Individual Fruit Weight Research Articles

Effect of foliar spray of water soluble fertilizer on growth and yield of chilli hybrid (Capsicum annuum L.)

Field experiment was carried out in the Department of Horticulture, Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal during the year 2009. Among the 16 treatments, the combination of 100 per cent RDF + 1.0 per cent water soluble fertilizer + 5 spray produced maximum plant height, number of branches per plant, fruit length, fruit girth, individual fruit weight, number of fruits per plant, yield per plant and yield per hectare when compared to water spray and other treatments.

Genetic divergence of indigenous pummelo genotypes

The genetic divergence was studied in33pummelogenotypes using D2 statistics and principal component analysis at Regional Agricultural Research Station, BARI, Akbarpur, Moulvibazar during 2012 to 2014. The genotypes were grouped into 5 clusters and the maximum number of genotypes was included in cluster IV and V and the minimum number in cluster I. The inter cluster distance in all of the cases were higher than the intra cluster distance indicating wider genetic diversity among the accessions of different groups. The highest inter-cluster distance was observed between cluster I and II followed by cluster II and V and the lowest between III and IV. The highest intra- cluster distance was observed for the cluster II and the lowest for the cluster III. For cluster II, the highest mean values for plant height (6.13m), individual fruit weight (1141.67g), fruit length (13.03 cm) and breadth (13.15 cm), number of segments per fruit (14.41), number and weight of seeds per fruit (123.67 and 50.41g), yield per plant (50.94 kg) were observed. The first axis largely accounted for the variation among the pummelo accessions (26.16%) followed by second axis (18.75%). The first 8 axes accounted 90.56 % of the total variation. The characters individual fruit weight (g) and weight of seeds per fruit (g) showing positive value in both the vectors contributed maximum towards divergence. Considering magnitude of genetic distance, contribution of different traits toward the total divergence, magnitude of cluster means for different traits and performance the genotypes of cluster I, II, and IV may be considered as parents for future hybridization program.Res. Agric., Livest. Fish.3(1): 37-43, April 2016

Plum cultivars Zlatka and Pozna Plava (Prunus domestica L.) bred at the Fruit Research Institute in Čačak

This study was carried out to compare the most relevant biological characteristics and field resistance to economically important diseases of the new (Zlatka and Pozna Plava) and standard plum cultivars (Čačanska Lepotica and Čačanska Rodna) in the Region of Čačak. The experimental area climate belongs to the temperate type. The mean annual air temperature during the experimental period was 12.65°C, and humidity was 80.4%. The average annual rainfall was 571.2 mm. The ripening time of the cv. Zlatka occurred between August 3-23, while the cv. Pozna Plava ripened between August 26-September 25. Compared to cv. Čačanska Lepotica, cv. Zlatka had a significantly lower mean fruit weight, reducing sugars and total acids content, but a significantly higher proportion of flesh, yield and sucrose content. Compared to cv. Čačanska Rodna as the standard cultivar, cv. Pozna Plava had a significantly higher mean individual fruit weight and total acids content, but also a significantly lower orchard yield and sweetness measured as fruit soluble solids, total sugars, reducing sugars and sucrose content. As regards the field resistance to economically important diseases such as red leaf spot, rust, fruit root, pockets plum disease and sharka disease, both new cultivars demonstrated better results than the reference cultivars.

Effect of Defoliation on Growth and Yield Response in Two Tomato (Solanum lycopersicum Mill.) Varieties

