Horticulture -pomology

FIELD experiment was conducted during two successive seasons of 2013/2014 and 2014/2015 in a private orchard located at Sharnoob village, El-Behera governorate, Egypt, this study aim to evaluate the effect of foliar application of benzyladenine, yeast extract and potassium solution on yield, fruit quality and leaf mineral content of Valencia orange trees (Citrus sinensis, osbeck) about 50 years old budded on sour orange (C. aurantium, L) rootstock planted in clay soil. The obtained results proved that spraying trees with a mixture of (BA 40 ppm+ yeast 0.4% + K 0.4%) resulted in a higher number of fruit set/branch, although it caused an increase of fruit juice acidity compared with the control and the differences were significant during both seasons of the study. Also, this treatment, significantly increased fruit length and diameter, only in one season. Moreover, benzyladenine spray treatment at 40 ppm, in both seasons, produced the highest number of fruits/tree, an average fruit weight and yield and participated with potassium at either 0.2 or 0.4% to improve fruit shape (fruits were more circular in shape). In most cases, BA 40ppm spraying treatment markedly increased fruit length, and fruit growth rate comparing to control treatment. The data also revealed that Valencia orange trees sprayed with a combination of (BA 20ppm + yeast 0.2% +K 0.2%), in both seasons, gave significantly higher fruit diameter and fruit growth rate in most measuring dates, increased vitamin C content in the fruit juice. Trees sprayed with dry yeast extract at 0.2%, in both seasons, markedly increased total soluble solid percentages in fruit juice. In addition, potassium spray treatment at 0.4% markedly increased fruit diameter, only in one season and participated with benzyladenine at 40ppm and dry yeast extract at 0.2% to improve fruit physical properties (length, diameter, pulp and rind weights, fruit weight and juice volume). Different foliar application increased total nitrogen, phosphorus and potassium in the leaves. Trees sprayed with a mixture of (BA 20ppm+ yeast 0.2%+ K 0.2%) and 0.4% potassium solution treatment, in both seasons, significantly increased leaf total nitrogen content as well as potassium spray treatments at either 0.2% or 0.4%, markedly increased leaf phosphorus and potassium content.

A STUDY was conducted on one-year old sour orange seedlings in long term experiment during 2014 and 2015, held in greenhouse of EL-Maamora station, Horticulture Research Institute. The aim of trial was to evaluate foliar chitosan or putrescine application at 0, 50, 100, 150 ppm and three levels of irrigation (7, 14 and 21 days) contributing to three levels of drought stress (zero, moderate and severe, respectively) on growth, leaf biochemical attributes and antioxidant enzymes activity. Results showed that most of the vegetative growth indices, plant height %, stem diameter %, leaves number, area, fresh and dry weight and relative water content(RWC) %,leaf carbohydrates and protein % were significantly decreased with increasing drought level and that chitosan and putrescine application resulted in enhancement gradually of the previous parameters by increasing concentrations applied. Putrescine was more effective at 50 and 100ppm compared to 150 ppm, whereas chitosan was more effective at 100 and 150ppm than 50 ppm .

The study was conducted during 2014 and 2015 seasons on ten-years old orange trees (Citrus sinensis [L.] Osbeck) cv. Washington navel orange grown in private orchard in El-Maamoura regions, Alexandria governorate. The main goal of this work was to investigate the efficiency of inoculation with Azotobacter (N-fixing bacteria) and Mycorrhiza fungi separately or in dual either alone or integrated with different mineral N and P fertilizer levels (25, 50 and 75%) of recommended dose on tree vigorous, leaf nutrient content and quantitative and qualitative yield, as well as some biological properties of soils were examined. Generally, results proved that biofertilizer combined with mineral fertilizer had more positive effects than both microbial inoculants solely and non-inoculated control. Azotobacter + AM at 75% induced significant increment in growth criteria (leaf fresh and dry weights, chlorophyll content and tree height or volume), leaf N, P and K contents, and yield attributes (fruit retained after June drop%, No. fruit / tree or Kg/ tree) followed by Azotobacter + 50% N, Azotobacter + AM at 50% NP and Azotobacter + 75% N, respectively. Moreover, the two latter treatments promoted the fruit physical (fruit weight, length and diameter and juice volume) and chemical properties i.e. TSS%, TSS/acid ratios and reduced juice acidity % followed AM+ 25 or 50% P and Azotobacter + AM, which revealed improvement in fruit quality as compared to uninoculated control and biofertilizer only. Finally, a similar trend was observed regarding the total population of both microbial and Aozotobacter in the rhizosphere region of orange tree, where Azotobacter + AM at 75 and 50% NP stimulated the highest number of total microbial or Azotobacter counts and nitrogenase activity. On the other hand , the colonization percentage of AMF and number of spores/g soil, as well as the enzyme activities of both dehydrogenase and phosphatase attained higher values from using Azotobacter + AM integrated with 50 and 25% NP application as compared to unioculated control and biofertilizer singly.

