Blossom-end Rot Research Articles

Tomato growth responses to foliar application of ammonium sulfate in hydroponic culture

ABSTRACTThis study was done to evaluate the growth responses of tomato plants (Lycopersicon esculentum Mill.) to foliar application of ammonium sulfate in different concentrations of 0, 50, 100, or 200 mM once per week, as well as 50 mM in every other day under greenhouse and hydroponic culture system. The results showed that foliar application of ammonium restricted the plant height, yield, and vitamin C content of fruits, but it increased the chlorophyll content in treated plants. The highest and the lowest yield were obtained from zero (control) and 200 mM treated plants, respectively. Fruit hardness was not affected by treatments, while blossom end rot disorder was increased by higher concentrations of ammonium sulfate. In general, the result indicated that tomato plant is rather sensitive to foliar application of ammonium sulfate particularly to higher concentrations and application numbers.

Standardization of production technology for hybrid coloured capsicum (Capsicum annuum var grossum) based on yield and economic benefit under different protected structures in plains of India

The present experiment was conducted to evaluate the yield and economic gain in cultivation of coloured capsicum (Capsicum annuum var grossum (L.) Sendt) hybrids in different protected structures. Six hybrids of coloured capsicum, i.e. Indra, Natasha, Bomby in red coloured group and Orobelle, Swarna, Kanchan in yellow coloured group were tried in 3 different types of protected structures compared to open field (OF) conditions. It was found that protected technology significantly enhanced crop duration (300) days in fan-pad cum force ventilated polyhouse (FFVP), 265 days in naturally ventilated polyhouse (NVP),250 days in insect proof net house (IPNH) as compared to 200 days in open fields. FFVP technology registered maximum fruit weight and yield (1.98 kg/plant, 11.83 kg/m2) followed by NVP(1.75 kg/plant, 10.42 kg/m2), IPNH(1.11kg/plant, 6.68 kg/m2) and OF (0.33 kg/plant, 1.98 kg/m2), respectively. Economic analysis of different protected structures exhibited considerably higher net returns of Rupees 247.33/m2 in FFVP, Rupees 309.67/m2 in NVP, Rupees 86.43/m2 in IPNH and Rupees 14.75/m2 in OF condition. The benefit cost ratio was calculated as 1.73in FFVP, 2.47 in NVP, 1.48 in IPNH while the lowest value of 1.32 in OF condition. Disease incidence cum mortality of plant (2.43%) was minimum in all capsicum varieties grown under FFVP, while it was higher in NVP (6.52%) followed by IPNH (9.75%) with maximum in OF (43.65%). Whereas blossom end rot of fruits was minimum in FFVP (2.98%) followed by OF (3.28%). It is evident from the results that protected structures enhanced the production of coloured capsicum as compared to open field condition particularly during off-season in plains. Further, among different hybrid varieties evaluated, Indra in red group and Orobelle in yellow group are found more suitable for growing in these conditions while Bomby and Swarna were also performed at par under protected structure.

Erratum to: Effect of foliar application of fulvic acid on plant growth and fruit quality of tomato (Lycopersicon esculentum L.)

This study was conducted to investigate the effects of foliar application of fulvic acid on plant growth, fruit quality, and yield of tomato. Fulvic acid (20 mL) was sprayed on the leaves of tomato plants at 10, 20 and 30 days after transplant (DAT) at rates of 0 (control), 0.8, 1.1, or 1.6 g·L-1 in water. The 0.8 g·L-1 treatment led to a significant increase in plant height and fresh and dry weight, while the 1.6 g·L-1 treatment led to a significant reduction. The contents of P and Ca were increased, but those of most of the other elements were unchanged in response to the 0.8 and 1.1 g·L-1 treatments. Fruit number and yield of medium- and large-sized fruits were significantly increased in the 0.8 and 1.1 g·L-1 treatments, which subsequently resulted in an increase of marketable yield. The incidence of cracking was generally high in all treatments, except for the 1.6 g·L-1 treatment, which showed a significant reduction in cracking and much smaller fruit size. Blossom-end rot was greatly reduced in all fulvic acid treated plants, and no incidence was observed in the 1.6 g·L-1 treatment. Our study demonstrated that foliar application of fulvic acid at about 0.8 g·L-1 could be used to promote plant growth and increase marketable yield in tomato production.

