Application Of Naphthalene Acetic Acid Research Articles

The influence of exogenously applied 2,4-D and NAA on fruit drop reduction in pummelo cv. Thong Dee

ABSTRACTEffect of 2,4-D and naphthalene acetic acid (NAA) on fruit drop reduction in pummelo cv. Thong Dee was investigated in the pummelo growing areas of Nakhon Pathom province, Thailand. Five similar sized and aged of pummelo trees were selected to set up the experiment. Ten mature branches with the same size from each pummelo tree were randomly selected around the canopy for 2,4-D (20 and 40 mg L−1), NAA (20 and 40 mg L−1) application and control. All treatments were applied to selected pummelo branches 2 times at full bloom and 2 months after fruit set. The results showed that 20 mg L−1 NAA (14.84%) and 40 mg L−1 NAA (12.26%) gave significantly higher percent of fruit retention at 6 months after fruit set. However, leaf total nonstructural carbohydrate concentration analysis showed that 40 mg L−1 2,4-D (104.86 mg g−1) and 20 mg L−1 2,4-D (96.55 mg g−1) gave significantly higher total nonstructural carbohydrate than those in control (78.44 mg g−1). For fruit quality, 40 mg L−1 2,4-D and 20 mg L−1 2,4-D gave the highest peel weight with 435.55 and 358.57 g, respectively, and 40 mg L−1 2,4-D gave the highest peel thickness with 20.25 mm, while 20 mg L−1 NAA gave statistically higher total soluble solid than those in 20 mg L−1 2,4-D and 40 mg L−1 2,4-D. Therefore, 20 mg L−1 of NAA sprayed 2 times at full bloom and 2 month after fruit set effectively reduced fruit drop and increased percentage of fruit retention in pummelo cv. Thong Dee.

Effects of exogenous application of CPPU, NAA and GA4+7 on parthenocarpy and fruit quality in cucumber (Cucumis sativus L.)

In protected vegetable fields, plant growth regulators are often used to improve cucumber fruit growth. However, the effects of plant growth regulators on the appearance and nutritional quality of cucumber (Cucumis sativus L.) remain largely unknown. In the present study, 100 mg/L N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU), naphthaleneacetic acid (NAA) or gibberellin A4+A7 (GA4+7) was applied to the female cucumber flowers 1 day before anthesis and at anthesis. The CPPU, NAA and GA4+7 treatments resulted in parthenocarpic fruits with similar weights, sizes and shapes as the pollinated fruits. NAA treatment did not affect the appearance and nutritional characteristics of cucumber at harvest and after storage. CPPU treatment increased the flesh firmness at harvest but decreased phenolic acid and vitamin C contents after storage. GA4+7 treatment decreased the flesh firmness but increased total flavonoids and protein content after storage.

Growth Responses, Pigment and Stomatal Behaviour of Maize to Foliar Application of NAA

An investigation was conducted to find out the responses of two varieties of maize BHM- 7 (V1) and BHM-9 (V2) to Naphthalene acetic acid (NAA) on the growth, dry matter, pigment and stomatal behaviour. In case of V1, plant height was found to decrease due to all the treatments at all the ages except at 7 DAS due to T3 treatment. In V2, increase in plant height was recorded following T1 and T3 treatments at all the ages except at 21 DAS. In both the varieties at all the ages, maximum number of leaves per plant were obtained from T3 treatment. In case of V1 number of leaves per plant increased only due to T3 treatment in comparison to control whereas, in V2 number of leaves per plant increased following all the treatments. In case of V1, dry weight of shoot increased due to T3 treatment at 8 and 15 DAS. But in case of V2, there was increasing tendency in dry weight of shoot due to all treatments at all ages except at 8 DAS due to T2 treatment. In both the varieties dry weight of root increased due to T3 treatment at all ages. Chl. a was more than chl. b at all the stages in both the varieties and both chl. a and chl. b were recorded lowest at the flowering stage. In case of V1, amount of chl. b was remarkably higher at the tillering stage whereas, in case of V2, amount of chl. a and carotenoid were remarkably higher at the grain filling stage. In both the varieties, the amount of chl. a was found to increase and decrease due to all the treatments at all the stages. Chlorophyll b both increased and decreased in V1 and the maximum increase was due to T3 at the tillering and grain filling stages. In case of V2, chl. b increased at the tillering stage following all the treatments and maximum increase was also due to T3. However, in V1 carotenoid contents of leaf increased following all the treatments at the tillering stage and decreased following all the treatments at flowering and grain filling stages. Number of stomata increased except due to T2 in V1, whereas, number of epidermal cell decreased due to T0 and T2 in V1. Stomatal density in V2 was found relatively higher due to NAA application. It was also found that NAA increased the stomatal density with the increase of concentration except 50 ppm (T2) in V2. Stomatal index was found to decrease due to T1 inV1 and due to T0 in V2.Journal of Bangladesh Academy of Sciences, Vol. 41, No. 1, 1-9 2017

