, with kale, collard (Acephala Group), and brussels sprouts (Germmiter Group) experiencing relatively high and kohlrabi (Gongtlodes Group) intermediate infestations. Relative ranking of crops was similar in an autumn field study, with the exception of brussels sprouts, which had an intermediate level of infestation. Differences in numbers of whiteflies among cultivars within crops were negligible or inconsistent, except that red cultivars of brussels sprouts (`Rubine') and cabbage (`Red Acre') were much less infested than green cultivars. In a laboratory test, differences of whitefly oviposition and nymphal survival and development were small, indicating that nonpreference factors, rather than antibiosis, are the best explanations for differences in the numbers of whiteflies among the B. oleracea cultivars that were tested,
Timothy Coolong, Derek M. Law, John C. Snyder, Brent Rowell, and Mark A. Williams
chemopreventive properties ( Liang and Yuan, 2012 ). Consumption of kale and collard greens, which are rich in carotenoids, has been shown to increase macular pigment optic density in humans, which has been associated with improved eye health ( Kopsell et al
Lavesta C. Hand, Kayla M. Eason, Taylor M. Randell, Timothy L. Grey, John S. Richburg, Timothy W. Coolong, and A. Stanley Culpepper
Cole crop [broccoli, cabbage ( Brassica oleracea var. oleracea L.), and cauliflower ( Brassica oleracea var. botrytis L.)] and leafy green [collards and kale ( Brassica oleracea var. sabellica L.)] production in the United States
Jinrong Liu, W. Roland Leatherwood, and Neil S. Mattson
conditions. Plug seedlings of ‘Vates’ collards, ‘Nagoya Mix’ flowering kale, ‘Buttercrunch’ lettuce, ‘Sweet Banana’ pepper, and ‘Sweet 100’ tomato were obtained from a commercial producer. The lettuce and flowering kale were from 288-cell plug flats, whereas
Emillie M. Skinner, Juan Carlos Díaz-Pérez, Sharad C. Phatak, Harry H. Schomberg, and William Vencill
sativum L.), bell pepper ‘California Wonder’ ( Capsicum annuum L.), rye ‘Wrens Abruzzi’ ( Secale cereale L.), collard ‘Georgia Southern’ ( Brassica oleracea L.), cowpea ‘Colossus’ ( Vigna unguiculata L.), crimson clover ‘Dixie Reseeding’ ( Trifolium
C. Stevens, V. A. Khan, J. Y. Lu, A. Y. Tang, and A. E. Hiltbold
Partial steam and chemical sterilization of soil rich in organic matter increased the soil nutrients, little information exists with regard to the effect of soil solarization (SS) in this regard. A study was established to determine the effects of SS in combination with wheat residue and subsequent crop residue on increased growth response (IGR) of cole crops and soil fertility for two years. SS for 90 days increased K+, P, Ca++ and Mg++ 3 times more within five months after SS. The SS effect released higher levels of total N in the soil. However, increase levels of N was lower than that required for maximum IGR of collard. The IGR of cole crops without fertilizers was higher in SS plots as compared to bare soil. The IGR of collard was evident almost two years after SS.