Physiological aspects of post harvest berry drop in certain grape varieties

Storage experiments were conduced with fruit of two grape varieties, Muscat of Hambourg and Dabouki.The drop of Muscat of Hambourg is a "dry drop" while the Dabouki has no definite drop. Shed berries in this latter variety were due mostly to mechanical injury.The dry drop due to an abscission layer was found to be a "physiological drop".This drop could be:Prevented by subjecting the fruit to cold store immediately after picking.Reduced by spraying the fruit 4 days before picking with 10-20 ppm of NAA or PCPA if storage has to be postponed for more than 36 hours.Growth regulators as well as delayed cold storage had no effect on the drop of Dabouki berries during storage.A mechanism for the shedding in varieties with a physiological drop was suggested

IAA reversible growth inhibition of grape shoots (Vitis vinifera) by maleic hydrazide compared to gibberellic acid induced growth

The growth rate of irrigated grape shoots on mature vines was determined. A linear growing period was found between 20 and 55 d after bud opening. Maleic hydrazide (MH) was found to reduce this growth rate without affecting its linearity. The degree of inhibition is concentration dependent. A lag period of 5 d was found from application to a measurable change of the growth rate. IAA had no effect on grape shoot growth rate when applied in the linear growth phase at concentrations up to 80 mg/l. This is true also when applied to shoots with a reduced growth rate induced by MH. IAA applied during the 5-d lag period after MH treatment could, however, reverse the MH inhibition. The degree of reversion is concentration dependent. Gibberellic acid (GA3) has a pronounced promoting effect on grape shoot growth. No direct interaction between MH-induced growth reduction and GA3-induced growth stimulation was found.Die Hemmung des Triebwachstums von Reben (Vitis vinifera) durch Maleinsäurehydrazid und ihre Aufhebung durch IES im Vergleich mit der  Wachstumsförderung durch GibberellinsäureBei bewässerten vollentwickelten Reben der Sorte Madlene wurde die Wachstumsgeschwindigkeit der Triebe untersucht. Zwischen dem 20. und 55. d nach dem Austrieb wurde eine Periode linearen Längenwachstums festgestellt. Maleinsäurehydrazid (MH) verringerte die Wachstumsgeschwindigkeit, beeinflußte aber die Linearität des Wachstumsverlaufs nicht. Das Ausmaß der Wachstumshemmung war konzentrationsabhängig. Die Wachstumsgeschwindigkeit war erst 5 d nach der Applikation meßbar verändert. IES in Konzentrationen bis zu 80 mg/l hatte keinen Einfluß auf die Wachstumsgeschwindigkeit, wenn sie während der linearen Wachstumsphase angewandt wurde. Dies war auch der Fall, wenn Triebe behandelt wurden, deren Wachstumsgeschwindigkeit durch MR-Vorbehandlung verringert war. IES-Applikation während der 5tägigen Zwischenphase nach der MR-Vorbehandlung konnte - in Abhängigkeit von der IES-Konzentration - die MR-bedingte Hemmung jedoch aufheben. Zwischen der MR-induzierten Wachstumsverringerung und der GS3-induzierten Förderung wurde keine unmittelbare Wechselwirkung gefunden

Necrosis in grapevine buds (Vitis vinifera cv. Queen of Vineyard) III. Endogenous gibberellin levels in leaves and buds

The endogenous content of free and bound gibberellins (GA) in leaves and buds of Queen of Vineyard grapevines was determined. Lateral buds on shoots from vigorous vines had about double the free GA activity of buds from less vigorous vines. No difference in the activity of bound GA was found. The GA content in the leaves of Queen of Vineyard was uniform, regardless of the vigor of the plants. The relation between vigor, GA content and bud necrosis in Queen of Vineyard vines is discussed and a causal dependence is suggested

Control of vegetative growth of grapevine shoots by ethylene-releasing substances Conditions and sites of action

Grapevine shoots of the cvs. Muscat Hamburg and Perlette were treated with two commercial ethylene-releasing substances, Ethrel (2-chloroethylphosphonic acid) and Alsol (2Tchloroethyl-tris-(2-methoxyethoxy)silane) at acid and neutral pH. Ethrel caused significant shoot growth inhibition, Alsol had no effect on the growth rate. Ethrel was more active at pH 6.9 than at pH 2.2, and its uptake was significantly higher at the low pH. In many cases the apical meristem of Ethrel-treated shoots was damaged. The relation of uptake to growth response was determined. Leaf blade treatments alone did not inhibit the growth of the apex.Die Kontrolle des vegetativen Wachstums von Rebtrieben durch Äthylen-liefernde Substanzen Einwirkungsbedingungen und -orteTriebe der Rebsorten Muskat Hamburg und Perlette wurden mit zwei Äthylen-freisetzenden Handelspräparaten behandelt: Ethrel (2-Chloräthylphosphonsäure) und Alsol (2-Chloräthyl-tris-(2-methoxyäthoxy)silan) bei saurem und neutralem pH. Ethrel verursachte eine signifikante Hemmung des Triebwachstums, Alsol hatte keinen Einfluß auf die Wachstumsgeschwindigkeit. Ethrel war bei pH 6,9 wirksamer als bei pH 2,2; im niedrigen pH-Bereich war seine Aufnahme signifikant erhöht. In den behandelten Sprossen war vielfach das apikale Meristem geschädigt. Die Beziehung zwischen Substanzaufnahme und Wachstumsreaktion wurde bestimmt. Bei alleiniger Blattbehandlung war das Wachstum der Triebspitze nicht gehemmt