Ácido naftalenoacético associado à adubação potássica na brotação de café conilon

Os gastos com mão de obra podem representar mais de 50% do custo total de produção do café Conilon, sendo a poda e a desbrota responsáveis por maior parte desses custos, ficando atrás somente dos gastos com colheita. Alguns fitorreguladores de crescimento do grupo das auxinas associados ao potássio (K2O) podem reduzir a emissão de brotos. Objetivaram-se com o trabalho verificar o efeito do ácido naftalenoacético (ANA) associado à adubação potássica na brotação de café Conilon. O experimento foi realizado de junho de 2014 a dezembro de 2015, em lavoura adulta de café Conilon não irrigada, da cultivar “G35-Verdebrás”, localizada no Instituto Federal do Espírito Santo – Campus Santa Teresa. Utilizaram-se o delineamento em blocos casualizados, com o arranjo fatorial 5x4 entre níveis de ANA e níveis de K2O, respectivamente. Foram empregadas cinco doses de ANA (0, 50, 100, 250 e 500 mg L-1), e quatro de K2O na adubação, (60, 120, 240 e 480 kg ha-1). Observou-se que a aplicação de ANA influencia a emissão de brotos por favorecer a dominância apical das plantas. Os níveis aplicados de K2O interferem na ação do ANA, sendo que a aplicação de dosagens elevadas do nutriente pode inibir a ação deste fitorregulador. A aplicação de 344 mg L-1 de ANA associada à adubação de 120 Kg ha-1 de K2O reduziu o número de brotos por planta sem interferir na produtividade e desenvolvimento das brotações remanescentes.

Improvement of growth and productivity of cotton (Gossypium hirsutum L.) through foliar applications of naphthalene acetic acid

Plant growth regulators like naphthalene acetic acid (NAA) positively affect the growth and yield of crop plants. An experiment was conducted to check the foliar application of NAA on growth and yield components of cotton variety Bt.121 under field condition at research area of agriculture farm near Cholistan Institute of Desert Studies (CIDS), The Islamia University of Bahawalpur, Pakistan. The experiment was comprised of foliar application of NAA (1%) viz. T0 (control), T1 (One spray of NAA), T2 (Two sprays of NAA), T3 (Three sprays of NAA), T4 (Four sprays of NAA). The first foliar spray was applied at 45 days after sowing (DAS) and later on it was continued with 15 days interval with skilled labour by hand pump sprayer. The experiment was laid out in randomized complete block design and each treatment was replicated three times. Data recorded on growth, chlorophyll contents, yield and yield components showed a significant increase with the application of NAA. Furthermore, earliness index, mean maturity date and production rate index were also influenced with foliar application of NAA. On the basis of growth and yield parameters it can be concluded that four spray of NAA (1%) can be applied commercially under field conditions.

