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  • Author or Editor: G. H. Snyder x
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Abstract

Nitrogen fertilization of ‘Tifgreen’ bermudagrass (Cynodon sp.) through an irrigation system (fertigation) was examined in a replicated factorial design study on Pompano fine sand soil. Nitrogen was applied at 2 rates: 9.77 and 4.89 g/m2/month, by 3 methods: 1) fertigation daily with urea, 2) fertigation weekly with urea, and 3) dry fertilization bi-monthly with ureaformaldehyde. All plots received daily irrigation. Turf appearance and clipping yields were significantly better at the higher N rate, but were generally unaffected by the 3 methods of application. Fertigation appeared to be a practical and convenient method of making frequent light applications of N.

Open Access
Authors: and

Abstract

Fertilization of field grown roses, R. hybrida cv. Christian Dior, in south Florida with fertilizer packets and tablets was compared with a proven plastic mulch method of reducing fertilizer losses. Flower yields for the 3 methods were similar during the first 9 months of the study. In the second year, comparatively low yields were obtained with tablets, and the highest yields with the plastic mulch. The packets gave intermediate results, with 5 packets providing acceptable yields. Twenty-one months after placement, the tablets contained 56, 56, and less than 0.1% of their original N, P, and K, respectively. Nitrogen release at this time appeared comparatively slow. Considerable variation in nutrient content existed among packets 21 months after placement, with an average of 17, 33, and 38% of the original N, P, and K, respectively, being found. The packets still appeared to be releasing fertilizer at that time.

Open Access

Diagnosis and Recommendation Integrated System (DRIS) norms were derived for crisphead lettuce (Lactuca sativa L.) from field fertility experiments conducted over the past 20 years on mineral and organic soils in Florida. Preliminary testing indicates that DRIS diagnoses generally agree with diagnoses using the sufficiency range approach, with the advantage of predicting the degree of nutrient limitation. DRIS also appeared to correctly predict a response to K where sufficiency ranges currently used did not. Overall, DRIS appears to be a useful adjunct to the sufficiency range approach currently used to diagnose nutritional deficiencies in crisphead lettuce.

Free access

Abstract

‘Christian Dior’ and ‘Happiness’ roses on Rosa fortuniana stock, fertilized with 3 rates each of N, P, and K factorially combined, were grown for 3 years at Ft. Pierce, Florida. All fertilizer was applied at the beginning of the experiment under plastic mulch just before the bushes were planted. About 2300 lb./A of N on ‘Christian Dior’ and 2100 lb. on ‘Happiness’ produced the greatest number of flowers. Leaf N at 18 months was also maximized by 2100 lb. N. Nitrogen levels maximizing stem lengths were slightly lower. The independent effects of P were minor and low levels best, perhaps because residual soil P at start of the study was adequate. Flower production decreased with K fertilization beyond low rates, whereas stem lengths increased to a max at about 1700 lb./A. At times, various nutrient interactions were noted. ‘Christian Dior’ consistently yielded more flowers than ‘Happiness’. With minor exceptions, ‘Happiness’ had longer stems.

Open Access

Annual pruning was compared with nonpruning for 8 years and to two biennial pruning treatments for 4 years in a mature full-canopied `Ashley' walnut (Juglans regia L.) orchard. Light penetration and nut distribution through the canopy was improved by pruning. Nut size and percent edible kernel was consistently lower in nonpruned trees than in trees pruned annually or biennially. Yield from annually pruned trees was not significantly different from that of the nonpruned trees because of the removal of fruitful spurs. Yield of biennially pruned trees was similar to annually pruned or nonpruned trees in the year following pruning, but yield was usually greater during years in which trees were not pruned.