Tomato Fruit Marketability, Blossom-End Rot Incidence and Quality as Affected by Different Calcium Sources and Time of Application Under Calcareous Soil

Two field experiments were carried out during the winter seasons of 2011/2012 and 2012/ 2013 at The Experimental Farm of The Faculty of Environmental Agricultural Sciences, El-Arish, Suez Canal University, North Sinai Governorate, Egypt. The experiment aimed to study the effect of spraying tomato plants (Solanum lycopersicum) GS 12 cv. with different calcium sources (calcium chloride, calcium carbonate and calcium chelate as well as without calcium) at different times of application, viz, T1: spraying one time at full blooming, T2: spraying one time after 15 days from T1, and T3: spraying two times at T1 + T2 on marketable yield, unmarketable yield (expressed as fruits infected by blossom end rot (BER)), and quality of fruits after 10 days of beginning the storage period. Plants were grown under low tunnels. Spraying tomato plants with Ca+ as CaCl2 or CaCO3 and other Ca sources increased the marketable yield/ fed. , and also increased fruit shelf life period expressed as decreasing in fruit weight loss and increasing fruit firmness. Foliar application of CaCl2 recorded the lowest values of lycopene contents in both seasons. Time of calcium application did not reflect any significant effect on both marketable and nonmarketable yield as well as marketability (%) and BER incidence (%), and almost pH and TSS values. Application of T3 increased the fruit contents of vitamin C (V.C), while using T2 decreased the content of lycopene. All interaction treatments with control (without application of calcium) decreased marketable yield, marketability (%), but it increased unmarketable yield, BER incidence (%), fruit weight loss and TSS in the 2nd season. Therfore, spraying tomato plants grown under low tunnels in calcareous soil with Ca in different sources had positive effects on both marketable yield and blossom-end rot incidence, total yield, marketability%, BER% and on fruit quality after 10 days of storage period compared to control.

Fruit Calcium: Transport and Physiology.

Calcium has well-documented roles in plant signaling, water relations and cell wall interactions. Significant research into how calcium impacts these individual processes in various tissues has been carried out; however, the influence of calcium on fruit ripening has not been thoroughly explored. Here, we review the current state of knowledge on how calcium may impact the development, physical traits and disease susceptibility of fruit through facilitating developmental and stress response signaling, stabilizing membranes, influencing water relations and modifying cell wall properties through cross-linking of de-esterified pectins. We explore the involvement of calcium in hormone signaling integral to the physiological mechanisms behind common disorders that have been associated with fruit calcium deficiency (e.g., blossom end rot in tomatoes or bitter pit in apples). This review works toward an improved understanding of how the many roles of calcium interact to influence fruit ripening, and proposes future research directions to fill knowledge gaps. Specifically, we focus mostly on grapes and present a model that integrates existing knowledge around these various functions of calcium in fruit, which provides a basis for understanding the physiological impacts of sub-optimal calcium nutrition in grapes. Calcium accumulation and distribution in fruit is shown to be highly dependent on water delivery and cell wall interactions in the apoplasm. Localized calcium deficiencies observed in particular species or varieties can result from differences in xylem morphology, fruit water relations and pectin composition, and can cause leaky membranes, irregular cell wall softening, impaired hormonal signaling and aberrant fruit development. We propose that the role of apoplasmic calcium-pectin crosslinking, particularly in the xylem, is an understudied area that may have a key influence on fruit water relations. Furthermore, we believe that improved knowledge of the calcium-regulated signaling pathways that control ripening would assist in addressing calcium deficiency disorders and improving fruit pathogen resistance.