The Role of Plant Growth Regulators in a Plant–Aphid–Parasitoid Tritrophic System

Plant growth regulators (PGRs) play important roles in regulating plant growth. Application of PGRs may conversely affect the tritrophic plant–herbivore–parasitoid interactions. To manipulate the growth of winter wheat for rearing the English grain aphid, Sitobion avenae, which is used to rear an aphid parasitoid, Aphidius gifuensis, we determined the effects of four commonly used PGRs, indole-3-acetic acid (IAA), naphthalene acetic acid (NAA), gibberellic acid (GA3), and one plant growth retardant paclobutrazol (PBZ), on winter wheat seedlings and their indirect effects on the aphids and the parasitoids. Foliar application of IAA, NAA, and GA3 to wheat seedlings significantly affected the growth of the winter wheat plants, promoted plant height and leaf length, and increased fresh and dry weights. In contrast, PBZ had a negative effect on wheat growth. The PGRs did not affect the development, but had negative effects on fecundity and intrinsic rates of natural increase of S. avenae. The PGRs also exhibited negative effects on the parasitoids by having lower parasitism, emergence rate, and proportion of females when the host (aphids) fed on the PGRs-treated winter wheat seedlings than on untreated wheat plants. In conclusion, the PGRs-mediated effects strongly impact not only plant growth, but also the herbivores and the parasitoids. Our results suggest that the PGRs should be cautiously used to regulate plant growth if aphid parasitoids are dominant natural enemies. The information should be useful for understanding potential consequences related to biological control of aphids via parasitoids when plant growth regulators are used on crops.

Influence of naphthalene acetic acid (NAA) and integrated nutrient management (INM) on yield and economics attributes of chilli (Capsicum annuum L.)

The present experiment was conducted to study the response of naphthalene acetic acid NAA and integrated nutrient management on yield and yield attributes as well as and economics of chilli (Capsicum annuum L.) with four levels of NAA (0 ppm, 25 ppm, 50 ppm and 75 ppm) and five levels of vermicompost (VC) along with RDF (V0-100% Recommended dose of fertilizer i.e. 120:60:60 Kg N P K /ha ), V1-100% N through Vermicompost, V2-75% N through VC + 25% (RDF), V3-50% N through VC + 50% (RDF) , V4-25% N through VC + 75% (RDF), having 20 treatment combinations. The results revealed that the combine application of 50 ppm NAA and 100% N through vermicomposti.e. P2V1 performed well in respect of fruit length (8.73 cm), fruit diameter (1.46 cm) and fruit weight (2.91 g) while the application of NAA 50 ppm + 50% N through vermicompost along with 50% RDF i.e. P2V3 gave significantly (P=0.05) maximum number of fruits/plant (73.86) and fruit yield per hectare (121.20 q) with higher gross income (Rs.2,66,640.00/ ha), net profit (Rs.1,98,946.00/ ha) and benefit - cost ratio (2.94). Therefore, it can be concluded that the combine effect of NAA 50 ppm along with 50 % N through vermicompost +50% inorganic fertilizers (RDF) gave better result regarding growth and yield attributes and also generated maximum gross income, net return and B:C ratio while the next best treatment was application of NAA 75 ppm along with 25 % N through vermicompost + 75 % inorganic fertilizers (RDF).

Vegetative propagation of native fruit species of páramo <i>Thibaudia floribunda</I> and <i>Cavendishia bracteata</i> by cuttings

Cavendishia bracteata and Thibaudia floribunda (Ericaceae) are wild fruit shrubs native to the Andes region. This study aimed to characterize the rooting potential of basal and apical cuttings using naphthalene acetic acid (NAA) in different concentrations (0, 200, 500, or 1,000 mg L-1). In C. bracteata, the cutting position on the branch affected its sprouting and rooting, with apical cuttings presenting the best performance with auxin application. The rooting of cuttings was more successful in C. bracteata than in T. floribunda. NAA applications between 200 to 500 mg L-1 were more suitable for the propagation of C. bracteata due to the higher percentages of rooting and shoot production. For propagation of T. floribunda, the use of apical cuttings without the application of auxins is recommended. Adventitious roots in cuttings of both species were originated from parenchyma cells of the stem.