An experiment was conducted at Plant Physiology laboratory of Bangladesh Institute of Nuclear Agriculture, Mymensingh, Bangladesh to investigate the effect of defoliations on crop characters, yield attributes and yield of two tomato varieties. The experiment comprised five levels of defoliation viz., 0 (control), 3, 6, 9 and 12 leaves defoliation out of 16 leaves and two varieties viz., Binatomato-4 and Binatomato-5. The experiment was laid out in two factors completely randomized design with four replications. Results revealed that defoliation and variety had significant effect on the studied crop characters and yield except the number of effective flower clusters per plant and fruit yield for variety. Most of the parameters like plant height, number of branches and leaves per plant, straw weight per plant, number of effective and non effective flower cluster per plant, number of flowers and fruits per plant, individual fruit weight and fruit yield per plant increased with defoliations over control up to 6 leaves and produced the highest in 3 leaves defoliated plant whereas the lowest was obtained in 12 leaves defoliated plants followed by 9 leaves defoliated plants. Therefore, due to the performance of morphological and yield attributing traits especially number of fruits per plant and number of fruits per cluster were superior in Binatomato-5 but fruit yield was inferior compared to Binatomato-4 in respect of smaller fruit size.

Assessment of genetic variability in the endangered Citrus macroptera Mont. (“hatkora”) from Mizoram, north-east India

Assessment of genetic variability in the available germplasm is the prerequisite for development of improved genotypes through planned breeding programmes. In view of this, 39 “hatkora” (Citrus macroptera Mont.) genotypes collected from different locations of Mizoram, India were evaluated for physico-chemical characteristics during 2013–2015. The study reveals that there was significant variation among the collections in these particular traits. Individual fruit weight ranged from 277.78 to 617.69 g; fruit diameter 9.32–12.52 cm; fruit length 7.74–10.19 cm, fruit volume 238.33–583.33 cc; pulp weight 153.75–320.94 g; pulp:peel ratio 1.50–3.24 and seed number 9.33–23.6. Similarly, the chemical parameters also varied significantly among different germplasms. The juice content varied from 13.45 to 32.53 %, ascorbic acid 34.81–73.64 mg/100 mL, TSS 6.15–9.10 %, acidity 5.03–8.75 %, total sugars 5.16–7.97 % and sugar:acid ratio 0.75–1.52. From the analysis of genetic parameters, it could be concluded that characters like fruit weight, fruit length, fruit diameter, fruit volume, pulp weight, pulp–peel ratio, juice, Total soluble solids (TSS), acidity, ascorbic acid, total sugars, and sugar–acid ratio could be used as selection criteria for development of effective and productive plant types in “hatkora”. Wide range of variation in physico-chemical parameters of “hatkora” fruits indicated the great scope of individual plant selection based on these characters for future genetic improvement programme.

Effect of gibberellic acid application on plant growth attributes, return bloom, and fruit quality of rabbiteye blueberry

Gibberellic acid (GA3) plays an important role in many plant growth and development processes. In order to evaluate the effect of GA3 on plant growth, return bloom, and fruit quality of rabbiteye blueberry, three representative cultivars (Powder blue, Garden blue, Climax) were treated by 500mg/L GA3. Foliar application of GA3 dramatically increased return bloom for three cultivars. Compared to the untreated control plants, ‘Powder blue’, ‘Garden blue’, and ‘Climax’ treated with GA3 increased inflorescences number by 54.3%, 69.7%, and 60.0% in the next year, respectively (p<0.05). Foliar GA3 application also increased leaf area, leaf fresh weight, leaf dry weight, chlorophyll content, the level of chlorophyll a and b, individual fruit weight, and number of fertile seeds. However fruit ripening and the harvest date of all three cultivars were delayed in the following year. GA3 application did not significantly change length/diameter ratio of rabbiteye blueberry fruits. All the results suggest that GA3 application is potentially promising for enhancing plant growth and fruit quality of rabbiteye blueberry with delayed ripening time.