Effects of shoot pruning and inflorescence thinning on plant growth, yield and fruit quality of greenhouse tomatoes in a tropical climate

The combined effects of shoot pruning (one or two stems) and inflorescence thinning (five or ten flowers per inflorescence) on greenhouse tomato yield and fruit quality were studied during the dry season (DS) and rainy season (RS) in Central Thailand. Poor fruit set, development of undersized (mostly parthenocarpic) fruits, as well as the physiological disorders blossom-end rot (BER) and fruit cracking (FC) turned out to be the prevailing causes deteriorating fruit yield and quality. The proportion of marketable fruits was less than 10% in the RS and around 65% in the DS. In both seasons, total yield was significantly increased when plants were cultivated with two stems, resulting in higher marketable yields only in the DS. While the fraction of undersized fruits was increased in both seasons when plants were grown with a secondary stem, the proportions of BER and FC were significantly reduced. Restricting the number of flowers per inflorescence invariably resulted in reduced total yield. However, in neither season did fruit load considerably affect quantity or proportion of the marketable yield fraction. Inflorescence thinning tended to promote BER and FC, an effect which was only significant for BER in the RS. In conclusion, for greenhouse tomato production under climate conditions as they are prevalent in Central Thailand, the cultivation with two stems appears to be highly recommendable whereas the measures to control fruit load tested in this study did not proof to be advisable.

Agricultural reuse of cheese whey wastewater treated by NaOH precipitation for tomato production under several saline conditions and sludge management

NaOH precipitation applied to cheese whey wastewater (CWW) has been investigated in the pH range of 8.5–12.5. Optimum conditions were found at pH 11.0. High reductions of chemical oxygen demand—COD (40%), turbidity—T (91%), total suspended solids—TSS (69%), sulphates (93%), phosphorus (53%), total hardness (40%), calcium (50%), magnesium (27%), chlorides (12%), Kjeldahl nitrogen (23%), etc. were achieved. Treated CWW by the aforementioned process has been used for agricultural irrigation of two tomato cultivars (Roma and Rio Grande) after dilution with fresh water, which was used as control experiment (1.44dSm−1). Five different irrigation treatments, with salinity level in the range of 1.75–10.02dSm−1, were implemented with treated wastewater. Treatment did not show a significant effect on the total and marketable yield, production losses and tomato yield with physiological disorder of blossom-end rot. Nevertheless, the cultivar Rio Grande presented an increase up to 21% in the marketable yield, for salinity levels of 1.75–3.22dSm−1, owing to an increment of the fruit fresh weight. Furthermore, treatment significantly influenced the tomato yield with epidermis deformations by solar exposure, unit fruit fresh weight and tomato number per kilogram. Fruit epidermis deformations due to solar exposition were minimized in about 27–93% when using treated wastewater. Raw sludge generated in the NaOH precipitation presented an average content of organic matter, phosphorus and nitrogen of (gkg−1 on a dry basis) 512, 5.8 and 11.2, respectively. Additionally, this sludge was treated by means of several processes. Centrifugation was quite efficient in the sludge volume reduction. The integrated sequence: aerobic digestion+sedimentation+centrifugation constituted a suitable treatment line, achieving a sludge volume reduction of 80% and simultaneously producing an effluent with organic matter depletion around 40%. Infiltrated water from sand filters was more contaminated organic and inorganically than the effluent obtained in the sequence: aerobic digestion+sedimentation+centrifugation.

Kaolin improves salinity tolerance, water use efficiency and quality of tomato

Many areas in Southern Italy covered by tomato crops suffer from problems of high salinity in the irrigation water, that adversely affects yield. The reduction in transpiration rate mitigates the adverse effects of salinity. Thus, spraying the crop with kaolin-based aqueous suspension, which has an antitranspirant effect, can help improve tolerance to salinity.A three-year research study was carried out in open-field conditions in the Basilicata region (Southern Italy), to study the combined effect of three irrigation-water salinity levels (ECw=0.5, 5, and 10dSm−1) and spraying or non-spraying of kaolin on tomato cultivars, in terms of yield, fruit quality, biomass and yield water use efficiency (respectively B_WUE and Y_WUE). Irrigation with brackish water reduced tomato yield mainly because of declining fruit weight, but fruit quality was better in terms of dry matter content and total soluble solids. In addition, salinity increased blossom-end rot mainly on cultivars with elongated fruits.Overall, using the average from the three years, kaolin improved total (12.7%) and marketable yield (17.7%), fruit weight (8.1%) and harvest index (10.3%), and reduced fruit sunburn by 76.4%. In addition, kaolin contributed to reducing insect attack on the fruit (58.7%), improvement in total soluble solids (6.2%) and redness (10.2% for the skin and 16.6% for the pulp) of fruits, and increased Y_WUE (19.7%). Furthermore, kaolin mitigated the detrimental effects of salinity through a smaller decrease (averaging the three years) in total yield (22.8%), marketable yield (34.4%), fruit weight (21.1%), B_WUE (22.9%) and Y_WUE (34.7%), between the control irrigated with fresh water and the more saline treatment.Kaolin can be used to increase salinity tolerance, as well as to protect the tomato crop from pests damage, radiation and heat stress.