INFLUENCE OF GROWTH REGULATORS ON OVULES ABORTION, SEED SET AND ITS GERMENATION OF TWO ALFALFA CULTIVARS

A field experiment was conducted at the experimental farm, College of Agriculture, Abu-Ghraib, Baghdad, Iraq during the period from mid. of March 2012 to mid. of July 2014 to investigate the effects of plant growth regulators and foliar application stages on ovules abortion, seed set and its germination of two alfalfa cultivars. Layout of the experiment was R.C.B.D. arranged in split-split plot with three replications. Cultivars (local and hamedan) were assigned as a main plot and foliar application stages (vegetative growth, flower buds emergence, 50% flowering and 80% flowering) were assigned as sub-plots, while growth regulators (Alar, Ethephon, Naphthalene acetic acid(NAA) and control treatment) were assigned in the sub-sub-plots. Result showed that there were no significant differences between cultivars in all traits. Foliar application of NAA increased No. of ovules per floret (9.11) compare with other treatments, but it was not significantly different compare with Alar. In 1st and 2nd seed crop, plants sprayed with Alar at flower buds emergence stage gave highest seed set (5.17, 6.93) respectively. Percentage of ovules abortion significantly influenced by growth regulaters, folair application stages and their interaction. Since, foliar application of Alar at beginning of flower buds emergence reduce % of ovules abortion (30.89). In general, plants sprayed at vegetation growth stage increased % of seed germination. It was clear from this study that more than 40% of ovules were aborted, this may be one of the reasons for reduction of seed yield in alfalfa, therefore, we recommended to do more researches in this field in order to know the causes of ovules abortion.

Vegetative propagation of twelve fodder tree species indigenous to the Sahel, West Africa

In the Sahel region, many woody species are used as fodder because of their high nitrogen content, especially during the dry season, in contrast to grasses and crop residues. Unfortunately, this resource is being threatened by regular pruning, increasing livestock browsing and impeding their natural regeneration. Therefore, there is a need to find appropriate regeneration options to sustain fodder production. Thus, a series of vegetative propagation experiments were conducted to identify the most appropriate multiplication methods of some of the species used as fodder. This series included testing the effects of naphthalene acetic acid (NAA) and indole butyric acid (IBA) on rooting ability of stem cuttings of 12 species: Afzelia africana, Balanites aegyptiaca, Bauhinia rufescens, Commiphora africana, Faidherbia albida, Ficus gnaphalocarpa, Guiera senegalensis, Kigelia africana, Pterocarpus erinaceus, Pterocarpus lucens, Pterocarpus santalinoides and Terminalia avicennioides. The series also evaluated the impacts of the size (C. africana) and the age (P. erinaceus) of the cuttings on their rooting success. Pterocarpus santalinoides was revealed to be an easy-to-root species, showing a high percentage of rooted cuttings (up to 88±3%), followed by P. erinaceus, P. lucens and B. aegyptiaca (up to 37±4%, 31±5% and 26±6%, respectively), in contrast to A. africana, cuttings of which did not root at all. The application of NAA and IBA enhanced the number of roots and secondary roots per rooted cutting. Large-diameter cuttings (15–20 mm) of deeply planted C. africana gave the highest percentage of rooted cuttings (78.3±4.4%). Tree pruning improved the rooting capacity of cuttings collected from P. erinaceus with one-month resprouts giving the highest percentage of rooted cuttings (50.0±6.7%). These results indicate that P. santalinoides, C. africana, P. erinaceus, P. lucens and B. aegyptiaca are amenable to vegetative propagation as an alternative to sexual propagation.

Biochemical characteristics of red bean (Phaseolus vulgaris L.) genotypes as affected by seed pre-treatment with growth regulators .

In order to investigate the effect of seed pretreatment with growth regulators on biochemical characteristics of red bean genotypes, a factorial experiment was carried out in a randomized complete block design with three replications. In this research, seed pretreatment with growth regulators namely salicylic acid (SA) and naphthalene acetic acid (NAA) were applied at four levels including P0: control (pretreated with distilled water); P1: pretreated with NAA hormone (0.5 mM/lit); P2: pretreated with SA hormone (0.7 mM/lit); P3: pretreated with combination of NAA hormones (0.5 and 0.7 mM/lit) and two genotypes of red beans (KS31169 and D81083). The ANOVA results showed that the simple effects and the interactive effects of genotypes × priming with growth regulators on all traits were significant except the relative chlorophyll content. The results of mean comparison for the interactive effect of genotypes and priming with growth regulators showed that application of SA increased the amount of chlorophyll a in D81083 genotype. The highest rate of chlorophyll b and total chlorophyll belonged to D81083 genotype with application of NAA. The rates of flavonoids and carotenoids decreased by using growth regulators, therefore the highest rates of these traits were observed in control × D81083 genotype. Seed priming with combined treatments (NAA+SA) led to the highest stability of cytoplasmic membrane in KS31169 genotype. In general, the results of the present study indicated that the use of growth regulators as seed pretreatment will increase the main pigments of photosynthesis and cytoplasmic membrane stability.