Control of vegetative growth of grape vines (Vitis vinifera) with chloroethylphosphonic acid (Ethephon) and other growth inhibitors

In order to arrest vegetative growth of grape shoots, various growth regulating substances were applicated on five grapeVine cultivars: Alphonse Lavallee, Muscat of Hamburg, Cardinal, Perlette, and Queen of the Vineyards. Ethephon at a concentration of 480 ppm efficiently inhibited the terminal growth of the canes and prevented the opening of lateral buds on the shoots for about 8 to 10 weeks. This treatment somewhat enhanced maturation of the current yield. No negative effect on bud differentiation, bud opening and growth in the following season was found. The use of Ethephon was much more effective than the other regulators tested such as Alar, NC 9634, pp 413, and morphactin 7311. Alar caused a shortening of the canes, not effecting the number of nodes. pp 413 had no activity in our system while both the morphactin and NC 9634 did inhibit growth partially. The Ethephon treatment was far more efficient and uniform than repeated manual topping.Regulierung des vegetativen Wachstums von Reben (Vitis vinifera) durch Etephon und andere HemmstoffeDie hemmende Wirkung verschiedener Wachstumsregulatoren wurde an fünf Rebsorten geprüft: Alphonse Lavallee, Muskat Hamburg, Cardinal, Perlette und Queen of the Vineyards. Etephon hemmte bei einer Konzentration von 480 ppm deutlich das Spitzenwachstum der Triebe und verzögerte den Austrieb der lateralen Knospen um 8 bis 10 Wochen. Diese Behandlung erhöhte den Reifegrad der Traubenernte. Ein negativer Einfluß auf Knospendifferenzierung, Knospenaustrieb und Wachstum in der folgenden Wachstumsperiode wurde nicht gefunden. Etephon war erheblich wirksamer als die anderen verwendeten Substanzen: Alar, NC 9634, PP 413 und Morphaktin 7311. Alar verursachte eine- Verkürzung der Triebe, ohne die Zahl der Nodi zu verändern. pp 413 hatte keine Wirkung, während Morphaktin und NC 9634 das Wachstum teilweise hemmten. Etephon wirkte weitaus nachhaltiger und gleichförmiger als wiederholtes Gipfeln in Handarbeit

The Determination of induction and differentiation in grape vines

The induction and differentiation of 8-year-old Alphonse Lavallee and Sultana grape vines were studied.Defoliation methods enabled us to determine the induction time in grape vines as in other fruit species.Induction and differentiation in the tested varieties were not connected with temporary growth cessation; on the contrary, process took place during the most intensive growth.A correlation was found between the number of leaves and induction period. 18-21 leaves above the examined buds were needed in bot-h varieties to complete the induction.The leaf area needed for induction in a bud of Sultana was lYe times larger than that needed for Alphonse. The efficiency of the leaves of Alphonse to induce differentiation was thus greater.The primordia ,development from induction to detection under the microscope (differentiation) was connected with a constant vegetative development. The time needed for this development was determined by the growth rate of the variety (18 days in Sultana, 14 days in Alphonse).The translocation of materials inducing differentiation from the base of the shoot upwar,ds has not been proved in our work.In Alphonse a lag period of two days was found for the differentiation of each bud along the cane

Quality and yield of Alicante Grenache and Semillon on various rootstocks in an arid climate

