Vigorous Vine Research Articles

Reaction of Grape Rootstocks to Ring NematodeMesocriconema xenoplax

The reaction of grape rootstocks to the ring nematode <i>Mesocriconema xenoplax</i> was studied in glasshouse experiments and in a vineyard trial. Growth of one Oregon population of <i>M. xenoplax</i> differed among 20 rootstock and self-rooted cultivars grown in the glasshouse for eight months. The reproductive factor, Rf (final nematode density divided by initial nematode density), was ≤0.5 for 420A Mgt rootstock and ≤2.4 for 101-14 Mgt and 110R rootstocks; Rf values ≤1 indicate high nematode resistance. Other rootstocks had Rf values between 6.9 and 52.5. Root dry weights of all varieties except 420A Mgt were reduced by <i>M. xenoplax</i>. In another glasshouse experiment, 420A Mgt and 101-14 Mgt were found to be resistant to one Washington State and four Oregon populations of <i>M. xenoplax</i>, although both were moderately susceptible to a California population. A root-stock trial was planted in 1997 in a vineyard infested with <i>M. xenoplax</i>. After six and seven years, population densities of <i>M. xenoplax</i> were lowest in vines on 420A Mgt (≤0.08 g⁻¹ soil) and 101-14 Mgt (≤0.24 g⁻¹ soil) rootstocks. Population densities on other rootstocks ranged from 1.25 to 4.57 g⁻¹ soil. 420A Mgt produced good vine vigor and yield and showed the highest degree of <i>M. xenoplax</i> resistance. Rootstock 101-14 Mgt, which is widely used in Oregon, was also resistant but produced only average vigor and yield. Other common Oregon rootstocks, Riparia Gloire, 3309C, and self-rooted Pinot noir, were highly susceptible to <i>M. xenoplax</i> and were among the least vigorous vines.

Squash Bug Control By Basal Stem Treatments, Rocky Ford, Co 1995

Abstract Trials were established at the Arkansas Valley Research Center in Rocky Ford, CO with plantings made 13 June. Plots consisted of single rows, 20-ft in length, at a 60-inch in-row spacing. Alfalfa mulch treatments were applied around the base of plants on 11 July, in an 18 inch band through the plots. All other treatments were first applied 18 July, at which time first oviposition was observed. The reflective collar treatments consisted of a square of aluminized cloth (AluminetR), approximately 1 ft2, placed around the base of the plants. Diatomaceous earth (Organic Plus Crawling Insect Killer), Adios, and Sevimol treatments were all directed at the base of the plant, with repeat applications on 25 July (diatomaceous earth) and 1 Aug (diatomaceous earth, Adios, Sevimol). Evaluations were made 12 September and consisted of a 6 point rating of squash bug injury to vines (0 = plant death; 5 = highly vigorous vines w/o injury).

Substantial Leaf Shedding—A Consistent Phenomenon among High-yielding Sweetpotato Cultivars

Four high-yielding sweetpotato [Ipomoea batatas (L.) Lam.] cultivars displayed substantial leaf shedding, under typical field production conditions, that was not due to pathological or herbivory causes. Losses ranged from ≈ 45% to 60% of the total leaves formed by the normal harvest date during 2 years. There was a strong positive correlation between leaf shedding and the number of vines (r2 = 0.80) and nodes (r2 = 0.89) per plant. Likewise, positive correlations were found between leaf shedding and total dry weight (r2 = 0.67), root fresh weight (r2 = 0.65), root dry weight (r2 = 0.60), and vine dry weight (r2 = 0.68). Distinct differences were found among cultivars in dry-matter allocation within the plant. `Jewel' allocated a lower percentage of dry matter into vines and a higher percentage into storage roots. Estimated leaf dry matter losses due to leaf shedding ranged from 1.2 to 2.6 t·ha-1. High leaf losses appear to be closely related to vigorous vine growth and subsequent shading of older leaves but did not have a negative impact on storage root yield in the cultivars tested.