Chemical thinning of ‘Barouni’ and ‘Manzanilla’ olives with naphthalene acetic acid under South African conditions

Table olives grown in the Mediterranean-type climate of Western Cape province of South Africa are prone to alternate bearing, as elsewhere in the world. To date, South African producers have tolerated the negative effects of alternate bearing, but due to increased olive production costs, profit margins are decreasing and producers have to reduce alternate bearing. Trials were conducted to evaluate the use of naphthalene acetic acid (NAA) on ‘Barouni’ and ‘Manzanilla’, the most important green table olive cultivars grown in South Africa. NAA is used elsewhere in the world, but local research is required since the efficacy of NAA is modulated by environmental conditions and genotype. NAA decreased the fruit number per tree, thereby improving fruit size in both cultivars. Thinning did not affect return bloom in ‘Barouni’, possibly due to the low level of thinning achieved, whereas adverse climatic conditions during flower development may be to blame for the lack of return bloom in ‘Manzanilla’. Although NAA application did not affect the income per hectare, profitability may increase as harvesting costs account for roughly 50% of the input costs. Based on these results, 200 mg L−1 NAA, applied 10–15 d after full bloom, is recommended for local conditions.

Effect of pre-harvest application of NAA and potassium nitrate on storage quality of winter guava (<i>Psidium guajava</i>)

A study was conducted at Punjab Agricultural University, Ludhiana during 2006–08 in winter crop of guava cv. Sardar to evaluate the influence of pre-harvest foliar application of naphthalene acetic acid (NAA) and potassium nitrate on quality attributes in different interval of cold storage. The plants were sprayed with NAA and potassium nitrate at colour break stage of fruit and harvested at optimum maturity, packed in CFB boxes with newspaper lining and stored at 6- 8oC and 90-95% RH. Fruits treated with NAA (100 ppm) effectively reduced spoilage maintained higher fruit firmness, TSS and ascorbic acid and remain slightly desirable after 30 days of storage. Thus, pre-harvest spray with NAA (100 ppm) seems to be effective method for decreasing post- harvest losses and maintaining quality of guava fruits.

Effect of naphthalene acetic acid (NAA) as growth regulator along with chelated zinc and iron on the availability of manganese, zinc, copper and iron in Mentha piperita Linn cultivar Kukrail

A field experiment was displayed at the research plot of chemistry Department of Allahabad Agricultural Institute Deemed University, Allahabad to study the effect of NAA along with chelated Zinc and Iron on the availability of micronutrients of Mentha piperrita cultivar Kukrail during winter season. It is quite obvious that Mn was influenced significantly by application of NAA and Zn/Fe EDTA through foliar spray. The concentration of Mn increased with increasing levels of NAA with or without application of Zn/Fe EDTA and markedly higher in Mentha plants at 60 ppm NAA with 10ppm Zn/Fe EDTA. The higher concentration of NAA suppressed the uptake of nutrients above 60 ppm. However, the intake of Mn, Zn and Cu was much higher in second year trial with NAA and Zn while Fe obtained higher uptake in first year than that of second year experiment. The application of NAA was found to increase the Cu uptake with increasing doses till 60ppm with or without the incorporation of Zn/Fe and then gradually a fall at higher concentrations. The second cutting value in second year trial was higher than the corresponding year cutting affected by NAA with Zn. The result was found significant over control due to foliar application of NAA and Fe separately in second year experiment. Fe uptake in mint plants grown with different doses of NAA and Fe in second year trial was greater than first year trial. The Fe uptake in menta piperita plants in both trials were found higher over control. But the Fe uptake in mint plants narrowed down above 60ppm of NAA application with or without Zn/Fe EDTA spray.DOI: http://dx.doi.org/10.3126/ije.v3i2.10636 International Journal of the Environment Vol.3(2) 2014: 238-245