Cultivars Response to Morphological and Yield Attributes of Okra at Sylhet Region

An experiment was conducted at the field laboratory of Department of Crop Botany and Tea Production Technology, Sylhet Agricultural University from May to October 2013 with a view to select the superior Okra cultivar (s). The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. A total of 8 cultivars viz. BARI Dherosh-1 (control), Orka Onamika, Bankim, Durga, JO (Japanese Okra)-1, JO-2, JO-3 and JO-4 were evaluated in relation to morphological and yield attributes in acidic soil conditions. Significant variations were observed in almost all parameters. Results revealed that high yielding cultivar Bankim exhibited taller plant at final harvest, produced early flowers with maximum fruit setting (%) and fruit length. The cultivar JO-3 produced maximum number of branches and leaves at final harvest. Local check cultivar showed highest internodes number and length along with maximum number of flowers and 100 seed weight. The cultivars JO-1 and JO-4 showed highest individual fruit weight and maximum fruit

Quality and capsaicinoid concentration on genotypes of Serrano pepper (Capsicum annuum L.) produced under organic fertilization

The aim of this study was to evaluate the effect of threeorganic fertilization sources on the agronomic and biochemical qualitiesof four genotypes of Serrano pepper. The experiment was performedat the field in Gomez Palacio, Durango (Mexico). The capsaicinoids(CAP´s) are compounds responsible of the pungency ofthe peppers, and they are valuable for health and food and cosmeticfood. The organic treatments applied were: solarized bovine manure(60 Mg/ha), vermicompost (10 Mg/ha) and poultry manure (5 Mg/ha). A non-fertilized treatment was used as control. The evaluatedvariables were: length, diameter and individual weight on fruits, andcapsaicin and dihidrocapsaicin concentrations in pulp and seeds. Theresults showed significant differences among treatments in the evaluatedvariables, as well as regarding the fertilization treatments. Thegenotype Don Diego I fertilized with vermicompost had the largerfruit weight, while the genotypes Don Vicente and Don Diego Ishowed the highest values of length, diameter and individual fruitweight without considering the fertilization source. Regarding the3 organic treatments applied, the genotype Don Vicente fertilizedwith poultry manure had the highest concentration of capsaicinoids.The organic materials evaluated can be applied as a nutritional sourcefor production of Serrano pepper in arid zones, obtaining the highestfruit quality by fertilization with vermicompost. The genotypes DonDiego I and Pepper Don Vicente obtained the highest capsaicinoidconcentration.

Mitigating Climate Change Impact on Tomato (Solanum lycopersicum Mill.) under Protected Cultivation

Under the climate change scenario, protected cultivation may possibly provide ample scope for ‘off'season production of high-value vegetable crops. Among the highvalue crops, tomato (Solanum lycopersicum Mill.) is most important and rich sources of lycopene, β-carotene, phenols, flavonoids and many vitamins. The performances of eight tomato varieties, namely Himsona, Naveen, NS-524, Red Beauty (cherry tomato), Arka Samrat, Abhilash, Shahenshah and Arka Rakshak in terms of their yield and quality parameters under polyhouse condition were evaluated. Conducive temperature and relative humidity inside polyhouse were maintained in the range of 26–28°C and 65–90%, respectively. The total fruit weight/plant ranged from 3.50 to 10.45 kg/plant and was maximum in Himsona with minimum in Red Beauty. The fruit number per plant varied from 69 to 700, and individual fruit weight ranged from 5.0 to 88.0 g. Himsona registered higher yield along with maximum marketable shelf life (12 days) as compared with other cultivars. Red Beauty recorded higher lycopene content besides total soluble solid (TSS) and TSS/acidity ratio at red-ripe stage. Thus, Himsona and Red Beauty can be used for cultivation under protected condition in subtropical areas for higher yield and quality.

Assessment of physico-chemical properties of jackfruit collections from Kuttanad region of Kerala

HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE ABSTRACT : Artocarpus heterophyllus Lam (Jackfruit) which belongs to the family Moraceae, is believed to be indigenous to the south western rain forest of India. It is an important component of homestead gardens in Kerala. A lot of variability exists among jack trees as most of them are raised from seedlings. Hence, a study was conducted at Regional Agricultural Research Station, Kumarakom during 2011-14 to assess the variation in fruit quality and bearing habit of jack trees grown under the agro climatic conditions of Kuttanad and to recommend the promising types of jack types suitable to this region. To identify the superior indigenous jackfruit types a survey work has been carried out in Kuttanad region and identified 21 firm fleshed jack types. Organoleptic test was conducted for these genotypes and selected 10 promising types with good sensory quality. Physico-chemical properties of these genotypes were evaluated. A significant variation in physico-chemical characters of jackfruit were observed among these jack selections. The physical characters of fruit such as individual fruit weight ranged from 1.69 to17.50 kg, bulb mass 0.80 10.25 kg, flake mass 0.64 – 6.62 kg, single bulb weight 13.20 48.36 g and flake thickness 0.31 0.63 cm. Similarly, the chemical parameters also varied significantly among these selections. The TSS varied from 12.60 31.80 °Brix, ascorbic acid 1.50 10.55 mg/ 100g, acidity 0.20 1.02 per cent, total sugar 20.84 61.88 per cent and reducing sugar 3.18 9.39 per cent. The selected superior jack types met the standard parameters for high quality fruits, and can be recommended for their performance and sustainable yield in such type of environment. These promising selections were propagated through patch budding and are maintained in our station as part of our germplasm conservation. The result of this study is a useful information for further crop improvement programmes in jack.

Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development

A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions – pollen originating from plants raised in charcoal-Purafil® filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O3. The O3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O3 × CFA and CFA × O3 crossed plants. This suggests O3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol−1 O3 (10 h d−1) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit – a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O3, and potentially other gaseous pollutants, on reproductive biology during ‘risk assessment’ exercises.

Plant growth regulators promote growth and yield of summer tomato (lycopersicone sculentum Mill.)

An experiment was conducted at the Horticulture Farm of Bangladesh Agricultural University, Mymensingh to test the impact of plant growth regulators on growth and yield of summer tomato. The experiment consisted of two tomato varieties viz. BARI Hybrid Tomato-4 and BARI Hybrid Tomato-8 and four types of plant growth regulator (PGR)viz.,(i) control (without PGR), (ii) 4-CPA (4-chlorophenoxy acetic acid), GA3 (gibberellic acid) and 4-CPA +GA3. The two-factor experiment was laid out in randomized complete block design with three replications. The results of the experiment revealed that significant variations were observed for most of the characters studied. At 75 DAT, the tallest plant (79.35 cm), number of flowers and fruits (38.11 and 19.04, respectively) plant-1, individual weight (58.44 g) and fruit yield (22.75 t ha-1) were found in BARI Hybrid Tomato-8.At 75 DAT the maximum plant height (87.90 cm), number of flowers and fruits (49.04 and 21.9, respectively) plant-1, individual fruit weight (61.16 g), and fruit yield (27.28 tha-1) were found when 4-CPA + GA3 applied together, whereas the minimum for these characters were recorded from control plants. In case of combined effect of variety and plant growth regulator, the maximum plant height (87.90 cm), number of flowers and fruits (49.04 and 21.91, respectively) plant-1, individual fruit weight (61.16 g) and fruit yield (27.28 t ha-1) were observed in BARI Hybrid Tomato-8 when treated with 4-CPA + GA3together, and the minimum for all these parameters were found in control plants. The results of the present study suggest thatboth 4-CAP and GA3together can be practiced for increasing summer tomato production for both the varieties.Progressive Agriculture 26:32-37, 2015

Influence of various nutrient concentrations on the growth and yield of summer strawberry cultivars cultivated in a hydroponic system