Alicante Grenache and Semillon wine grape varieties, were studied on their own roots and on seven rootstocks, for yield and quality criteria, in an arid climate. Grenache on its own roots was outstanding in yield, vigour, T.S.S. and acid content. Of the grafted rootstock combinations, 140 Ru yielded highest, followed by 110 R, 41 B MG, 1103 P. Acid content was lowest with 41 B MG. Bunch weight was lowest on ungrafted vines and highest on 140 Ru and 1103 P. Semillon had the highest yield and acid content on 41 B MG, followed by ownroot vines, 161-49 C (low vigour) and 1103 P. Highest bunch weights were observed with 140 Ru and 41 B MG, while high T.S.S. were observed with 161-49 C, own root-vines and 99 R.On 1103 P and 140 Ru, both varieties showed less decline in vigour with age, relative to other combinations.Qualitäts- und Ertragseigenschaften von Alicante Grenache und Semillon auf verschiedenen Unterlagen in einem ariden KlimaIn einem ariden Klima wurden Ertrags- und Qualitätskriterien der Keltertraubensorten Alicante Grenache und Semillon bei wurzelechtem Anbau und in Kombination mit sieben Unterlagen untersucht.Grenache zeigte bei wurzelechtem Anbau überdurchschnittliche Leistungen in Ertrag, Wüchsigkeit, löslicher Trockensubstanz und Säuregehalt. Bei den Pfropfkombinationen wirkte sich 140 Ru auf den Ertrag am vorteilhaftesten aus; es folgten 110 R, 41 B MG, 1103 P. Der Säuregehalt war in Verbindung mit 41 B MG am niedrigsten. Das Traubengewicht war bei den wurzelechten Reben am niedrigsten und auf 140 Ru und 1103 P am höchsten.Semillon hatte auf 41 B den höchsten Ertrag und Säuregehalt, gefolgt von der wurzelechten Rebe und den Kombinationen mit 161-49 C (schwache Wüchsigkeit) sowie mit 1103 P. Das höchste Traubengewicht wurde nach Pfropfung auf 140 Ru und 41 B MG gemessen, während auf 161-49 C, im wurzelechten Zustand und auf 99 R ein hoher Gehalt an löslicher Trockensubstanz beobachtet wurde.Auf 1103 P und 140 Ru ließ die Wüchsigkeit beider Sorten mit fortschreitendem Alter weniger nach als bei anderen Pfropfkombinationen

Performance of table grape cultivars on different rootstocks in an arid climate

The performance of the table grape varieties Queen of the Vineyards, Muscat of Hamburg and Dabouki on eight different rootstocks, was studied in the arid Negev, on a loess soil under irrigation.The highest yields (nine years of bearing) from Queen of the Vineyards were recorded on 161-49, followed by 1202 and 99 R; from Muscat of Hamburg on ownroot plants, 41 B and 110 R; from Dabouki on 41 B, 110 R and 161-49. Maximum vigor in Queen of the Vineyards was obtained on 1202, followed by own-root plants and 1103; in Muscat of Hamburg, on 140 R and 1202; in Dabouki, 0n 110 R and 1202.Highest relative fruitfulness (ratio of total crop per total weight of prunings) 1Jf Queen of the Vineyards was found on 161-49, followed by 41 B and 216-3; of Muscat of Hamburg, on 110 Rand 41 B; of Dabouki, on 41 B and 216-3.No correlation was noted between the ranking of stionic combinations as to vigor and their ranking as yielders. There was a marked tendency toward decreased vigor with age, except on 140 with all three varieties, on 1103 and 1202 with Muscat, on 216-3 with Dabouki, and on 1103 with Queen of the Vineyards. A comparatively large overgrowth in the Dabouki variety with some rootstocks n.id not impair performance.Great variation was noted in the performance of different varieties of V. vinifera on their own roots; high relative yields were obtained with Muscat of Hamburg, and low yield with Queen of the Vineyards. Only small differences were found in quality, cluster weight and berry weight on different rootstocks

Analysis of water consumption of various grapevine cultivars

The efficiency of water use (transpiration ratio) was investigated in various cultivars of grapevine by gravimetric and gasometric methods. Results of gravimetric measurements showed positive correlation between water use efficiency and vigor. Regression lines of the transpiration ratio on the final dry weight differed significantly in their curves and their distance from the coordinate axes. Statistical analysis showed that the quantitative effect of vigor on the water use efficiency was smaller in the cultivar Muscat Hamburg than in Sultanina and Queen of the Vineyards. Covariance analysis showed that Sultanina was a less efficient water user than Queen of the Vineyards for plants with the same vigor. Gasometric methods did not reveal any significant differences between the cultivars, probably due to the elimination of interference and boundary layer resistance effect

Evaluation of salt tolerance of in vitro-grown grapevine rootstock varieties

The response of 11 grapevine rootstock varieties to increasing salt concentrations (0, 50, 85, 120, 155 mM NaCl) was studied under in vitro and growth chamber conditions. The effect of salinity on the mortality of explants was compared with that of plantlets grown under growth chamber conditions and with data in literature on rootstock resistance under field conditions. In addition, in vitro stem elongation bud number, and rooting ability were related to salinity. The rootstock varieties can be divided into sensitive (41 B, R.Lot, 110 R, 140 R and 161-49), moderately tolerant (13.5 and Ramsey) and tolerant (196-17, CH-1, CH-2 and Superior). Measurements of the water and nutrient contents of plantlets indicate that increasing salt concentrations decreased the hydration of aerial parts and roots of all plants; however, the decrease of hydration was smaller in salt tolerant varieties. Increasing salt concentrations significantly reduced the K content and, to a smaller extent, the P and Ca contents. With and without salt treatments the levels of K and P were lower in sensitive plants. Na and Cl accumulated to a higher extent in tolerant plants. The tolerance to NaCl of in vitro-grown rootstocks seems to be due to their capacity to accumulate salt, to increase K concentration in the tissue and to maintain a high water content. Our results indicate that salt tolerance of grapevine varieties may be tested under growth chamber conditions and using in vitro explants