LEAF LOSS EFFECTS ON GROWTH PARAMETERS OF FOUR SWEETPOTATO CULTIVARS

Under typical field production conditions, four high-yielding sweetpotato cultivars (Centennial, Jewel, Regal and Resisto) were found to lose substantial amounts of leaves due to natural senescense rather than pathological or herbivory causes. Leaf loss by the normal harvest date ranged from 46 to 63% of the total leaves formed in 1991 and 48 to 59% in 1992. There was a strong positive correlation between leaves lost and the number of vines (r2 = 0.80) and nodes (r2 = 0.89) per plant. Positive correlations were also found between leaf loss and total dry weight of the plant (r2 = 0.67). root fresh weight (r2 = 0.65). root dry weight (r2 = 0.60), and vine dry weight (r2 = 0.68). Distinct differences were found among cultivars in dry matter allocation within the plant. Of the cultivars tested, 'Jewel' allotted a lower percentage of dry matter into vines and a greater percentage into storage roots. Estimated leaf dry matter losses due to leaf shedding ranged from 1.2 to 2.6 MT·ha-1. Amount of leaf loss appeared to be closely related to vigorous vine growth and subsequent shading of older leaves, though leaf loss did not have a negative impact on storage root yield in the cultivars tested.

RESPONSE OF REPEATED 2,4-D SPRAYS ON THE NODE DIAMETER, INTERNODE LENGTH AND CARBOHYDRATES IN THE CANES AND COLD HARDINESS OF CONCORD GRAPE BUDS

Field grown high and low vigor Vitis labruscana cv, Concord grapevines were sprayed with 2,4-D amine in concentrations of 0, 2.5, 10 and 25 ppmw at 1st leaf; 1st and 3rd leaf; 1st, 3rd and 5th leaf and 1st, 3rd, 5th and 7th leaf stages of vine growth for two consecutive years. Cane and bud samples were collected for determining node diameter, internode length, carbohydrates in the canes, and T50 of buds. Data on yield and vegetable growth were also collected. There were significant differences among treatments in the node diameter and cold hardiness of buds (T50) both in high and low vigor vines. Repeated applications of 2,4-D reduced the cane diameter significantly but the carbohydrates in the canes were not affected. When 2,4-D symptoms were severe in July, yields were reduced by as much as 85%, but there was slight or no reduction in yield when symptoms were not severe.

Russet Nugget: A fresh market and processing potato cultivar with resistance to common scab

Russet Nugget is an oblong, smooth, high yielding potato with fresh market and processing qualities. It emerges quickly, produces an erect, large, vigorous vine with a profusion of white flowers, and is late maturing. Russet Nugget is very resistant to common scab, and moderately resistant to leafroll net necrosis,Vertcillium wilt, and early blight (tuber and foliage). In the San Luis Valley of Colorado, yield of Russet Nugget is comparable to Russet Burbank, with a significantly greater percentage of U.S. No. 1 tubers. In Texas, total yield is comparable to Norgold 40, with a slightly lower percentage of U.S. No. 1 tubers. Tubers of Russet Nugget have high specific gravity and vitamin C content.

Effects of soil aeration on root demography in kiwifruit

Abstract Kiwifruit (Actinidia deliciosa (A Chev.) C.P. Liang et A.R. Ferguson) vines are usually very sensitive to soil aeration stress in the laboratory and field. However, at some sites previously vigorous vines have shown no foliar symptoms of stress despite waterlogging for up to 7 days. This research attempted to explain such anomalies through intensive study of root demography and soil aeration using a rhizotron. One previously vigorous vine was waterlogged by continuous irrigation for 12 days, another was lightly irrigated twice over the same period. Both vines showed a marked turnover of feeder roots, but net losses were much greater on the waterlogged vine. Roots on the waterlogged vine were rapidly killed as soil aeration became impaired; c. 65% of the initial root length died. However, this vine showed no signs of stress above ground. Our results suggest some healthy kiwifruit vines have many more roots than necessary for water uptake under normal conditions. Such vines can survive waterlogging...

Krantz: A Russet cultivar for the irrigated sands

Krantz is an oblong to slightly blocky, russet-skinned potato cultivar with medium-late maturity and a vigorous vine. It is resistant to hollow heart, has high resistance to common scab and possesses high field resistance to late blight. It is moderately resistant toVerticillium wilt, susceptible to early blight, viruses S and X, and exhibits symptoms of bacterial ring rot. Krantz is adapted to the irrigated sands, but will growth crack in heavier soils.