HE OBJECTIVE of the present study was to evaluate the effects of Salicylic acid (SA), Zinc (Zn) and Potassium (K) on reducing fruit drop and improving fruit quality of Balady mandarin (C. reticulata, Blanco) at flowering initiation, fruit sized 5 mm and at pre-coloring stage. The experiment was conducted in a commercial orchard in Sharnoob, Behera governorate where 30-year-old trees budded on sour orange rootstock were sprayed with SA at 10mg/L, zinc sulfate at 0.02% and potassium sulfate at 0.25% separately or in combinations. The results showed that K applications alone or combined with SA led to the best results regarding the yield evidenced as fruit number or by weight resulting from markedly increased fruit retention after June drop and final fruit retention percentages. The latter treatment was statistically superior in increasing fruit set followed by Zn or SA solely. All treatments reduced fruit drop, SA separately or plus K or Zn reduced fruit drop than the control treatments. No definite results were obtained concerning fruit physical properties i.e. weight of fruit or peel, fruit length and diameter. However, Zn and Zn plus SA applications significantly increased TSS and TSS/acid ratio, as well as K treatments increased TSS and V.C. as compared to control. Lastly, K or Zn treatments and their combinations with SA resulted in considerable higher values in leaf k and Zn content.

A STUDY was conducted on one-year old sour orange seedlings in long term experiment during 2014 and 2015, held in greenhouse of EL-Maamora station, Horticulture Research Institute. The aim of trial was to evaluate foliar chitosan or putrescine application at 0, 50, 100, 150 ppm and three levels of irrigation (7, 14 and 21 days) contributing to three levels of drought stress (zero, moderate and severe, respectively) on growth, leaf biochemical attributes and antioxidant enzymes activity. Results showed that most of the vegetative growth indices, plant height %, stem diameter %, leaves number, area, fresh and dry weight and relative water content(RWC) %,leaf carbohydrates and protein % were significantly decreased with increasing drought level and that chitosan and putrescine application resulted in enhancement gradually of the previous parameters by increasing concentrations applied. Putrescine was more effective at 50 and 100ppm compared to 150 ppm, whereas chitosan was more effective at 100 and 150ppm than 50 ppm .

The current study was carried out during successive seasons of 2016 and 2017 on 40-years old Washington navel orange trees, budded on Volkamer lemon rootstock grown in a private orchard at Qalub district, El Qalubia Governorate, Egypt. The study was conducted to find the effect of foliar spray application with agrochemical GA 3 at 30 ppm and a natural one such as chitosan at two doses of 2 g/L and 4 g/L. The treatments were sprayed either once during mid-January and mid-April or twice on mid-January and April. The results revealed that all the examined aspects were significantly affected by GA 3 or chitosan foliar applications and the spraying application time, beside the interaction between them as compared to control water spray. GA3 spraying once either during mid-April or mid-January increased vegetative growth parameters and leaf C/N ratio or leaf DM%. Foliar chitosan applications with two doses of 2 g/L and 4g/L had more impacts on leafy inflorescence%, fruit set % and Canopy yield as weight (kg/m 3 ), as well as leaf pigments (chl.a, chl.b and its total) and carotenoid, when sprayed during both mid-January and mid-April. Moreover, chitosan at 2g/L during the same previous date participated in improving physical and chemical fruit properties. However, no significant difference were found between the two applied doses of chitosan so, it was suggested that chitosan at 2g/L could be instead of 4g/L under experiment conditions.

S UNBURN is one of the most important problems that may affect the growth, productivity and quality of Balady mandarin trees. This study was conducted to determine the effects of two kaolin clay products i.e. Screen Duo ® (applied once or twice) and Surround ® (3 and 6%) used as anti-sunburn treatment on controlling sunburn of Balady mandarin fruits Citrus reticulata.

A STUDY was conducted on one-year old sour orange seedlings in long term experiment during 2014 and 2015, held in greenhouse of EL-Maamora station, Horticulture Research Institute. The aim of trial was to evaluate foliar chitosan or putrescine application at 0, 50, 100, 150 ppm and three levels of irrigation (7, 14 and 21 days) contributing to three levels of drought stress (zero, moderate and severe, respectively) on growth, leaf biochemical attributes and antioxidant enzymes activity. Results showed that most of the vegetative growth indices, plant height %, stem diameter %, leaves number, area, fresh and dry weight and relative water content(RWC) %,leaf carbohydrates and protein % were significantly decreased with increasing drought level and that chitosan and putrescine application resulted in enhancement gradually of the previous parameters by increasing concentrations applied. Putrescine was more effective at 50 and 100ppm compared to 150 ppm, whereas chitosan was more effective at 100 and 150ppm than 50 ppm .

