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  • Author or Editor: C. A. Jaworski x
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Abstract

The effect of daminozide as a plant growth retardant to protect potato seedlings from metribuzin injury was investigated. Plants of 6 potato cultivars were sprayed 42 days after planting with daminozide at 0, 2500, 5000 ppm concentrations. Four days after daminozide treatment, metribuzin at 0.56 kg/ha was applied. Within 3 days after metribuzin treatment, differences between potato cultivars in metribuzin tolerance was observed. Seven days after metribuzin application 25.2% to 42% of the control plants had more than 20% necrosis, and of this percentage, 0% to 13.9% plants were dead. Only 2.3% to 10.7% of the plants exhibited more than 20% metribuzin injury when pretreated with 2500 ppm daminozide. Potato plants treated with 5000 ppm daminozide were not damaged. The soluble solids of stem sap increased with daminozide rate. Protection from metribuzin injury in potato was associated with the increase in soluble solids in daminozide treated plants. Chemical name used: butanedioic acid mono (2, 2-dimethylhydrazide) (daminozide).

Open Access

Abstract

The Fourth Annual Tomato Transplant Research Workshop was held at the Georgia Coastal Plain Experiment Station, Tifton, Georgia, on December 1, 1966. The 52 participants came from 11 states and the District of Columbia, and represented various areas of research, production (canning industry and transplant growers), extension, regulatory, and administration. The research participants included horticulturists, plant physiologists, geneticists, plant pathologists, nematologists, soil scientists, and agricultural engineers. The main topics discussed during the workshop were disease and nematode control, and management practices needed to facilitate mechanization of the transplant harvest.

Open Access

Caphea glutinosa is a herbaceous, low-growing annual, bearing numerous attractive purple flowers and has potential as an ornamental and as a ground cover. Plants exhibit winter hardiness in USDA plant hardiness zone 8. Tissue culture techniques were developed to obtain large numbers of uniform plants. Whole leaf explants (approximately 1.0 cm2) callused profusely in MS (Murashige and Skoog, 1962) medium containing 84 mM sucrose, 1% (w/v) Difco Bacto agar and 8.8 μM N6benzyladenine. Shoot formation from calli was observed in the same medium 4 weeks after explanting. Detached shoots were rooted (100%) in half strength MS medium and rooted shoots were transferred to Promix® in the greenhouse 2 weeks after rooting. Tissue cultured plants flowered after 60 days in the greenhouse and no phenotypic differences were observed in floral or foliar characteristics.

Free access

Abstract

Polyethylene mulched bed widths (28, 56, 84 and 112 cm) with methyl bromide-chloropicrin gas mixture (67-33%, 280 kg/ha) soil fumigation were evaluated in 2 tests for soil pest control and production of tomato (Lycopersicon esculentum Mill.). In 2 other tests, methyl bromide-chloropicrin rates of 0, 70, 140, 210 and 280 kg/ha applied under a 112-cm wide mulched bed were evaluated. Populations of root-knot nematodes, parasitic soil fungi, and root-gall indices decreased with increases in mulched bed width. All fumigation rates resulted in decreased populations of root-knot larvae, Fusarium spp., Pythium spp., Rhizoctonia solani and root-gall indices compared with non-fumigated plots. In greenhouse tests, tomato seedlings emerged and survived best in potted soil from mulched plots with the widest bed and those treated with the highest rate of fumigant. Marketable tomato yields increased linearly with increased bed width in 1 test whereas yields were similar among treatments in the other tests.

Open Access

Abstract

Bacterial wilt or brown rot caused by Pseudomonas solanaceamm E.F. Sm. is a major limiting factor of potato (Solanum tuberosum L.) production in the warm, humid regions of the world, including the coastal plain region of southeastern United States (5).

Open Access

The functional male sterile (fms) eggplant (Solanum melohgena L.) germplasm UGA 1-MS was crossed with two cultivars, `UGA 18 White' and `Florida Market' with normal anthers to derive F1, F2, and BC populations. Functional male sterility (fms) was governed by a single recessive allele. The gene symbol fms is proposed for this male sterile characteristic. The functional male sterility gene was linked to purple fruit color at the X/x locus. Our observations also revealed that the purple or violet color ware not only on the fruit peel, but also on the anthers and leaf buds if the eggplant fruit was purple or violet. In the transmission of parents and progenies of the cross of UGA 1-MS × `UGA 18 White', the purple line on the anther and leaf bud purple color ware tightly associated with fruit purple color. Thus, it is assumed that the allele X controls not only purple fruit, but also the expression of the purple line on the anther and purple leaf bud.