中玉トマト‘シンディスィート’の尻腐れ果発生および果実中の水溶性Ca濃度の季節変化と果実肥大速度の関係

中玉トマト‘シンディスィート’の尻腐れ果発生および果実中の水溶性Ca濃度の季節変化と果実肥大速度の関係

The Effects of Saline Water Drip Irrigation on Tomato Yield, Quality, and Blossom-End Rot Incidence --- A 3a Case Study in the South of China.

Saline water resources are abundant in the coastal areas of south China. Most of these resources still have not been effectively utilized. A 3-year study on the effects of saline water irrigation on tomato yield, quality and blossom-end rot (BER) was conducted at different lower limits of soil matric potential (-10 kPa, -20 kPa, -30 kPa, -40 kPa and -50 kPa). Saline water differing in electrical conductivity (EC) (3 dS/m, 4 dS/m, 4.5 dS/m, 5 dS/m and 5.5 dS/m) was supplied to the plant after the seedling establishment. In all three years, irrigation water with 5.5 dS/m salinity reduced the maximum leaf area index (LAIm) and chlorophyll content the most significantly when compared with other salinity treatments. However, compared with the control treatment (CK), a slight increase in LAIm and chlorophyll content was observed with 3~4 dS/m salinity. Saline water improved tomato quality, including fruit density, soluble solid, total acid, vitamin C and the sugar-acid ratio. There was a positive relationship between the overall tomato quality and salinity of irrigation water, as analyzed by principal component analysis (PCA). The tomato yield decreased with increased salinity. The 5.5 dS/m treatment reduced the tomato yield (Yt) by 22.4~31.1%, 12.6~28.0% and 11.7~27.3%, respectively in 2012, 2013 and 2014, compared with CK. Moreover, a significant (P≤0.01) coupling effect of salinity and soil matric potential on Yt was detected. Saline water caused Yt to increase more markedly when the lower limit of soil matric potential was controlled at a relatively lower level. The critical salinity level that produced significant increases in the BERi was 3 dS/m~4 dS/m. Following the increase in BERi under saline water irrigation, marketable tomato yield (Ym) decreased by 8.9%~33.8% in 2012, 5.1%~30.4% in 2013 and 10.1%~32.3% in 2014 compared with CK. In terms of maintaining the Yt and Ym, the salinity of irrigation water should be controlled under 4 dS/m, and the lower limit of soil matric potential should be greater than -20 kPa.

Measuring calcium, potassium, and nitrate in plant nutrient solutions using ion-selective electrodes in hydroponic greenhouse of some vegetables.

Generally, the life cycle of plants depends on the uptake of essential nutrients in a balanced manner and on toxic elements being under a certain concentration. Lack of control of nutrient levels in nutrient solution can result in reduced plant growth and undesired conditions such as blossom-end rot. In this study, sensitivity and selectivity tests for various polyvinylchloride (PVC)-based ion-selective membranes were conducted to identify those suitable for measuring typical concentration ranges of macronutrients, that is, NO(3-), K(+), and Ca(2+), in hydroponic solutions. The sensitivity and selectivity of PVC-membrane-based ion-selective sensors prepared with tetradodecylammoniumnitrate for NO(3-), valinomycin for K(+), and Ca ionophore IV for Ca(2+) were found to be satisfactory for measuring NO(3-), K(+), and Ca(2+) ions in nutrient solutions over typical ranges of hydroponic concentrations. Potassium, calcium, and nitrate levels that were utilized by cucumber and tomato seedlings in the greenhouse were different. The findings show that tomato plants consumed less amounts of nitrate than cucumber plants over the first 2 months of their growth. We also found that the potassium intake was higher than other nutritional elements tested for all plants.