Effects of hydrogen cyanamide in manipulating budburst and advancing fruit maturity of table grapes in south-eastern Queensland

Four times of winter pruning and hydrogen cyanamide application were evaluated for their effects on budburst, growth, flowering and yield of the table grape cultivar Muscat Hamburg in south- eastern Queensland (lat. 263.). Hydrogen cyanamide hastened budburst at all times of application. When cyanamide was applied 8-10 weeks before natural bud- burst, fruit maturity was advanced by 14-18 days, However, application within 4-6 weeks of natural bud-burst had little or no effect on time of fruit maturity. Low temperatures during flowering, which can adversely affect pollination, seed development and hence yield, may limit the use of early pruning and cyanamide application, particularly under cooler subtropical conditions. Depending on market prices, any loss of yield associated with early pruning and cyanamide applications will need to be compensated for by higher prices received for earlier maturing fruit. Cyanamide may have greater commercial potential for use on young, vigorous vines growing under warm subtropical conditions. Under these conditions, cyanamide application at 4-6 weeks before natural budburst gave significant yield increases by increasing the number of bunches produced per spur. No deleterious effects of cyanamide on fruit quality were recorded.

Variation in Chloride Accumulation in Hybrids and Backcrosses ofVitis berlandieriandVitis viniferaunder Glasshouse Conditions

Two glasshouse trials were conducted to examine vineyard data which suggested that the action of a single dominant gene is responsible for low chloride concentrations in petioles of vines of <i>Vitis berlandieri</i> and <i>V. berlandieri</i> x <i>V. vinifera</i> hybrids. Both trials employed a nutrient solution technique with NaCl at a concentration of 25 m<i>M</i>. To an extent, the data from the trials indicated a single gene for Cl^- exclusion derived from <i>Vitis berlandieri</i>. There was a marked segregation for high and low petiole Cl^- concentrations in one pair of backcross families, MF77-13 (<i>V. berlandieri</i> x Sultana) x Biancone or Koshu Sanjaku. However, the other pair of backcrosses investigated, MF78-01 (<i>V. berlandieri</i> x Sultana) x Biancone or Koshu Sanjaku, did not segregate in a 1:1 ratio expected from vineyard data. This result is discussed in terms of possible incorrect classification in the vineyard due to variations in rootzone salinities and/or the action of genes derived from <i>V. vinifera</i> parents which may have modified the phenotypic expression of a major gene. While there was little evidence for genotypic differences in shoot Cl^- concentrations being affected by genotypic differences in vine vigor, there were exceptions which raised the question of whether initial vine size affects the expression of a major gene for Cl^- exclusion in short-term glasshouse trials. For example, two F1 hybrids, MF77-13 (<i>V. berlandieri</i> x Sultana) and MU21-91 (<i>V. berlandieri</i> x Biancone), had high petiole Cl^- concentrations contrary to the assumption of a dominant gene for Cl^- exclusion derived from <i>V. berlandieri</i>. Both of these genotypes were less vigorous than others, and it is possible that as young vines they were less tolerant of NaCl than more vigorous vines. As a result, they accumulated greater petiole Cl^- concentrations than expected. The ratio of genotypic to phenotypic variance was greater for backcross families than for F1 hybrids (<i>V. berlandieri x V. vinifera</i>), which supported a segregation of a major dominant gene in the backcross generation.

Factors Affecting Soluble Solids, Acid, pH, and Color in Grapes

Vines were grown from two-node cuttings and induced to retain one bunch of grapes per plant. These plants were grown in a greenhouse and parameters, such as leaf number and area, berry number, °Brix, acid, pH, and color, were recorded. Correlations between pairs of variables were made and analyzed. Plants with low berry numbers grew more than those with high numbers. Low berry number, high leaf growth rate, and high leaf/fruit ratio are related to high sugar levels, but acid levels were low and pH levels high. These levels were not simply a response to advanced maturity. While soluble solids levels increased only until a certain leaf/fruit ratio was attained, pH and acid continued to change as the shoots grew. Under the warm conditions of this experiment, unacceptably high pH levels and low acid levels were recorded. The effect of extended shoot growth increasing pH and lowering acid was not mediated by shade and leaf/bunch exposure since shading was not permitted. The general hypothesis that low vigor vines produce higher quality can, therefore, be explained in part by a direct response of pH and acid to shoot growth.