Improvement in yield and fruit size and quality of the main Italian table olive cultivar 'Nocellara del Belice'

Olive (Olea europaea L.) shows alternate bearing, with unreliable cropping patterns and inconsistent fruit size and quality every year. In many countries, thinning with naphthaleneacetic acid (NAA) is used to minimise alternate bearing behavior in olives. However, in Italy, growers are reluctant to employ this practice and no detailed knowledge is available for specific cultivars. We evaluated the effects of spraying NAA on various dates on the productive and vegetative characteristics of the main Italian table olive cultivar'Nocellara del Belice'. Trunk cross-sectional area, fruit set, fruit drop, fruit size, pit size, yield per tree, crop density and flesh to pit ratio were analysed. The NAA treatment applied on the earliest of the dates selected increased fruit weight and flesh to pit ratio, by reducing crop density and enhancing the leaf to fruit ratio, without reducing yield. Two distinct negative relationships were found between fruit weight and crop density during "on" and "off" years, but a unique relationship between pit weight vs. crop density in both years, suggested that the pit is the strongest sink. Fruit size and quality of'Nocellara del Belice' can be enhanced by NAA application, thereby increasing economic returns in the "on" year.

Naphthaleneacetic Acid and Ethephon Are Florigenic in the Biennial Apple Cultivars Golden Delicious and York Imperial

‘Golden Delicious’ and ‘York Imperial’ are apple cultivars that are prone to develop a biennial bearing habit. A successful chemical thinning program with carbaryl plus 6-benzyladenine applied at the 10-mm fruit diameter stage reduced cropload and increased return bloom of ‘York Imperial’, although the improvement in return bloom resulting from chemical thinning was insufficient to ensure a commercial cropload in the year after treatment (fewer than 10% of spurs developing flowers). A chemical thinning program with multiple applications of a naphthaleneacetic acid (NAA) and ethephon mixture during the period from 36 to 73 days after bloom increased return bloom of ‘York Imperial’ trees to commercially acceptable levels (25% or greater of spurs flowering). NAA applied during the period from 50 to 100 days after bloom (summer NAA program) or from 110 to 140 days after bloom (preharvest NAA program) increased return bloom of ‘Golden Delicious’. When aminoethoxyvinylglycine (AVG) was included with the first NAA spray in a summer program, the efficacy was reduced, indicating that ethylene may be partly involved in the florigenic activity of NAA. Dissection of ‘Golden Delicious’ buds sampled from three locations (Asheville, NC; Amherst, MA; Wenatchee, WA) at ≈14-day intervals beginning 50 days after bloom indicated that the time of floral transition (doming of the meristem apex) occurred during the period from 65 to 105 days after bloom at each location. Thus, NAA applications in a summer program for return bloom coincided with the period when floral determination normally occurred. Preharvest NAA programs effectively promoted return bloom in the experiments where a summer NAA program was also effective. These responses indicate that NAA can trigger floral development within vegetative buds relatively late in the summer and outside of the time period when it is generally believed possible to influence flower bud formation.

Response of Fuchsia hybrida cuttings to flurprimidol and naphthaleneacetic acid application

Auxins are the only compounds used in commercial plant propagation to stimulate rooting, although efforts have been made to find other efficient compounds. Another group of rooting promoters could be plant growth retardants (PGRs) which act as inhibitors of gibberellin synthesis. The aim of the experiment was to determine the effect of flurprimidol and naphthalene-1-acetic acid (NAA) applied by quick-dip method on rooting and development of <em>Fuchsia hybrida</em> 'Swingtime' cuttings and their subsequent growth. Anatomical analysis of the rooting process was also done. Flurprimidol and NAA did not influence the percentage of rooted fuchsia cuttings but increased the number of adventitious roots. Both compounds were involved in earlier formation of root primordia. Flurprimidol and NAA, used simultaneously or separately, increased the number and length of axillary shoots of fuchsia cuttings. The effect of flurprimidol on the number of roots and shoots was stronger than that of NAA, but diminished after transplanting the rooted cuttings. The influence of flurprimidol on axillary shoot length was weaker as its concentration increased.