Biopesticidal effect of leaf extract of neem (Azadirachta indica A. Juss) on growth parameters and diseases of tomato

This paper investigates the potential use of neem (Azadirachta indica A. Juss) aqueous leaf extract on the growth, yield and disease control of a common vegetable plant tomato (Solanum lycopersicum L.). The neem extract increased shoot height, number of branches, number of leaves, number of buds, number of flowers and number of fruits of tomato plant over controls in different treatments. Numbers of diseases were calculated as percentage and disease/plant. The percentage of reduction of disease was calculated after the spray of neem extract on plants. Neem extract was found effectively in controlling canker (50.32%), early blight (55.12%), wilt (59.45%), leaf spot (55.48%), fruit spot (41.93%), blossom end rot (40.86%) and sun scald (25.61%) in comparison to controls under field condition. Thus, biopesticides can contribute in reducing use of chemical pesticides and subsequently minimize its hazards to the environment and human health.

Selection of tomato plant families using characters related to water deficit resistance

The present work aimed at to evaluate parameters related to water deficit in 20 F 3 RC 1 families of tomato plant ( Solanum lycopersicum ) derived from the crossing with a (WELL) genotype originated from a drought resistant species, S. pennellii . The delineation was in randomized blocks design with three replications. Two experiments were made, the first in the municipality of Lavras, MG, that consisted in evaluating nine F 3 RC 1 families derived from two self-fertilizations of the following crosses: [TOM-684 x (WELL x M-82)]. The second experiment was made in the town of Ijaci, MG, and evaluated the same nine families from the previous experiment and another eleven families obtained from the same crossing. The plants were submitted to water deficit by means of the suspension of irrigation at 35 days after transplanting the seedlings to the field. The families T4, T5, T6, T15, T17 were highlighted regarding fruit production and, among the nine families evaluated in both cultivation environments, the T6 was the most productive, indicating good productive stability. Families T5 and T9 were highlighted for presenting low incidence of blossom-end rot and higher relative water content in leaves. The blossom-end rot incidence and relative water content are good parameter to be indirect selection of plants more resistant to drought.

Evaluation of substitutes for rock wool as growing substrate for hydroponic tomato production

To reduce the rock wool waste, the present study is focused on the evaluation of sheep wool, Sphagnum and hemp slabs, which may be used as replacement for rock wool as growing substrate for hydroponic tomato production. As such, physical and chemical properties of substrates, the plant growth, yield, fruit characteristics, as well as primary and secondary metabolites of tomatoes were considered. The marketable fruit yield of plants grown in Sphagnum slabs (12.8 kg plant -1 ) was reduced to only a small extent compared to the yield produced by rock wool slabs (13.8 kg plant -1 ). Sheep wool (12.3 kg plant -1 ) and hemp (10.4 kg plant -1 ), however, showed higher deviations. The lowest yield of blossom end rot (BER) fruit was produced by Sphagnum . Compared to this result, the BER-yield was nearly 2-fold higher caused by sheep wool. The soluble solid content in fruit ripened by the hemp material was decreased compared to those caused by the remaining substrates. Furthermore, it was found that the volume of easy available water (EAW) was mainly responsible for changes in plant development. As such, a high correlation was found between EAW and: leaf area (r = 0.851); flowers (r = 0.785); lycopene (r = -0.918); s-carotene (r = -0.997); penolics (r = -0.918); LAA (r = -0.848). The findings suggested that Sphagnum slabs can be used as replacement for rock wool slabs, whereas the usage of slabs consisting of hemp and sheep wool is not suitable as growing substrate for hydroponic tomato production.