The study was conducted during 2014 and 2015 seasons on ten years old orange trees (Citrus sinensis [L.] Osbeck) cv. Washington navel orange grown in private orchard in El-Maamoura regions, Alexandria governorate. The main goal of this work was to investigate the efficiency of inoculation with Azotobacter (Nfixing bacteria) and Mycorrhiza fungi separately or in dual either alone or integrated with different mineral N and P fertilizer levels (25, 50 and 75%) of recommended dose on tree vigorous, leaf nutrient content and quantitative and qualitative yield, as well as some biological properties of soils were examined. Generally, results proved that biofertilizer combined with mineral fertilizer had more positive effects than both microbial inoculants solely and non-inoculated control. Azotobacter + AM at 75% induced significant increment in growth criteria (leaf fresh and dry weights, chlorophyll content and tree height or volume), leaf N, P and K contents, and yield attributes (fruit...

HE OBJECTIVE of the present study was to evaluate the effects of Salicylic acid (SA), Zinc (Zn) and Potassium (K) on reducing fruit drop and improving fruit quality of Balady mandarin (C. reticulata, Blanco) at flowering initiation, fruit sized 5 mm and at precoloring stage. The experiment was conducted in a commercial orchard in Sharnoob, Behera governorate where 30-year-old trees budded on sour orange rootstock were sprayed with SA at 10mg/L, zinc sulfate at 0.02% and potassium sulfate at 0.25% separately or in combinations. The results showed that K applications alone or combined with SA led to the best results regarding the yield evidenced as fruit number or by weight resulting from markedly increased fruit retention after June drop and final fruit retention percentages. The latter treatment was statistically superior in increasing fruit set followed by Zn or SA solely. All treatments reduced fruit drop, SA separately or plus K or Zn reduced fruit drop than the control treatments. No definite results were obtained concerning fruit physical properties i.e. weight of fruit or peel, fruit length and diameter. However, Zn and Zn plus SA applications significantly increased TSS and TSS/acid ratio, as well as K treatments increased TSS and V.C. as compared to control. Lastly, K or Zn treatments and their combinations with SA resulted in considerable higher values in leaf k and Zn content.

S UNBURN is one of the most important problems that may affect the growth, productivity and quality of Balady mandarin trees. This study was conducted to determine the effects of two kaolin clay products i.e. Screen Duo ® (applied once or twice) and Surround ® (3 and 6%) used as anti-sunburn treatment on controlling sunburn of Balady mandarin fruits Citrus reticulata. Data indicated that percentage of injured fruits were decreased by treatments in comparison with control in both seasons of study. The percentage of injured fruits in Surround ® 6 and 3 % treatments were 11.66 and 14.02% in first season and 9.33 and 15.5% in the second one, respectively, while those treated with Screen Duo ® once and twice, possessed 19.6 and 14.9 % in the first season and 20.5 and 16.3 % in the second one compared with control treatment that gained 31.68 and 32.6 % in the first and second seasons, respectively. Surround ® 6% treatment caused significant increase in fruits weight and volume. The treatments did not affect fruits juice TSS, acidity and TSS/acidity ratio, except Surround ® 6% treatment, which caused significant increase in both TSS and acidity and significant decrease in TSS/acidity ratio in comparison with injured fruits. In the present study, the economic gain was estimated in term of assumed percentage of increase per fadan value in comparison with the control, where the estimated percentage of increase ranged between 11.6-20.66 in first season and 12.6-21.33 in the second one.

A field study was carried out during 2013/2014 and 2014/2015 seasons on Anna apple trees growing in calcareous loamy sandy soil and irrigated with Nile water. Apple trees were sprayed with water only (control), 300 mg/l B in the form borax (17.5% B) and 1.5 g/l zinc chelate (12 % Zn) either alone or in combinations at three foliar spraying dates; after harvest (AH) in mid-November of 2013 and 2014 seasons, before flowering (BF) in first February of 2014 and 2015 or at full bloom (FB) in first March of 2014 and 2015 seasons. Zinc and boron sprays especially the combined application had positive influence in reducing the percentage of non-opened flower buds, as well as increasing fruit set, tree yield and enhancing fruit physico-chemical quality at harvest. Also, the treatments resulted in a positive reduction in fruit blossom end breakdown. The FB spray was the most effective on decreasing blossom end breakdown as compared with the AH or BF spray at harvest or after storage. In the mean time, trees showed higher fruit setting and retention when sprayed AH or BF than at FB. However, higher tree yield, fruit weight and better fruit physico-chemical characters at harvest and after cold storage were obtained at FB followed by BF and AH spraying dates. A general enhancement in fruit storage potentials was observed as Zn and/or B sprays decreased the percentages of fruit weight loss, firmness loss and fruit end breakdown , and increased fruit storage life.