Uso de fitorreguladores no desenvolvimento de frutos na atemoieira (Annona cherimola x A. squamosa cv. Gefner)

Este trabalho foi realizado com atemoieiras 'Gefner', com o objetivo de avaliar o efeito de fitorreguladores no pegamento de frutos. Foram realizados três experimentos, no município de Matias Cardoso, Minas Gerais. No primeiro, avaliaram-se quatro tipos de auxinas: os ácidos indol butírico (AIB), indol acético (AIA), naftaleno acético (ANA) e diclorofenoxiacético (2,4-D), combinados com três concentrações (150, 300 e 450 mg L-1). O ácido giberélico (GA3) também foi aplicado, na dosagem de 1 g L-1, aos 14 e 21 dias após a primeira aplicação das auxinas. No segundo experimento, testaram-se o AIA, AIB e ANA, combinados em duas concentrações (450 e 600 mg L-1). No terceiro experimento, avaliou-se a aplicação do ANA na dose de 450 mg L-1 associado com número de aplicações: semanal até 35 dias; semanal até 70 dias; semanal até 105 dias e a cada duas semanas. O GA3 foi utilizado na dosagem de 1 g L-1, em quatro aplicações, aos 13, 27, 41 e 54 dias após a primeira aplicação do ANA. Em todos os experimentos, a testemunha foram flores polinizadas artificialmente. ANA foi a auxina sintética que propiciou as maiores médias de pegamento dos frutos, com 8% até aos 148 dias após a primeira aplicação. A utilização de 2,4-D acarretou as menores percentagens de pegamento dos frutos; no 14° dia da aplicação, mais nenhum fruto foi observado. Independentemente do tipo de fitorregulador, os tratamentos não permitiram o desenvolvimento de frutos comerciais de atemoia.

Jujube post-harvest fruit quality and storagability in response to agro-chemicals preharvest application

The present study was conducted on Peyuan jujube cultivar (Ziziphus Mauritania Lamk) during the two successive seasons, 2010 and 2011 at Research and Agricultural Experimental Station, King Saud University, Saudi Arabia in order to investigate the effects of preharvest application of putrescine (Put), gibberellic acid (GA3), salicylic acid (SA), naphthalene acetic acid (NAA), cytofex (CPPU) and calcium chloride (CaCl2) on fruit yield, ripening date and quality at harvest and after cold storage at 5°C and 85 to 90% relative humidity (RH). Fruits were sprayed once three weeks before harvest (at the beginning of fruit color break) when they reached a diameter of 6 to 7 mm. Data showed that, the latest harvest was obtained with NAA followed by GA3 and CPPU treatments and then SA and CaCl2. The CaCl2 and NAA gave the shortest harvest spread (period). All agro-chemical substances gave the lowest yield percentage at the first harvest date, while at the second harvest date, GA3, putrescine (Put) and SA sprays resulted in the highest yield followed by CPPU and then NAA applications. At the third harvest date the NAA, GA3, Put and CPPU gave the highest yield percent followed by SA and then CaCl2. Fruit vitamin C, total soluble solids (TSS), acidity, firmness and quality grade increased significantly by all treatments as compared with the control either at harvest time or after cold storage. The percentage of fruit weight loss, commercially unacceptable peel as well as, fruit browning index tended to decrease with all sprayed substances. Key words: Jujube, fruit quality, storagability, agro-chemicals, pre-harvest application.

Effect of hormone treatments on deformed fruit development in pear

Fruit shape is one of the most important limiting factors in the quality of pear fruits. The effects of applied plant growth regulators on fruit shape have been determined in pear. The application of naphthalene acetic acid (NAA, 20 mg/L), indole-3-butyric acid (IBA, 30 mg/L), 6-benzalyamino acid (6BA, 30 mg/L), cleaner production promotion unit (CPPU, 10 mg/L), gibberrelin (GA4+7, 3%) and gibberrelic acid (GA3, 2.7%) at the young fruit period enhanced fruit growth, improved final fruit size, and decreased the occurrence of deformed fruit. CPPU and 6-BA significantly enhanced the growth of horizontal diameter, while GA3 and GA4+7 stimulated fruit vertical diameter that tend to grow more apparently.