Summer strawberry (Fragaria x ananassa) is an important berry crop for the Korean fresh market and confectionary industry due to its pleasant taste and the health-promoting properties of its phytochemicals. ‘Albion’ and ‘Goha’ strawberry were grown hydroponically in highland altitudes (800 m above sea level) in Pyeongchang, Gangwon Province, Korea, to evaluate the effect of four nutrient concentrations [electrical conductivity (EC) 0.5, 1.0, 1.5, and 2.0 dS·m −1] on growth and yield of the varieties. Plug-grown seedlings at the 3rd leaf stage were transplanted to the hydroponic system bed containing coir dust medium on May 13, 2014. Plant growth parameters including plant height, dry weight, and root weight, as well as yield were measured during experiments. The elevation of nutrient solution EC from 0.5 to 1.0 dS·m −1 resulted in significant increase of plant height and shoot dry weight in both cultivars. As the EC was elevated in nutrient solution, the roots became longer in ‘Goha’ strawberry, but those in ‘Albion’ strawberry shortened. When the solution EC was increased to 1.0 dS·m −1, the leaf area increased significantly in ‘Goha’ but did not change significantly in ‘Albion’ strawberry. The various solution ECs did not significantly affect the yield of ‘Goha’ strawberry. However, elevation of the solution EC to 2.0 dS·m −1 significantly reduced the yield of ‘Albion’ strawberry. The treatment at 1.5 dS·m −1 led to the highest number of fruits, but the average weight of individual fruit was the lowest among treatments in ‘Goha’ strawberry. Physiological disorders were observed in the treatments of 0.5 and 2.0 dS·m −1. The above results suggested that 1.0 dS·m −1 in nutrient solution strength was the most effective for the overall production of ‘Albion’ and ‘Goha’ strawberries.

Effect of Deficit Irrigation on Growth and Yield of Tomato under Drip Irrigation in Shade Net House

The effect of deficit irrigation on growth and production of drip irrigated tomato under shade net house was studied through field experiment. Four different levels of drip irrigation equivalent to 100%, 80%, 60% and 40% of crop evapotranspiration with five replications were considered for their effect on crop growth and crop yield inside the shade net house. Tomato (Solanum Lycopersicon, Badshah Variety) plants were grown under the shade net house with 50% shade. Plant height, number of leaves and individual fruit weight were found to be highest with 80 % irrigation, giving highest yield of 108.30 t.ha-1. Actual irrigation water application between 1.62 and 4.58 mm.day-1 was thus recommended for tomato crop in a shade net house.

Bio-friendly management of Guava fruit fly (Bactrocera correcta Bezzi) through wrapping technique

Fruit fly (Bactrocera correcta Bezzi) is the major pest of Guava grown in Baruipur region of West Bengal, contributing upto 90% yield loss. The present study was undertaken during 2011-12 at farmers’ field to validate the wrapping of individual fruits at tree and to standardize the wrapping material and the correct technique of wrapping. Performance of nine different types of wrapping materials (butter paper bag, polypropylene bag of 20? gauge with and without paper piece inside, non-woven poly fabric bags of white, green and blue colour with 20 gsm and 40 gsm thickness) along with two chemical approaches were studied against untreated control. Fruit fly infestation varied between 1.32 % and 17.31% in all treatments using wrapping materials and 13.14% in case of combined use of pheromone trap (Bacu lure) and Dichlorvos spray as compared to 21.71% in sole use of Dichlorvos and 66.67% in control plots. Wrapping resulted in increased weight of individual fruits (112.58 g in butter paper bag compared to 68.40 g in control). Wrapping with transparent polypropylene bags (20? gauge) with partial paper cover inside, resulted in lowest yield loss (1.66%), earlier fruit maturity, better fruit quality (in respect of colour and glossiness), highest market price (`30 per kg) and highest net profit (`1.357 lakh/ha). This material is durable enough to be reused for 4-5 times. The partial paper cover helped to prevent scorching injury to the fruit as well as to control the humidity inside the polypropylene bag.