Free access

Evaluations of 21 entries (commercial cultivars and breeders' experimental hybrids) of triploid watermelon (Citrullus lanatus) were conducted in northern and central Mississippi during 2000 and 2001. The purpose of this research was to identify high-yielding, medium-sized triploid cultivars with good horticultural characteristics and consumer qualities for commercial production in Mississippi. Most entries were similar to `Tri-X 313' and had red flesh, oval shape, and a mottle stripe rind pattern. SXW 5052, `Triple Crown,' `Crimson Trio,' `SeedWay 4502,' and `Millionaire' produced the highest total marketable yields; however, SXW 5052 is no longer available. `Crimson Trio' produced slightly smaller-sized melons compared to other entries and `SeedWay 4502' produced melons with relatively low soluble solids concentration. Based on total marketable yield, average size of melons, soluble solids concentration, and lack of undesirable characteristics such as hollowheart, black and colored seed, and rind necrosis, `Triple Crown,' `Millionaire,' `Cooperstown,' `Summer Sweet 5244,' and `Crimson Trio' can be recommended as mid- to late-maturing cultivars for commercial production in Mississippi. Based on early marketable yield, and using the same criteria listed above, `Tri-X 313' and `Tri-X Carousel' can be recommended as early-maturing cultivars for commercial production in Mississippi. `Tri-X 313' exhibited only one undesirable trait, producing a relatively high number of black and colored seeds. `Diamond' had high early and total yields, as well as high soluble solids concentration, but it should be recommended only on a trial basis to determine its potential susceptibility to hollowheart.

Full access

Abstract

Sprigs of ‘Tifgreen’ bermudagrass (Cynodon dactylon L.) and seeds of ‘Argentine’ bahiagrass (Paspalum notatum Flügge) were planted in 10 different media consisting of combinations of 5 waste products spread 10 cm deep on black polyethylene plastic sheets. Experiments were conducted in 1976 and 1977 utilizing the following media components: composted heat-treated sewage sludge (SS); composted sugarcane processing byproducts (SB); composted municipal wood chips (WC); sandy muck soil (SM); and water treatment sludge (WS). In 51 days the bahiagrass had formed sod which was comparable in tear strength to commercially available sod. Excellent rooting of the experimental sod occurred in 7 days; commercially cut sod had rooted much less as determined by root weights and the force required to uproot the sod. Bermudagrass sprigs did not develop sufficient coverage in 51 days to yield acceptable sod but did so by 65 days. The sod also rooted more quickly than commercial bermudagrass sod. Both grasses rooted better than commercial sod because root apical meristems were not cut off during harvesting. The media which resulted in the best and worst combinations of evaluations were different for each grass species. Excellent quality bahiagrass sod was produced in media containing SS, and the least acceptable in WC+SS and WS+SB media. A system now exists to make use of a number of urban waste products for sod production, while at the same time shortening production time.

Open Access

Abstract

At any stage of the ripeness of ‘Bartlett’ pear fruits, subsequent ripening was inhibited if the fruits were warmed to 40°C. Both production of, and sensitivity to, ethylene (C2H4) were almost totally suppressed. Even at 30°C, C2H4 production was greatly reduced in both early- and late-season fruit. Unless treated with C2H4, early-season fruit failed to ripen at 30°C although late-season fruit ripened spontaneously, presumably because of high internal concentrations of the gas. In both cases ripening was characterized by a watery breakdown of the floral end of the fruit.

At 40° and 50°C, respiratory rates declined progressively unless the fruits were treated with C2H4, whereupon a stimulation occurred although ripening was unaffected.

Gas exchange was not limiting at temperatures as high as 50°C, even when the ends of the fruits were sealed with paraffin wax. Maximum modification of the internal atmosphere of any individual fruit resulted in 15.7% O2 and 7.2% CO2. Ripening of fruits held at 20°C in that atmosphere was delayed about 3 days, presumably via mild competitive CO2 inhibition of C2H4 action.

We conclude that failure of ‘Bartlett’ pears to ripen at 40°C results from lack of C2H4 production and loss of sensitivity to the gas. The mechanisms are unknown.

Open Access