Tolerance to potato leafhopper inSolanum tuberosum L. gp. Tuberosum clones

We identified clones inSolanum tuberosum L. gp. Tuberosum breeding populations that, although susceptible to infestation by potato leafhopper,Empoasca fabae (Harris), exhibited a tolerance which was manifested by the ability to produce higher than expected tuber yields when heavily infested with leafhoppers. Such tolerance was noted in a number of clones in varying degrees, but one, B6930-1, was exceptional. It sustained only a 19% loss in tuber yield compared to ‘Katahdin,’ a susceptible cultivar, that averaged 33% lower tuber yields under similar infestation levels. We studied the seasonal growth patterns of this clone and compared them to those of Katahdin, and B6705-10, a breeding clone with known resistance to leafhopper infestation. We found that much of B6930-l’s tolerance results from its early, vigorous vine growth and its early and rapid rate of tuber bulking, enabling this clone to escape some of the effects of leafhopper feeding, whereas Katahdin was usually just beginning to tuberize at the height of leafhopper infestation.

Effect of Canopy Widening and Shoot Tip Removal on the French Hybrid Grape Cultivar de Chaunac1

Abstract In a 3 year study widening the foliage canopy by spreading the shoots, or narrowing the canopy by shoot tip removal did not affect yield, cluster wt or berry wt of mature moderately vigorous vines of ‘de Chaunac’ grape. Widening the canopy by training shoots horizontally and away from the row widened the zone of light interception and tended to increase fruit soluble solids content compared to the check. Shoot tip removal narrowed the zone of light interception and resulted in a lower fruit soluble solids content than the check. Shoot tip removal reduced vigor as shown by a reduced wt of one year old wood removed at dormant pruning.

‘Great Northern Valley’ Dry Bean1

Abstract Common blight, caused by the bacterium Xanthomonas phaseoli (E. F. Smith) Dowson, is one of the most serious seed-borne bacterial diseases of beans, Phaseolus vulgaris L. Recommended controls are use of certified disease-free seed and rotation. There is no satisfactory chemical control. Great Northern (GN) cultivars ‘Tara’ (2) and ‘Jules’ (3) have high tolerance to X. phaseoli and high yield but combine the disadvantages of late maturity and vigorous vines, the latter creating conditions favorable for white mold. These 2 cultivars were derived by pedigree selection from the cross of the late maturing, common blight tolerant GN Nebraska #1 sel. 27 line with the early maturing susceptible ‘GN 1140’. The reaction to X. phaseoli was inherited quantitatively (4) while maturity was inherited qualitatively (1). Linkage occurred between genes controlling common blight tolerance and late maturity (4).

Effects of the combination of nitrogenous fertilizer on the top growth, tuber-formation and tuber-thickening growth in sweet potato

Wooden frame experiments were carried out to clarify the suitable combination of nitrogenous dertilizer between the basic fertilizer and the side-fressing upon the tuber-formation and tuber-thickening growth in sweet potato. Four types of soil were used.1. In spite of the differences of soil used, tuber yield at the plot of NH4NO3+(NH4)2SO4 was the highest among the following three treatments, that is, NH4NO3+(NH4)2SO4, NH4NO3+CO(NH2)2, and NH4•NO3+NH4NO3.2. In the plot of NH4NO3+(NH4)2SO4, it was more unfavourable to tuber-formation than other treatments owing to the considerable elongation of vines during the tuber-formation stage from the middle of July to the middle of August. On the other hand, yield of tubers at the plot of NH4NO3+(NH4)2SO4 was increased, especially that of large tubers, as it was favourable to the accumulation of assimilation nutrients owing to the vigorous vine growth during the tuber-thickening period.3. From the results of this investigation, it is evident that dry matter content of tubers at the plot of NH4NO3+(NH4)2SO4 was the highest among these treatments in the light soil, that is, sand to loam, with the exception of clayey loam, in which it was rather low.