Rain-Fed Plantations Of The Domesticated Ziziphus Mauritiana In The Sahel: Effects Of Varieties And Rootstocks On Yields And Fruit Quality

Abstract A long-term study was conducted to explore the possibility of using traditional rain-fed systems for growing domesticated Ziziphus mauritiana (so-called Pomme du Sahel) in the Sahel. Five varieties, Gola, Ben Gurion, Seb, Umran and Kaithli, were grafted on six rootstocks of Z. mauritiana from various agroecological zones of Niger. Trees were planted inside microcatchments at 8 × 8 m spacing. Over a period of six years, the variety Umran gave the highest fruit yield (3600 kg·ha−1) and the lowest fruit yield was documented for variety Seb (1970 kg·ha−1). Individual fruit weight ranged from 25.8 g for ‘Umran’ to 9.5 g for ‘Seb’. The rootstocks had no effect on average fruits yields and fruit size. There was a significant linear correlation between fruit yield and annual rainfall. In a rainy year (680 mm), the average yield of the five varieties was 7580 kg·ha−1. The results of the current study indicate that dry land plantations of Pomme du Sahel can guarantee food security during dry years in the Sahel. However, further studies are required to evaluate the economic feasibility of this system.

EVALUATION OF ROOTSTOCK EFFECT ON TOLERANCE TO IRON CHLOROSIS AND CYTOSPORA CANKER IN PEACHES

The Western Colorado peach growing area is characterized by semi-arid conditions with heavy soils, and high soil and water pHs contributing to severe leaf chlorosis. ‘Redhaven’ peach trees grafted to 17 rootstocks were planted in a randomized block design with 8 replications in 2009 at the Western Colorado Research Center. One of the objectives of this study was to evaluate the performance of the trees under Colorado climatic and edaphic conditions. Tree growth measurements and survival were recorded each year. By the third year after planting, trees showed different levels of foliar chlorosis probably caused by micronutrient deficiency aggravated by high soil pH. These trees were rated for chlorosis based on visual observation (0-10 scale) where 0= no chlorosis to 10 having almost total canopy chlorosis in appearance. Fruit data collected in the third year showed a significant (P=<0.0001 and r2 = 0.59) impact of rootstocks on chlorosis where trees on different rootstocks produced different levels of chlorosis. The highest chlorosis was observed with ‘HBOK 10’, followed by ‘KV010-123’, and ‘KV010-127’; whereas many trees on rootstocks such as ‘Viking’, ‘Atlas’, ‘Guardian®’, ‘Mirobac’ (aka ‘Replantpac’) had lower chlorosis levels and most of the others were intermediate. Tree circumference was significantly affected by the chlorosis (P= 0.004). There was no impact of chlorosis on total fruit yield per tree, total number of fruits per tree, individual fruit weight, or incidence and severity of Cytospora canker among the trees grafted to different rootstocks. Trees on rootstocks such as ‘Atlas’, ‘Fortuna’, and ‘Mirobac’ had 100% disease infection. The majority of rootstocks had at least 12.5% tree death except ‘Viking’, which had 50% mortality. Tree death on ‘Viking’ occurred during the first year after planting; whereas most other trees on different rootstocks died in the second and third year due to Cytospora Canker.

Effect of nitrogen, phosphorus, potassium and sulphur on the yield of mango

The experiment was conducted at the research field of Regional Horticulture Research Station, Chapai Nawabganj during 2010-11, 2011-12 and 2012-13 to find out the proper combination of fertilizer nutrients (N, P, K and S) in presence of organic manure for obtaining higher yield of mango (var. BARI Aam-1). The treatments were native nutrient i.e. control (T1), N360P80K150S50 (T2), N560P120K200S70 (T3), N760P160K250S90 (T4), N960P200K300S110 (T5), and N1100P300K500S120 i.e. farmers practice (T6) g/tree/year. In addition, 20 kg cowdung/tree was used as blanket dose. Number of fruits/tree, individual fruit weight, fruit size, stone weight, peel weight, TSS content and yield of mango varied significantly due to variations of nutrients in all the years. The highest yield and yield attributes were recorded under treatment N960P200K300S110 g/tree and it was statistically identical with N760P160K250S90 g/tree. The lowest yield was obtained from untreated control plot (native nutrient). The yield benefit for the best treatment (T5) over the control was 86% in 2010-11, 64% in 2011-12 and 73% in 2012-13. The highest gross margin (Tk 2509/tree in 2010-11, Tk 2651/tree in 2011-12 and Tk 2478/tree in 2012-13) and marginal rate of return (2375% in 2010-11, 2225% in 2011-12 and 2300% in 2012-13) was also obtained from the same treatment. Three years’ study revealed that application of N960P200K300S110 g/tree along with a blanket dose of 20 kg cowdung/tree appears to be the best treatment and economically optimum for achieving higher yield of mango in Chapai Nawabganj region. DOI: http://dx.doi.org/10.3329/bjar.v39i4.22542 Bangladesh J. Agril. Res. 39(4): 631-640, December 2014