Free access

Abstract

The performance of H-1350, H-1409, C-17, ‘Fireball’, and ‘Roma’ tomato transplants that received different clipping treatments at Tifton, Georgia, were evaluated at Lafayette, Indiana, and the Plant Industry Station, Beltsville, Maryland. Field-grown transplants were either left unclipped, control clipped (1 inch of growth was removed but the terminal bud was left intact), or moderately clipped (the terminal bud and flower cluster were removed).

Moderately clipped transplants of all 5 cultivars performed as well as non-clipped plants, but usable fruit yield was reduced by control clipping. At New Brunswick, New Jersey, fruit yields of the C-17 transplants moderately clipped at various intervals were reduced. In view of the other 2 tests and other recently published reports, moderate clipping appeared to have little effect on fruit yields in northern production areas.

Open Access

Abstract

Six general-purpose fumigants applied by different methods were evaluated for control of the fungal-nematode complex on onion (Allium cepa L.) for transplant production. Most soil treatments improved plant vigor, size, uniformity, and yield, and these positive responses were correlated with reduced populations of soil-borne fungi and nematodes. Growth response and control of pathogens varied with the fumigant used and the method of application. Populations of Pythium spp. and Fusarium spp. were reduced with methyl bromide, methyl bromide-chloropicrin mixture, chloropicrin, DD-MENCS (Vorlex), metham (748 liters/ha, drenched) and Bunema (drenched). Metham (748 liters/ha, drenched or drenched and incorporated) controlled Rhizoctonia solani Kuehn. Complete control of root-knot nematodes was obtained with methyl bromide and methyl bromide-chloropicrin mixture and nearly complete control with chloropicrin and DD-MENCS.

Open Access

Abstract

Field studies were conducted in 1973 and 1974 to determine the effects of various reflective film mulches, vegetal barriers of millet (Pennisetum americanum (L.) K. Schum), and soil- and foliar-applied pesticides on yields and control of the watermelon virus complex (WMV), insects, nematodes, and soil-borne pathogens affecting yellow summer squash (Cucurbita pepo var melopepo L. Alefi, ‘Dixie’). All film mulches used (aluminum; white and blue plastic; brown paper) significantly reduced WMV in both fruits and plants. The millet barrier caused a significant reduction in WMV infected plants. In 1974, the systemic insecticide, carbofuran (Furadan) and/or sprays of mineral oil, significantly reduced WMV in non-mulched plots. Brown paper mulch significantly increased infestation of pickleworms, Diaphania nitidalis (Stoll) and all mulches significantly reduced infestations of serpentine leafminers, Liriomyza munda Frick. Leafminers were also controlled with carbofuran. Film mulches had no significant effect on populations of plant-parasitic nematodes and plant-pathogenic fungi. Both groups of pests were controlled with DD-MENCS (a mixture of 1,3-dichloropropene, 1,3-dichloropropane, methylisothiocyanate), but not with carbofuran or sodium azide. Film mulch increased squash yield 70 to 610% over the unmulched control. Plants in non-fumigated plots covered with aluminum and white plastic mulches produced significantly greater yields than plants in plots covered with blue plastic and brown paper mulches. Soil pesticides significantly increased yields over the non-fumigated control, and, averaged across main plots, DD-MENCS = DD-MENCS + carbofuran > carbofuran + sodium azide > sodium azide = nontreated check. The effects of film mulch were greatest in the non-fumigated check. Conversely, the effects of soil fumigation were negligible under film mulch and one could be substituted for the other.

Open Access

Abstract

Potato (Solanum tuberosum L.), the most important dicotyledonous food crop in the world, is grown mostly under temperate climatic conditions and is usually planted vegetatively with tubers (often called “seed” tubers) (12). Use of seed tubers for potato production has many advantages, including ease of planting, vigorous plant growth, uniform tubers, and high tuber yields (27). However, with increased interest in production of potatoes in warm regions, use of seed tubers often becomes costly and has disadvantages (1, 2, 23, 27, 30). Some of the disadvantages of seed tubers in warm or developing regions of the world are: there is a lack of seed tuber certification programs; imported seed tubers are expensive; seed tubers often are contaminated with plant pathogens and other pests; and available potato cultivars often are not adapted to warm regions (2, 18, 19). Consequently, during the past decade, research efforts on adopting true potato seed (TPS) instead of seed tubers for potato production were initiated in many areas of the world (5, 8, 16, 17, 20).

Open Access