Effects of the application ratio of potassium to nitrogen on top growth, tuber-formation and thickening of sweet potatoes grown on different types of soil

Wooden frame experiments were conducted to study the effects of the application ratio of potassium to nitrogen on top growth, tuber-formation and-thickening of sweet potatoes. Four types of soil differing in their clay content were used. Two cuttings were planted in each frame.1. According to the increase of the application ratio of potassium to nitrogen, top growth was gradually weaken throughout the growing period in every type of soil, and also the percentage of parts of young vines decreased.2. Small application ratio of potassium to nitrogen was unfavourable to tuber-formation due to the vigorous vine growth during the period of tuber-formation, however, it was favourable to the increase of tuber yield, especially that of large tubers, as the vine growth was vigorous after tubers began to thicken.3. As the application ratio of potassium to nitrogen increased, the percentage of dry matter content of tubers in every type of soil gradually decreased.

Effects of Several Nematode-Resistant Rootstocks on Vine Vigor, Crop Level, and Nutrition with the Grape Variety, Grenache

A regulated level of pruning, in which the number of fruiting units retained is balanced with the past vegetative growth of the vine, did not entirely overcome the low-yielding tendencies of very vigorous grafted vines. Fruiting efficiency of the individual spur, based on the ratio of prunings to fruit produced, was markedly lower from vines on the very vigorous stock, Dogridge, and highest on the own-rooted Grenache vines. Over the six-year period that harvest records were obtained, the heaviest-yielding vines and those showing the best balance between growth and fruit production were on the <i>V. Champini</i> selection, Salt Creek. Total carbohydrate content was markedly increased and total nitrogen level decreased in the shoots by girdling during bloom. Only the yields of the vigorous vines on Dogridge were increased by this treatment. Topping the vine at bloom did not change carbohydrate levels in the shoots at the time of berry shatter, but gave some reduction in vine vigor. A growth retardant, maleic hydrazide, used at 500 ppm as a foliar spray during bloom, was not effective in changing nutrient levels in the shoots. However, evident leaf symptoms and reduction in shoot elongation was noted late in the growing season.

Effects of heavy application of nitrogen and potassium on top growth, tuber-formation and -thickening of sweet potatoes grown on different types of soil

Pot experiments were conducted to study the effects of heavy application of fertilizers on top growth, tuber-formation and -thickening of sweet potatoes. Four kinds of soil differing in their clay content were used. Amounts of nitrogen and potassium were applied each at three levels, the ratio of nitrogen to potassium being 1:1. One cutting was planted in each pot.Heavy application of fertilizers maintained the top growth vigorous throughout the growing period in every type of soil. The difference in top growth among the fertilizer levels was significant in the soils having higher clay contents.Though heavy application of fertilizers was unfavorable to tuber formation owing to the vigorous vine growth during the period of tuber formation, it increased tuber yield, especially that of large tubers, as it kept vine growth vigorous during tuber-thickening stage.The higher was the clay content of of soil, the higher was the fertilizer level favoring the highest dry matter content of tubers, with the exception of clay loam, containing the largest amount of clay among the soils used, in which it was rather low.

Effects of application of nitrogenous fertilizer and soil type on the top growth and tuber-formation and-thickening in sweetpotato

Pot experiments were conducted on the effects of application of nitrogenous fertilizer and soil type on the top growth and tuber-formation and -thickening in sweetpotato. Four types of soil differing in their clay content were used.Application of whole amount of nitrogenous fertilizer at one time after cuttings were planted was unfavourable to tuber formation owing to the vigorous vine growth during the tuber formation. It was true to the thickening of tubers, too, because top growth was gradually weakened after tubers began to thicken.On the other hand, fractional application of nitrogenous fertilizer was favourable to both tuberformation and -thickening due to the limited growth of vines during tuber formation and also moderately maintained top growth during tuber thickening. Total weight of tubers was heavier in the fractionary application plot than in the basic application plot, though yield of large tubers was less in the former than in the latter.When nitrogen was almost doubled in its amount and was applied fractionally, yield of tubers was increased regardless of the amount of potassium on the sandy soil, while on the caly soil it wa sdecreased unless the amount of potassium was increased.