Responses of olive tree yield determinants and components to shading during potentially critical phenological phases

Shading for short periods during potentially critical phenological phases can improve our understanding of the processes underlying the reductions in crop performance when solar radiation is limiting in high density orchards. Our objective was to evaluate the effects of three separate 30 day-long shade periods imposed during fruit set (FS), endocarp sclerification (ES), and early oil accumulation (OA) on some oil yield determinants and components in olive. Four shading levels (3, 20, 40, and 70% of incident photosynthetically active radiation; PAR) were applied in each period using shade cloths that surrounded one-half of large individual trees. Individual fruit dry weight, oil concentration (%) on a dry weight basis, and non-fruiting branch growth were determined at the end of each shading period, 45 days after their completion, and at the end of the season. The previously shaded- and the unshaded-halves of each tree were also harvested at the end of the season to obtain fruit number and oil yield for each half-tree. Individual fruit dry weight and oil concentration at the end of all three shading periods were decreased by shading due to reduced absolute rates of fruit growth and oil accumulation, respectively. However, at final harvest, there were no statistically significant treatment differences in individual fruit weight. By contrast, a small reduction in oil concentration persisted in the fruit from trees subjected to heavy shading during the OA period. Oil yield per half-tree at end of the season was decreased by shading applied during FS and OA periods, principally due to decreases in fruit number and oil concentration, respectively. Final oil yield was not affected by shading during the ES period. Elongation of non-fruiting branches was only decreased by shading during the early spring FS period, when vegetative growth was somewhat more sensitive to shading than fruit growth. Lastly, no consistent response of return bloom to the shading periods was detected the following spring. Our results suggest that the FS period when fruit number is defined and the OA period are more critical for determining final oil yield than the ES period. This information could provide guidance for the design of more effective management strategies in high density orchards where shading can play a key role.

Growth of Individual Tomato Fruits under Assimilate Limitation Associated with Successively-later Set Fruits

The time course of growth of individual tomato fruits (Solanum lycopersicum) was analyzed in relation to the fruit initiation date and cumulative degree days of growth. Experimental data of dry weight (DW), fresh weight (FW), radial diameter (FDIAM), and dry matter concentration (DMC) of three different cohorts of fruits of determinate fresh-market tomato cultivar Florida 47 were determined under field conditions in Florida during spring of 2006 and 2007. Successively later cohorts (1 week intervals) had longer lags prior to rapid growth, slower maximum growth during the rapid phase, and smaller DW, FW, and FDIAM at maturity. These growth patterns were analyzed by fitting the data to a three-parameter Gompertz function for DW, FW, and FDIAM, and to a fourparameter modified Gompertz function for DMC. The good agreement of predicted and measured Original Research Article Rybak et al.; AJEA, 6(2): 60-73, 2015; Article no.AJEA.2015.065 61 values indicates that the growth of individual tomato fruits followed the classical S-shaped Gompertz function. The Gompertz function was suitable to describe the slow growth that occurs in tomato fruits immediately after fertilization. The equation was able to predict the increasing duration of this lag and slower maximum growth and smaller final DW, FW, and size for successively later initiated cohorts of fruits. These results confirm the role of sink-source relationships (time of fruit set) on the growth of tomato fruits over time. This study will provide information potentially useful to improve existing tomato crop growth models that are presently limited because they do not predict practical outputs such as fresh weight and size of individual fruits.