Selection of tomato plant families using characters related to water deficit resistance

Environmental stress, such as drought stress, constantly cause production loss. Breeding programs search for genotypes which may overcome climate adversities, producing in ideal as well as in stressful environments. The present work aimed at to evaluate parameters related to water deficit in 20 F3RC1 families of tomato plants derived from the crossing with a (WELL) genotype, originated from a drought resistant species, as well as select plants using characters related to water deficit resistance. The delineation was in randomized blocks design with three replications. Two experiments were carried out, the first in Lavras, Minas Gerais state, Brazil, that consisted in evaluating nine F3RC1 families derived from two self-fertilizations of the following crosses: {TOM-684 x (WELL x M-82)}. The second experiment was carried out in Ijaci, in the same state, and evaluated the same nine families from the previous experiment and another eleven families obtained from the same crossing. The plants were submitted to water deficit by means of the suspension of irrigation at 35 days after transplanting the seedlings to the field. The families T4, T5, T6, T15, T17 were highlighted regarding fruit production and, among the nine families evaluated in both cultivation environments, the T6 was the most productive, indicating good productive stability. Families T5 and T9 were highlighted for presenting low incidence of blossom-end rot and higher relative water content in leaves. The blossom-end rot incidence and relative water content are good parameter to be indirect selection of plants more resistant to drought.

Effect of mulch and different fungicide spray regimes on yield of tomato (Solanum lycopersicum L.) in Tanzania

In many areas in Tanzania, pests management for tomato involves weekly pesticide sprays. The practice poses a threat to the environment and health of consumers. In this study the effect of pesticide spray regimes and use of mulch we re evaluated on ‘Tanya VF’ and ‘Tengeru 97’ tomato varieties. Field experiment consisting of a 2×2×4 factorial arrangement in a split-split plot design with three replication s was conducted at Sokoine University of Agriculture, Morogoro (6 o 05’S, 35 o 37’E and 525m above sea level). Treatment factors comprised two varieties (main plot factor), mulching/number of mulching (subplot factor) and three fungicide spray regimes (sub subplot factor). Results showed that the spray regimes: farmers’ practice (FP), Integrated Pests Management (IPM) based on pests scouting, sprays based on manufacturers’ recommendation (MR); produced significantly more fruits per plant and higher fruit weight compared to the control. There was no significant difference (p < 0.05) between FP, IPM and MR on fruit yield para meters. The results further revealed that use of mulch significantly led to higher fruit number per plant (p = 0 .020). Although average fruit weight was similar (p < 0.05), other marketable fruit yield parameters were statistically different between mulched and non-mulched plots ( p = 0.007). ‘Tanya VF’ had consistently higher yields compared to ‘Tengeru 97’. Fungicide sprays were statistically different to the control with respect to blossom end rot (p = 0.002), fruit rot (p < 0.001) and percentage of non-marketable yield (p = 0.001). Mulching significantly reduced American bollworm and blossom end rot (p = 0.012, p = 0 .003, respectively). The major contributor to tomato fruit loss was Blossom End Rot (BER) and Fruit Rot for ‘Tengeru 97’ and ‘Tanya VF’, respectively. It is evident, therefore, that: a proper combination of tomato cultural management practices can significantly reduce the use of pesticides, and improve tomato fruit quality and marketable yield which would increase profit margin accrued by farmers.

Genetic dissection of tomato rootstock effects on scion traits under moderate salinity.

Rootstock HKT1 genotype affected fruit [Na(+)] and non-commercial fruit yield; QTL analysis of rootstock-mediated scion nutrition is a powerful forward genetic approach to identify wild genes for rootstock breeding. The present study approaches the QTL dissection of rootstock effects on a commercial hybrid variety grafted on a population of RILs derived from Solanum pimpinellifolium, genotyped for 4370 segregating SNPs from the SolCAP tomato panel and grown under moderate salinity. Results are compared to those previously obtained under high salinity. The most likely functional candidate genes controlling the scion [Na(+)] were rootstock HKT1;1 and HKT1;2 as it was previously reported for non-grafted genotypes. The higher fruit [Na(+)] found when rootstock genotype was homozygote for SpHKT1 supports the thesis that scion HKT1 is loading Na(+) into the phloem sap in leaves and unloading it in sink organs. A significant increment of small, mostly seedless, fruits was found associated with SlHKT1 homozygous rootstocks. Just grafting increased the incidence of blossom end rot and delayed fruit maturation but there were rootstock RILs that increased commercial fruit yield under moderate salinity. The heritability and number of QTLs involved were lower and different than those found under high salinity. Four large contributing (>17%) rootstock QTLs, controlling the leaf concentrations of B, K, Mg and Mo were detected whose 2 Mbp physical intervals contained B, K, Mg and Mo transporter-coding genes, respectively. Since a minimum of 3 QTLs (two of them coincident with leaf K and Ca QTLs) were also found governing rootstock-mediated soluble-solids content of the fruit under moderate salinity, grafting desirable crop varieties on stress-tolerant rootstocks tenders an opportunity to increase both salt tolerance and quality.

