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  • Author or Editor: M. E. Miller x
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Rotting muskmelon fruits commonly are associated with commercial fields that are affected by the root rot/vine decline disease syndrome found in southern Texas. Four isolates of Fusarium solani previously shown to be either weakly pathogenic or nonpathogenic to muskmelon seedlings caused extensive rot on mechanically wounded muskmelon fruits. Two of these isolates caused more extensive fruit rot than either F. solani (Mart.) Sacc. f. sp. cucurbitae W.C. Snyder & H.N. Hans. or F. oxysporum Schlechtend.:Fr. melonis (Leach & Currence) W.C. Snyder & H.N. Hans., causal agents of fusarium crown and foot rot of cucurbits and fusarium wilt of muskmelon, respectively. In other tests, root-dip inoculation of seedlings showed that all muskmelon cultigens included in this study and the breeding line MR-1 were susceptible to a California and an Arkansas strain of F. s. f. sp. cucurbitae race 1.

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The effect of fruit temperature and fruit maturity on the development of blossom end clearing (BEC) in Florida grapefruit (Citrus paradisi Macf. vars. Ruby Red and Marsh) was investigated. Field and storage temperature studies indicated that development of BEC was directly associated with temperature; BEC increased when fruit temperature rose above 21 °C. Cooling fruit prior to packingline operations reduced BEC significantly. Older fruit were more susceptible to BEC than were younger fruit.

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Abstract

Known populations (0, 269, 538, and 1075/ha) of pine voles (Microtus pinetorum LeConte) were maintained in wire mesh-enclosed blocks of ‘McIntosh’/M26 apple trees (Malus domestica Borkh.) for 2 years. There was little effect of the voles the 1st year, but the 2nd year the highest population was associated with the death of one tree; severe reductions in growth, yield, and fruit size; and a dramatic reduction in the value of the crop. Neither the low nor the medium population affected yield significantly, but there was a reduction in vegetative growth in the medium population plot in the 2nd year.

Open Access

Abstract

In vitro propagation of ‘Nemaguard’ peach rootstock [Prunus persica (L.) Batsch] was obtained on a modified Murashige and Skoog (MS) medium using shoot tips as primary explants. Shoot proliferation was induced on MS medium supplemented with 50 mg/liter L-ascorbic acid, 20 ml/liter Staba vitamin mixture, 2.0 mg/liter 6-benzylamino purine (BA), and 0.1 mg/liter naphthaleneacetic acid (NAA). Rooting was induced by subculturing plantlets on a similar medium without the Staba vitamins and without BA. When the Staba vitamin mixture was present, rooting was reduced; the inhibition resulted from the presence of riboflavin.

Open Access

A disease of muskmelon (Cucumis melo L.) characterized by a vine decline and a cortical root rot was first observed in the Lower Rio Grande Valley of Texas in 1986. In 1990, isolations from diseased plants collected from four commercial production fields yielded the fungus Monosporascus cannonballus. Pathogenicity tests with eight isolates confirmed Koch's postulates; however, there were differences in aggressiveness observed among isolates. M. cannonballus is an ascomycete fungus that typically produces only one (rarely two), round, jet-black ascospore per ascus. There is no known asexual stage. Temperature optimum of one isolate was 35 C. The optimum pH for growth was 6-7, but it grew well up to pH 9. M. cannonballus was first reported on muskmelon in 1970 from Arizona and recently was found in Japan under glass house culture. The presence of this fungus in Texas marks only the third report of this species worldwide, although a similar species (M. eutypoides) is the cause of a collapse of melon plants in Israel.

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Thirty-seven species within Cucurbitaceae representing the genera Citrullus, Cucumis, Cucurbita, Lagenaria, and Luffa were evaluated for disease reaction to an Acremonium cucurbitacearum A. Alfaro-Garcia, W. Gams, and Garcia-Jimenez, isolate (TX 941022) from the Lower Rio Grande Valley of Texas. After 28 days in the greenhouse, seedling disease ratings were made on the hypocotyl, stem-root junction, primary root, and secondary roots. An additional disease measure was derived by averaging the four root disease ratings to establish a disease severity index (DSI). Vine and root dry weight were poor measures of plant damage caused by A. cucurbitacearum. According to the DSI, all species within Cucurbita, Lagenaria, Luffa, and three Cucumis sativus L. cultigens were rated as highly resistant to A. cucurbitacearum. Cucumis melo L. and Citrullus lanatus (Thunb.) Matsum. & Nakai cultigens were the only cucurbits receiving DSI ratings of moderately resistant to susceptible.

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Abstract

‘Royal Blackeye’ southernpea [Vigna unguiculata (L.) Walp.] was released in 1985 by the Louisiana Agricultural Experiment Station. This southernpea was developed primarily for local fresh market use. The purple hulls and blackeye seed coat pattern combination is unique among released cultivars.

Open Access

Our objective was to determine the feasibility of using waste tire rubber and fiber from the processing of waste tires as a root-zone medium for greenhouse crops. Two cultivars of zonal geraniums, `Danielle' and `Kim' were grown in media containing three grind sizes of rubber (10, 6, and 2.4 mm) and fiber from the fabric belting processed from waste tires in three proportions (1 rubber: 1 peat moss, 1 rubber: 1 vermiculite: 2 peat moss, and 2 rubber: 1 vermiculite: 1 peat moss, by volume). Two control media were also included: 1 vermiculite: 1 peat moss and 1 rock wool: 1 peat moss, by volume. The largest plants were grown in the 1 vermiculite: 1 peat moss medium, whereas the smallest plants were grown in the media containing the rubber grinds 2.4 mm and 6 mm making up 50% of the media. The media 1 rubber: 1 vermiculite: 2 peatmoss, regardless of grind or fiber, produced plants equal to the 1 rock wool: 1 peatmoss medium. All plants grown in media containing rubber by products had elevated levels of Zn and Cu in the foliage, but was greatest in media containing 50% rubber. Foliar P: Zn ratio was less for plants grown in media where rubber was 50% of the volume. The P: Zn ratio also was lower in plants grown in media with smaller grind sizes of rubber. Geranium plants can be successfully grown in media containing up to 25% rubber waste products without reducing plant quality.

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Abstract

The development of a high yielding, pink root-resistant [Pyrenochaeta terrestris (Hansen) Gorenz, Walker, and Larson], mild, sweet, shortday onion (Allium cepa L.) with improved shipping quality was the objective for the onion breeding program in the Texas Agricultural Experiment Station. ‘Texas Grano 1015Y’ (TG1015Y) is a very mild and sweet cultivar with those quality characteristics.

Open Access