A field study was carried out during 2009 and 2010 seasons on adult Zaghloul date palm trees growing in sandy soil at a private orchard in Edko region, El-Behaira Governorate near Alexandria, Egypt in order to study the effect of polyethylene bagging on fruit ripening, improve productivity and postharvest fruit quality of palm date. Spathes bagging were carried out at pollination time using transparent and blue polyethylene bags at a thickness of 30 ìm. Bags were removed at three phenological fruit growth stages; stage one (S1= kimri stage, 1.1-1.3 cm fruit diameter), stage two (S2 = mature stage, fruits were green) and stage three (S3 = partially-ripe, 50-60% fruits coloring). In general, polyethylene bagging with removing at later growth stages caused a significant early fruit ripping date; increased fruit weight, length, diameter and yield, as well as decreased the percentage of tip cracked fruits at harvest time comparing with no bagging control. Also, harvest spread was shorter with bagging treatments and when covers were removed at later stages (S2 and S3). However, fruit showed an increase in the percentage of rutab, decay, unfit for marketing by bagging treatments and removal at later growth stage compared with the non covered control.

This study was carried out during the years 2008 and 2009 at the Research and Agricultural Experimental Station at Dirab, King Saud University, Riyadh in order to examine the differences in grape but fertility, production and fruit quality between newly planted and local grapevine cultivars grown under arid environments and irrigated with domestic wastewater. The local cultivars were; Kamaly, Soltany, Taify, White Shatta, Des El-Anz and Halawany whereas, the newly planted cultivars were; Red Glop, Perlette, Flame Seedless, Crimson, Superior, Thompson Seedless and King Ruby. Data indicated that Flame Seedless, King Ruby, Kamaly, Soltany, White Shatta and Halawany cultivars had a significantly higher bud fertility percent than all other cultivars. Kamaly had a significantly higher bud fertility coefficient percent than King Ruby, Des El-Anz, Taiefy, White Shatta and Halawany. In general, both Kamaly and Soltany cultivars had similar and a significantly higher yield than the other cult...

A field study was carried out during 2013/2014 and 2014/2015 seasons on Anna apple trees growing in calcareous loamy sandy soil and irrigated with Nile water. Apple trees were sprayed with water only (control), 300 mg/l B in the form borax (17.5% B) and 1.5 g/l zinc chelate (12 % Zn) either alone or in combinations at three foliar spraying dates; after harvest (AH) in mid-November of 2013 and 2014 seasons, before flowering (BF) in first February of 2014 and 2015 or at full bloom (FB) in first March of 2014 and 2015 seasons. Zinc and boron sprays especially the combined application had positive influence in reducing the percentage of non-opened flower buds, as well as increasing fruit set, tree yield and enhancing fruit physico-chemical quality at harvest. Also, the treatments resulted in a positive reduction in fruit blossom end breakdown. The FB spray was the most effective on decreasing blossom end breakdown as compared with the AH or BF spray at harvest or after storage. In the m...

An experiment was conducted during two successive seasons, 2008/2009 and 2009/2010, on the Zaghloul date palm cultivar grown in calcareous loamy sand and irrigated with drainage water. The purpose of the experiment was to investigate the effects of 1,000 g total N per palm applied as either ammonium sulphate, ammonium nitrate or urea and two levels of potassium (K 2 O) and elemental sulphur (S) on the nutritional status, productivity and fruit quality of the cultivar. The results of the study showed that the ammonium sulphate form (N1) increased the fruit yield, weight, length and colour compared to the ammonium nitrate (N2) or the urea form (N3). Fruit TSS, sugars, anthocyanin and dry matter content increased, whereas fruit acidity and tannins decreased under N1 fertilisation. Furthermore, the potassium and sulphur fertilisation enhanced the physico-chemical characteristics of the fruit. The N1 application increased the leaf N, K, Ca, Fe and Zn contents, as did the potassium and sulphur application. The N1 application increased the fruit N, P, K, Fe and Zn contents, whereas the fruit Cd, Pb and NO 3 were highest with N2. The potassium and sulphur applications increased the fruit N, Fe, Mn, Cd, Pb and NO 3 contents.