ФИТОПАТОЛОГИЧЕСКАЯ ОЦЕНКА ГЕРМОПЛАЗМЫ ВИДА CAPSICUM ANNUUM L. (ПЕРЕЦ СЛАДКИЙ И ЧИЛИ) ИЗ ГЕНОФОНДА ВСЕМИРНОГО ЦЕНТРА ОВОЩЕВОДСТВА (AVRDC) В УСЛОВИЯХ АРАРАТСКОЙ ДОЛИНЫ АРМЕНИИ

On an experimental basis of the Scientific Center of vegetable, melon and industrial crops (Republic of Armenia) 20 accessions of the world germplasm of Capsicum annuum L. (sweet pepper, chili) provided by the World Vegetable Center (AVRDC) have been studied. The accessions resistant to such diseases as verticillium wilt (Verticillium albo-atrum Reincke), bacterial wilt (Ralstonia solanacearum (= Pseudomonas solanacearum), tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV), blossom end rot of fruit, and tip-burn have been selected. These genotypes of chili and sweet pepper are the promising initial material in breeding for resistance to common diseases. In collaboration with other breeders, five varieties of peppers were developed and released: sweet pepper cultivars Natalie, Emily, Miles, and chili cultivars Zita and Gita.

Influence of three rootstocks on yield and commercial quality of "Italian Sweet" pepper

Pepper crops (Capsicum annuum L.) represent a very important production sector in the Southeast of Spain. Specifically, in the province of Almería, approximately 7000 hectares are grown every year. Due to the economic importance that this crop has for the region and the withdrawal of soil fumigants from the market, agronomic techniques have been adopted with the aim of controlling some soil pathogens and increasing the yield and quality parameters of the fruits obtained. The use of grafted pepper plants is not, as yet, very well established in this region, due mainly to the lack of commercial rootstocks that satisfy the producers of this vegetable. In this experiment three pepper rootstocks were assessed. An experiment was designed with four treatments and three replications of each one (12 experimental plots), which were distributed in randomised blocks. Three of the treatments corresponded to grafted plants of the "Palermo" cultivar onto: "Oscos", "AR40" and "Tresor", using non-grafted "Palermo" cultivar as the control test. The average yield expressed in kg/plant, showed significant differences between grafted and non-grafted plants. The highest fruit weight was obtained in Palermo onto Tresor. The presence of Blossom end rot (BER) in the assessed fruits also showed significant differences between the different treatments, with the fruits from plants grafted onto Tresor showing a higher proportion of BER and the fruits coming from plants grafted onto AR40 showing the lowest proportion.

Foliar Application of Salicylic Acid and Methyl Jasmonate on Yield , Yield Components and Chemical Properties of Tomato = تأثير الرش بحمض الساليساليك و ميثيل جاسمونات على الانتاج و مكونات الانتاج و الخصائص الكيماوية للبندورة

This study aimed at studying the role of pre-application with salicylic acid (SA) (0.5 and 1 mM) and methyl jasmonate (MJ) (0.5 and 1 mM) and their combination on yield quantity and quality of tomato fruits. The results showed that the foliar spray of SA (0.5 mM) significantly increased vegetative and reproductive growth, yield and fruit quality, while reduced blossom end rot. On the contrary, MJ (1 mM) application significantly decreased vegetative growth while increasing reproductive growth. The application of 0.5 mM MJ+0.5 mM SA increased total soluble solids (TSS), titratable acidity (TA) and vitamin C content. In conclusion, application of 0.5 mM MJ+0.5 mM SA improved the yield and fruit quality of tomato.